jfbuild/src/polymost.c

/**************************************************************************************************
"POLYMOST" code written by Ken Silverman
Ken Silverman's official web site: http://www.advsys.net/ken

Motivation:
When 3D Realms released the Duke Nukem 3D source code, I thought somebody would do a OpenGL or
Direct3D port. Well, after a few months passed, I saw no sign of somebody working on a true
hardware-accelerated port of Build, just people saying it wasn't possible. Eventually, I realized
the only way this was going to happen was for me to do it myself. First, I needed to port Build to
Windows. I could have done it myself, but instead I thought I'd ask my Australian buddy, Jonathon
Fowler, if he would upgrade his Windows port to my favorite compiler (MSVC) - which he did. Once
that was done, I was ready to start the "POLYMOST" project.

About:
This source file is basically a complete rewrite of the entire rendering part of the Build engine.
There are small pieces in ENGINE.C to activate this code, and other minor hacks in other source
files, but most of it is in here. If you're looking for polymost-related code in the other source
files, you should find most of them by searching for either "polymost" or "rendmode". Speaking of
rendmode, there are now 4 rendering modes in Build:

	rendmode 0: The original code I wrote from 1993-1997
	rendmode 1: Solid-color rendering: my debug code before I did texture mapping
	rendmode 2: Software rendering before I started the OpenGL code (Note: this is just a quick
						hack to make testing easier - it's not optimized to my usual standards!)
	rendmode 3: The OpenGL code

The original Build engine did hidden surface removal by using a vertical span buffer on the tops
and bottoms of walls. This worked nice back in the day, but it it's not suitable for a polygon
engine. So I decided to write a brand new hidden surface removal algorithm - using the same idea
as the original Build - but one that worked with vectors instead of already rasterized data.

Brief history:
06/20/2000: I release Build Source code
04/01/2003: 3D Realms releases Duke Nukem 3D source code
10/04/2003: Jonathon Fowler gets his Windows port working in Visual C
10/04/2003: I start writing POLYMOST.BAS, a new hidden surface removal algorithm for Build that
					works on a polygon level instead of spans.
10/16/2003: Ported POLYMOST.BAS to C inside JonoF KenBuild's ENGINE.C; later this code was split
					out of ENGINE.C and put in this file, POLYMOST.C.
12/10/2003: Started OpenGL code for POLYMOST (rendmode 3)
12/23/2003: 1st public release
01/01/2004: 2nd public release: fixed stray lines, status bar, mirrors, sky, and lots of other bugs.

----------------------------------------------------------------------------------------------------

Todo list (in approximate chronological order):

High priority:
	*   BOTH: Do accurate software sorting/chopping for sprites: drawing in wrong order is bad :/
	*   BOTH: Fix hall of mirrors near "zenith". Call polymost_drawrooms twice?
	* OPENGL: drawmapview()

Low priority:
	* SOFT6D: Do back-face culling of sprites during up/down/tilt transformation (top of drawpoly)
	* SOFT6D: Fix depth shading: use saturation&LUT
	* SOFT6D: Optimize using hyperbolic mapping (similar to KUBE algo)
	* SOFT6D: Slab6-style voxel sprites. How to accelerate? :/
	* OPENGL: KENBUILD: Write flipping code for floor mirrors
	*   BOTH: KENBUILD: Parallaxing sky modes 1&2
	*   BOTH: Masked/1-way walls don't clip correctly to sectors of intersecting ceiling/floor slopes
	*   BOTH: Editart x-center is not working correctly with Duke's camera/turret sprites
	*   BOTH: Get rid of horizontal line above Duke full-screen status bar
	*   BOTH: Combine ceilings/floors into a single triangle strip (should lower poly count by 2x)
	*   BOTH: Optimize/clean up texture-map setup equations

**************************************************************************************************/

#include "build.h"

#if USE_POLYMOST

#include "glbuild.h"
#include "pragmas.h"
#include "baselayer.h"
#include "osd.h"
#include "engine_priv.h"
#include "polymost_priv.h"
#if USE_OPENGL
# include "hightile_priv.h"
# include "polymosttex_priv.h"
# include "polymosttexcache.h"
# include "mdsprite_priv.h"
#endif
extern char textfont[2048], smalltextfont[2048];

int rendmode = 0;
int usemodels=1, usehightile=1, usegoodalpha=0;

#include <math.h> //<-important!
typedef struct { float x, cy[2], fy[2]; int n, p, tag, ctag, ftag; } vsptyp;
#define VSPMAX 4096 //<- careful!
static vsptyp vsp[VSPMAX];
static int vcnt, gtag;

double dxb1[MAXWALLSB], dxb2[MAXWALLSB];

#define SCISDIST 1.0 //1.0: Close plane clipping distance
#define USEZBUFFER 1 //1:use zbuffer (slow, nice sprite rendering), 0:no zbuffer (fast, bad sprite rendering)
#define LINTERPSIZ 4 //log2 of interpolation size. 4:pretty fast&acceptable quality, 0:best quality/slow!
#define DEPTHDEBUG 0 //1:render distance instead of texture, for debugging only!, 0:default
#define FOGSCALE 0.0000384

double gxyaspect, grhalfxdown10x;
static double gyxscale, gviewxrange, ghalfx, grhalfxdown10, ghoriz;
double gcosang, gsinang, gcosang2, gsinang2;
double gchang, gshang, gctang, gstang;
static double gvisibility;
float gtang = 0.0;
double guo, gux, guy; //Screen-based texture mapping parameters
double gvo, gvx, gvy;
double gdo, gdx, gdy;

#if (USEZBUFFER != 0)
intptr_t zbufmem = 0;
int zbufysiz = 0, zbufbpl = 0, *zbufoff = 0;
#endif

#if USE_OPENGL
int gfogpalnum = 0;
float gfogdensity = 0.f;

int glredbluemode = 0;
static int lastglredbluemode = 0, redblueclearcnt = 0;

struct glfiltermodes glfiltermodes[numglfiltermodes] = {
	{"GL_NEAREST",GL_NEAREST,GL_NEAREST},
	{"GL_LINEAR",GL_LINEAR,GL_LINEAR},
	{"GL_NEAREST_MIPMAP_NEAREST",GL_NEAREST_MIPMAP_NEAREST,GL_NEAREST},
	{"GL_LINEAR_MIPMAP_NEAREST",GL_LINEAR_MIPMAP_NEAREST,GL_LINEAR},
	{"GL_NEAREST_MIPMAP_LINEAR",GL_NEAREST_MIPMAP_LINEAR,GL_NEAREST},
	{"GL_LINEAR_MIPMAP_LINEAR",GL_LINEAR_MIPMAP_LINEAR,GL_LINEAR}
};

int glanisotropy = 0;            // 0 = maximum supported by card
int glusetexcompr = 1;
int gltexcomprquality = 0;	// 0 = fast, 1 = slow and pretty, 2 = very slow and pretty
int gltexfiltermode = 5;   // GL_LINEAR_MIPMAP_LINEAR
int glusetexcache = 1;
int glmultisample = 0, glnvmultisamplehint = 0;
int gltexmaxsize = 0;      // 0 means autodetection on first run
int gltexmiplevel = 0;		// discards this many mipmap levels
static int lastglpolygonmode = 0;
int glpolygonmode = 0;     // 0:GL_FILL,1:GL_LINE,2:GL_POINT,3:clear+GL_FILL

static GLuint texttexture = 0;
static GLuint nulltexture = 0;

#define SHADERDEV 1
static struct {
	GLuint vao;					// Vertex array object.
	GLuint program;             // GLSL program object.
	GLuint elementbuffer;
	GLint attrib_vertex;		// Vertex (vec3)
	GLint attrib_texcoord;		// Texture coordinate (vec2)
	GLint uniform_modelview;	// Modelview matrix (mat4)
	GLint uniform_projection;	// Projection matrix (mat4)
	GLint uniform_texture;      // Base texture (sampler2D)
	GLint uniform_glowtexture;  // Glow texture (sampler2D)
	GLint uniform_alphacut;     // Alpha test cutoff (float)
	GLint uniform_colour;		// Colour (vec4)
	GLint uniform_fogcolour;    // Fog colour   (vec4)
	GLint uniform_fogdensity;   // Fog density  (float)
} polymostglsl;

static struct {
	GLuint vao;					// Vertex array object.
	GLuint program;
	GLuint elementbuffer;
	GLuint indexbuffer;
	GLint attrib_vertex;		// Vertex (vec3)
	GLint attrib_texcoord;		// Texture coordinate (vec2)
	GLint uniform_projection;	// Projection matrix (mat4)
	GLint uniform_texture;      // Character bitmap (sampler2D)
	GLint uniform_colour;		// Colour (vec4)
	GLint uniform_bgcolour;     // Background colour (vec4)
	GLint uniform_mode;	        // Operation mode (int)
		// 0 = texture is mask, render vertex colour/bgcolour.
		// 1 = texture is image, blend with bgcolour.
		// 2 = draw solid colour.
} polymostauxglsl;

static GLuint elementindexbuffer = 0;
static GLuint elementindexbuffersize = 0;

const GLfloat gidentitymat[4][4] = {
	{1.f, 0.f, 0.f, 0.f},
	{0.f, 1.f, 0.f, 0.f},
	{0.f, 0.f, 1.f, 0.f},
	{0.f, 0.f, 0.f, 1.f},
};
GLfloat gdrawroomsprojmat[4][4];      // Proj. matrix for drawrooms() calls.
GLfloat grotatespriteprojmat[4][4];   // Proj. matrix for rotatesprite() calls.
GLfloat gorthoprojmat[4][4];          // Proj. matrix for 2D (aux) calls.

static int polymost_preparetext(void);
#endif //USE_OPENGL

#ifdef DEBUGGINGAIDS
static int polymostshowcallcounts = 0;
struct polymostcallcounts polymostcallcounts;
#endif

#if defined(_MSC_VER) && defined(_M_IX86) && USE_ASM
static inline void ftol (float f, int *a)
{
	_asm
	{
		mov eax, a
		fld f
		fistp dword ptr [eax]
	}
}

static inline void dtol (double d, int *a)
{
	_asm
	{
		mov eax, a
		fld d
		fistp dword ptr [eax]
	}
}
#elif defined(__WATCOMC__) && USE_ASM

#pragma aux ftol =\
	"fistp dword ptr [eax]",\
	parm [eax 8087]
#pragma aux dtol =\
	"fistp dword ptr [eax]",\
	parm [eax 8087]

#elif defined(__GNUC__) && defined(__i386__) && USE_ASM

static inline void ftol (float f, int *a)
{
	__asm__ __volatile__ (
#if 0 //(__GNUC__ >= 3)
			"flds %1; fistpl %0;"
#else
			"flds %1; fistpl (%0);"
#endif
			: "=r" (a) : "m" (f) : "memory","cc");
}

static inline void dtol (double d, int *a)
{
	__asm__ __volatile__ (
#if 0 //(__GNUC__ >= 3)
			"fldl %1; fistpl %0;"
#else
			"fldl %1; fistpl (%0);"
#endif
			: "=r" (a) : "m" (d) : "memory","cc");
}

#else
static inline void ftol (float f, int *a)
{
	*a = (int)f;
}

static inline void dtol (double d, int *a)
{
	*a = (int)d;
}
#endif

static inline int imod (int a, int b)
{
	if (a >= 0) return(a%b);
	return(((a+1)%b)+b-1);
}

static void drawline2d (float x0, float y0, float x1, float y1, unsigned char col)
{
	float f, dx, dy, fxres, fyres;
	int e, inc, x, y;
	unsigned int up16;

	dx = x1-x0; dy = y1-y0; if ((dx == 0) && (dy == 0)) return;
	fxres = (float)xdimen; fyres = (float)ydimen;
		  if (x0 >= fxres) { if (x1 >= fxres) return; y0 += (fxres-x0)*dy/dx; x0 = fxres; }
	else if (x0 <      0) { if (x1 <      0) return; y0 += (    0-x0)*dy/dx; x0 =     0; }
		  if (x1 >= fxres) {                          y1 += (fxres-x1)*dy/dx; x1 = fxres; }
	else if (x1 <      0) {                          y1 += (    0-x1)*dy/dx; x1 =     0; }
		  if (y0 >= fyres) { if (y1 >= fyres) return; x0 += (fyres-y0)*dx/dy; y0 = fyres; }
	else if (y0 <      0) { if (y1 <      0) return; x0 += (    0-y0)*dx/dy; y0 =     0; }
		  if (y1 >= fyres) {                          x1 += (fyres-y1)*dx/dy; y1 = fyres; }
	else if (y1 <      0) {                          x1 += (    0-y1)*dx/dy; y1 =     0; }

	if (fabs(dx) > fabs(dy))
	{
		if (x0 > x1) { f = x0; x0 = x1; x1 = f; f = y0; y0 = y1; y1 = f; }
		y = (int)(y0*65536.f)+32768;
		inc = (int)(dy/dx*65536.f+.5f);
		x = (int)(x0+.5); if (x < 0) { y -= inc*x; x = 0; } //if for safety
		e = (int)(x1+.5); if (e > xdimen) e = xdimen;       //if for safety
		up16 = (ydimen<<16);
		for(;x<e;x++,y+=inc) if ((unsigned int)y < up16) *(unsigned char *)(ylookup[y>>16]+x+frameoffset) = col;
	}
	else
	{
		if (y0 > y1) { f = x0; x0 = x1; x1 = f; f = y0; y0 = y1; y1 = f; }
		x = (int)(x0*65536.f)+32768;
		inc = (int)(dx/dy*65536.f+.5f);
		y = (int)(y0+.5); if (y < 0) { x -= inc*y; y = 0; } //if for safety
		e = (int)(y1+.5); if (e > ydimen) e = ydimen;       //if for safety
		up16 = (xdimen<<16);
		for(;y<e;y++,x+=inc) if ((unsigned int)x < up16) *(unsigned char *)(ylookup[y]+(x>>16)+frameoffset) = col;
	}
}

#if USE_OPENGL

static int drawingskybox = 0;

int polymost_texmayhavealpha (int dapicnum, int dapalnum)
{
	PTHead * pth;
	int i;

	pth = PT_GetHead(dapicnum, dapalnum, 0, 1);
	if (!pth) {
		return 1;
	}

	if (!pth->pic[PTHPIC_BASE]) {
		// we haven't got a PTMHead reference yet for the base layer, so we
		// don't know if the texture actually does have alpha, so err on
		// the side of caution
		return 1;
	}

	return ((pth->pic[PTHPIC_BASE]->flags & PTH_HASALPHA) == PTH_HASALPHA);
}

void polymost_texinvalidate (int dapicnum, int dapalnum, int dameth)
{
	PTIter iter;
	PTHead * pth;

	iter = PTIterNewMatch(
		PTITER_PICNUM | PTITER_PALNUM | PTITER_FLAGS,
		dapicnum, dapalnum, PTH_CLAMPED, (dameth & METH_CLAMPED) ? PTH_CLAMPED : 0
		);
	while ((pth = PTIterNext(iter)) != 0) {
		if (pth->pic[PTHPIC_BASE]) {
			pth->pic[PTHPIC_BASE]->flags |= PTH_DIRTY;
		}
		/*buildprintf("invalidating picnum:%d palnum:%d effects:%d skyface:%d flags:%04X repldef:%p\n",
			   pth->picnum, pth->palnum, pth->effects, pth->skyface,
			   pth->flags, pth->repldef);*/
	}
	//buildprintf("done\n");
	PTIterFree(iter);
}

	//Make all textures "dirty" so they reload, but not re-allocate
	//This should be much faster than polymost_glreset()
	//Use this for palette effects ... but not ones that change every frame!
void polymost_texinvalidateall ()
{
	PTIter iter;
	PTHead * pth;

	iter = PTIterNew();
	while ((pth = PTIterNext(iter)) != 0) {
		if (pth->pic[PTHPIC_BASE]) {
			pth->pic[PTHPIC_BASE]->flags |= PTH_DIRTY;
		}
	}
	PTIterFree(iter);
	clearskins();
	//buildprintf("gltexinvalidateall()\n");
}


void gltexapplyprops (void)
{
	int i;
	PTIter iter;
	PTHead * pth;

	if (glinfo.maxanisotropy > 1.0)
	{
		if (glanisotropy <= 0 || glanisotropy > glinfo.maxanisotropy) glanisotropy = (int)glinfo.maxanisotropy;
	}

	if (gltexfiltermode < 0) gltexfiltermode = 0;
	else if (gltexfiltermode >= (int)numglfiltermodes) gltexfiltermode = numglfiltermodes-1;

	iter = PTIterNew();
	while ((pth = PTIterNext(iter)) != 0) {
		for (i = 0; i < PTHPIC_SIZE; i++) {
			if (pth->pic[i] == 0 || pth->pic[i]->glpic == 0) {
				continue;
			}
			glfunc.glBindTexture(GL_TEXTURE_2D,pth->pic[i]->glpic);
			glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,glfiltermodes[gltexfiltermode].mag);
			glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,glfiltermodes[gltexfiltermode].min);
			if (glinfo.maxanisotropy > 1.0) {
				glfunc.glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAX_ANISOTROPY_EXT,glanisotropy);
			}
		}
	}
	PTIterFree(iter);

	{
		int j;
		mdskinmap_t *sk;
		md2model *m;

		for (i=0;i<nextmodelid;i++)
		{
			m = (md2model *)models[i];
			if (m->mdnum < 2) continue;
			for (j=0;j<m->numskins*(HICEFFECTMASK+1);j++)
			{
				if (!m->tex[j] || !m->tex[j]->glpic) continue;
				glfunc.glBindTexture(GL_TEXTURE_2D,m->tex[j]->glpic);
				glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,glfiltermodes[gltexfiltermode].mag);
				glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,glfiltermodes[gltexfiltermode].min);
				if (glinfo.maxanisotropy > 1.0)
					glfunc.glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAX_ANISOTROPY_EXT,glanisotropy);
			}

			for (sk=m->skinmap;sk;sk=sk->next)
				for (j=0;j<(HICEFFECTMASK+1);j++)
				{
					if (!sk->tex[j] || !sk->tex[j]->glpic) continue;
					glfunc.glBindTexture(GL_TEXTURE_2D,sk->tex[j]->glpic);
					glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,glfiltermodes[gltexfiltermode].mag);
					glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,glfiltermodes[gltexfiltermode].min);
					if (glinfo.maxanisotropy > 1.0)
						glfunc.glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAX_ANISOTROPY_EXT,glanisotropy);
				}
			}
		}
}

//--------------------------------------------------------------------------------------------------

float glox1, gloy1, glox2, gloy2;

	//Use this for both initialization and uninitialization of OpenGL.
static int gltexcacnum = -1;
void polymost_glreset ()
{
	int i;

	//Reset if this is -1 (meaning 1st texture call ever), or > 0 (textures in memory)
	if (gltexcacnum < 0)
	{
		gltexcacnum = 0;

			//Hack for polymost_dorotatesprite calls before 1st polymost_drawrooms()
		gcosang = gcosang2 = ((double)16384)/262144.0;
		gsinang = gsinang2 = ((double)    0)/262144.0;
	}
	else
	{
		PTReset();
		clearskins();
	}

	glox1 = -1;
	lastglpolygonmode = -1;
	lastglredbluemode = -1;

	if (glfunc.glUseProgram) {
		glfunc.glUseProgram(0);
#if (USE_OPENGL == USE_GL3)
		glfunc.glBindVertexArray(0);
#endif
		glfunc.glBindBuffer(GL_ARRAY_BUFFER, 0);
		glfunc.glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
	}

	if (elementindexbuffer) {
		glfunc.glDeleteBuffers(1, &elementindexbuffer);
		elementindexbuffersize = 0;
		elementindexbuffer = 0;
	}

#if (USE_OPENGL == USE_GL3)
	if (polymostglsl.vao) {
		glfunc.glDeleteVertexArrays(1, &polymostglsl.vao);
		polymostglsl.vao = 0;
	}
#endif
	if (polymostglsl.elementbuffer) {
		glfunc.glDeleteBuffers(1, &polymostglsl.elementbuffer);
		polymostglsl.elementbuffer = 0;
	}
	if (polymostglsl.program) {
		glfunc.glDeleteProgram(polymostglsl.program);
		polymostglsl.program = 0;
	}

#if (USE_OPENGL == USE_GL3)
	if (polymostauxglsl.vao) {
		glfunc.glDeleteVertexArrays(1, &polymostauxglsl.vao);
		polymostauxglsl.vao = 0;
	}
#endif
	if (polymostauxglsl.indexbuffer) {
		glfunc.glDeleteBuffers(1, &polymostauxglsl.indexbuffer);
		polymostauxglsl.indexbuffer = 0;
	}
	if (polymostauxglsl.elementbuffer) {
		glfunc.glDeleteBuffers(1, &polymostauxglsl.elementbuffer);
		polymostauxglsl.elementbuffer = 0;
	}
	if (polymostauxglsl.program) {
		glfunc.glDeleteProgram(polymostauxglsl.program);
		polymostauxglsl.program = 0;
	}

	if (texttexture) {
		glfunc.glDeleteTextures(1, &texttexture);
		texttexture = 0;
	}

	if (nulltexture) {
		glfunc.glDeleteTextures(1, &nulltexture);
		nulltexture = 0;
	}
}

static GLint polymost_get_attrib(GLuint program, const GLchar *name)
{
	GLint attribloc = glfunc.glGetAttribLocation(program, name);
	if (attribloc < 0) {
		buildprintf("polymost_get_attrib: could not get location of attribute \"%s\"\n", name);
	}
	return attribloc;
}

static GLint polymost_get_uniform(GLuint program, const GLchar *name)
{
	GLint uniformloc = glfunc.glGetUniformLocation(program, name);
	if (uniformloc < 0) {
		buildprintf("polymost_get_uniform: could not get location of uniform \"%s\"\n", name);
	}
	return uniformloc;
}

static GLuint polymost_load_shader(GLuint shadertype, const char *defaultsrc, const char *filename)
{
	const GLchar *shadersrc = defaultsrc;
	GLuint shader = 0;

#ifdef SHADERDEV
	GLchar *fileshadersrc = NULL;
	int shadersrclen = 0;
	BFILE *shaderfh = NULL;

	shaderfh = fopen(filename, "rb");
	if (shaderfh) {
		fseek(shaderfh, 0, SEEK_END);
		shadersrclen = (int)ftell(shaderfh);
		fseek(shaderfh, 0, SEEK_SET);

		fileshadersrc = (GLchar *)calloc(1, shadersrclen + 1);
		fread(fileshadersrc, shadersrclen, 1, shaderfh);

		fclose(shaderfh);
		shaderfh = NULL;

		buildprintf("polymost_load_shader: loaded %s (%d bytes)\n", filename, shadersrclen);
		shadersrc = fileshadersrc;
	}
#endif

	shader = glbuild_compile_shader(shadertype, shadersrc);

#ifdef SHADERDEV
	if (fileshadersrc) {
		free(fileshadersrc);
		fileshadersrc = NULL;
	}
#endif

	return shader;
}

static void checkindexbuffer(unsigned int size)
{
	GLushort *indexes, i;

	if (size <= elementindexbuffersize) return;

	indexes = (GLushort *) malloc(sizeof(GLushort)*size);
	for (i = 0; i < size; i++) indexes[i] = i;
	glfunc.glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementindexbuffer);
	glfunc.glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLushort)*size, indexes, GL_STATIC_DRAW);
	free(indexes);

	elementindexbuffersize = size;
}

static void polymost_loadshaders(void)
{
	extern const char default_polymost_fs_glsl[];
	extern const char default_polymost_vs_glsl[];

	extern const char default_polymostaux_fs_glsl[];
	extern const char default_polymostaux_vs_glsl[];

	GLuint shader[2] = {0,0};

	// General texture rendering shader.
	if (polymostglsl.program) {
		glfunc.glDeleteProgram(polymostglsl.program);
		polymostglsl.program = 0;
	}

	shader[0] = polymost_load_shader(GL_VERTEX_SHADER, default_polymost_vs_glsl, "polymost_vs.glsl");
	shader[1] = polymost_load_shader(GL_FRAGMENT_SHADER, default_polymost_fs_glsl, "polymost_fs.glsl");
	if (shader[0] && shader[1]) {
		polymostglsl.program = glbuild_link_program(2, shader);
	}
	if (shader[0]) glfunc.glDeleteShader(shader[0]);
	if (shader[1]) glfunc.glDeleteShader(shader[1]);

	if (polymostglsl.program) {
		polymostglsl.attrib_vertex       = polymost_get_attrib(polymostglsl.program, "a_vertex");
		polymostglsl.attrib_texcoord     = polymost_get_attrib(polymostglsl.program, "a_texcoord");
		polymostglsl.uniform_modelview   = polymost_get_uniform(polymostglsl.program, "u_modelview");
		polymostglsl.uniform_projection  = polymost_get_uniform(polymostglsl.program, "u_projection");
		polymostglsl.uniform_texture     = polymost_get_uniform(polymostglsl.program, "u_texture");
		polymostglsl.uniform_glowtexture = polymost_get_uniform(polymostglsl.program, "u_glowtexture");
		polymostglsl.uniform_alphacut    = polymost_get_uniform(polymostglsl.program, "u_alphacut");
		polymostglsl.uniform_colour      = polymost_get_uniform(polymostglsl.program, "u_colour");
		polymostglsl.uniform_fogcolour   = polymost_get_uniform(polymostglsl.program, "u_fogcolour");
		polymostglsl.uniform_fogdensity  = polymost_get_uniform(polymostglsl.program, "u_fogdensity");

#if (USE_OPENGL == USE_GL3)
		glfunc.glGenVertexArrays(1, &polymostglsl.vao);
        glfunc.glBindVertexArray(polymostglsl.vao);
        glfunc.glEnableVertexAttribArray(polymostglsl.attrib_vertex);
        glfunc.glEnableVertexAttribArray(polymostglsl.attrib_texcoord);
#endif

		glfunc.glUseProgram(polymostglsl.program);
		glfunc.glUniform1i(polymostglsl.uniform_texture, 0);		//GL_TEXTURE0
		glfunc.glUniform1i(polymostglsl.uniform_glowtexture, 1);	//GL_TEXTURE1

		// Generate a buffer object for vertex/colour elements.
		glfunc.glGenBuffers(1, &polymostglsl.elementbuffer);
	}

	// A fully transparent texture for the case when a glow texture is not needed.
	if (!nulltexture) {
		const char pix[4] = {0,0,0,0};
		glfunc.glGenTextures(1, &nulltexture);
		glfunc.glBindTexture(GL_TEXTURE_2D, nulltexture);
		glfunc.glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,1,1,0,GL_RGBA,GL_UNSIGNED_BYTE,(GLvoid*)&pix);
		glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
		glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
	}

	// Engine auxiliary shader.
	if (polymostauxglsl.program) {
		glfunc.glDeleteProgram(polymostauxglsl.program);
		polymostauxglsl.program = 0;
	}

	shader[0] = polymost_load_shader(GL_VERTEX_SHADER, default_polymostaux_vs_glsl, "polymostaux_vs.glsl");
	shader[1] = polymost_load_shader(GL_FRAGMENT_SHADER, default_polymostaux_fs_glsl, "polymostaux_fs.glsl");
	if (shader[0] && shader[1]) {
		polymostauxglsl.program = glbuild_link_program(2, shader);
	}
	if (shader[0]) glfunc.glDeleteShader(shader[0]);
	if (shader[1]) glfunc.glDeleteShader(shader[1]);

	if (polymostauxglsl.program) {
		polymostauxglsl.attrib_vertex    = polymost_get_attrib(polymostauxglsl.program, "a_vertex");
		polymostauxglsl.attrib_texcoord  = polymost_get_attrib(polymostauxglsl.program, "a_texcoord");
		polymostauxglsl.uniform_projection = polymost_get_uniform(polymostauxglsl.program, "u_projection");
		polymostauxglsl.uniform_texture  = polymost_get_uniform(polymostauxglsl.program, "u_texture");
		polymostauxglsl.uniform_colour   = polymost_get_uniform(polymostauxglsl.program, "u_colour");
		polymostauxglsl.uniform_bgcolour = polymost_get_uniform(polymostauxglsl.program, "u_bgcolour");
		polymostauxglsl.uniform_mode     = polymost_get_uniform(polymostauxglsl.program, "u_mode");

#if (USE_OPENGL == USE_GL3)
		glfunc.glGenVertexArrays(1, &polymostauxglsl.vao);
        glfunc.glBindVertexArray(polymostauxglsl.vao);
        glfunc.glEnableVertexAttribArray(polymostauxglsl.attrib_vertex);
        glfunc.glEnableVertexAttribArray(polymostauxglsl.attrib_texcoord);
#endif

		glfunc.glUseProgram(polymostauxglsl.program);
		glfunc.glUniform1i(polymostauxglsl.uniform_texture, 0);	//GL_TEXTURE0

		// Generate a buffer object for vertex/colour elements and pre-allocate its memory.
		glfunc.glGenBuffers(1, &polymostauxglsl.elementbuffer);

		// Generate a buffer object for ad-hoc indexes.
		glfunc.glGenBuffers(1, &polymostauxglsl.indexbuffer);
	}

	// Generate a buffer object for element indexes and populate it with an
	// initial set of ascending indices, the way drawpoly() will generate points.
	glfunc.glGenBuffers(1, &elementindexbuffer);
	checkindexbuffer(MINVBOINDEXES);
}

// one-time initialisation of OpenGL for polymost
void polymost_glinit()
{
	GLfloat col[4];

	glfunc.glClearColor(0,0,0,0.5); //Black Background
	glfunc.glDisable(GL_DITHER);

	glfunc.glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);

	glfunc.glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

	if (glmultisample > 0 && glinfo.multisample) {
#if (USE_OPENGL != USE_GLES2)
		if (glinfo.nvmultisamplehint)
			glfunc.glHint(GL_MULTISAMPLE_FILTER_HINT_NV, glnvmultisamplehint ? GL_NICEST:GL_FASTEST);
		glfunc.glEnable(GL_MULTISAMPLE_ARB);
#endif
	}

	polymost_loadshaders();
}

void resizeglcheck ()
{
	float m[4][4];

	if (glredbluemode < lastglredbluemode) {
		glox1 = -1;
		glfunc.glColorMask(1,1,1,1);
	} else if (glredbluemode != lastglredbluemode) {
		redblueclearcnt = 0;
	}
	lastglredbluemode = glredbluemode;

#if (USE_OPENGL != USE_GLES2)
	if (lastglpolygonmode != glpolygonmode)
	{
		lastglpolygonmode = glpolygonmode;
		switch(glpolygonmode)
		{
			default:
			case 0: glfunc.glPolygonMode(GL_FRONT_AND_BACK,GL_FILL); break;
			case 1: glfunc.glPolygonMode(GL_FRONT_AND_BACK,GL_LINE); break;
			case 2: glfunc.glPolygonMode(GL_FRONT_AND_BACK,GL_POINT); break;
		}
	}
#endif

	if ((glox1 != windowx1) || (gloy1 != windowy1) || (glox2 != windowx2) || (gloy2 != windowy2))
	{
		glox1 = windowx1; gloy1 = windowy1;
		glox2 = windowx2; gloy2 = windowy2;

		glfunc.glViewport(windowx1,yres-(windowy2+1),windowx2-windowx1+1,windowy2-windowy1+1);
	}
}

void polymost_aftershowframe(void)
{
#if (USE_OPENGL != USE_GLES2)
	if (glpolygonmode)
	{
		glfunc.glClearColor(1.0,1.0,1.0,0.0);
		glfunc.glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	}
#endif
}

void polymost_setview(void)
{
	memset(gdrawroomsprojmat,0,sizeof(gdrawroomsprojmat));
	gdrawroomsprojmat[0][0] = (float)ydimen; gdrawroomsprojmat[0][2] = 1.0;
	gdrawroomsprojmat[1][1] = (float)xdimen; gdrawroomsprojmat[1][2] = 1.0;
	gdrawroomsprojmat[2][2] = 1.0; gdrawroomsprojmat[2][3] = (float)ydimen;
	gdrawroomsprojmat[3][2] =-1.0;

	memset(grotatespriteprojmat,0,sizeof(grotatespriteprojmat));
	grotatespriteprojmat[0][0] = grotatespriteprojmat[2][3] = 1.0;
	grotatespriteprojmat[1][1] = ((float)xdim)/((float)ydim);
	grotatespriteprojmat[2][2] = 1.0001;
	grotatespriteprojmat[3][2] = 1-grotatespriteprojmat[2][2];

	memset(gorthoprojmat,0,sizeof(gorthoprojmat));
	gorthoprojmat[0][0] = 2/(float)xdim;
	gorthoprojmat[1][1] = -2/(float)ydim;
	gorthoprojmat[2][2] = -1.0;
	gorthoprojmat[3][3] = 1.0;
	gorthoprojmat[3][0] = -1.0;
	gorthoprojmat[3][1] = 1.0;
}

void polymost_drawpoly_glcall(GLenum mode, struct polymostdrawpolycall *draw)
{
#ifdef DEBUGGINGAIDS
	polymostcallcounts.drawpoly_glcall++;
#endif

	glfunc.glUseProgram(polymostglsl.program);

#if (USE_OPENGL == USE_GL3)
    glfunc.glBindVertexArray(polymostglsl.vao);
#else
    glfunc.glEnableVertexAttribArray(polymostglsl.attrib_vertex);
    glfunc.glEnableVertexAttribArray(polymostglsl.attrib_texcoord);
#endif

	if (draw->elementbuffer > 0) {
		glfunc.glBindBuffer(GL_ARRAY_BUFFER, draw->elementbuffer);
	} else {
		// Drawing from the passed elementvbo items.
		glfunc.glBindBuffer(GL_ARRAY_BUFFER, polymostglsl.elementbuffer);
		glfunc.glBufferData(GL_ARRAY_BUFFER, draw->elementcount * sizeof(struct polymostvboitem), draw->elementvbo, GL_STREAM_DRAW);
	}

	if (draw->indexbuffer > 0) {
		glfunc.glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, draw->indexbuffer);
	} else {
		glfunc.glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementindexbuffer);
		checkindexbuffer(draw->indexcount);
	}

	glfunc.glVertexAttribPointer(polymostglsl.attrib_vertex, 3, GL_FLOAT, GL_FALSE,
		sizeof(struct polymostvboitem), (const GLvoid *)offsetof(struct polymostvboitem, v));
	glfunc.glVertexAttribPointer(polymostglsl.attrib_texcoord, 2, GL_FLOAT, GL_FALSE,
		sizeof(struct polymostvboitem), (const GLvoid *)offsetof(struct polymostvboitem, t));

	glfunc.glActiveTexture(GL_TEXTURE0);
	glfunc.glBindTexture(GL_TEXTURE_2D, draw->texture0);

	glfunc.glActiveTexture(GL_TEXTURE1);
	glfunc.glBindTexture(GL_TEXTURE_2D, draw->texture1 ? draw->texture1 : nulltexture);

	glfunc.glUniform1f(polymostglsl.uniform_alphacut, draw->alphacut);

	glfunc.glUniform4f(
		polymostglsl.uniform_colour,
		draw->colour.r, draw->colour.g, draw->colour.b, draw->colour.a
	);
	glfunc.glUniform4f(
		polymostglsl.uniform_fogcolour,
		draw->fogcolour.r, draw->fogcolour.g, draw->fogcolour.b, draw->fogcolour.a
	);
	glfunc.glUniform1f(
		polymostglsl.uniform_fogdensity,
		draw->fogdensity
	);

	glfunc.glUniformMatrix4fv(polymostglsl.uniform_modelview, 1, GL_FALSE, draw->modelview);
	glfunc.glUniformMatrix4fv(polymostglsl.uniform_projection, 1, GL_FALSE, draw->projection);

	glfunc.glDrawElements(mode, draw->indexcount, GL_UNSIGNED_SHORT, 0);

#if (USE_OPENGL == USE_GL3)
    glfunc.glBindVertexArray(0);
#else
	glfunc.glDisableVertexAttribArray(polymostglsl.attrib_vertex);
	glfunc.glDisableVertexAttribArray(polymostglsl.attrib_texcoord);
#endif
}

static void polymost_drawaux_glcall(GLenum mode, struct polymostdrawauxcall *draw)
{
#ifdef DEBUGGINGAIDS
	polymostcallcounts.drawaux_glcall++;
#endif

	glfunc.glUseProgram(polymostauxglsl.program);

#if (USE_OPENGL == USE_GL3)
    glfunc.glBindVertexArray(polymostauxglsl.vao);
#else
    glfunc.glEnableVertexAttribArray(polymostauxglsl.attrib_vertex);
	glfunc.glEnableVertexAttribArray(polymostauxglsl.attrib_texcoord);
#endif

	glfunc.glBindBuffer(GL_ARRAY_BUFFER, polymostauxglsl.elementbuffer);
	glfunc.glBufferData(GL_ARRAY_BUFFER, draw->elementcount * sizeof(struct polymostvboitem), draw->elementvbo, GL_STREAM_DRAW);

	if (draw->indexes) {
		glfunc.glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, polymostauxglsl.indexbuffer);
		glfunc.glBufferData(GL_ELEMENT_ARRAY_BUFFER, draw->indexcount * sizeof(GLushort), draw->indexes, GL_STREAM_DRAW);
	} else {
		glfunc.glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementindexbuffer);
		checkindexbuffer(draw->indexcount);
	}

	glfunc.glVertexAttribPointer(polymostauxglsl.attrib_vertex, 3, GL_FLOAT, GL_FALSE,
		sizeof(struct polymostvboitem), (const GLvoid *)offsetof(struct polymostvboitem, v));
	glfunc.glVertexAttribPointer(polymostauxglsl.attrib_texcoord, 2, GL_FLOAT, GL_FALSE,
		sizeof(struct polymostvboitem), (const GLvoid *)offsetof(struct polymostvboitem, t));

	glfunc.glActiveTexture(GL_TEXTURE0);
	glfunc.glBindTexture(GL_TEXTURE_2D, draw->texture0);

	glfunc.glUniform4f(
		polymostauxglsl.uniform_colour,
		draw->colour.r, draw->colour.g, draw->colour.b, draw->colour.a
	);
	glfunc.glUniform4f(
		polymostauxglsl.uniform_bgcolour,
		draw->bgcolour.r, draw->bgcolour.g, draw->bgcolour.b, draw->bgcolour.a
	);
	glfunc.glUniform1i(polymostauxglsl.uniform_mode, draw->mode);

	glfunc.glUniformMatrix4fv(polymostauxglsl.uniform_projection, 1, GL_FALSE, &gorthoprojmat[0][0]);

	glfunc.glDrawElements(mode, draw->indexcount, GL_UNSIGNED_SHORT, 0);

#if (USE_OPENGL == USE_GL3)
    glfunc.glBindVertexArray(0);
#else
	glfunc.glDisableVertexAttribArray(polymostauxglsl.attrib_vertex);
	glfunc.glDisableVertexAttribArray(polymostauxglsl.attrib_texcoord);
#endif
}

static void polymost_palfade(void)
{
	struct polymostdrawauxcall draw;
	struct polymostvboitem vboitem[4];

	if ((rendmode != 3) || (qsetmode != 200)) return;
	if (palfadedelta == 0) return;

	draw.mode = 2;	// Solid colour.

	draw.colour.r = palfadergb.r / 255.f;
	draw.colour.g = palfadergb.g / 255.f;
	draw.colour.b = palfadergb.b / 255.f;
	draw.colour.a = palfadedelta / 255.f;

	vboitem[0].v.x = 0.f;
	vboitem[0].v.y = 0.f;
	vboitem[0].v.z = 0.f;

	vboitem[1].v.x = (float)xdim;
	vboitem[1].v.y = 0.f;
	vboitem[1].v.z = 0.f;

	vboitem[2].v.x = (float)xdim;
	vboitem[2].v.y = (float)ydim;
	vboitem[2].v.z = 0.f;

	vboitem[3].v.x = 0.f;
	vboitem[3].v.y = (float)ydim;
	vboitem[3].v.z = 0.f;

	draw.indexcount = 4;
	draw.indexes = NULL;
	draw.elementcount = 4;
	draw.elementvbo = vboitem;

	glfunc.glDisable(GL_DEPTH_TEST);
	glfunc.glEnable(GL_BLEND);

	polymost_drawaux_glcall(GL_TRIANGLE_FAN, &draw);
}

#endif //USE_OPENGL

void polymost_nextpage(void)
{
#if USE_OPENGL
	polymost_palfade();
#endif

#ifdef DEBUGGINGAIDS
	if (polymostshowcallcounts) {
		char buf[1024];
		sprintf(buf,
			"drawpoly_gl(%d) drawaux_gl(%d) drawpoly(%d) "
			"domost(%d) drawalls(%d) drawmaskwall(%d) drawsprite(%d)",
	    		polymostcallcounts.drawpoly_glcall,
	    		polymostcallcounts.drawaux_glcall,
	    		polymostcallcounts.drawpoly,
	    		polymostcallcounts.domost,
	    		polymostcallcounts.drawalls,
	    		polymostcallcounts.drawmaskwall,
	    		polymostcallcounts.drawsprite
		);
		if (rendmode == 3) {
			polymost_printext256(0, 8, 31, -1, buf, 0);
		} else {
			printext256(0, 8, 31, -1, buf, 0);
		}
	}
	memset(&polymostcallcounts, 0, sizeof(polymostcallcounts));
#endif
}

	//(dpx,dpy) specifies an n-sided polygon. The polygon must be a convex clockwise loop.
	//    n must be <= 8 (assume clipping can double number of vertices)
	//method: 0:solid, 1:masked(255 is transparent), 2:transluscent #1, 3:transluscent #2
	//    +4 means it's a sprite, so wraparound isn't needed
void drawpoly (double *dpx, double *dpy, int n, int method)
{
	#define PI 3.14159265358979323
	double ngdx = 0.0, ngdy = 0.0, ngdo = 0.0, ngux = 0.0, nguy = 0.0, nguo = 0.0;
	double ngvx = 0.0, ngvy = 0.0, ngvo = 0.0, dp, up, vp, rdp, du0 = 0.0, du1 = 0.0, dui, duj;
	double ngdx2, ngux2, ngvx2;
	double f, r, ox, oy, oz, ox2, oy2, oz2, dd[16], uu[16], vv[16], px[16], py[16], uoffs;
	int i, j, k, x, y, z, nn, ix0, ix1, mini, maxi, tsizx, tsizy, tsizxm1 = 0, tsizym1 = 0, ltsizy = 0;
	int xx, yy, xi, d0, u0, v0, d1, u1, v1, xmodnice = 0, ymulnice = 0, dorot;
	unsigned char dacol = 0, *walptr, *palptr = NULL, *vidp, *vide;

#ifdef DEBUGGINGAIDS
	polymostcallcounts.drawpoly++;
#endif

	if (method == -1) return;

	if (n == 3)
	{
		if ((dpx[0]-dpx[1])*(dpy[2]-dpy[1]) >= (dpx[2]-dpx[1])*(dpy[0]-dpy[1])) return; //for triangle
	}
	else
	{
		f = 0; //f is area of polygon / 2
		for(i=n-2,j=n-1,k=0;k<n;i=j,j=k,k++) f += (dpx[i]-dpx[k])*dpy[j];
		if (f <= 0) return;
	}

		//Load texture (globalpicnum)
	if ((unsigned int)globalpicnum >= MAXTILES) globalpicnum = 0;
	setgotpic(globalpicnum);
	tsizx = tilesizx[globalpicnum];
	tsizy = tilesizy[globalpicnum];
	if (!palookup[globalpal]) globalpal = 0;
	if (!waloff[globalpicnum])
	{
		loadtile(globalpicnum);
		if (!waloff[globalpicnum])
		{
			if (rendmode != 3) return;
			tsizx = tsizy = 1; method = METH_MASKED; //Hack to update Z-buffer for invalid mirror textures
		}
	}
	walptr = (unsigned char *)waloff[globalpicnum];

	j = 0; dorot = ((gchang != 1.0) || (gctang != 1.0));
	if (dorot)
	{
		for(i=0;i<n;i++)
		{
			ox = dpx[i]-ghalfx;
			oy = dpy[i]-ghoriz;
			oz = ghalfx;

				//Up/down rotation
			ox2 = ox;
			oy2 = oy*gchang - oz*gshang;
			oz2 = oy*gshang + oz*gchang;

				//Tilt rotation
			ox = ox2*gctang - oy2*gstang;
			oy = ox2*gstang + oy2*gctang;
			oz = oz2;

			if ((oz < SCISDIST) && (rendmode != 3)) return; //annoying hack to avoid bugs in software rendering

			r = ghalfx / oz;

			dd[j] = (dpx[i]*gdx + dpy[i]*gdy + gdo)*r;
			uu[j] = (dpx[i]*gux + dpy[i]*guy + guo)*r;
			vv[j] = (dpx[i]*gvx + dpy[i]*gvy + gvo)*r;

			px[j] = ox*r + ghalfx;
			py[j] = oy*r + ghoriz;
			if ((!j) || (px[j] != px[j-1]) || (py[j] != py[j-1])) j++;
		}
	}
	else
	{
		for(i=0;i<n;i++)
		{
			px[j] = dpx[i];
			py[j] = dpy[i];
			if ((!j) || (px[j] != px[j-1]) || (py[j] != py[j-1])) j++;
		}
	}
	while ((j >= 3) && (px[j-1] == px[0]) && (py[j-1] == py[0])) j--;
	if (j < 3) return;
	n = j;

#if USE_OPENGL
	if (rendmode == 3)
	{
		float hackscx, hackscy;
		unsigned short ptflags = 0;
		int picidx = PTHPIC_BASE;
		PTHead * pth = 0;
		struct polymostdrawpolycall draw;
		struct polymostvboitem vboitem[MINVBOINDEXES];

		if (usehightile) ptflags |= PTH_HIGHTILE;
		if (method & METH_CLAMPED) ptflags |= PTH_CLAMPED;
		if (drawingskybox) ptflags |= PTH_SKYBOX;

		pth = PT_GetHead(globalpicnum, globalpal, ptflags, 0);

		// Base texture.
		draw.texture0 = 0;
		if (pth) {
			if (drawingskybox) {
				picidx = drawingskybox - 1;
			}
			if (pth->pic[picidx]) {
				draw.texture0 = pth->pic[picidx]->glpic;
			}
		}

		// Glow texture.
		draw.texture1 = nulltexture;
		if ((method & METH_LAYERS) && pth && !drawingskybox) {
			if (pth->pic[ PTHPIC_GLOW ]) {
				draw.texture1 = pth->pic[ PTHPIC_GLOW ]->glpic;
			}
		}

		if (!(method & (METH_MASKED | METH_TRANS))) {
			glfunc.glDisable(GL_BLEND);
			draw.alphacut = 0.f;
		} else {
			float alphac = 0.32;
			if (pth && pth->repldef && pth->repldef->alphacut >= 0.0) {
				alphac = pth->repldef->alphacut;
			}
			if (usegoodalpha) alphac = 0.0;
			if (!waloff[globalpicnum]) alphac = 0.0;	// invalid textures ignore the alpha cutoff settings

			glfunc.glEnable(GL_BLEND);
			draw.alphacut = alphac;
		}

		draw.fogcolour.r = (float)palookupfog[gfogpalnum].r / 63.f;
		draw.fogcolour.g = (float)palookupfog[gfogpalnum].g / 63.f;
		draw.fogcolour.b = (float)palookupfog[gfogpalnum].b / 63.f;
		draw.fogcolour.a = 1.f;
		draw.fogdensity = gfogdensity;

		hackscx = pth->scalex;
		hackscy = pth->scaley;
		tsizx   = pth->pic[picidx]->tsizx;
		tsizy   = pth->pic[picidx]->tsizy;
		xx      = pth->pic[picidx]->sizx;
		yy      = pth->pic[picidx]->sizy;
		ox2     = (double)1.0/(double)xx;
		oy2     = (double)1.0/(double)yy;

		if (!dorot)
		{
			for(i=n-1;i>=0;i--)
			{
				dd[i] = px[i]*gdx + py[i]*gdy + gdo;
				uu[i] = px[i]*gux + py[i]*guy + guo;
				vv[i] = px[i]*gvx + py[i]*gvy + gvo;
			}
		}

		draw.colour.r = draw.colour.g = draw.colour.b =
			((float)(numpalookups-min(max(globalshade,0),numpalookups)))/((float)numpalookups);
		switch(method & (METH_MASKED | METH_TRANS))
		{
			case METH_SOLID:   draw.colour.a = 1.0; break;
			case METH_MASKED:  draw.colour.a = 1.0; break;
			case METH_TRANS:   draw.colour.a = 0.66; break;
			case METH_INTRANS: draw.colour.a = 0.33; break;
		}
		// tinting happens only to hightile textures, and only if the texture we're
		// rendering isn't for the same palette as what we asked for
		if (pth && (pth->flags & PTH_HIGHTILE) && (globalpal != pth->repldef->palnum)) {
			// apply tinting for replaced textures
			draw.colour.r *= (float)hictinting[globalpal].r / 255.0;
			draw.colour.g *= (float)hictinting[globalpal].g / 255.0;
			draw.colour.b *= (float)hictinting[globalpal].b / 255.0;
		}

		draw.modelview = &gidentitymat[0][0];
		if (method & METH_ROTATESPRITE) {
			draw.projection = &grotatespriteprojmat[0][0];
		} else {
			draw.projection = &gdrawroomsprojmat[0][0];
		}

		draw.indexbuffer = 0;
		draw.elementbuffer = 0;
		draw.elementvbo = vboitem;

			//Hack for walls&masked walls which use textures that are not a power of 2
		if ((method & METH_POW2XSPLIT) && (tsizx != xx))
		{
			if (!dorot)
			{
				ngdx = gdx; ngdy = gdy; ngdo = gdo+(ngdx+ngdy)*.5;
				ngux = gux; nguy = guy; nguo = guo+(ngux+nguy)*.5;
				ngvx = gvx; ngvy = gvy; ngvo = gvo+(ngvx+ngvy)*.5;
			}
			else
			{
				ox = py[1]-py[2]; oy = py[2]-py[0]; oz = py[0]-py[1];
				r = 1.0 / (ox*px[0] + oy*px[1] + oz*px[2]);
				ngdx = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
				ngux = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
				ngvx = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
				ox = px[2]-px[1]; oy = px[0]-px[2]; oz = px[1]-px[0];
				ngdy = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
				nguy = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
				ngvy = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
				ox = px[0]-.5; oy = py[0]-.5; //.5 centers texture nicely
				ngdo = dd[0] - ox*ngdx - oy*ngdy;
				nguo = uu[0] - ox*ngux - oy*nguy;
				ngvo = vv[0] - ox*ngvx - oy*ngvy;
			}

			ngux *= hackscx; nguy *= hackscx; nguo *= hackscx;
			ngvx *= hackscy; ngvy *= hackscy; ngvo *= hackscy;
			uoffs = ((double)(xx-tsizx)*.5);
			ngux -= ngdx*uoffs;
			nguy -= ngdy*uoffs;
			nguo -= ngdo*uoffs;

				//Find min&max u coordinates (du0...du1)
			for(i=0;i<n;i++)
			{
				ox = px[i]; oy = py[i];
				f = (ox*ngux + oy*nguy + nguo) / (ox*ngdx + oy*ngdy + ngdo);
				if (!i) { du0 = du1 = f; continue; }
					  if (f < du0) du0 = f;
				else if (f > du1) du1 = f;
			}

			f = 1.0/(double)tsizx;
			ix0 = (int)floor(du0*f);
			ix1 = (int)floor(du1*f);
			for(;ix0<=ix1;ix0++)
			{
				du0 = (double)((ix0  )*tsizx); // + uoffs;
				du1 = (double)((ix0+1)*tsizx); // + uoffs;

				i = 0; nn = 0;
				duj = (px[i]*ngux + py[i]*nguy + nguo) / (px[i]*ngdx + py[i]*ngdy + ngdo);
				do
				{
					j = i+1; if (j == n) j = 0;

					dui = duj; duj = (px[j]*ngux + py[j]*nguy + nguo) / (px[j]*ngdx + py[j]*ngdy + ngdo);

					if ((du0 <= dui) && (dui <= du1)) { uu[nn] = px[i]; vv[nn] = py[i]; nn++; }
					if (duj <= dui)
					{
						if ((du1 < duj) != (du1 < dui))
						{
								//ox*(ngux-ngdx*du1) + oy*(nguy-ngdy*du1) + (nguo-ngdo*du1) = 0
								//(px[j]-px[i])*f + px[i] = ox
								//(py[j]-py[i])*f + py[i] = oy

								///Solve for f
								//((px[j]-px[i])*f + px[i])*(ngux-ngdx*du1) +
								//((py[j]-py[i])*f + py[i])*(nguy-ngdy*du1) + (nguo-ngdo*du1) = 0

							f = -(       px[i] *(ngux-ngdx*du1) +  py[i]       *(nguy-ngdy*du1) + (nguo-ngdo*du1)) /
								  ((px[j]-px[i])*(ngux-ngdx*du1) + (py[j]-py[i])*(nguy-ngdy*du1));
							uu[nn] = (px[j]-px[i])*f + px[i];
							vv[nn] = (py[j]-py[i])*f + py[i]; nn++;
						}
						if ((du0 < duj) != (du0 < dui))
						{
							f = -(       px[i] *(ngux-ngdx*du0) +        py[i] *(nguy-ngdy*du0) + (nguo-ngdo*du0)) /
								  ((px[j]-px[i])*(ngux-ngdx*du0) + (py[j]-py[i])*(nguy-ngdy*du0));
							uu[nn] = (px[j]-px[i])*f + px[i];
							vv[nn] = (py[j]-py[i])*f + py[i]; nn++;
						}
					}
					else
					{
						if ((du0 < duj) != (du0 < dui))
						{
							f = -(       px[i] *(ngux-ngdx*du0) +        py[i] *(nguy-ngdy*du0) + (nguo-ngdo*du0)) /
								  ((px[j]-px[i])*(ngux-ngdx*du0) + (py[j]-py[i])*(nguy-ngdy*du0));
							uu[nn] = (px[j]-px[i])*f + px[i];
							vv[nn] = (py[j]-py[i])*f + py[i]; nn++;
						}
						if ((du1 < duj) != (du1 < dui))
						{
							f = -(       px[i] *(ngux-ngdx*du1) +  py[i]       *(nguy-ngdy*du1) + (nguo-ngdo*du1)) /
								  ((px[j]-px[i])*(ngux-ngdx*du1) + (py[j]-py[i])*(nguy-ngdy*du1));
							uu[nn] = (px[j]-px[i])*f + px[i];
							vv[nn] = (py[j]-py[i])*f + py[i]; nn++;
						}
					}
					i = j;
				} while (i);
				if (nn < 3) continue;

				for(i=0;i<nn;i++)
				{
					ox = uu[i]; oy = vv[i];
					dp = ox*ngdx + oy*ngdy + ngdo;
					up = ox*ngux + oy*nguy + nguo;
					vp = ox*ngvx + oy*ngvy + ngvo;
					r = 1.0/dp;

					vboitem[i].v.x = (ox-ghalfx)*r*grhalfxdown10x;
					vboitem[i].v.y = (ghoriz-oy)*r*grhalfxdown10;
					vboitem[i].v.z = r*(1.0/1024.0);
					vboitem[i].t.s = (up*r-du0+uoffs)*ox2;
					vboitem[i].t.t = vp*r*oy2;
				}
				draw.indexcount = nn;
				draw.elementcount = nn;

				glfunc.glDepthMask(GL_TRUE);
				polymost_drawpoly_glcall(GL_TRIANGLE_FAN, &draw);
			}
		}
		else if (n > 0)
		{
			ox2 *= hackscx; oy2 *= hackscy;

			for(i=0;i<n;i++)
			{
				r = 1.0/dd[i];

				vboitem[i].v.x = (px[i]-ghalfx)*r*grhalfxdown10x;
				vboitem[i].v.y = (ghoriz-py[i])*r*grhalfxdown10;
				vboitem[i].v.z = r*(1.0/1024.0);
				vboitem[i].t.s = uu[i]*r*ox2;
				vboitem[i].t.t = vv[i]*r*oy2;
			}
			draw.indexcount = n;
			draw.elementcount = n;

			glfunc.glDepthMask(GL_TRUE);
			polymost_drawpoly_glcall(GL_TRIANGLE_FAN, &draw);
		}

		return;
	}
#endif

	if (rendmode == 2)
	{
#if (USEZBUFFER != 0)
		if ((!zbufmem) || (zbufbpl != bytesperline) || (zbufysiz != ydim))
		{
			zbufbpl = bytesperline;
			zbufysiz = ydim;
			zbufmem = (intptr_t)realloc((void *)zbufmem,zbufbpl*zbufysiz*4);
		}
		zbufoff = (int *)(zbufmem-(frameplace<<2));
#endif
		if ((!transluc)) method = (method & ~(METH_MASKED | METH_TRANS)) + METH_MASKED; //In case translucent table doesn't exist

		if (!dorot)
		{
			ngdx = gdx; ngdy = gdy; ngdo = gdo+(ngdx+ngdy)*.5;
			ngux = gux; nguy = guy; nguo = guo+(ngux+nguy)*.5;
			ngvx = gvx; ngvy = gvy; ngvo = gvo+(ngvx+ngvy)*.5;
		}
		else
		{
				//General equations:
				//dd[i] = (px[i]*gdx + py[i]*gdy + gdo)
				//uu[i] = (px[i]*gux + py[i]*guy + guo)/dd[i]
				//vv[i] = (px[i]*gvx + py[i]*gvy + gvo)/dd[i]
				//
				//px[0]*gdx + py[0]*gdy + 1*gdo = dd[0]
				//px[1]*gdx + py[1]*gdy + 1*gdo = dd[1]
				//px[2]*gdx + py[2]*gdy + 1*gdo = dd[2]
				//
				//px[0]*gux + py[0]*guy + 1*guo = uu[0]*dd[0] (uu[i] premultiplied by dd[i] above)
				//px[1]*gux + py[1]*guy + 1*guo = uu[1]*dd[1]
				//px[2]*gux + py[2]*guy + 1*guo = uu[2]*dd[2]
				//
				//px[0]*gvx + py[0]*gvy + 1*gvo = vv[0]*dd[0] (vv[i] premultiplied by dd[i] above)
				//px[1]*gvx + py[1]*gvy + 1*gvo = vv[1]*dd[1]
				//px[2]*gvx + py[2]*gvy + 1*gvo = vv[2]*dd[2]
			ox = py[1]-py[2]; oy = py[2]-py[0]; oz = py[0]-py[1];
			r = 1.0 / (ox*px[0] + oy*px[1] + oz*px[2]);
			ngdx = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
			ngux = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
			ngvx = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
			ox = px[2]-px[1]; oy = px[0]-px[2]; oz = px[1]-px[0];
			ngdy = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
			nguy = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
			ngvy = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
			ox = px[0]-.5; oy = py[0]-.5; //.5 centers texture nicely
			ngdo = dd[0] - ox*ngdx - oy*ngdy;
			nguo = uu[0] - ox*ngux - oy*nguy;
			ngvo = vv[0] - ox*ngvx - oy*ngvy;
		}
		palptr = &palookup[globalpal][min(max(globalshade,0),numpalookups-1)<<8]; //<-need to make shade not static!

		tsizxm1 = tsizx-1; xmodnice = (!(tsizxm1&tsizx));
		tsizym1 = tsizy-1; ymulnice = (!(tsizym1&tsizy));
		if ((method & METH_CLAMPED) && (!xmodnice)) //Sprites don't need a mod on texture coordinates
			{ xmodnice = 1; for(tsizxm1=1;tsizxm1<tsizx;tsizxm1=(tsizxm1<<1)+1); }
		if (!ymulnice) { for(tsizym1=1;tsizym1+1<tsizy;tsizym1=(tsizym1<<1)+1); }
		ltsizy = (picsiz[globalpicnum]>>4);
	}
	else
	{
		dacol = palookup[0][(int)(*(unsigned char *)(waloff[globalpicnum]))+(min(max(globalshade,0),numpalookups-1)<<8)];
	}

	if (grhalfxdown10x < 0) //Hack for mirrors
	{
		for(i=((n-1)>>1);i>=0;i--)
		{
			r = px[i]; px[i] = ((double)xdimen)-px[n-1-i]; px[n-1-i] = ((double)xdimen)-r;
			r = py[i]; py[i] = py[n-1-i]; py[n-1-i] = r;
		}
		ngdo += ((double)xdimen)*ngdx; ngdx = -ngdx;
		nguo += ((double)xdimen)*ngux; ngux = -ngux;
		ngvo += ((double)xdimen)*ngvx; ngvx = -ngvx;
	}

	ngdx2 = ngdx*(1<<LINTERPSIZ);
	ngux2 = ngux*(1<<LINTERPSIZ);
	ngvx2 = ngvx*(1<<LINTERPSIZ);

	mini = (py[0] >= py[1]); maxi = 1-mini;
	for(z=2;z<n;z++)
	{
		if (py[z] < py[mini]) mini = z;
		if (py[z] > py[maxi]) maxi = z;
	}

	i = maxi; dtol(py[i],&yy); if (yy > ydimen) yy = ydimen;
	do
	{
		j = i+1; if (j == n) j = 0;
		dtol(py[j],&y); if (y < 0) y = 0;
		if (y < yy)
		{
			f = (px[j]-px[i])/(py[j]-py[i]); dtol(f*16384.0,&xi);
			dtol((((double)yy-.5-py[j])*f + px[j])*16384.0+8192.0,&x);
			for(;yy>y;yy--,x-=xi) lastx[yy-1] = (x>>14);
		}
		i = j;
	} while (i != mini);
	do
	{
		j = i+1; if (j == n) j = 0;
		dtol(py[j],&yy); if (yy > ydimen) yy = ydimen;
		if (y < yy)
		{
			f = (px[j]-px[i])/(py[j]-py[i]); dtol(f*16384.0,&xi);
			dtol((((double)y+.5-py[j])*f + px[j])*16384.0+8192.0,&x);
			for(;y<yy;y++,x+=xi)
			{
				ix0 = lastx[y]; if (ix0 < 0) ix0 = 0;
				ix1 = (x>>14); if (ix1 > xdimen) ix1 = xdimen;
				if (ix0 < ix1)
				{
					if (rendmode == 1)
						memset((void *)(ylookup[y]+ix0+frameoffset),dacol,ix1-ix0);
					else
					{
						vidp = (unsigned char *)(ylookup[y]+frameoffset+ix0);
						dp = ngdx*(double)ix0 + ngdy*(double)y + ngdo;
						up = ngux*(double)ix0 + nguy*(double)y + nguo;
						vp = ngvx*(double)ix0 + ngvy*(double)y + ngvo;
						rdp = 65536.0/dp; dp += ngdx2;
						dtol(   rdp,&d0);
						dtol(up*rdp,&u0); up += ngux2;
						dtol(vp*rdp,&v0); vp += ngvx2;
						rdp = 65536.0/dp;

						switch (method & (METH_MASKED | METH_TRANS))
						{
							case METH_SOLID:
								if (xmodnice&ymulnice) //both u&v texture sizes are powers of 2 :)
								{
									for(xx=ix0;xx<ix1;xx+=(1<<LINTERPSIZ))
									{
										dtol(   rdp,&d1); dp += ngdx2; d1 = ((d1-d0)>>LINTERPSIZ);
										dtol(up*rdp,&u1); up += ngux2; u1 = ((u1-u0)>>LINTERPSIZ);
										dtol(vp*rdp,&v1); vp += ngvx2; v1 = ((v1-v0)>>LINTERPSIZ);
										rdp = 65536.0/dp; vide = &vidp[min(ix1-xx,1<<LINTERPSIZ)];
										while (vidp < vide)
										{
#if (DEPTHDEBUG == 0)
#if (USEZBUFFER != 0)
											zbufoff[(intptr_t)vidp] = d0+16384; //+ hack so wall&floor sprites don't disappear
#endif
											vidp[0] = palptr[walptr[(((u0>>16)&tsizxm1)<<ltsizy) + ((v0>>16)&tsizym1)]]; //+((d0>>13)&0x3f00)];
#else
											vidp[0] = ((d0>>16)&255);
#endif
											d0 += d1; u0 += u1; v0 += v1; vidp++;
										}
									}
								}
								else
								{
									for(xx=ix0;xx<ix1;xx+=(1<<LINTERPSIZ))
									{
										dtol(   rdp,&d1); dp += ngdx2; d1 = ((d1-d0)>>LINTERPSIZ);
										dtol(up*rdp,&u1); up += ngux2; u1 = ((u1-u0)>>LINTERPSIZ);
										dtol(vp*rdp,&v1); vp += ngvx2; v1 = ((v1-v0)>>LINTERPSIZ);
										rdp = 65536.0/dp; vide = &vidp[min(ix1-xx,1<<LINTERPSIZ)];
										while (vidp < vide)
										{
#if (DEPTHDEBUG == 0)
#if (USEZBUFFER != 0)
											zbufoff[(intptr_t)vidp] = d0;
#endif
											vidp[0] = palptr[walptr[imod(u0>>16,tsizx)*tsizy + ((v0>>16)&tsizym1)]]; //+((d0>>13)&0x3f00)];
#else
											vidp[0] = ((d0>>16)&255);
#endif
											d0 += d1; u0 += u1; v0 += v1; vidp++;
										}
									}
								}
								break;
							case METH_MASKED:
								if (xmodnice) //both u&v texture sizes are powers of 2 :)
								{
									for(xx=ix0;xx<ix1;xx+=(1<<LINTERPSIZ))
									{
										dtol(   rdp,&d1); dp += ngdx2; d1 = ((d1-d0)>>LINTERPSIZ);
										dtol(up*rdp,&u1); up += ngux2; u1 = ((u1-u0)>>LINTERPSIZ);
										dtol(vp*rdp,&v1); vp += ngvx2; v1 = ((v1-v0)>>LINTERPSIZ);
										rdp = 65536.0/dp; vide = &vidp[min(ix1-xx,1<<LINTERPSIZ)];
										while (vidp < vide)
										{
											dacol = walptr[(((u0>>16)&tsizxm1)*tsizy) + ((v0>>16)&tsizym1)];
#if (DEPTHDEBUG == 0)
#if (USEZBUFFER != 0)
											if ((dacol != 255) && (d0 <= zbufoff[(intptr_t)vidp]))
											{
												zbufoff[(intptr_t)vidp] = d0;
												vidp[0] = palptr[((int)dacol)]; //+((d0>>13)&0x3f00)];
											}
#else
											if (dacol != 255) vidp[0] = palptr[((int)dacol)]; //+((d0>>13)&0x3f00)];
#endif
#else
											if ((dacol != 255) && (vidp[0] > (d0>>16))) vidp[0] = ((d0>>16)&255);
#endif
											d0 += d1; u0 += u1; v0 += v1; vidp++;
										}
									}
								}
								else
								{
									for(xx=ix0;xx<ix1;xx+=(1<<LINTERPSIZ))
									{
										dtol(   rdp,&d1); dp += ngdx2; d1 = ((d1-d0)>>LINTERPSIZ);
										dtol(up*rdp,&u1); up += ngux2; u1 = ((u1-u0)>>LINTERPSIZ);
										dtol(vp*rdp,&v1); vp += ngvx2; v1 = ((v1-v0)>>LINTERPSIZ);
										rdp = 65536.0/dp; vide = &vidp[min(ix1-xx,1<<LINTERPSIZ)];
										while (vidp < vide)
										{
											dacol = walptr[imod(u0>>16,tsizx)*tsizy + ((v0>>16)&tsizym1)];
#if (DEPTHDEBUG == 0)
#if (USEZBUFFER != 0)
											if ((dacol != 255) && (d0 <= zbufoff[(intptr_t)vidp]))
											{
												zbufoff[(intptr_t)vidp] = d0;
												vidp[0] = palptr[((int)dacol)]; //+((d0>>13)&0x3f00)];
											}
#else
											if (dacol != 255) vidp[0] = palptr[((int)dacol)]; //+((d0>>13)&0x3f00)];
#endif
#else
											if ((dacol != 255) && (vidp[0] > (d0>>16))) vidp[0] = ((d0>>16)&255);
#endif
											d0 += d1; u0 += u1; v0 += v1; vidp++;
										}
									}
								}
								break;
							case METH_TRANS: //Transluscence #1
								for(xx=ix0;xx<ix1;xx+=(1<<LINTERPSIZ))
								{
									dtol(   rdp,&d1); dp += ngdx2; d1 = ((d1-d0)>>LINTERPSIZ);
									dtol(up*rdp,&u1); up += ngux2; u1 = ((u1-u0)>>LINTERPSIZ);
									dtol(vp*rdp,&v1); vp += ngvx2; v1 = ((v1-v0)>>LINTERPSIZ);
									rdp = 65536.0/dp; vide = &vidp[min(ix1-xx,1<<LINTERPSIZ)];
									while (vidp < vide)
									{
										dacol = walptr[imod(u0>>16,tsizx)*tsizy + ((v0>>16)&tsizym1)];
										//dacol = walptr[(((u0>>16)&tsizxm1)<<ltsizy) + ((v0>>16)&tsizym1)];
#if (DEPTHDEBUG == 0)
#if (USEZBUFFER != 0)
										if ((dacol != 255) && (d0 <= zbufoff[(intptr_t)vidp]))
										{
											zbufoff[(intptr_t)vidp] = d0;
											vidp[0] = transluc[(((int)vidp[0])<<8)+((int)palptr[((int)dacol)])]; //+((d0>>13)&0x3f00)])];
										}
#else
										if (dacol != 255)
											vidp[0] = transluc[(((int)vidp[0])<<8)+((int)palptr[((int)dacol)])]; //+((d0>>13)&0x3f00)])];
#endif
#else
										if ((dacol != 255) && (vidp[0] > (d0>>16))) vidp[0] = ((d0>>16)&255);
#endif
										d0 += d1; u0 += u1; v0 += v1; vidp++;
									}
								}
								break;
							case METH_INTRANS: //Transluscence #2
								for(xx=ix0;xx<ix1;xx+=(1<<LINTERPSIZ))
								{
									dtol(   rdp,&d1); dp += ngdx2; d1 = ((d1-d0)>>LINTERPSIZ);
									dtol(up*rdp,&u1); up += ngux2; u1 = ((u1-u0)>>LINTERPSIZ);
									dtol(vp*rdp,&v1); vp += ngvx2; v1 = ((v1-v0)>>LINTERPSIZ);
									rdp = 65536.0/dp; vide = &vidp[min(ix1-xx,1<<LINTERPSIZ)];
									while (vidp < vide)
									{
										dacol = walptr[imod(u0>>16,tsizx)*tsizy + ((v0>>16)&tsizym1)];
										//dacol = walptr[(((u0>>16)&tsizxm1)<<ltsizy) + ((v0>>16)&tsizym1)];
#if (DEPTHDEBUG == 0)
#if (USEZBUFFER != 0)
										if ((dacol != 255) && (d0 <= zbufoff[(intptr_t)vidp]))
										{
											zbufoff[(intptr_t)vidp] = d0;
											vidp[0] = transluc[((int)vidp[0])+(((int)palptr[((int)dacol)/*+((d0>>13)&0x3f00)*/])<<8)];
										}
#else
										if (dacol != 255)
											vidp[0] = transluc[((int)vidp[0])+(((int)palptr[((int)dacol)/*+((d0>>13)&0x3f00)*/])<<8)];
#endif
#else
										if ((dacol != 255) && (vidp[0] > (d0>>16))) vidp[0] = ((d0>>16)&255);
#endif
										d0 += d1; u0 += u1; v0 += v1; vidp++;
									}
								}
								break;
						}
					}
				}
			}
		}
		i = j;
	} while (i != maxi);

	if (rendmode == 1)
	{
		if (method & (METH_MASKED | METH_TRANS)) //Only draw border around sprites/maskwalls
		{
		for(i=0,j=n-1;i<n;j=i,i++) drawline2d(px[i],py[i],px[j],py[j],31); //hopefully color index 31 is white
		}

		//ox = 0; oy = 0;
		//for(i=0;i<n;i++) { ox += px[i]; oy += py[i]; }
		//ox /= (double)n; oy /= (double)n;
		//for(i=0,j=n-1;i<n;j=i,i++) drawline2d(px[i]+(ox-px[i])*.125,py[i]+(oy-py[i])*.125,px[j]+(ox-px[j])*.125,py[j]+(oy-py[j])*.125,31);
	}
}

	/*Init viewport boundary (must be 4 point convex loop):
	//      (px[0],py[0]).----.(px[1],py[1])
	//                  /      \
	//                /          \
	// (px[3],py[3]).--------------.(px[2],py[2])
	*/
static void initmosts (double *px, double *py, int n)
{
	int i, j, k, imin;

	vcnt = 1; //0 is dummy solid node

	if (n < 3) return;
	imin = (px[1] < px[0]);
	for(i=n-1;i>=2;i--) if (px[i] < px[imin]) imin = i;


	vsp[vcnt].x = px[imin];
	vsp[vcnt].cy[0] = vsp[vcnt].fy[0] = py[imin];
	vcnt++;
	i = imin+1; if (i >= n) i = 0;
	j = imin-1; if (j < 0) j = n-1;
	do
	{
		if (px[i] < px[j])
		{
			if ((vcnt > 1) && (px[i] <= vsp[vcnt-1].x)) vcnt--;
			vsp[vcnt].x = px[i];
			vsp[vcnt].cy[0] = py[i];
			k = j+1; if (k >= n) k = 0;
				//(px[k],py[k])
				//(px[i],?)
				//(px[j],py[j])
			vsp[vcnt].fy[0] = (px[i]-px[k])*(py[j]-py[k])/(px[j]-px[k]) + py[k];
			vcnt++;
			i++; if (i >= n) i = 0;
		}
		else if (px[j] < px[i])
		{
			if ((vcnt > 1) && (px[j] <= vsp[vcnt-1].x)) vcnt--;
			vsp[vcnt].x = px[j];
			vsp[vcnt].fy[0] = py[j];
			k = i-1; if (k < 0) k = n-1;
				//(px[k],py[k])
				//(px[j],?)
				//(px[i],py[i])
			vsp[vcnt].cy[0] = (px[j]-px[k])*(py[i]-py[k])/(px[i]-px[k]) + py[k];
			vcnt++;
			j--; if (j < 0) j = n-1;
		}
		else
		{
			if ((vcnt > 1) && (px[i] <= vsp[vcnt-1].x)) vcnt--;
			vsp[vcnt].x = px[i];
			vsp[vcnt].cy[0] = py[i];
			vsp[vcnt].fy[0] = py[j];
			vcnt++;
			i++; if (i >= n) i = 0; if (i == j) break;
			j--; if (j < 0) j = n-1;
		}
	} while (i != j);
	if (px[i] > vsp[vcnt-1].x)
	{
		vsp[vcnt].x = px[i];
		vsp[vcnt].cy[0] = vsp[vcnt].fy[0] = py[i];
		vcnt++;
	}


	for(i=0;i<vcnt;i++)
	{
		vsp[i].cy[1] = vsp[i+1].cy[0]; vsp[i].ctag = i;
		vsp[i].fy[1] = vsp[i+1].fy[0]; vsp[i].ftag = i;
		vsp[i].n = i+1; vsp[i].p = i-1;
	}
	vsp[vcnt-1].n = 0; vsp[0].p = vcnt-1;
	gtag = vcnt;

		//VSPMAX-1 is dummy empty node
	for(i=vcnt;i<VSPMAX;i++) { vsp[i].n = i+1; vsp[i].p = i-1; }
	vsp[VSPMAX-1].n = vcnt; vsp[vcnt].p = VSPMAX-1;
}

static void vsdel (int i)
{
	int pi, ni;
		//Delete i
	pi = vsp[i].p;
	ni = vsp[i].n;
	vsp[ni].p = pi;
	vsp[pi].n = ni;

		//Add i to empty list
	vsp[i].n = vsp[VSPMAX-1].n;
	vsp[i].p = VSPMAX-1;
	vsp[vsp[VSPMAX-1].n].p = i;
	vsp[VSPMAX-1].n = i;
}

static int vsinsaft (int i)
{
	int r;
		//i = next element from empty list
	r = vsp[VSPMAX-1].n;
	vsp[vsp[r].n].p = VSPMAX-1;
	vsp[VSPMAX-1].n = vsp[r].n;

	vsp[r] = vsp[i]; //copy i to r

		//insert r after i
	vsp[r].p = i; vsp[r].n = vsp[i].n;
	vsp[vsp[i].n].p = r; vsp[i].n = r;

	return(r);
}

static int testvisiblemost (float x0, float x1)
{
	int i, newi;

	for(i=vsp[0].n;i;i=newi)
	{
		newi = vsp[i].n;
		if ((x0 < vsp[newi].x) && (vsp[i].x < x1) && (vsp[i].ctag >= 0)) return(1);
	}
	return(0);
}

static void domost (float x0, float y0, float x1, float y1, int polymethod)
{
	double dpx[4], dpy[4];
	float d, f, n, t, slop, dx, dx0, dx1, nx, nx0, ny0, nx1, ny1;
	float spx[4], spy[4], cy[2], cv[2];
	int i, j, k, z, ni, vcnt = 0, scnt, newi, dir, spt[4];

#ifdef DEBUGGINGAIDS
	polymostcallcounts.domost++;
#endif
	polymethod |= METH_LAYERS;

	if (x0 < x1)
	{
		dir = 1; //clip dmost (floor)
		y0 -= .01; y1 -= .01;
	}
	else
	{
		if (x0 == x1) return;
		f = x0; x0 = x1; x1 = f;
		f = y0; y0 = y1; y1 = f;
		dir = 0; //clip umost (ceiling)
		//y0 += .01; y1 += .01; //necessary?
	}

	slop = (y1-y0)/(x1-x0);
	for(i=vsp[0].n;i;i=newi)
	{
		newi = vsp[i].n; nx0 = vsp[i].x; nx1 = vsp[newi].x;
		if ((x0 >= nx1) || (nx0 >= x1) || (vsp[i].ctag <= 0)) continue;
		dx = nx1-nx0;
		cy[0] = vsp[i].cy[0]; cv[0] = vsp[i].cy[1]-cy[0];
		cy[1] = vsp[i].fy[0]; cv[1] = vsp[i].fy[1]-cy[1];

		scnt = 0;

			//Test if left edge requires split (x0,y0) (nx0,cy(0)),<dx,cv(0)>
		if ((x0 > nx0) && (x0 < nx1))
		{
			t = (x0-nx0)*cv[dir] - (y0-cy[dir])*dx;
			if (((!dir) && (t < 0)) || ((dir) && (t > 0)))
				{ spx[scnt] = x0; spy[scnt] = y0; spt[scnt] = -1; scnt++; }
		}

			//Test for intersection on umost (j == 0) and dmost (j == 1)
		for(j=0;j<2;j++)
		{
			d = (y0-y1)*dx - (x0-x1)*cv[j];
			n = (y0-cy[j])*dx - (x0-nx0)*cv[j];
			if ((fabs(n) <= fabs(d)) && (d*n >= 0) && (d != 0))
			{
				t = n/d; nx = (x1-x0)*t + x0;
				if ((nx > nx0) && (nx < nx1))
				{
					spx[scnt] = nx; spy[scnt] = (y1-y0)*t + y0;
					spt[scnt] = j; scnt++;
				}
			}
		}

			//Nice hack to avoid full sort later :)
		if ((scnt >= 2) && (spx[scnt-1] < spx[scnt-2]))
		{
			f = spx[scnt-1]; spx[scnt-1] = spx[scnt-2]; spx[scnt-2] = f;
			f = spy[scnt-1]; spy[scnt-1] = spy[scnt-2]; spy[scnt-2] = f;
			j = spt[scnt-1]; spt[scnt-1] = spt[scnt-2]; spt[scnt-2] = j;
		}

			//Test if right edge requires split
		if ((x1 > nx0) && (x1 < nx1))
		{
			t = (x1-nx0)*cv[dir] - (y1-cy[dir])*dx;
			if (((!dir) && (t < 0)) || ((dir) && (t > 0)))
				{ spx[scnt] = x1; spy[scnt] = y1; spt[scnt] = -1; scnt++; }
		}

		vsp[i].tag = vsp[newi].tag = -1;
		for(z=0;z<=scnt;z++,i=vcnt)
		{
			if (z < scnt)
			{
				vcnt = vsinsaft(i);
				t = (spx[z]-nx0)/dx;
				vsp[i].cy[1] = t*cv[0] + cy[0];
				vsp[i].fy[1] = t*cv[1] + cy[1];
				vsp[vcnt].x = spx[z];
				vsp[vcnt].cy[0] = vsp[i].cy[1];
				vsp[vcnt].fy[0] = vsp[i].fy[1];
				vsp[vcnt].tag = spt[z];
			}

			ni = vsp[i].n; if (!ni) continue; //this 'if' fixes many bugs!
			dx0 = vsp[i].x; if (x0 > dx0) continue;
			dx1 = vsp[ni].x; if (x1 < dx1) continue;
			ny0 = (dx0-x0)*slop + y0;
			ny1 = (dx1-x0)*slop + y0;

				//      dx0           dx1
				//       ~             ~
				//----------------------------
				//     t0+=0         t1+=0
				//   vsp[i].cy[0]  vsp[i].cy[1]
				//============================
				//     t0+=1         t1+=3
				//============================
				//   vsp[i].fy[0]    vsp[i].fy[1]
				//     t0+=2         t1+=6
				//
				//     ny0 ?         ny1 ?

			k = 1+3;
			if ((vsp[i].tag == 0) || (ny0 <= vsp[i].cy[0]+.01)) k--;
			if ((vsp[i].tag == 1) || (ny0 >= vsp[i].fy[0]-.01)) k++;
			if ((vsp[ni].tag == 0) || (ny1 <= vsp[i].cy[1]+.01)) k -= 3;
			if ((vsp[ni].tag == 1) || (ny1 >= vsp[i].fy[1]-.01)) k += 3;

			if (!dir)
			{
				switch(k)
				{
					case 1: case 2:
						dpx[0] = dx0; dpy[0] = vsp[i].cy[0];
						dpx[1] = dx1; dpy[1] = vsp[i].cy[1];
						dpx[2] = dx0; dpy[2] = ny0; drawpoly(dpx,dpy,3,polymethod);
						vsp[i].cy[0] = ny0; vsp[i].ctag = gtag; break;
					case 3: case 6:
						dpx[0] = dx0; dpy[0] = vsp[i].cy[0];
						dpx[1] = dx1; dpy[1] = vsp[i].cy[1];
						dpx[2] = dx1; dpy[2] = ny1; drawpoly(dpx,dpy,3,polymethod);
						vsp[i].cy[1] = ny1; vsp[i].ctag = gtag; break;
					case 4: case 5: case 7:
						dpx[0] = dx0; dpy[0] = vsp[i].cy[0];
						dpx[1] = dx1; dpy[1] = vsp[i].cy[1];
						dpx[2] = dx1; dpy[2] = ny1;
						dpx[3] = dx0; dpy[3] = ny0; drawpoly(dpx,dpy,4,polymethod);
						vsp[i].cy[0] = ny0; vsp[i].cy[1] = ny1; vsp[i].ctag = gtag; break;
					case 8:
						dpx[0] = dx0; dpy[0] = vsp[i].cy[0];
						dpx[1] = dx1; dpy[1] = vsp[i].cy[1];
						dpx[2] = dx1; dpy[2] = vsp[i].fy[1];
						dpx[3] = dx0; dpy[3] = vsp[i].fy[0]; drawpoly(dpx,dpy,4,polymethod);
						vsp[i].ctag = vsp[i].ftag = -1; break;
					default: break;
				}
			}
			else
			{
				switch(k)
				{
					case 7: case 6:
						dpx[0] = dx0; dpy[0] = ny0;
						dpx[1] = dx1; dpy[1] = vsp[i].fy[1];
						dpx[2] = dx0; dpy[2] = vsp[i].fy[0]; drawpoly(dpx,dpy,3,polymethod);
						vsp[i].fy[0] = ny0; vsp[i].ftag = gtag; break;
					case 5: case 2:
						dpx[0] = dx0; dpy[0] = vsp[i].fy[0];
						dpx[1] = dx1; dpy[1] = ny1;
						dpx[2] = dx1; dpy[2] = vsp[i].fy[1]; drawpoly(dpx,dpy,3,polymethod);
						vsp[i].fy[1] = ny1; vsp[i].ftag = gtag; break;
					case 4: case 3: case 1:
						dpx[0] = dx0; dpy[0] = ny0;
						dpx[1] = dx1; dpy[1] = ny1;
						dpx[2] = dx1; dpy[2] = vsp[i].fy[1];
						dpx[3] = dx0; dpy[3] = vsp[i].fy[0]; drawpoly(dpx,dpy,4,polymethod);
						vsp[i].fy[0] = ny0; vsp[i].fy[1] = ny1; vsp[i].ftag = gtag; break;
					case 0:
						dpx[0] = dx0; dpy[0] = vsp[i].cy[0];
						dpx[1] = dx1; dpy[1] = vsp[i].cy[1];
						dpx[2] = dx1; dpy[2] = vsp[i].fy[1];
						dpx[3] = dx0; dpy[3] = vsp[i].fy[0]; drawpoly(dpx,dpy,4,polymethod);
						vsp[i].ctag = vsp[i].ftag = -1; break;
					default: break;
				}
			}
		}
	}

	gtag++;

		//Combine neighboring vertical strips with matching collinear top&bottom edges
		//This prevents x-splits from propagating through the entire scan
	i = vsp[0].n;
	while (i)
	{
		ni = vsp[i].n;
		if ((vsp[i].cy[0] >= vsp[i].fy[0]) && (vsp[i].cy[1] >= vsp[i].fy[1])) { vsp[i].ctag = vsp[i].ftag = -1; }
		if ((vsp[i].ctag == vsp[ni].ctag) && (vsp[i].ftag == vsp[ni].ftag))
			{ vsp[i].cy[1] = vsp[ni].cy[1]; vsp[i].fy[1] = vsp[ni].fy[1]; vsdel(ni); }
		else i = ni;
	}
}

static void polymost_scansector (int sectnum);

static void polymost_drawalls (int bunch)
{
	sectortype *sec, *nextsec;
	walltype *wal, *wal2, *nwal;
	double ox, oy, oz, ox2, oy2, px[3], py[3], dd[3], uu[3], vv[3];
	double fx, fy, x0, x1, y0, y1, cy0, cy1, fy0, fy1, xp0, yp0, xp1, yp1, ryp0, ryp1, nx0, ny0, nx1, ny1;
	double t, r, t0, t1, ocy0, ocy1, ofy0, ofy1, oxp0, oyp0, ft[4];
	double oguo, ogux, oguy;
	int i, x, y, z, cz, fz, wallnum, sectnum, nextsectnum, domostmethod;

#ifdef DEBUGGINGAIDS
	polymostcallcounts.drawalls++;
#endif

	sectnum = thesector[bunchfirst[bunch]]; sec = &sector[sectnum];

#if USE_OPENGL
	gfogpalnum = sec->floorpal;
	gfogdensity = gvisibility*((float)((unsigned char)(sec->visibility+16)) / 255.f);
#endif

		//DRAW WALLS SECTION!
	for(z=bunchfirst[bunch];z>=0;z=p2[z])
	{
		wallnum = thewall[z]; wal = &wall[wallnum]; wal2 = &wall[wal->point2];
		nextsectnum = wal->nextsector; nextsec = &sector[nextsectnum];

			//Offset&Rotate 3D coordinates to screen 3D space
		x = wal->x-globalposx; y = wal->y-globalposy;
		xp0 = (double)y*gcosang  - (double)x*gsinang;
		yp0 = (double)x*gcosang2 + (double)y*gsinang2;
		x = wal2->x-globalposx; y = wal2->y-globalposy;
		xp1 = (double)y*gcosang  - (double)x*gsinang;
		yp1 = (double)x*gcosang2 + (double)y*gsinang2;

		oxp0 = xp0; oyp0 = yp0;

			//Clip to close parallel-screen plane
		if (yp0 < SCISDIST)
		{
			if (yp1 < SCISDIST) continue;
			t0 = (SCISDIST-yp0)/(yp1-yp0); xp0 = (xp1-xp0)*t0+xp0; yp0 = SCISDIST;
			nx0 = (wal2->x-wal->x)*t0+wal->x;
			ny0 = (wal2->y-wal->y)*t0+wal->y;
		}
		else { t0 = 0.f; nx0 = wal->x; ny0 = wal->y; }
		if (yp1 < SCISDIST)
		{
			t1 = (SCISDIST-oyp0)/(yp1-oyp0); xp1 = (xp1-oxp0)*t1+oxp0; yp1 = SCISDIST;
			nx1 = (wal2->x-wal->x)*t1+wal->x;
			ny1 = (wal2->y-wal->y)*t1+wal->y;
		}
		else { t1 = 1.f; nx1 = wal2->x; ny1 = wal2->y; }

		ryp0 = 1.f/yp0; ryp1 = 1.f/yp1;

			//Generate screen coordinates for front side of wall
		x0 = ghalfx*xp0*ryp0 + ghalfx;
		x1 = ghalfx*xp1*ryp1 + ghalfx;
		if (x1 <= x0) continue;

		ryp0 *= gyxscale; ryp1 *= gyxscale;

		getzsofslope(sectnum,(int)nx0,(int)ny0,&cz,&fz);
		cy0 = ((float)(cz-globalposz))*ryp0 + ghoriz;
		fy0 = ((float)(fz-globalposz))*ryp0 + ghoriz;
		getzsofslope(sectnum,(int)nx1,(int)ny1,&cz,&fz);
		cy1 = ((float)(cz-globalposz))*ryp1 + ghoriz;
		fy1 = ((float)(fz-globalposz))*ryp1 + ghoriz;

		domostmethod = 0;
		globalpicnum = sec->floorpicnum; globalshade = sec->floorshade; globalpal = (int)((unsigned char)sec->floorpal);
		globalorientation = sec->floorstat;
		if (picanm[globalpicnum]&192) globalpicnum += animateoffs(globalpicnum,sectnum);
		if (!(globalorientation&1))
		{
				//(singlobalang/-16384*(sx-ghalfx) + 0*(sy-ghoriz) + (cosviewingrangeglobalang/16384)*ghalfx)*d + globalposx    = u*16
				//(cosglobalang/ 16384*(sx-ghalfx) + 0*(sy-ghoriz) + (sinviewingrangeglobalang/16384)*ghalfx)*d + globalposy    = v*16
				//(                  0*(sx-ghalfx) + 1*(sy-ghoriz) + (                             0)*ghalfx)*d + globalposz/16 = (sec->floorz/16)
			if (!(globalorientation&64))
				{ ft[0] = globalposx; ft[1] = globalposy; ft[2] = cosglobalang; ft[3] = singlobalang; }
			else
			{
					//relative alignment
				fx = (double)(wall[wall[sec->wallptr].point2].x-wall[sec->wallptr].x);
				fy = (double)(wall[wall[sec->wallptr].point2].y-wall[sec->wallptr].y);
				r = 1.0/sqrt(fx*fx+fy*fy); fx *= r; fy *= r;
				ft[2] = cosglobalang*fx + singlobalang*fy;
				ft[3] = singlobalang*fx - cosglobalang*fy;
				ft[0] = ((double)(globalposx-wall[sec->wallptr].x))*fx + ((double)(globalposy-wall[sec->wallptr].y))*fy;
				ft[1] = ((double)(globalposy-wall[sec->wallptr].y))*fx - ((double)(globalposx-wall[sec->wallptr].x))*fy;
				if (!(globalorientation&4)) globalorientation ^= 32; else globalorientation ^= 16;
			}
			gdx = 0;
			gdy = gxyaspect; if (!(globalorientation&2)) gdy /= (double)(sec->floorz-globalposz);
			gdo = -ghoriz*gdy;
			if (globalorientation&8) { ft[0] /= 8; ft[1] /= -8; ft[2] /= 2097152; ft[3] /= 2097152; }
									  else { ft[0] /= 16; ft[1] /= -16; ft[2] /= 4194304; ft[3] /= 4194304; }
			gux = (double)ft[3]*((double)viewingrange)/-65536.0;
			gvx = (double)ft[2]*((double)viewingrange)/-65536.0;
			guy = (double)ft[0]*gdy; gvy = (double)ft[1]*gdy;
			guo = (double)ft[0]*gdo; gvo = (double)ft[1]*gdo;
			guo += (double)(ft[2]-gux)*ghalfx;
			gvo -= (double)(ft[3]+gvx)*ghalfx;

				//Texture flipping
			if (globalorientation&4)
			{
				r = gux; gux = gvx; gvx = r;
				r = guy; guy = gvy; gvy = r;
				r = guo; guo = gvo; gvo = r;
			}
			if (globalorientation&16) { gux = -gux; guy = -guy; guo = -guo; }
			if (globalorientation&32) { gvx = -gvx; gvy = -gvy; gvo = -gvo; }

				//Texture panning
			fx = (float)sec->floorxpanning*((float)(1<<(picsiz[globalpicnum]&15)))/256.0;
			fy = (float)sec->floorypanning*((float)(1<<(picsiz[globalpicnum]>>4)))/256.0;
			if ((globalorientation&(2+64)) == (2+64)) //Hack for panning for slopes w/ relative alignment
			{
				r = (float)sec->floorheinum / 4096.0; r = 1.0/sqrt(r*r+1);
				if (!(globalorientation&4)) fy *= r; else fx *= r;
			}
			guy += gdy*fx; guo += gdo*fx;
			gvy += gdy*fy; gvo += gdo*fy;

			if (globalorientation&2) //slopes
			{
				px[0] = x0; py[0] = ryp0 + ghoriz;
				px[1] = x1; py[1] = ryp1 + ghoriz;

					//Pick some point guaranteed to be not collinear to the 1st two points
				ox = nx0 + (ny1-ny0);
				oy = ny0 + (nx0-nx1);
				ox2 = (double)(oy-globalposy)*gcosang  - (double)(ox-globalposx)*gsinang;
				oy2 = (double)(ox-globalposx)*gcosang2 + (double)(oy-globalposy)*gsinang2;
				oy2 = 1.0/oy2;
				px[2] = ghalfx*ox2*oy2 + ghalfx; oy2 *= gyxscale;
				py[2] = oy2 + ghoriz;

				for(i=0;i<3;i++)
				{
					dd[i] = px[i]*gdx + py[i]*gdy + gdo;
					uu[i] = px[i]*gux + py[i]*guy + guo;
					vv[i] = px[i]*gvx + py[i]*gvy + gvo;
				}

				py[0] = fy0;
				py[1] = fy1;
				py[2] = (getflorzofslope(sectnum,(int)ox,(int)oy)-globalposz)*oy2 + ghoriz;

				ox = py[1]-py[2]; oy = py[2]-py[0]; oz = py[0]-py[1];
				r = 1.0 / (ox*px[0] + oy*px[1] + oz*px[2]);
				gdx = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
				gux = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
				gvx = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
				ox = px[2]-px[1]; oy = px[0]-px[2]; oz = px[1]-px[0];
				gdy = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
				guy = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
				gvy = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
				gdo = dd[0] - px[0]*gdx - py[0]*gdy;
				guo = uu[0] - px[0]*gux - py[0]*guy;
				gvo = vv[0] - px[0]*gvx - py[0]*gvy;

				if (globalorientation&64) //Hack for relative alignment on slopes
				{
					r = (float)sec->floorheinum / 4096.0;
					r = sqrt(r*r+1);
					if (!(globalorientation&4)) { gvx *= r; gvy *= r; gvo *= r; }
												  else { gux *= r; guy *= r; guo *= r; }
				}
			}
			domostmethod = (globalorientation>>7)&3;
			if (globalposz >= getflorzofslope(sectnum,globalposx,globalposy)) domostmethod = -1; //Back-face culling
			domost(x0,fy0,x1,fy1,domostmethod); //flor
		}
		else if ((nextsectnum < 0) || (!(sector[nextsectnum].floorstat&1)))
		{
				//Parallaxing sky... hacked for Ken's mountain texture; paper-sky only :/
#if USE_OPENGL
			float tempfogdensity = gfogdensity;
			if (rendmode == 3)
			{
				gfogdensity = 0.f;

					//Use clamping for tiled sky textures
				for(i=(1<<pskybits)-1;i>0;i--)
					if (pskyoff[i] != pskyoff[i-1])
						{ domostmethod = METH_CLAMPED; break; }
			}
			if (bpp == 8 || !usehightile || !hicfindsubst(globalpicnum,globalpal,1))
#endif
			{
				dd[0] = (float)xdimen*.0000001; //Adjust sky depth based on screen size!
				t = (double)((1<<(picsiz[globalpicnum]&15))<<pskybits);
				vv[1] = dd[0]*((double)xdimscale*(double)viewingrange)/(65536.0*65536.0);
				vv[0] = dd[0]*((double)((tilesizy[globalpicnum]>>1)+parallaxyoffs)) - vv[1]*ghoriz;
				i = (1<<(picsiz[globalpicnum]>>4)); if (i != tilesizy[globalpicnum]) i += i;
				vv[0] += dd[0]*((double)sec->floorypanning)*((double)i)/256.0;


					//Hack to draw black rectangle below sky when looking down...
				gdx = 0; gdy = gxyaspect / 262144.0; gdo = -ghoriz*gdy;
				gux = 0; guy = 0; guo = 0;
				gvx = 0; gvy = (double)(tilesizy[globalpicnum]-1)*gdy; gvo = (double)(tilesizy[globalpicnum-1])*gdo;
				oy = (((double)tilesizy[globalpicnum])*dd[0]-vv[0])/vv[1];
				if ((oy > fy0) && (oy > fy1)) domost(x0,oy,x1,oy,domostmethod);
				else if ((oy > fy0) != (oy > fy1))
				{     //  fy0                      fy1
						//     \                    /
						//oy----------      oy----------
						//        \              /
						//         fy1        fy0
					ox = (oy-fy0)*(x1-x0)/(fy1-fy0) + x0;
					if (oy > fy0) { domost(x0,oy,ox,oy,domostmethod); domost(ox,oy,x1,fy1,domostmethod); }
							  else { domost(x0,fy0,ox,oy,domostmethod); domost(ox,oy,x1,oy,domostmethod); }
				} else domost(x0,fy0,x1,fy1,domostmethod);


				gdx = 0; gdy = 0; gdo = dd[0];
				gux = gdo*(t*((double)xdimscale)*((double)yxaspect)*((double)viewingrange))/(16384.0*65536.0*65536.0*5.0*1024.0);
				guy = 0; //guo calculated later
				gvx = 0; gvy = vv[1]; gvo = vv[0];

				i = globalpicnum; r = (fy1-fy0)/(x1-x0); //slope of line
				oy = ((double)viewingrange)/(ghalfx*256.0); oz = 1/oy;

				y = ((((int)((x0-ghalfx)*oy))+globalang)>>(11-pskybits));
				fx = x0;
				do
				{
					globalpicnum = pskyoff[y&((1<<pskybits)-1)]+i;
					guo = gdo*(t*((double)(globalang-(y<<(11-pskybits))))/2048.0 + (double)sec->floorxpanning) - gux*ghalfx;
					y++;
					ox = fx; fx = ((double)((y<<(11-pskybits))-globalang))*oz+ghalfx;
					if (fx > x1) { fx = x1; i = -1; }

					domost(ox,(ox-x0)*r+fy0,fx,(fx-x0)*r+fy0,domostmethod); //flor
				} while (i >= 0);

			}
#if USE_OPENGL
			else  //NOTE: code copied from ceiling code... lots of duplicated stuff :/
			{     //Skybox code for parallax ceiling!
				double _xp0, _yp0, _xp1, _yp1, _oxp0, _oyp0, _t0, _t1, _nx0, _ny0, _nx1, _ny1;
				double _ryp0, _ryp1, _x0, _x1, _cy0, _fy0, _cy1, _fy1, _ox0, _ox1;
				double nfy0, nfy1;
				int skywalx[4] = {-512,512,512,-512}, skywaly[4] = {-512,-512,512,512};

				domostmethod = METH_CLAMPED;

				for(i=0;i<4;i++)
				{
					x = skywalx[i&3]; y = skywaly[i&3];
					_xp0 = (double)y*gcosang  - (double)x*gsinang;
					_yp0 = (double)x*gcosang2 + (double)y*gsinang2;
					x = skywalx[(i+1)&3]; y = skywaly[(i+1)&3];
					_xp1 = (double)y*gcosang  - (double)x*gsinang;
					_yp1 = (double)x*gcosang2 + (double)y*gsinang2;

					_oxp0 = _xp0; _oyp0 = _yp0;

						//Clip to close parallel-screen plane
					if (_yp0 < SCISDIST)
					{
						if (_yp1 < SCISDIST) continue;
						_t0 = (SCISDIST-_yp0)/(_yp1-_yp0); _xp0 = (_xp1-_xp0)*_t0+_xp0; _yp0 = SCISDIST;
						_nx0 = (skywalx[(i+1)&3]-skywalx[i&3])*_t0+skywalx[i&3];
						_ny0 = (skywaly[(i+1)&3]-skywaly[i&3])*_t0+skywaly[i&3];
					}
					else { _t0 = 0.f; _nx0 = skywalx[i&3]; _ny0 = skywaly[i&3]; }
					if (_yp1 < SCISDIST)
					{
						_t1 = (SCISDIST-_oyp0)/(_yp1-_oyp0); _xp1 = (_xp1-_oxp0)*_t1+_oxp0; _yp1 = SCISDIST;
						_nx1 = (skywalx[(i+1)&3]-skywalx[i&3])*_t1+skywalx[i&3];
						_ny1 = (skywaly[(i+1)&3]-skywaly[i&3])*_t1+skywaly[i&3];
					}
					else { _t1 = 1.f; _nx1 = skywalx[(i+1)&3]; _ny1 = skywaly[(i+1)&3]; }

					_ryp0 = 1.f/_yp0; _ryp1 = 1.f/_yp1;

						//Generate screen coordinates for front side of wall
					_x0 = ghalfx*_xp0*_ryp0 + ghalfx;
					_x1 = ghalfx*_xp1*_ryp1 + ghalfx;
					if (_x1 <= _x0) continue;
					if ((_x0 >= x1) || (x0 >= _x1)) continue;

					_ryp0 *= gyxscale; _ryp1 *= gyxscale;

					_cy0 = -8192.f*_ryp0 + ghoriz;
					_fy0 =  8192.f*_ryp0 + ghoriz;
					_cy1 = -8192.f*_ryp1 + ghoriz;
					_fy1 =  8192.f*_ryp1 + ghoriz;

					_ox0 = _x0; _ox1 = _x1;

						//Make sure: x0<=_x0<_x1<=_x1
					nfy0 = fy0; nfy1 = fy1;
					if (_x0 < x0)
					{
						t = (x0-_x0)/(_x1-_x0);
						_cy0 += (_cy1-_cy0)*t;
						_fy0 += (_fy1-_fy0)*t;
						_x0 = x0;
					}
					else if (_x0 > x0) nfy0 += (_x0-x0)*(fy1-fy0)/(x1-x0);
					if (_x1 > x1)
					{
						t = (x1-_x1)/(_x1-_x0);
						_cy1 += (_cy1-_cy0)*t;
						_fy1 += (_fy1-_fy0)*t;
						_x1 = x1;
					}
					else if (_x1 < x1) nfy1 += (_x1-x1)*(fy1-fy0)/(x1-x0);

						//   (skybox floor)
						//(_x0,_fy0)-(_x1,_fy1)
						//   (skybox wall)
						//(_x0,_cy0)-(_x1,_cy1)
						//   (skybox ceiling)
						//(_x0,nfy0)-(_x1,nfy1)

						//ceiling of skybox
					ft[0] = 512/16; ft[1] = 512/-16;
					ft[2] = ((float)cosglobalang)*(1.f/2147483648.f);
					ft[3] = ((float)singlobalang)*(1.f/2147483648.f);
					gdx = 0;
					gdy = gxyaspect*(1.f/4194304.f);
					gdo = -ghoriz*gdy;
					gux = (double)ft[3]*((double)viewingrange)/-65536.0;
					gvx = (double)ft[2]*((double)viewingrange)/-65536.0;
					guy = (double)ft[0]*gdy; gvy = (double)ft[1]*gdy;
					guo = (double)ft[0]*gdo; gvo = (double)ft[1]*gdo;
					guo += (double)(ft[2]-gux)*ghalfx;
					gvo -= (double)(ft[3]+gvx)*ghalfx;
					gvx = -gvx; gvy = -gvy; gvo = -gvo; //y-flip skybox floor

					drawingskybox = 6; //ceiling/5th texture/index 4 of skybox
					if ((_fy0 > nfy0) && (_fy1 > nfy1)) domost(_x0,_fy0,_x1,_fy1,domostmethod);
					else if ((_fy0 > nfy0) != (_fy1 > nfy1))
					{
							//(ox,oy) is intersection of: (_x0,_cy0)-(_x1,_cy1)
							//                            (_x0,nfy0)-(_x1,nfy1)
							//ox = _x0 + (_x1-_x0)*t
							//oy = _cy0 + (_cy1-_cy0)*t
							//oy = nfy0 + (nfy1-nfy0)*t
						t = (_fy0-nfy0)/(nfy1-nfy0-_fy1+_fy0);
						ox = _x0 + (_x1-_x0)*t;
						oy = _fy0 + (_fy1-_fy0)*t;
						if (nfy0 > _fy0) { domost(_x0,nfy0,ox,oy,domostmethod); domost(ox,oy,_x1,_fy1,domostmethod); }
										else { domost(_x0,_fy0,ox,oy,domostmethod); domost(ox,oy,_x1,nfy1,domostmethod); }
					} else domost(_x0,nfy0,_x1,nfy1,domostmethod);

						//wall of skybox
					drawingskybox = i+1; //i+1th texture/index i of skybox
					gdx = (_ryp0-_ryp1)*gxyaspect*(1.f/512.f) / (_ox0-_ox1);
					gdy = 0;
					gdo = _ryp0*gxyaspect*(1.f/512.f) - gdx*_ox0;
					gux = (_t0*_ryp0 - _t1*_ryp1)*gxyaspect*(64.f/512.f) / (_ox0-_ox1);
					guo = _t0*_ryp0*gxyaspect*(64.f/512.f) - gux*_ox0;
					guy = 0;
					_t0 = -8192.0*_ryp0 + ghoriz;
					_t1 = -8192.0*_ryp1 + ghoriz;
					t = ((gdx*_ox0 + gdo)*8.f) / ((_ox1-_ox0) * _ryp0 * 2048.f);
					gvx = (_t0-_t1)*t;
					gvy = (_ox1-_ox0)*t;
					gvo = -gvx*_ox0 - gvy*_t0;
					if ((_cy0 > nfy0) && (_cy1 > nfy1)) domost(_x0,_cy0,_x1,_cy1,domostmethod);
					else if ((_cy0 > nfy0) != (_cy1 > nfy1))
					{
							//(ox,oy) is intersection of: (_x0,_fy0)-(_x1,_fy1)
							//                            (_x0,nfy0)-(_x1,nfy1)
							//ox = _x0 + (_x1-_x0)*t
							//oy = _fy0 + (_fy1-_fy0)*t
							//oy = nfy0 + (nfy1-nfy0)*t
						t = (_cy0-nfy0)/(nfy1-nfy0-_cy1+_cy0);
						ox = _x0 + (_x1-_x0)*t;
						oy = _cy0 + (_cy1-_cy0)*t;
						if (nfy0 > _cy0) { domost(_x0,nfy0,ox,oy,domostmethod); domost(ox,oy,_x1,_cy1,domostmethod); }
										else { domost(_x0,_cy0,ox,oy,domostmethod); domost(ox,oy,_x1,nfy1,domostmethod); }
					} else domost(_x0,nfy0,_x1,nfy1,domostmethod);
				}

					//Floor of skybox
				drawingskybox = 5; //floor/6th texture/index 5 of skybox
				ft[0] = 512/16; ft[1] = -512/-16;
				ft[2] = ((float)cosglobalang)*(1.f/2147483648.f);
				ft[3] = ((float)singlobalang)*(1.f/2147483648.f);
				gdx = 0;
				gdy = gxyaspect*(-1.f/4194304.f);
				gdo = -ghoriz*gdy;
				gux = (double)ft[3]*((double)viewingrange)/-65536.0;
				gvx = (double)ft[2]*((double)viewingrange)/-65536.0;
				guy = (double)ft[0]*gdy; gvy = (double)ft[1]*gdy;
				guo = (double)ft[0]*gdo; gvo = (double)ft[1]*gdo;
				guo += (double)(ft[2]-gux)*ghalfx;
				gvo -= (double)(ft[3]+gvx)*ghalfx;
				domost(x0,fy0,x1,fy1,domostmethod);

				drawingskybox = 0;
			}
			if (rendmode == 3)
			{
				gfogdensity = tempfogdensity;
			}
#endif
		}

		domostmethod = 0;
		globalpicnum = sec->ceilingpicnum; globalshade = sec->ceilingshade; globalpal = (int)((unsigned char)sec->ceilingpal);
		globalorientation = sec->ceilingstat;
		if (picanm[globalpicnum]&192) globalpicnum += animateoffs(globalpicnum,sectnum);
		if (!(globalorientation&1))
		{
			if (!(globalorientation&64))
				{ ft[0] = globalposx; ft[1] = globalposy; ft[2] = cosglobalang; ft[3] = singlobalang; }
			else
			{
					//relative alignment
				fx = (double)(wall[wall[sec->wallptr].point2].x-wall[sec->wallptr].x);
				fy = (double)(wall[wall[sec->wallptr].point2].y-wall[sec->wallptr].y);
				r = 1.0/sqrt(fx*fx+fy*fy); fx *= r; fy *= r;
				ft[2] = cosglobalang*fx + singlobalang*fy;
				ft[3] = singlobalang*fx - cosglobalang*fy;
				ft[0] = ((double)(globalposx-wall[sec->wallptr].x))*fx + ((double)(globalposy-wall[sec->wallptr].y))*fy;
				ft[1] = ((double)(globalposy-wall[sec->wallptr].y))*fx - ((double)(globalposx-wall[sec->wallptr].x))*fy;
				if (!(globalorientation&4)) globalorientation ^= 32; else globalorientation ^= 16;
			}
			gdx = 0;
			gdy = gxyaspect;
			if (!(globalorientation&2)) gdy /= (double)(sec->ceilingz-globalposz);
			gdo = -ghoriz*gdy;
			if (globalorientation&8) { ft[0] /= 8; ft[1] /= -8; ft[2] /= 2097152; ft[3] /= 2097152; }
									  else { ft[0] /= 16; ft[1] /= -16; ft[2] /= 4194304; ft[3] /= 4194304; }
			gux = (double)ft[3]*((double)viewingrange)/-65536.0;
			gvx = (double)ft[2]*((double)viewingrange)/-65536.0;
			guy = (double)ft[0]*gdy; gvy = (double)ft[1]*gdy;
			guo = (double)ft[0]*gdo; gvo = (double)ft[1]*gdo;
			guo += (double)(ft[2]-gux)*ghalfx;
			gvo -= (double)(ft[3]+gvx)*ghalfx;

				//Texture flipping
			if (globalorientation&4)
			{
				r = gux; gux = gvx; gvx = r;
				r = guy; guy = gvy; gvy = r;
				r = guo; guo = gvo; gvo = r;
			}
			if (globalorientation&16) { gux = -gux; guy = -guy; guo = -guo; }
			if (globalorientation&32) { gvx = -gvx; gvy = -gvy; gvo = -gvo; }

				//Texture panning
			fx = (float)sec->ceilingxpanning*((float)(1<<(picsiz[globalpicnum]&15)))/256.0;
			fy = (float)sec->ceilingypanning*((float)(1<<(picsiz[globalpicnum]>>4)))/256.0;
			if ((globalorientation&(2+64)) == (2+64)) //Hack for panning for slopes w/ relative alignment
			{
				r = (float)sec->ceilingheinum / 4096.0; r = 1.0/sqrt(r*r+1);
				if (!(globalorientation&4)) fy *= r; else fx *= r;
			}
			guy += gdy*fx; guo += gdo*fx;
			gvy += gdy*fy; gvo += gdo*fy;

			if (globalorientation&2) //slopes
			{
				px[0] = x0; py[0] = ryp0 + ghoriz;
				px[1] = x1; py[1] = ryp1 + ghoriz;

					//Pick some point guaranteed to be not collinear to the 1st two points
				ox = nx0 + (ny1-ny0);
				oy = ny0 + (nx0-nx1);
				ox2 = (double)(oy-globalposy)*gcosang  - (double)(ox-globalposx)*gsinang ;
				oy2 = (double)(ox-globalposx)*gcosang2 + (double)(oy-globalposy)*gsinang2;
				oy2 = 1.0/oy2;
				px[2] = ghalfx*ox2*oy2 + ghalfx; oy2 *= gyxscale;
				py[2] = oy2 + ghoriz;

				for(i=0;i<3;i++)
				{
					dd[i] = px[i]*gdx + py[i]*gdy + gdo;
					uu[i] = px[i]*gux + py[i]*guy + guo;
					vv[i] = px[i]*gvx + py[i]*gvy + gvo;
				}

				py[0] = cy0;
				py[1] = cy1;
				py[2] = (getceilzofslope(sectnum,(int)ox,(int)oy)-globalposz)*oy2 + ghoriz;

				ox = py[1]-py[2]; oy = py[2]-py[0]; oz = py[0]-py[1];
				r = 1.0 / (ox*px[0] + oy*px[1] + oz*px[2]);
				gdx = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
				gux = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
				gvx = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
				ox = px[2]-px[1]; oy = px[0]-px[2]; oz = px[1]-px[0];
				gdy = (ox*dd[0] + oy*dd[1] + oz*dd[2])*r;
				guy = (ox*uu[0] + oy*uu[1] + oz*uu[2])*r;
				gvy = (ox*vv[0] + oy*vv[1] + oz*vv[2])*r;
				gdo = dd[0] - px[0]*gdx - py[0]*gdy;
				guo = uu[0] - px[0]*gux - py[0]*guy;
				gvo = vv[0] - px[0]*gvx - py[0]*gvy;

				if (globalorientation&64) //Hack for relative alignment on slopes
				{
					r = (float)sec->ceilingheinum / 4096.0;
					r = sqrt(r*r+1);
					if (!(globalorientation&4)) { gvx *= r; gvy *= r; gvo *= r; }
												  else { gux *= r; guy *= r; guo *= r; }
				}
			}
			domostmethod = (globalorientation>>7)&3;
			if (globalposz <= getceilzofslope(sectnum,globalposx,globalposy)) domostmethod = -1; //Back-face culling
			domost(x1,cy1,x0,cy0,domostmethod); //ceil
		}
		else if ((nextsectnum < 0) || (!(sector[nextsectnum].ceilingstat&1)))
		{
#if USE_OPENGL
			float tempfogdensity = gfogdensity;
			if (rendmode == 3)
			{
				gfogdensity = 0.f;

					//Use clamping for tiled sky textures
				for(i=(1<<pskybits)-1;i>0;i--)
					if (pskyoff[i] != pskyoff[i-1])
						{ domostmethod = METH_CLAMPED; break; }
			}
				//Parallaxing sky...
			if (bpp == 8 || !usehightile || !hicfindsubst(globalpicnum,globalpal,1))
#endif
			{
					//Render for parallaxtype == 0 / paper-sky
				dd[0] = (float)xdimen*.0000001; //Adjust sky depth based on screen size!
				t = (double)((1<<(picsiz[globalpicnum]&15))<<pskybits);
				vv[1] = dd[0]*((double)xdimscale*(double)viewingrange)/(65536.0*65536.0);
				vv[0] = dd[0]*((double)((tilesizy[globalpicnum]>>1)+parallaxyoffs)) - vv[1]*ghoriz;
				i = (1<<(picsiz[globalpicnum]>>4)); if (i != tilesizy[globalpicnum]) i += i;
				vv[0] += dd[0]*((double)sec->ceilingypanning)*((double)i)/256.0;

					//Hack to draw black rectangle below sky when looking down...
				gdx = 0; gdy = gxyaspect / -262144.0; gdo = -ghoriz*gdy;
				gux = 0; guy = 0; guo = 0;
				gvx = 0; gvy = 0; gvo = 0;
				oy = -vv[0]/vv[1];
				if ((oy < cy0) && (oy < cy1)) domost(x1,oy,x0,oy,domostmethod);
				else if ((oy < cy0) != (oy < cy1))
				{      /*         cy1        cy0
						//        /             \
						//oy----------      oy---------
						//    /                    \
						//  cy0                     cy1
						*/
					ox = (oy-cy0)*(x1-x0)/(cy1-cy0) + x0;
					if (oy < cy0) { domost(ox,oy,x0,oy,domostmethod); domost(x1,cy1,ox,oy,domostmethod); }
								else { domost(ox,oy,x0,cy0,domostmethod); domost(x1,oy,ox,oy,domostmethod); }
				} else domost(x1,cy1,x0,cy0,domostmethod);

				gdx = 0; gdy = 0; gdo = dd[0];
				gux = gdo*(t*((double)xdimscale)*((double)yxaspect)*((double)viewingrange))/(16384.0*65536.0*65536.0*5.0*1024.0);
				guy = 0; //guo calculated later
				gvx = 0; gvy = vv[1]; gvo = vv[0];

				i = globalpicnum; r = (cy1-cy0)/(x1-x0); //slope of line
				oy = ((double)viewingrange)/(ghalfx*256.0); oz = 1/oy;

				y = ((((int)((x0-ghalfx)*oy))+globalang)>>(11-pskybits));
				fx = x0;
				do
				{
					globalpicnum = pskyoff[y&((1<<pskybits)-1)]+i;
					guo = gdo*(t*((double)(globalang-(y<<(11-pskybits))))/2048.0 + (double)sec->ceilingxpanning) - gux*ghalfx;
					y++;
					ox = fx; fx = ((double)((y<<(11-pskybits))-globalang))*oz+ghalfx;
					if (fx > x1) { fx = x1; i = -1; }
					domost(fx,(fx-x0)*r+cy0,ox,(ox-x0)*r+cy0,domostmethod); //ceil
				} while (i >= 0);
			}
#if USE_OPENGL
			else
			{     //Skybox code for parallax ceiling!
				double _xp0, _yp0, _xp1, _yp1, _oxp0, _oyp0, _t0, _t1, _nx0, _ny0, _nx1, _ny1;
				double _ryp0, _ryp1, _x0, _x1, _cy0, _fy0, _cy1, _fy1, _ox0, _ox1;
				double ncy0, ncy1;
				int skywalx[4] = {-512,512,512,-512}, skywaly[4] = {-512,-512,512,512};

				domostmethod = METH_CLAMPED;

				for(i=0;i<4;i++)
				{
					x = skywalx[i&3]; y = skywaly[i&3];
					_xp0 = (double)y*gcosang  - (double)x*gsinang;
					_yp0 = (double)x*gcosang2 + (double)y*gsinang2;
					x = skywalx[(i+1)&3]; y = skywaly[(i+1)&3];
					_xp1 = (double)y*gcosang  - (double)x*gsinang;
					_yp1 = (double)x*gcosang2 + (double)y*gsinang2;

					_oxp0 = _xp0; _oyp0 = _yp0;

						//Clip to close parallel-screen plane
					if (_yp0 < SCISDIST)
					{
						if (_yp1 < SCISDIST) continue;
						_t0 = (SCISDIST-_yp0)/(_yp1-_yp0); _xp0 = (_xp1-_xp0)*_t0+_xp0; _yp0 = SCISDIST;
						_nx0 = (skywalx[(i+1)&3]-skywalx[i&3])*_t0+skywalx[i&3];
						_ny0 = (skywaly[(i+1)&3]-skywaly[i&3])*_t0+skywaly[i&3];
					}
					else { _t0 = 0.f; _nx0 = skywalx[i&3]; _ny0 = skywaly[i&3]; }
					if (_yp1 < SCISDIST)
					{
						_t1 = (SCISDIST-_oyp0)/(_yp1-_oyp0); _xp1 = (_xp1-_oxp0)*_t1+_oxp0; _yp1 = SCISDIST;
						_nx1 = (skywalx[(i+1)&3]-skywalx[i&3])*_t1+skywalx[i&3];
						_ny1 = (skywaly[(i+1)&3]-skywaly[i&3])*_t1+skywaly[i&3];
					}
					else { _t1 = 1.f; _nx1 = skywalx[(i+1)&3]; _ny1 = skywaly[(i+1)&3]; }

					_ryp0 = 1.f/_yp0; _ryp1 = 1.f/_yp1;

						//Generate screen coordinates for front side of wall
					_x0 = ghalfx*_xp0*_ryp0 + ghalfx;
					_x1 = ghalfx*_xp1*_ryp1 + ghalfx;
					if (_x1 <= _x0) continue;
					if ((_x0 >= x1) || (x0 >= _x1)) continue;

					_ryp0 *= gyxscale; _ryp1 *= gyxscale;

					_cy0 = -8192.f*_ryp0 + ghoriz;
					_fy0 =  8192.f*_ryp0 + ghoriz;
					_cy1 = -8192.f*_ryp1 + ghoriz;
					_fy1 =  8192.f*_ryp1 + ghoriz;

					_ox0 = _x0; _ox1 = _x1;

						//Make sure: x0<=_x0<_x1<=_x1
					ncy0 = cy0; ncy1 = cy1;
					if (_x0 < x0)
					{
						t = (x0-_x0)/(_x1-_x0);
						_cy0 += (_cy1-_cy0)*t;
						_fy0 += (_fy1-_fy0)*t;
						_x0 = x0;
					}
					else if (_x0 > x0) ncy0 += (_x0-x0)*(cy1-cy0)/(x1-x0);
					if (_x1 > x1)
					{
						t = (x1-_x1)/(_x1-_x0);
						_cy1 += (_cy1-_cy0)*t;
						_fy1 += (_fy1-_fy0)*t;
						_x1 = x1;
					}
					else if (_x1 < x1) ncy1 += (_x1-x1)*(cy1-cy0)/(x1-x0);

						//   (skybox ceiling)
						//(_x0,_cy0)-(_x1,_cy1)
						//   (skybox wall)
						//(_x0,_fy0)-(_x1,_fy1)
						//   (skybox floor)
						//(_x0,ncy0)-(_x1,ncy1)

						//ceiling of skybox

					drawingskybox = 5; //ceiling/5th texture/index 4 of skybox
					ft[0] = 512/16; ft[1] = -512/-16;
					ft[2] = ((float)cosglobalang)*(1.f/2147483648.f);
					ft[3] = ((float)singlobalang)*(1.f/2147483648.f);
					gdx = 0;
					gdy = gxyaspect*-(1.f/4194304.f);
					gdo = -ghoriz*gdy;
					gux = (double)ft[3]*((double)viewingrange)/-65536.0;
					gvx = (double)ft[2]*((double)viewingrange)/-65536.0;
					guy = (double)ft[0]*gdy; gvy = (double)ft[1]*gdy;
					guo = (double)ft[0]*gdo; gvo = (double)ft[1]*gdo;
					guo += (double)(ft[2]-gux)*ghalfx;
					gvo -= (double)(ft[3]+gvx)*ghalfx;
					if ((_cy0 < ncy0) && (_cy1 < ncy1)) domost(_x1,_cy1,_x0,_cy0,domostmethod);
					else if ((_cy0 < ncy0) != (_cy1 < ncy1))
					{
							//(ox,oy) is intersection of: (_x0,_cy0)-(_x1,_cy1)
							//                            (_x0,ncy0)-(_x1,ncy1)
							//ox = _x0 + (_x1-_x0)*t
							//oy = _cy0 + (_cy1-_cy0)*t
							//oy = ncy0 + (ncy1-ncy0)*t
						t = (_cy0-ncy0)/(ncy1-ncy0-_cy1+_cy0);
						ox = _x0 + (_x1-_x0)*t;
						oy = _cy0 + (_cy1-_cy0)*t;
						if (ncy0 < _cy0) { domost(ox,oy,_x0,ncy0,domostmethod); domost(_x1,_cy1,ox,oy,domostmethod); }
										else { domost(ox,oy,_x0,_cy0,domostmethod); domost(_x1,ncy1,ox,oy,domostmethod); }
					} else domost(_x1,ncy1,_x0,ncy0,domostmethod);

						//wall of skybox
					drawingskybox = i+1; //i+1th texture/index i of skybox
					gdx = (_ryp0-_ryp1)*gxyaspect*(1.f/512.f) / (_ox0-_ox1);
					gdy = 0;
					gdo = _ryp0*gxyaspect*(1.f/512.f) - gdx*_ox0;
					gux = (_t0*_ryp0 - _t1*_ryp1)*gxyaspect*(64.f/512.f) / (_ox0-_ox1);
					guo = _t0*_ryp0*gxyaspect*(64.f/512.f) - gux*_ox0;
					guy = 0;
					_t0 = -8192.0*_ryp0 + ghoriz;
					_t1 = -8192.0*_ryp1 + ghoriz;
					t = ((gdx*_ox0 + gdo)*8.f) / ((_ox1-_ox0) * _ryp0 * 2048.f);
					gvx = (_t0-_t1)*t;
					gvy = (_ox1-_ox0)*t;
					gvo = -gvx*_ox0 - gvy*_t0;
					if ((_fy0 < ncy0) && (_fy1 < ncy1)) domost(_x1,_fy1,_x0,_fy0,domostmethod);
					else if ((_fy0 < ncy0) != (_fy1 < ncy1))
					{
							//(ox,oy) is intersection of: (_x0,_fy0)-(_x1,_fy1)
							//                            (_x0,ncy0)-(_x1,ncy1)
							//ox = _x0 + (_x1-_x0)*t
							//oy = _fy0 + (_fy1-_fy0)*t
							//oy = ncy0 + (ncy1-ncy0)*t
						t = (_fy0-ncy0)/(ncy1-ncy0-_fy1+_fy0);
						ox = _x0 + (_x1-_x0)*t;
						oy = _fy0 + (_fy1-_fy0)*t;
						if (ncy0 < _fy0) { domost(ox,oy,_x0,ncy0,domostmethod); domost(_x1,_fy1,ox,oy,domostmethod); }
										else { domost(ox,oy,_x0,_fy0,domostmethod); domost(_x1,ncy1,ox,oy,domostmethod); }
					} else domost(_x1,ncy1,_x0,ncy0,domostmethod);
				}

					//Floor of skybox
				drawingskybox = 6; //floor/6th texture/index 5 of skybox
				ft[0] = 512/16; ft[1] = 512/-16;
				ft[2] = ((float)cosglobalang)*(1.f/2147483648.f);
				ft[3] = ((float)singlobalang)*(1.f/2147483648.f);
				gdx = 0;
				gdy = gxyaspect*(1.f/4194304.f);
				gdo = -ghoriz*gdy;
				gux = (double)ft[3]*((double)viewingrange)/-65536.0;
				gvx = (double)ft[2]*((double)viewingrange)/-65536.0;
				guy = (double)ft[0]*gdy; gvy = (double)ft[1]*gdy;
				guo = (double)ft[0]*gdo; gvo = (double)ft[1]*gdo;
				guo += (double)(ft[2]-gux)*ghalfx;
				gvo -= (double)(ft[3]+gvx)*ghalfx;
				gvx = -gvx; gvy = -gvy; gvo = -gvo; //y-flip skybox floor
				domost(x1,cy1,x0,cy0,domostmethod);

				drawingskybox = 0;
			}
			if (rendmode == 3)
			{
				gfogdensity = tempfogdensity;
			}
#endif
		}

			//(x0,cy0) == (u=             0,v=0,d=)
			//(x1,cy0) == (u=wal->xrepeat*8,v=0)
			//(x0,fy0) == (u=             0,v=v)
			//             u = (gux*sx + guy*sy + guo) / (gdx*sx + gdy*sy + gdo)
			//             v = (gvx*sx + gvy*sy + gvo) / (gdx*sx + gdy*sy + gdo)
			//             0 = (gux*x0 + guy*cy0 + guo) / (gdx*x0 + gdy*cy0 + gdo)
			//wal->xrepeat*8 = (gux*x1 + guy*cy0 + guo) / (gdx*x1 + gdy*cy0 + gdo)
			//             0 = (gvx*x0 + gvy*cy0 + gvo) / (gdx*x0 + gdy*cy0 + gdo)
			//             v = (gvx*x0 + gvy*fy0 + gvo) / (gdx*x0 + gdy*fy0 + gdo)
			//sx = x0, u = t0*wal->xrepeat*8, d = yp0;
			//sx = x1, u = t1*wal->xrepeat*8, d = yp1;
			//d = gdx*sx + gdo
			//u = (gux*sx + guo) / (gdx*sx + gdo)
			//yp0 = gdx*x0 + gdo
			//yp1 = gdx*x1 + gdo
			//t0*wal->xrepeat*8 = (gux*x0 + guo) / (gdx*x0 + gdo)
			//t1*wal->xrepeat*8 = (gux*x1 + guo) / (gdx*x1 + gdo)
			//gdx*x0 + gdo = yp0
			//gdx*x1 + gdo = yp1
		gdx = (ryp0-ryp1)*gxyaspect / (x0-x1);
		gdy = 0;
		gdo = ryp0*gxyaspect - gdx*x0;

			//gux*x0 + guo = t0*wal->xrepeat*8*yp0
			//gux*x1 + guo = t1*wal->xrepeat*8*yp1
		gux = (t0*ryp0 - t1*ryp1)*gxyaspect*(float)wal->xrepeat*8.f / (x0-x1);
		guo = t0*ryp0*gxyaspect*(float)wal->xrepeat*8.f - gux*x0;
		guo += (float)wal->xpanning*gdo;
		gux += (float)wal->xpanning*gdx;
		guy = 0;
			//Derivation for u:
			//   (gvx*x0 + gvy*cy0 + gvo) / (gdx*x0 + gdy*cy0 + gdo) = 0
			//   (gvx*x1 + gvy*cy1 + gvo) / (gdx*x1 + gdy*cy1 + gdo) = 0
			//   (gvx*x0 + gvy*fy0 + gvo) / (gdx*x0 + gdy*fy0 + gdo) = v
			//   (gvx*x1 + gvy*fy1 + gvo) / (gdx*x1 + gdy*fy1 + gdo) = v
			//   (gvx*x0 + gvy*cy0 + gvo*1) = 0
			//   (gvx*x1 + gvy*cy1 + gvo*1) = 0
			//   (gvx*x0 + gvy*fy0 + gvo*1) = t
		ogux = gux; oguy = guy; oguo = guo;

		if (nextsectnum >= 0)
		{
			getzsofslope(nextsectnum,(int)nx0,(int)ny0,&cz,&fz);
			ocy0 = ((float)(cz-globalposz))*ryp0 + ghoriz;
			ofy0 = ((float)(fz-globalposz))*ryp0 + ghoriz;
			getzsofslope(nextsectnum,(int)nx1,(int)ny1,&cz,&fz);
			ocy1 = ((float)(cz-globalposz))*ryp1 + ghoriz;
			ofy1 = ((float)(fz-globalposz))*ryp1 + ghoriz;

			if ((wal->cstat&48) == 16) maskwall[maskwallcnt++] = z;

			if (((cy0 < ocy0) || (cy1 < ocy1)) && (!((sec->ceilingstat&sector[nextsectnum].ceilingstat)&1)))
			{
				globalpicnum = wal->picnum; globalshade = wal->shade; globalpal = (int)((unsigned char)wal->pal);
				if (picanm[globalpicnum]&192) globalpicnum += animateoffs(globalpicnum,wallnum+16384);

				if (!(wal->cstat&4)) i = sector[nextsectnum].ceilingz; else i = sec->ceilingz;
				t0 = ((float)(i-globalposz))*ryp0 + ghoriz;
				t1 = ((float)(i-globalposz))*ryp1 + ghoriz;
				t = ((gdx*x0 + gdo) * (float)wal->yrepeat) / ((x1-x0) * ryp0 * 2048.f);
				i = (1<<(picsiz[globalpicnum]>>4)); if (i < tilesizy[globalpicnum]) i <<= 1;
				fy = (float)wal->ypanning * ((float)i) / 256.0;
				gvx = (t0-t1)*t;
				gvy = (x1-x0)*t;
				gvo = -gvx*x0 - gvy*t0 + fy*gdo; gvx += fy*gdx; gvy += fy*gdy;

				if (wal->cstat&8) //xflip
				{
					t = (float)(wal->xrepeat*8 + wal->xpanning*2);
					gux = gdx*t - gux;
					guy = gdy*t - guy;
					guo = gdo*t - guo;
				}
				if (wal->cstat&256) { gvx = -gvx; gvy = -gvy; gvo = -gvo; } //yflip

				domost(x1,ocy1,x0,ocy0,METH_POW2XSPLIT);

				if (wal->cstat&8) { gux = ogux; guy = oguy; guo = oguo; }
			}
			if (((ofy0 < fy0) || (ofy1 < fy1)) && (!((sec->floorstat&sector[nextsectnum].floorstat)&1)))
			{
				if (!(wal->cstat&2)) nwal = wal;
				else
				{
					nwal = &wall[wal->nextwall];
					guo += (float)(nwal->xpanning-wal->xpanning)*gdo;
					gux += (float)(nwal->xpanning-wal->xpanning)*gdx;
					guy += (float)(nwal->xpanning-wal->xpanning)*gdy;
				}
				globalpicnum = nwal->picnum; globalshade = nwal->shade; globalpal = (int)((unsigned char)nwal->pal);
				if (picanm[globalpicnum]&192) globalpicnum += animateoffs(globalpicnum,wallnum+16384);

				if (!(nwal->cstat&4)) i = sector[nextsectnum].floorz; else i = sec->ceilingz;
				t0 = ((float)(i-globalposz))*ryp0 + ghoriz;
				t1 = ((float)(i-globalposz))*ryp1 + ghoriz;
				t = ((gdx*x0 + gdo) * (float)wal->yrepeat) / ((x1-x0) * ryp0 * 2048.f);
				i = (1<<(picsiz[globalpicnum]>>4)); if (i < tilesizy[globalpicnum]) i <<= 1;
				fy = (float)nwal->ypanning * ((float)i) / 256.0;
				gvx = (t0-t1)*t;
				gvy = (x1-x0)*t;
				gvo = -gvx*x0 - gvy*t0 + fy*gdo; gvx += fy*gdx; gvy += fy*gdy;

				if (wal->cstat&8) //xflip
				{
					t = (float)(wal->xrepeat*8 + nwal->xpanning*2);
					gux = gdx*t - gux;
					guy = gdy*t - guy;
					guo = gdo*t - guo;
				}
				if (nwal->cstat&256) { gvx = -gvx; gvy = -gvy; gvo = -gvo; } //yflip

				domost(x0,ofy0,x1,ofy1,METH_POW2XSPLIT);

				if (wal->cstat&(2+8)) { guo = oguo; gux = ogux; guy = oguy; }
			}
		}

		if ((nextsectnum < 0) || (wal->cstat&32))   //White/1-way wall
		{
			if (nextsectnum < 0) globalpicnum = wal->picnum; else globalpicnum = wal->overpicnum;
			globalshade = wal->shade; globalpal = (int)((unsigned char)wal->pal);
			if (picanm[globalpicnum]&192) globalpicnum += animateoffs(globalpicnum,wallnum+16384);

			if (nextsectnum >= 0) { if (!(wal->cstat&4)) i = nextsec->ceilingz; else i = sec->ceilingz; }
								  else { if (!(wal->cstat&4)) i = sec->ceilingz;     else i = sec->floorz; }
			t0 = ((float)(i-globalposz))*ryp0 + ghoriz;
			t1 = ((float)(i-globalposz))*ryp1 + ghoriz;
			t = ((gdx*x0 + gdo) * (float)wal->yrepeat) / ((x1-x0) * ryp0 * 2048.f);
			i = (1<<(picsiz[globalpicnum]>>4)); if (i < tilesizy[globalpicnum]) i <<= 1;
			fy = (float)wal->ypanning * ((float)i) / 256.0;
			gvx = (t0-t1)*t;
			gvy = (x1-x0)*t;
			gvo = -gvx*x0 - gvy*t0 + fy*gdo; gvx += fy*gdx; gvy += fy*gdy;

			if (wal->cstat&8) //xflip
			{
				t = (float)(wal->xrepeat*8 + wal->xpanning*2);
				gux = gdx*t - gux;
				guy = gdy*t - guy;
				guo = gdo*t - guo;
			}
			if (wal->cstat&256) { gvx = -gvx; gvy = -gvy; gvo = -gvo; } //yflip
			domost(x0,-10000,x1,-10000,METH_POW2XSPLIT);
		}

		if (nextsectnum >= 0)
			if ((!(gotsector[nextsectnum>>3]&pow2char[nextsectnum&7])) && (testvisiblemost(x0,x1)))
				polymost_scansector(nextsectnum);
	}
}

static int polymost_bunchfront (int b1, int b2)
{
	double x1b1, x1b2, x2b1, x2b2;
	int b1f, b2f, i;

	b1f = bunchfirst[b1]; x1b1 = dxb1[b1f]; x2b2 = dxb2[bunchlast[b2]]; if (x1b1 >= x2b2) return(-1);
	b2f = bunchfirst[b2]; x1b2 = dxb1[b2f]; x2b1 = dxb2[bunchlast[b1]]; if (x1b2 >= x2b1) return(-1);

	if (x1b1 >= x1b2)
	{
		for(i=b2f;dxb2[i]<=x1b1;i=p2[i]);
		return(wallfront(b1f,i));
	}
	for(i=b1f;dxb2[i]<=x1b2;i=p2[i]);
	return(wallfront(i,b2f));
}

static void polymost_scansector (int sectnum)
{
	double d, xp1, yp1, xp2, yp2;
	walltype *wal, *wal2;
	spritetype *spr;
	int z, zz, startwall, endwall, numscansbefore, scanfirst, bunchfrst, nextsectnum;
	int xs, ys, x1, y1, x2, y2;

	if (sectnum < 0) return;
	if (automapping) show2dsector[sectnum>>3] |= pow2char[sectnum&7];

	sectorborder[0] = sectnum, sectorbordercnt = 1;
	do
	{
		sectnum = sectorborder[--sectorbordercnt];

		for(z=headspritesect[sectnum];z>=0;z=nextspritesect[z])
		{
			spr = &sprite[z];
			if ((((spr->cstat&0x8000) == 0) || (showinvisibility)) &&
				  (spr->xrepeat > 0) && (spr->yrepeat > 0) &&
				  (spritesortcnt < MAXSPRITESONSCREEN))
			{
				xs = spr->x-globalposx; ys = spr->y-globalposy;
				if ((spr->cstat&48) || (xs*gcosang+ys*gsinang > 0))
				{
					copybufbyte(spr,&tsprite[spritesortcnt],sizeof(spritetype));
					tsprite[spritesortcnt++].owner = z;
				}
			}
		}

		gotsector[sectnum>>3] |= pow2char[sectnum&7];

		bunchfrst = numbunches;
		numscansbefore = numscans;

		startwall = sector[sectnum].wallptr; endwall = sector[sectnum].wallnum+startwall;
		scanfirst = numscans;
		xp2 = 0; yp2 = 0;
		for(z=startwall,wal=&wall[z];z<endwall;z++,wal++)
		{
			wal2 = &wall[wal->point2];
			x1 = wal->x-globalposx; y1 = wal->y-globalposy;
			x2 = wal2->x-globalposx; y2 = wal2->y-globalposy;

			nextsectnum = wal->nextsector; //Scan close sectors
			if ((nextsectnum >= 0) && (!(wal->cstat&32)) && (!(gotsector[nextsectnum>>3]&pow2char[nextsectnum&7])))
			{
				d = (double)x1*(double)y2 - (double)x2*(double)y1; xp1 = (double)(x2-x1); yp1 = (double)(y2-y1);
				if (d*d <= (xp1*xp1 + yp1*yp1)*(SCISDIST*SCISDIST*260.0))
					sectorborder[sectorbordercnt++] = nextsectnum;
			}

			if ((z == startwall) || (wall[z-1].point2 != z))
			{
				xp1 = ((double)y1*(double)cosglobalang             - (double)x1*(double)singlobalang            )/64.0;
				yp1 = ((double)x1*(double)cosviewingrangeglobalang + (double)y1*(double)sinviewingrangeglobalang)/64.0;
			}
			else { xp1 = xp2; yp1 = yp2; }
			xp2 = ((double)y2*(double)cosglobalang             - (double)x2*(double)singlobalang            )/64.0;
			yp2 = ((double)x2*(double)cosviewingrangeglobalang + (double)y2*(double)sinviewingrangeglobalang)/64.0;
			if ((yp1 >= SCISDIST) || (yp2 >= SCISDIST))
				if ((double)xp1*(double)yp2 < (double)xp2*(double)yp1) //if wall is facing you...
				{
					if (yp1 >= SCISDIST)
						  dxb1[numscans] = (double)xp1*ghalfx/(double)yp1 + ghalfx;
					else dxb1[numscans] = -1e32;

					if (yp2 >= SCISDIST)
						  dxb2[numscans] = (double)xp2*ghalfx/(double)yp2 + ghalfx;
					else dxb2[numscans] = 1e32;

					if (dxb1[numscans] < dxb2[numscans])
						{ thesector[numscans] = sectnum; thewall[numscans] = z; p2[numscans] = numscans+1; numscans++; }
				}

			if ((wall[z].point2 < z) && (scanfirst < numscans))
				{ p2[numscans-1] = scanfirst; scanfirst = numscans; }
		}

		for(z=numscansbefore;z<numscans;z++)
			if ((wall[thewall[z]].point2 != thewall[p2[z]]) || (dxb2[z] > dxb1[p2[z]]))
				{ bunchfirst[numbunches++] = p2[z]; p2[z] = -1; }

		for(z=bunchfrst;z<numbunches;z++)
		{
			for(zz=bunchfirst[z];p2[zz]>=0;zz=p2[zz]);
			bunchlast[z] = zz;
		}
	} while (sectorbordercnt > 0);
}

void polymost_drawrooms ()
{
	int i, j, k, n, n2, closest;
	double ox, oy, oz, ox2, oy2, oz2, r, px[6], py[6], pz[6], px2[6], py2[6], pz2[6], sx[6], sy[6];
	static unsigned char tempbuf[MAXWALLS];

	if (!rendmode) return;

	begindrawing();
	frameoffset = frameplace + windowy1*bytesperline + windowx1;

#if USE_OPENGL
	if (rendmode == 3)
	{
		resizeglcheck();

		//glfunc.glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
		//glfunc.glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_MODULATE); //default anyway
		glfunc.glEnable(GL_DEPTH_TEST);
		glfunc.glDepthFunc(GL_ALWAYS); //NEVER,LESS,(,L)EQUAL,GREATER,(NOT,G)EQUAL,ALWAYS

		//glfunc.glPolygonOffset(1,1); //Supposed to make sprites pasted on walls or floors not disappear
#if (USE_OPENGL == USE_GLES2)
		glfunc.glDepthRangef(0.00001f,1.f); //<- this is more widely supported than glPolygonOffset
#else
		glfunc.glDepthRange(0.00001,1.0); //<- this is more widely supported than glPolygonOffset
#endif

		 //Enable this for OpenGL red-blue glasses mode :)
		if (glredbluemode)
		{
			float m[4][4];
			static int grbfcnt = 0; grbfcnt++;
			if (redblueclearcnt < numpages) { redblueclearcnt++; glfunc.glColorMask(1,1,1,1); glfunc.glClear(GL_COLOR_BUFFER_BIT); }
			if (grbfcnt&1)
			{
				glfunc.glViewport(windowx1-16,yres-(windowy2+1),windowx2-(windowx1-16)+1,windowy2-windowy1+1);
				glfunc.glColorMask(1,0,0,1);
				globalposx += singlobalang/1024;
				globalposy -= cosglobalang/1024;
			}
			else
			{
				glfunc.glViewport(windowx1,yres-(windowy2+1),windowx2+16-windowx1+1,windowy2-windowy1+1);
				glfunc.glColorMask(0,1,1,1);
				globalposx -= singlobalang/1024;
				globalposy += cosglobalang/1024;
			}
		}
	}
#endif

		//Polymost supports true look up/down :) Here, we convert horizon to angle.
		//gchang&gshang are cos&sin of this angle (respectively)
	gyxscale = ((double)xdimenscale)/131072.0;
	gxyaspect = ((double)xyaspect*(double)viewingrange)*(5.0/(65536.0*262144.0));
	gviewxrange = ((double)viewingrange)*((double)xdimen)/(32768.0*1024.0);
	gcosang = ((double)cosglobalang)/262144.0;
	gsinang = ((double)singlobalang)/262144.0;
	gcosang2 = gcosang*((double)viewingrange)/65536.0;
	gsinang2 = gsinang*((double)viewingrange)/65536.0;
	ghalfx = (double)halfxdimen; grhalfxdown10 = 1.0/(((double)ghalfx)*1024);
	ghoriz = (double)globalhoriz;

	gvisibility = ((float)globalvisibility)*gxyaspect*FOGSCALE;

		//global cos/sin height angle
	r = (double)((ydimen>>1)-ghoriz);
	gshang = r/sqrt(r*r+ghalfx*ghalfx);
	gchang = sqrt(1.0-gshang*gshang);
	ghoriz = (double)(ydimen>>1);

	  //global cos/sin tilt angle
	gctang = cos(gtang);
	gstang = sin(gtang);
	if (fabs(gstang) < .001) //This hack avoids nasty precision bugs in domost()
		{ gstang = 0; if (gctang > 0) gctang = 1.0; else gctang = -1.0; }

	if (inpreparemirror)
		gstang = -gstang;

		//Generate viewport trapezoid (for handling screen up/down)
	px[0] = px[3] = 0-1; px[1] = px[2] = windowx2+1-windowx1+2;
	py[0] = py[1] = 0-1; py[2] = py[3] = windowy2+1-windowy1+2; n = 4;
	for(i=0;i<n;i++)
	{
		ox = px[i]-ghalfx; oy = py[i]-ghoriz; oz = ghalfx;

			//Tilt rotation (backwards)
		ox2 = ox*gctang + oy*gstang;
		oy2 = oy*gctang - ox*gstang;
		oz2 = oz;

			//Up/down rotation (backwards)
		px[i] = ox2;
		py[i] = oy2*gchang + oz2*gshang;
		pz[i] = oz2*gchang - oy2*gshang;
	}

		//Clip to SCISDIST plane
	n2 = 0;
	for(i=0;i<n;i++)
	{
		j = i+1; if (j >= n) j = 0;
		if (pz[i] >= SCISDIST) { px2[n2] = px[i]; py2[n2] = py[i]; pz2[n2] = pz[i]; n2++; }
		if ((pz[i] >= SCISDIST) != (pz[j] >= SCISDIST))
		{
			r = (SCISDIST-pz[i])/(pz[j]-pz[i]);
			px2[n2] = (px[j]-px[i])*r + px[i];
			py2[n2] = (py[j]-py[i])*r + py[i];
			pz2[n2] = SCISDIST; n2++;
		}
	}
	if (n2 < 3) { enddrawing(); return; }
	for(i=0;i<n2;i++)
	{
		r = ghalfx / pz2[i];
		sx[i] = px2[i]*r + ghalfx;
		sy[i] = py2[i]*r + ghoriz;
	}
	initmosts(sx,sy,n2);

	if (searchit == 2)
	{
		short hitsect, hitwall, hitsprite;
		int vx, vy, vz, hitx, hity, hitz;

		ox2 = searchx-ghalfx; oy2 = searchy-ghoriz; oz2 = ghalfx;

			//Tilt rotation
		ox = ox2*gctang + oy2*gstang;
		oy = oy2*gctang - ox2*gstang;
		oz = oz2;

			//Up/down rotation
		ox2 = oz*gchang - oy*gshang;
		oy2 = ox;
		oz2 = oy*gchang + oz*gshang;

			//Standard Left/right rotation
		vx = (int)(ox2*((float)cosglobalang) - oy2*((float)singlobalang));
		vy = (int)(ox2*((float)singlobalang) + oy2*((float)cosglobalang));
		vz = (int)(oz2*16384.0);

		hitallsprites = 1;
		hitscan(globalposx,globalposy,globalposz,globalcursectnum, //Start position
			vx>>12,vy>>12,vz>>8,&hitsect,&hitwall,&hitsprite,&hitx,&hity,&hitz,0xffff0030);
		hitallsprites = 0;

		searchsector = hitsect;
		if (hitwall >= 0)
		{
			searchwall = hitwall; searchstat = 0;
			if (wall[hitwall].nextwall >= 0)
			{
				int cz, fz;
				getzsofslope(wall[hitwall].nextsector,hitx,hity,&cz,&fz);
				if (hitz > fz)
				{
					if (wall[hitwall].cstat&2) //'2' bottoms of walls
						searchwall = wall[hitwall].nextwall;
				}
				else if ((hitz > cz) && (wall[hitwall].cstat&(16+32))) //masking or 1-way
					searchstat = 4;
			}
		}
		else if (hitsprite >= 0) { searchwall = hitsprite; searchstat = 3; }
		else
		{
			int cz, fz;
			getzsofslope(hitsect,hitx,hity,&cz,&fz);
			if ((hitz<<1) < cz+fz) searchstat = 1; else searchstat = 2;
			//if (vz < 0) searchstat = 1; else searchstat = 2; //Won't work for slopes :/
		}
		searchit = 0;
	}

	numscans = numbunches = 0;

	if (globalcursectnum >= MAXSECTORS)
		globalcursectnum -= MAXSECTORS;
	else
	{
		i = globalcursectnum;
		updatesector(globalposx,globalposy,&globalcursectnum);
		if (globalcursectnum < 0) globalcursectnum = i;
	}

	polymost_scansector(globalcursectnum);

	if (inpreparemirror)
	{
		grhalfxdown10x = -grhalfxdown10;
		inpreparemirror = 0;
		polymost_drawalls(0);
		numbunches--;
		bunchfirst[0] = bunchfirst[numbunches];
		bunchlast[0] = bunchlast[numbunches];
	}
	else
		grhalfxdown10x = grhalfxdown10;

	while (numbunches > 0)
	{
		memset(tempbuf,0,numbunches+3); tempbuf[0] = 1;

		closest = 0;              //Almost works, but not quite :(
		for(i=1;i<numbunches;i++)
		{
			j = polymost_bunchfront(i,closest); if (j < 0) continue;
			tempbuf[i] = 1;
			if (!j) { tempbuf[closest] = 1; closest = i; }
		}
		for(i=0;i<numbunches;i++) //Double-check
		{
			if (tempbuf[i]) continue;
			j = polymost_bunchfront(i,closest); if (j < 0) continue;
			tempbuf[i] = 1;
			if (!j) { tempbuf[closest] = 1; closest = i; i = 0; }
		}

		polymost_drawalls(closest);

		if (automapping)
		{
			for(j=bunchfirst[closest];j>=0;j=p2[j])
				show2dwall[thewall[j]>>3] |= pow2char[thewall[j]&7];
		}

		numbunches--;
		bunchfirst[closest] = bunchfirst[numbunches];
		bunchlast[closest] = bunchlast[numbunches];
	}
#if USE_OPENGL
	if (rendmode == 3)
	{
		glfunc.glDepthFunc(GL_LEQUAL); //NEVER,LESS,(,L)EQUAL,GREATER,(NOT,G)EQUAL,ALWAYS

		//glfunc.glPolygonOffset(0,0);
#if (USE_OPENGL == USE_GLES2)
		glfunc.glDepthRangef(0.f,0.99999f); //<- this is more widely supported than glPolygonOffset
#else
		glfunc.glDepthRange(0.0,0.99999); //<- this is more widely supported than glPolygonOffset
#endif
	}
#endif

	enddrawing();
}

void polymost_drawmaskwall (int damaskwallcnt)
{
	double dpx[8], dpy[8], dpx2[8], dpy2[8];
	float fx, fy, x0, x1, sx0, sy0, sx1, sy1, xp0, yp0, xp1, yp1, oxp0, oyp0, ryp0, ryp1;
	float f, r, t, t0, t1, nx0, ny0, nx1, ny1, py[4], csy[4], fsy[4];
	int i, j, k, n, n2, x, z, sectnum, z1, z2, lx, rx, cz[4], fz[4], method;
	sectortype *sec, *nsec;
	walltype *wal, *wal2;

#ifdef DEBUGGINGAIDS
	polymostcallcounts.drawmaskwall++;
#endif

	z = maskwall[damaskwallcnt];
	wal = &wall[thewall[z]]; wal2 = &wall[wal->point2];
	sectnum = thesector[z]; sec = &sector[sectnum];
	nsec = &sector[wal->nextsector];
	z1 = max(nsec->ceilingz,sec->ceilingz);
	z2 = min(nsec->floorz,sec->floorz);

	globalpicnum = wal->overpicnum; if ((unsigned int)globalpicnum >= MAXTILES) globalpicnum = 0;
	if (picanm[globalpicnum]&192) globalpicnum += animateoffs(globalpicnum,(short)thewall[z]+16384);
	globalshade = (int)wal->shade;
	globalpal = (int)((unsigned char)wal->pal);
	globalorientation = (int)wal->cstat;

	sx0 = (float)(wal->x-globalposx); sx1 = (float)(wal2->x-globalposx);
	sy0 = (float)(wal->y-globalposy); sy1 = (float)(wal2->y-globalposy);
	yp0 = sx0*gcosang2 + sy0*gsinang2;
	yp1 = sx1*gcosang2 + sy1*gsinang2;
	if ((yp0 < SCISDIST) && (yp1 < SCISDIST)) return;
	xp0 = sy0*gcosang - sx0*gsinang;
	xp1 = sy1*gcosang - sx1*gsinang;

		//Clip to close parallel-screen plane
	oxp0 = xp0; oyp0 = yp0;
	if (yp0 < SCISDIST) { t0 = (SCISDIST-yp0)/(yp1-yp0); xp0 = (xp1-xp0)*t0+xp0; yp0 = SCISDIST; }
						  else t0 = 0.f;
	if (yp1 < SCISDIST) { t1 = (SCISDIST-oyp0)/(yp1-oyp0); xp1 = (xp1-oxp0)*t1+oxp0; yp1 = SCISDIST; }
						else { t1 = 1.f; }

	getzsofslope(sectnum,(int)((wal2->x-wal->x)*t0+wal->x),(int)((wal2->y-wal->y)*t0+wal->y),&cz[0],&fz[0]);
	getzsofslope(wal->nextsector,(int)((wal2->x-wal->x)*t0+wal->x),(int)((wal2->y-wal->y)*t0+wal->y),&cz[1],&fz[1]);
	getzsofslope(sectnum,(int)((wal2->x-wal->x)*t1+wal->x),(int)((wal2->y-wal->y)*t1+wal->y),&cz[2],&fz[2]);
	getzsofslope(wal->nextsector,(int)((wal2->x-wal->x)*t1+wal->x),(int)((wal2->y-wal->y)*t1+wal->y),&cz[3],&fz[3]);

	ryp0 = 1.f/yp0; ryp1 = 1.f/yp1;

		//Generate screen coordinates for front side of wall
	x0 = ghalfx*xp0*ryp0 + ghalfx;
	x1 = ghalfx*xp1*ryp1 + ghalfx;
	if (x1 <= x0) return;

	ryp0 *= gyxscale; ryp1 *= gyxscale;

	gdx = (ryp0-ryp1)*gxyaspect / (x0-x1);
	gdy = 0;
	gdo = ryp0*gxyaspect - gdx*x0;

		//gux*x0 + guo = t0*wal->xrepeat*8*yp0
		//gux*x1 + guo = t1*wal->xrepeat*8*yp1
	gux = (t0*ryp0 - t1*ryp1)*gxyaspect*(float)wal->xrepeat*8.f / (x0-x1);
	guo = t0*ryp0*gxyaspect*(float)wal->xrepeat*8.f - gux*x0;
	guo += (float)wal->xpanning*gdo;
	gux += (float)wal->xpanning*gdx;
	guy = 0;

	if (!(wal->cstat&4)) i = z1; else i = z2;
	i -= globalposz;
	t0 = ((float)i)*ryp0 + ghoriz;
	t1 = ((float)i)*ryp1 + ghoriz;
	t = ((gdx*x0 + gdo) * (float)wal->yrepeat) / ((x1-x0) * ryp0 * 2048.f);
	i = (1<<(picsiz[globalpicnum]>>4)); if (i < tilesizy[globalpicnum]) i <<= 1;
	fy = (float)wal->ypanning * ((float)i) / 256.0;
	gvx = (t0-t1)*t;
	gvy = (x1-x0)*t;
	gvo = -gvx*x0 - gvy*t0 + fy*gdo; gvx += fy*gdx; gvy += fy*gdy;

	if (wal->cstat&8) //xflip
	{
		t = (float)(wal->xrepeat*8 + wal->xpanning*2);
		gux = gdx*t - gux;
		guy = gdy*t - guy;
		guo = gdo*t - guo;
	}
	if (wal->cstat&256) { gvx = -gvx; gvy = -gvy; gvo = -gvo; } //yflip

	method = METH_MASKED;
	if (wal->cstat&128) { if (!(wal->cstat&512)) method = METH_TRANS; else method = METH_INTRANS; }
	method |= METH_POW2XSPLIT | METH_LAYERS;

#if USE_OPENGL
	gfogpalnum = sec->floorpal;
	gfogdensity = gvisibility*((float)((unsigned char)(sec->visibility+16)) / 255.f);
#endif

	for(i=0;i<2;i++)
	{
		csy[i] = ((float)(cz[i]-globalposz))*ryp0 + ghoriz;
		fsy[i] = ((float)(fz[i]-globalposz))*ryp0 + ghoriz;
		csy[i+2] = ((float)(cz[i+2]-globalposz))*ryp1 + ghoriz;
		fsy[i+2] = ((float)(fz[i+2]-globalposz))*ryp1 + ghoriz;
	}

		//Clip 2 quadrilaterals
		//               /csy3
		//             /   |
		// csy0------/----csy2
		//   |     /xxxxxxx|
		//   |   /xxxxxxxxx|
		// csy1/xxxxxxxxxxx|
		//   |xxxxxxxxxxx/fsy3
		//   |xxxxxxxxx/   |
		//   |xxxxxxx/     |
		// fsy0----/------fsy2
		//   |   /
		// fsy1/

	dpx[0] = x0; dpy[0] = csy[1];
	dpx[1] = x1; dpy[1] = csy[3];
	dpx[2] = x1; dpy[2] = fsy[3];
	dpx[3] = x0; dpy[3] = fsy[1];
	n = 4;

		//Clip to (x0,csy[0])-(x1,csy[2])
	n2 = 0; t1 = -((dpx[0]-x0)*(csy[2]-csy[0]) - (dpy[0]-csy[0])*(x1-x0));
	for(i=0;i<n;i++)
	{
		j = i+1; if (j >= n) j = 0;

		t0 = t1; t1 = -((dpx[j]-x0)*(csy[2]-csy[0]) - (dpy[j]-csy[0])*(x1-x0));
		if (t0 >= 0) { dpx2[n2] = dpx[i]; dpy2[n2] = dpy[i]; n2++; }
		if ((t0 >= 0) != (t1 >= 0))
		{
			r = t0/(t0-t1);
			dpx2[n2] = (dpx[j]-dpx[i])*r + dpx[i];
			dpy2[n2] = (dpy[j]-dpy[i])*r + dpy[i];
			n2++;
		}
	}
	if (n2 < 3) return;

		//Clip to (x1,fsy[2])-(x0,fsy[0])
	n = 0; t1 = -((dpx2[0]-x1)*(fsy[0]-fsy[2]) - (dpy2[0]-fsy[2])*(x0-x1));
	for(i=0;i<n2;i++)
	{
		j = i+1; if (j >= n2) j = 0;

		t0 = t1; t1 = -((dpx2[j]-x1)*(fsy[0]-fsy[2]) - (dpy2[j]-fsy[2])*(x0-x1));
		if (t0 >= 0) { dpx[n] = dpx2[i]; dpy[n] = dpy2[i]; n++; }
		if ((t0 >= 0) != (t1 >= 0))
		{
			r = t0/(t0-t1);
			dpx[n] = (dpx2[j]-dpx2[i])*r + dpx2[i];
			dpy[n] = (dpy2[j]-dpy2[i])*r + dpy2[i];
			n++;
		}
	}
	if (n < 3) return;

	drawpoly(dpx,dpy,n,method);
}

void polymost_drawsprite (int snum)
{
	double px[6], py[6];
	float f, r, c, s, fx, fy, sx0, sy0, sx1, sy1, xp0, yp0, xp1, yp1, oxp0, oyp0, ryp0, ryp1, ft[4];
	float x0, y0, x1, y1, sc0, sf0, sc1, sf1, px2[6], py2[6], xv, yv, t0, t1;
	int i, j, spritenum, xoff=0, yoff=0, method, npoints;
	spritetype *tspr;

#ifdef DEBUGGINGAIDS
	polymostcallcounts.drawsprite++;
#endif

	tspr = tspriteptr[snum];
	if (tspr->owner < 0 || tspr->picnum < 0) return;

	globalpicnum      = tspr->picnum;
	globalshade       = tspr->shade;
	globalpal         = tspr->pal;
	globalorientation = tspr->cstat;
	spritenum         = tspr->owner;

	if ((globalorientation&48) != 48) {	// only non-voxel sprites should do this
		if (picanm[globalpicnum]&192) globalpicnum += animateoffs(globalpicnum,spritenum+32768);

		xoff = (int)((signed char)((picanm[globalpicnum]>>8)&255))+((int)tspr->xoffset);
		yoff = (int)((signed char)((picanm[globalpicnum]>>16)&255))+((int)tspr->yoffset);
	}

	method = METH_MASKED;
	if (tspr->cstat&2) { if (!(tspr->cstat&512)) method = METH_TRANS; else method = METH_INTRANS; }
	method |= METH_CLAMPED | METH_LAYERS;

#if USE_OPENGL
	gfogpalnum = sector[tspr->sectnum].floorpal;
	gfogdensity = gvisibility*((float)((unsigned char)(sector[tspr->sectnum].visibility+16)) / 255.f);

	while (rendmode == 3 && !(spriteext[tspr->owner].flags&SPREXT_NOTMD)) {
		if (usemodels && tile2model[tspr->picnum].modelid >= 0 && tile2model[tspr->picnum].framenum >= 0) {
			if (mddraw(tspr, 0)) {
				if (automapping == 1) show2dsprite[spritenum>>3] |= pow2char[spritenum&7];
				return;
			}
			break;	// else, render as flat sprite
		}
		if (usevoxels && (tspr->cstat&48)!=48 && tiletovox[tspr->picnum] >= 0 && voxmodels[ tiletovox[tspr->picnum] ]) {
			if (voxdraw(voxmodels[ tiletovox[tspr->picnum] ], tspr, 0)) {
				if (automapping == 1) show2dsprite[spritenum>>3] |= pow2char[spritenum&7];
				return;
			}
			break;	// else, render as flat sprite
		}
		if ((tspr->cstat&48)==48 && voxmodels[ tspr->picnum ]) {
			voxdraw(voxmodels[ tspr->picnum ], tspr, 0);
			if (automapping == 1) show2dsprite[spritenum>>3] |= pow2char[spritenum&7];
			return;
		}
		break;
	}
#endif

	switch((globalorientation>>4)&3)
	{
		case 0: //Face sprite

				//Project 3D to 2D
			sx0 = (float)(tspr->x-globalposx);
			sy0 = (float)(tspr->y-globalposy);
			xp0 = sy0*gcosang  - sx0*gsinang;
			yp0 = sx0*gcosang2 + sy0*gsinang2;
			if (yp0 <= SCISDIST) return;
			ryp0 = 1/yp0;
			sx0 = ghalfx*xp0*ryp0 + ghalfx;
			sy0 = ((float)(tspr->z-globalposz))*gyxscale*ryp0 + ghoriz;

			f = ryp0*(float)xdimen/160.0;
			fx = ((float)tspr->xrepeat)*f;
			fy = ((float)tspr->yrepeat)*f*((float)yxaspect/65536.0);
			sx0 -= fx*(float)xoff; if (tilesizx[globalpicnum]&1) sx0 += fx*.5;
			sy0 -= fy*(float)yoff;
			fx *= ((float)tilesizx[globalpicnum]);
			fy *= ((float)tilesizy[globalpicnum]);

			px[0] = px[3] = sx0-fx*.5; px[1] = px[2] = sx0+fx*.5;
			if (!(globalorientation&128)) { py[0] = py[1] = sy0-fy; py[2] = py[3] = sy0; }
											 else { py[0] = py[1] = sy0-fy*.5; py[2] = py[3] = sy0+fy*.5; }

			gdx = gdy = guy = gvx = 0; gdo = ryp0*gviewxrange;
			if (!(globalorientation&4))
				  { gux = (float)tilesizx[globalpicnum]*gdo/(px[1]-px[0]+.002); guo = -gux*(px[0]-.001); }
			else { gux = (float)tilesizx[globalpicnum]*gdo/(px[0]-px[1]-.002); guo = -gux*(px[1]+.001); }
			if (!(globalorientation&8))
				  { gvy = (float)tilesizy[globalpicnum]*gdo/(py[3]-py[0]+.002); gvo = -gvy*(py[0]-.001); }
			else { gvy = (float)tilesizy[globalpicnum]*gdo/(py[0]-py[3]-.002); gvo = -gvy*(py[3]+.001); }

			//Clip sprites to ceilings/floors when no parallaxing and not sloped
			if (!(sector[tspr->sectnum].ceilingstat&3))
			{
				sy0 = ((float)(sector[tspr->sectnum].ceilingz-globalposz))*gyxscale*ryp0 + ghoriz;
				if (py[0] < sy0) py[0] = py[1] = sy0;
			}
			if (!(sector[tspr->sectnum].floorstat&3))
			{
				sy0 = ((float)(sector[tspr->sectnum].floorz-globalposz))*gyxscale*ryp0 + ghoriz;
				if (py[2] > sy0) py[2] = py[3] = sy0;
			}

			drawpoly(px,py,4,method);
			break;
		case 1: //Wall sprite

				//Project 3D to 2D
			if (globalorientation&4) xoff = -xoff;
			if (globalorientation&8) yoff = -yoff;

			xv = (float)tspr->xrepeat * (float)sintable[(tspr->ang     )&2047] / 65536.0;
			yv = (float)tspr->xrepeat * (float)sintable[(tspr->ang+1536)&2047] / 65536.0;
			f = (float)(tilesizx[globalpicnum]>>1) + (float)xoff;
			x0 = (float)(tspr->x-globalposx) - xv*f; x1 = xv*(float)tilesizx[globalpicnum] + x0;
			y0 = (float)(tspr->y-globalposy) - yv*f; y1 = yv*(float)tilesizx[globalpicnum] + y0;

			yp0 = x0*gcosang2 + y0*gsinang2;
			yp1 = x1*gcosang2 + y1*gsinang2;
			if ((yp0 <= SCISDIST) && (yp1 <= SCISDIST)) return;
			xp0 = y0*gcosang - x0*gsinang;
			xp1 = y1*gcosang - x1*gsinang;

				//Clip to close parallel-screen plane
			oxp0 = xp0; oyp0 = yp0;
			if (yp0 < SCISDIST) { t0 = (SCISDIST-yp0)/(yp1-yp0); xp0 = (xp1-xp0)*t0+xp0; yp0 = SCISDIST; }
								else { t0 = 0.f; }
			if (yp1 < SCISDIST) { t1 = (SCISDIST-oyp0)/(yp1-oyp0); xp1 = (xp1-oxp0)*t1+oxp0; yp1 = SCISDIST; }
								else { t1 = 1.f; }

			f = ((float)tspr->yrepeat) * (float)tilesizy[globalpicnum] * 4;

			ryp0 = 1.0/yp0;
			ryp1 = 1.0/yp1;
			sx0 = ghalfx*xp0*ryp0 + ghalfx;
			sx1 = ghalfx*xp1*ryp1 + ghalfx;
			ryp0 *= gyxscale;
			ryp1 *= gyxscale;

			tspr->z -= ((yoff*tspr->yrepeat)<<2);
			if (globalorientation&128)
			{
				tspr->z += ((tilesizy[globalpicnum]*tspr->yrepeat)<<1);
				if (tilesizy[globalpicnum]&1) tspr->z += (tspr->yrepeat<<1); //Odd yspans
			}

			sc0 = ((float)(tspr->z-globalposz-f))*ryp0 + ghoriz;
			sc1 = ((float)(tspr->z-globalposz-f))*ryp1 + ghoriz;
			sf0 = ((float)(tspr->z-globalposz))*ryp0 + ghoriz;
			sf1 = ((float)(tspr->z-globalposz))*ryp1 + ghoriz;

			gdx = (ryp0-ryp1)*gxyaspect / (sx0-sx1);
			gdy = 0;
			gdo = ryp0*gxyaspect - gdx*sx0;

				//Original equations:
				//(gux*sx0 + guo)/(gdx*sx1 + gdo) = tilesizx[globalpicnum]*t0
				//(gux*sx1 + guo)/(gdx*sx1 + gdo) = tilesizx[globalpicnum]*t1
				//
				// gvx*sx0 + gvy*sc0 + gvo = 0
				// gvy*sx1 + gvy*sc1 + gvo = 0
				//(gvx*sx0 + gvy*sf0 + gvo)/(gdx*sx0 + gdo) = tilesizy[globalpicnum]
				//(gvx*sx1 + gvy*sf1 + gvo)/(gdx*sx1 + gdo) = tilesizy[globalpicnum]

				//gux*sx0 + guo = t0*tilesizx[globalpicnum]*yp0
				//gux*sx1 + guo = t1*tilesizx[globalpicnum]*yp1
			if (globalorientation&4) { t0 = 1.f-t0; t1 = 1.f-t1; }
			gux = (t0*ryp0 - t1*ryp1)*gxyaspect*(float)tilesizx[globalpicnum] / (sx0-sx1);
			guy = 0;
			guo = t0*ryp0*gxyaspect*(float)tilesizx[globalpicnum] - gux*sx0;

				//gvx*sx0 + gvy*sc0 + gvo = 0
				//gvx*sx1 + gvy*sc1 + gvo = 0
				//gvx*sx0 + gvy*sf0 + gvo = tilesizy[globalpicnum]*(gdx*sx0 + gdo)
			f = ((float)tilesizy[globalpicnum])*(gdx*sx0 + gdo) / ((sx0-sx1)*(sc0-sf0));
			if (!(globalorientation&8))
			{
				gvx = (sc0-sc1)*f;
				gvy = (sx1-sx0)*f;
				gvo = -gvx*sx0 - gvy*sc0;
			}
			else
			{
				gvx = (sf1-sf0)*f;
				gvy = (sx0-sx1)*f;
				gvo = -gvx*sx0 - gvy*sf0;
			}

			//Clip sprites to ceilings/floors when no parallaxing
			if (!(sector[tspr->sectnum].ceilingstat&1))
			{
				f = ((float)tspr->yrepeat) * (float)tilesizy[globalpicnum] * 4;
				if (sector[tspr->sectnum].ceilingz > tspr->z-f)
				{
					sc0 = ((float)(sector[tspr->sectnum].ceilingz-globalposz))*ryp0 + ghoriz;
					sc1 = ((float)(sector[tspr->sectnum].ceilingz-globalposz))*ryp1 + ghoriz;
				}
			}
			if (!(sector[tspr->sectnum].floorstat&1))
			{
				if (sector[tspr->sectnum].floorz < tspr->z)
				{
					sf0 = ((float)(sector[tspr->sectnum].floorz-globalposz))*ryp0 + ghoriz;
					sf1 = ((float)(sector[tspr->sectnum].floorz-globalposz))*ryp1 + ghoriz;
				}
			}

			if (sx0 > sx1)
			{
				if (globalorientation&64) return; //1-sided sprite
				f = sx0; sx0 = sx1; sx1 = f;
				f = sc0; sc0 = sc1; sc1 = f;
				f = sf0; sf0 = sf1; sf1 = f;
			}

			px[0] = sx0; py[0] = sc0;
			px[1] = sx1; py[1] = sc1;
			px[2] = sx1; py[2] = sf1;
			px[3] = sx0; py[3] = sf0;
			drawpoly(px,py,4,method);
			break;
		case 2: //Floor sprite

			if ((globalorientation&64) != 0)
				if ((globalposz > tspr->z) == (!(globalorientation&8)))
					return;
			if ((globalorientation&4) > 0) xoff = -xoff;
			if ((globalorientation&8) > 0) yoff = -yoff;

			i = (tspr->ang&2047);
			c = sintable[(i+512)&2047]/65536.0;
			s = sintable[i]/65536.0;
			x0 = ((tilesizx[globalpicnum]>>1)-xoff)*tspr->xrepeat;
			y0 = ((tilesizy[globalpicnum]>>1)-yoff)*tspr->yrepeat;
			x1 = ((tilesizx[globalpicnum]>>1)+xoff)*tspr->xrepeat;
			y1 = ((tilesizy[globalpicnum]>>1)+yoff)*tspr->yrepeat;

				//Project 3D to 2D
			for(j=0;j<4;j++)
			{
				sx0 = (float)(tspr->x-globalposx);
				sy0 = (float)(tspr->y-globalposy);
				if ((j+0)&2) { sy0 -= s*y0; sx0 -= c*y0; } else { sy0 += s*y1; sx0 += c*y1; }
				if ((j+1)&2) { sx0 -= s*x0; sy0 += c*x0; } else { sx0 += s*x1; sy0 -= c*x1; }
				px[j] = sy0*gcosang  - sx0*gsinang;
				py[j] = sx0*gcosang2 + sy0*gsinang2;
			}

			if (tspr->z < globalposz) //if floor sprite is above you, reverse order of points
			{
				f = px[0]; px[0] = px[1]; px[1] = f;
				f = py[0]; py[0] = py[1]; py[1] = f;
				f = px[2]; px[2] = px[3]; px[3] = f;
				f = py[2]; py[2] = py[3]; py[3] = f;
			}

				//Clip to SCISDIST plane
			npoints = 0;
			for(i=0;i<4;i++)
			{
				j = ((i+1)&3);
				if (py[i] >= SCISDIST) { px2[npoints] = px[i]; py2[npoints] = py[i]; npoints++; }
				if ((py[i] >= SCISDIST) != (py[j] >= SCISDIST))
				{
					f = (SCISDIST-py[i])/(py[j]-py[i]);
					px2[npoints] = (px[j]-px[i])*f + px[i];
					py2[npoints] = (py[j]-py[i])*f + py[i]; npoints++;
				}
			}
			if (npoints < 3) return;

				//Project rotated 3D points to screen
			f = ((float)(tspr->z-globalposz))*gyxscale;
			for(j=0;j<npoints;j++)
			{
				ryp0 = 1/py2[j];
				px[j] = ghalfx*px2[j]*ryp0 + ghalfx;
				py[j] = f*ryp0 + ghoriz;
			}

				//gd? Copied from floor rendering code
			gdx = 0;
			gdy = gxyaspect / (double)(tspr->z-globalposz);
			gdo = -ghoriz*gdy;
				//copied&modified from relative alignment
			xv = (float)tspr->x + s*x1 + c*y1; fx = (double)-(x0+x1)*s;
			yv = (float)tspr->y + s*y1 - c*x1; fy = (double)+(x0+x1)*c;
			f = 1.0/sqrt(fx*fx+fy*fy); fx *= f; fy *= f;
			ft[2] = singlobalang*fy + cosglobalang*fx;
			ft[3] = singlobalang*fx - cosglobalang*fy;
			ft[0] = ((double)(globalposy-yv))*fy + ((double)(globalposx-xv))*fx;
			ft[1] = ((double)(globalposx-xv))*fy - ((double)(globalposy-yv))*fx;
			gux = (double)ft[3]*((double)viewingrange)/(-65536.0*262144.0);
			gvx = (double)ft[2]*((double)viewingrange)/(-65536.0*262144.0);
			guy = (double)ft[0]*gdy; gvy = (double)ft[1]*gdy;
			guo = (double)ft[0]*gdo; gvo = (double)ft[1]*gdo;
			guo += (double)(ft[2]/262144.0-gux)*ghalfx;
			gvo -= (double)(ft[3]/262144.0+gvx)*ghalfx;
			f = 4.0/(float)tspr->xrepeat; gux *= f; guy *= f; guo *= f;
			f =-4.0/(float)tspr->yrepeat; gvx *= f; gvy *= f; gvo *= f;
			if (globalorientation&4)
			{
				gux = ((float)tilesizx[globalpicnum])*gdx - gux;
				guy = ((float)tilesizx[globalpicnum])*gdy - guy;
				guo = ((float)tilesizx[globalpicnum])*gdo - guo;
			}

			drawpoly(px,py,npoints,method);
			break;

		case 3: //Voxel sprite
		    break;
	}
	if (automapping == 1) show2dsprite[spritenum>>3] |= pow2char[spritenum&7];
}

	//sx,sy       center of sprite; screen coods*65536
	//z           zoom*65536. > is zoomed in
	//a           angle (0 is default)
	//dastat&1    1:translucence
	//dastat&2    1:auto-scale mode (use 320*200 coordinates)
	//dastat&4    1:y-flip
	//dastat&8    1:don't clip to startumost/startdmost
	//dastat&16   1:force point passed to be top-left corner, 0:Editart center
	//dastat&32   1:reverse translucence
	//dastat&64   1:non-masked, 0:masked
	//dastat&128  1:draw all pages (permanent)
	//cx1,...     clip window (actual screen coords)
void polymost_dorotatesprite (int sx, int sy, int z, short a, short picnum,
	signed char dashade, unsigned char dapalnum, unsigned char dastat, int cx1, int cy1, int cx2, int cy2, int uniqid)
{
	static int onumframes = 0;
	int i, n, nn, x, zz, xoff, yoff, xsiz, ysiz, method;
	int ogpicnum, ogshade, ogpal, ofoffset, oxdimen, oydimen, oldviewingrange;
	double ogxyaspect, ogfogdensity;
	double ogchang, ogshang, ogctang, ogstang, oghalfx, oghoriz, fx, fy, x1, y1, z1, x2, y2;
	double ogrhalfxdown10, ogrhalfxdown10x;
	double d, cosang, sinang, cosang2, sinang2, px[8], py[8], px2[8], py2[8];
	float m[4][4];

#if USE_OPENGL
	if (rendmode == 3 && usemodels && hudmem[(dastat&4)>>2][picnum].angadd)
	{
		if ((tile2model[picnum].modelid >= 0) && (tile2model[picnum].framenum >= 0))
		{
			spritetype tspr;
			memset(&tspr,0,sizeof(spritetype));

			if (hudmem[(dastat&4)>>2][picnum].flags&1) return; //"HIDE" is specified in DEF

			ogchang = gchang; gchang = 1.0;
			ogshang = gshang; gshang = 0.0; d = (double)z/(65536.0*16384.0);
			ogctang = gctang; gctang = (double)sintable[(a+512)&2047]*d;
			ogstang = gstang; gstang = (double)sintable[a&2047]*d;
			ogshade  = globalshade;  globalshade  = dashade;
			ogpal    = globalpal;    globalpal    = (int)((unsigned char)dapalnum);
			ogxyaspect = gxyaspect; gxyaspect = 1.0;
			ogfogdensity = gfogdensity; gfogdensity = 0.0;
			oldviewingrange = viewingrange; viewingrange = 65536;

			x1 = hudmem[(dastat&4)>>2][picnum].xadd;
			y1 = hudmem[(dastat&4)>>2][picnum].yadd;
			z1 = hudmem[(dastat&4)>>2][picnum].zadd;
			if (!(hudmem[(dastat&4)>>2][picnum].flags&2)) //"NOBOB" is specified in DEF
			{
				fx = ((double)sx)*(1.0/65536.0);
				fy = ((double)sy)*(1.0/65536.0);

				if (dastat&16)
				{
					xsiz = tilesizx[picnum]; ysiz = tilesizy[picnum];
					xoff = (int)((signed char)((picanm[picnum]>>8)&255))+(xsiz>>1);
					yoff = (int)((signed char)((picanm[picnum]>>16)&255))+(ysiz>>1);

					d = (double)z/(65536.0*16384.0);
					cosang2 = cosang = (double)sintable[(a+512)&2047]*d;
					sinang2 = sinang = (double)sintable[a&2047]*d;
					if ((dastat&2) || (!(dastat&8))) //Don't aspect unscaled perms
						{ d = (double)xyaspect/65536.0; cosang2 *= d; sinang2 *= d; }
					fx += -(double)xoff*cosang2+ (double)yoff*sinang2;
					fy += -(double)xoff*sinang - (double)yoff*cosang;
			}

				if (!(dastat&2))
			{
					x1 += fx/((double)(xdim<<15))-1.0; //-1: left of screen, +1: right of screen
					y1 += fy/((double)(ydim<<15))-1.0; //-1: top of screen, +1: bottom of screen
			}
			else
			{
					x1 += fx/160.0-1.0; //-1: left of screen, +1: right of screen
					y1 += fy/100.0-1.0; //-1: top of screen, +1: bottom of screen
			}
			}
			tspr.ang = hudmem[(dastat&4)>>2][picnum].angadd+globalang;
			tspr.xrepeat = tspr.yrepeat = 32;

			if (dastat&4) { x1 = -x1; y1 = -y1; }
			tspr.x = (int)(((double)gcosang*z1 - (double)gsinang*x1)*16384.0 + globalposx);
			tspr.y = (int)(((double)gsinang*z1 + (double)gcosang*x1)*16384.0 + globalposy);
			tspr.z = (int)(globalposz + y1*16384.0*0.8);
			tspr.picnum = picnum;
			tspr.shade = dashade;
			tspr.pal = dapalnum;
			tspr.owner = uniqid+MAXSPRITES;
			globalorientation = (dastat&1)+((dastat&32)<<4)+((dastat&4)<<1);

			if ((dastat&10) == 2) glfunc.glViewport(windowx1,yres-(windowy2+1),windowx2-windowx1+1,windowy2-windowy1+1);
			else { glfunc.glViewport(0,0,xdim,ydim); glox1 = -1; } //Force fullscreen (glox1=-1 forces it to restore)

			if (hudmem[(dastat&4)>>2][picnum].flags&8) //NODEPTH flag
				glfunc.glDisable(GL_DEPTH_TEST);
			else
			{
				glfunc.glEnable(GL_DEPTH_TEST);
				if (onumframes != numframes)
				{
					onumframes = numframes;
					glfunc.glClear(GL_DEPTH_BUFFER_BIT);
				}
			}

			mddraw(&tspr, !!((dastat&10) != 2));

			viewingrange = oldviewingrange;
			gfogdensity = ogfogdensity;
			gxyaspect = ogxyaspect;
			globalshade  = ogshade;
			globalpal    = ogpal;
			gchang = ogchang;
			gshang = ogshang;
			gctang = ogctang;
			gstang = ogstang;
			return;
		}
	}
#endif

	ogpicnum = globalpicnum; globalpicnum = picnum;
	ogshade  = globalshade;  globalshade  = dashade;
	ogpal    = globalpal;    globalpal    = (int)((unsigned char)dapalnum);
	oghalfx  = ghalfx;       ghalfx       = (double)(xdim>>1);
	ogrhalfxdown10 = grhalfxdown10;    grhalfxdown10 = 1.0/(((double)ghalfx)*1024);
	ogrhalfxdown10x = grhalfxdown10x;  grhalfxdown10x = grhalfxdown10;
	oghoriz  = ghoriz;       ghoriz       = (double)(ydim>>1);
	ofoffset = frameoffset;  frameoffset  = frameplace;
	oxdimen  = xdimen;       xdimen       = xdim;
	oydimen  = ydimen;       ydimen       = ydim;
	ogchang = gchang; gchang = 1.0;
	ogshang = gshang; gshang = 0.0;
	ogctang = gctang; gctang = 1.0;
	ogstang = gstang; gstang = 0.0;

#if USE_OPENGL
	if (rendmode == 3)
	{
		glfunc.glViewport(0,0,xdim,ydim); glox1 = -1; //Force fullscreen (glox1=-1 forces it to restore)
		glfunc.glDisable(GL_DEPTH_TEST);
	}
#endif

	method = METH_SOLID;
	if (!(dastat&64))
	{
		 method = METH_MASKED;
		 if (dastat&1) { if (!(dastat&32)) method = METH_TRANS; else method = METH_INTRANS; }
	}
	method |= METH_CLAMPED; //Use OpenGL clamping - dorotatesprite never repeats
	method |= METH_ROTATESPRITE;	//Use rotatesprite projection

	xsiz = tilesizx[globalpicnum]; ysiz = tilesizy[globalpicnum];
	if (dastat&16) { xoff = 0; yoff = 0; }
	else
	{
		xoff = (int)((signed char)((picanm[globalpicnum]>>8)&255))+(xsiz>>1);
		yoff = (int)((signed char)((picanm[globalpicnum]>>16)&255))+(ysiz>>1);
	}
	if (dastat&4) yoff = ysiz-yoff;

	if (dastat&2)  //Auto window size scaling
	{
		if (!(dastat&8))
		{
			if (widescreen) {
				x = ydimenscale;   //= scale(xdimen,yxaspect,320);
				sx = ((cx1+cx2+2)<<15)+scale(sx-(320<<15),oydimen<<16,200*pixelaspect);
			} else {
				x = xdimenscale;   //= scale(xdimen,yxaspect,320);
				sx = ((cx1+cx2+2)<<15)+scale(sx-(320<<15),oxdimen,320);
			}
			sy = ((cy1+cy2+2)<<15)+mulscale16(sy-(200<<15),x);
		}
		else
		{
				//If not clipping to startmosts, & auto-scaling on, as a
				//hard-coded bonus, scale to full screen instead
			if (widescreen) {
				x = scale(ydim<<16,yxaspect,200*pixelaspect);
				sx = (xdim<<15)+32768+scale(sx-(320<<15),ydim<<16,200*pixelaspect);
			} else {
				x = scale(xdim,yxaspect,320);
				sx = (xdim<<15)+32768+scale(sx-(320<<15),xdim,320);
			}
			sy = (ydim<<15)+32768+mulscale16(sy-(200<<15),x);
		}
		z = mulscale16(z,x);
	}

	d = (double)z/(65536.0*16384.0);
	cosang2 = cosang = (double)sintable[(a+512)&2047]*d;
	sinang2 = sinang = (double)sintable[a&2047]*d;
	if ((dastat&2) || (!(dastat&8))) //Don't aspect unscaled perms
		{ d = (double)xyaspect/65536.0; cosang2 *= d; sinang2 *= d; }
	px[0] = (double)sx/65536.0 - (double)xoff*cosang2+ (double)yoff*sinang2;
	py[0] = (double)sy/65536.0 - (double)xoff*sinang - (double)yoff*cosang;
	px[1] = px[0] + (double)xsiz*cosang2;
	py[1] = py[0] + (double)xsiz*sinang;
	px[3] = px[0] - (double)ysiz*sinang2;
	py[3] = py[0] + (double)ysiz*cosang;
	px[2] = px[1]+px[3]-px[0];
	py[2] = py[1]+py[3]-py[0];
	n = 4;

	gdx = 0; gdy = 0; gdo = 1.0;
		//px[0]*gux + py[0]*guy + guo = 0
		//px[1]*gux + py[1]*guy + guo = xsiz-.0001
		//px[3]*gux + py[3]*guy + guo = 0
	d = 1.0/(px[0]*(py[1]-py[3]) + px[1]*(py[3]-py[0]) + px[3]*(py[0]-py[1]));
	gux = (py[3]-py[0])*((double)xsiz-.0001)*d;
	guy = (px[0]-px[3])*((double)xsiz-.0001)*d;
	guo = 0 - px[0]*gux - py[0]*guy;

	if (!(dastat&4))
	{     //px[0]*gvx + py[0]*gvy + gvo = 0
			//px[1]*gvx + py[1]*gvy + gvo = 0
			//px[3]*gvx + py[3]*gvy + gvo = ysiz-.0001
		gvx = (py[0]-py[1])*((double)ysiz-.0001)*d;
		gvy = (px[1]-px[0])*((double)ysiz-.0001)*d;
		gvo = 0 - px[0]*gvx - py[0]*gvy;
	}
	else
	{     //px[0]*gvx + py[0]*gvy + gvo = ysiz-.0001
			//px[1]*gvx + py[1]*gvy + gvo = ysiz-.0001
			//px[3]*gvx + py[3]*gvy + gvo = 0
		gvx = (py[1]-py[0])*((double)ysiz-.0001)*d;
		gvy = (px[0]-px[1])*((double)ysiz-.0001)*d;
		gvo = (double)ysiz-.0001 - px[0]*gvx - py[0]*gvy;
	}

	cx2++; cy2++;
		//Clippoly4 (converted from int to double)
	nn = z = 0;
	do
	{
		zz = z+1; if (zz == n) zz = 0;
		x1 = px[z]; x2 = px[zz]-x1; if ((cx1 <= x1) && (x1 <= cx2)) { px2[nn] = x1; py2[nn] = py[z]; nn++; }
		if (x2 <= 0) fx = cx2; else fx = cx1;  d = fx-x1;
		if ((d < x2) != (d < 0)) { px2[nn] = fx; py2[nn] = (py[zz]-py[z])*d/x2 + py[z]; nn++; }
		if (x2 <= 0) fx = cx1; else fx = cx2;  d = fx-x1;
		if ((d < x2) != (d < 0)) { px2[nn] = fx; py2[nn] = (py[zz]-py[z])*d/x2 + py[z]; nn++; }
		z = zz;
	} while (z);
	if (nn >= 3)
	{
		n = z = 0;
		do
		{
			zz = z+1; if (zz == nn) zz = 0;
			y1 = py2[z]; y2 = py2[zz]-y1; if ((cy1 <= y1) && (y1 <= cy2)) { py[n] = y1; px[n] = px2[z]; n++; }
			if (y2 <= 0) fy = cy2; else fy = cy1;  d = fy-y1;
			if ((d < y2) != (d < 0)) { py[n] = fy; px[n] = (px2[zz]-px2[z])*d/y2 + px2[z]; n++; }
			if (y2 <= 0) fy = cy1; else fy = cy2;  d = fy-y1;
			if ((d < y2) != (d < 0)) { py[n] = fy; px[n] = (px2[zz]-px2[z])*d/y2 + px2[z]; n++; }
			z = zz;
		} while (z);
		drawpoly(px,py,n,method);
	}

	globalpicnum = ogpicnum;
	globalshade  = ogshade;
	globalpal    = ogpal;
	ghalfx       = oghalfx;
	grhalfxdown10 = ogrhalfxdown10;
	grhalfxdown10x = ogrhalfxdown10x;
	ghoriz       = oghoriz;
	frameoffset  = ofoffset;
	xdimen       = oxdimen;
	ydimen       = oydimen;
	gchang = ogchang;
	gshang = ogshang;
	gctang = ogctang;
	gstang = ogstang;
}

#if USE_OPENGL

static float trapextx[2];
static void drawtrap (float x0, float x1, float y0, float x2, float x3, float y1,
	struct polymostdrawpolycall *draw)
{
	float px[4], py[4];
	int i, n;
	struct polymostvboitem vboitem[4];

	if (y0 == y1) return;
	px[0] = x0; py[0] = y0;  py[2] = y1;
		  if (x0 == x1) { px[1] = x3; py[1] = y1; px[2] = x2; n = 3; }
	else if (x2 == x3) { px[1] = x1; py[1] = y0; px[2] = x3; n = 3; }
	else               { px[1] = x1; py[1] = y0; px[2] = x3; px[3] = x2; py[3] = y1; n = 4; }

	for(i=0;i<n;i++)
	{
		px[i] = min(max(px[i],trapextx[0]),trapextx[1]);
		vboitem[i].t.s = px[i]*gux + py[i]*guy + guo;
		vboitem[i].t.t = px[i]*gvx + py[i]*gvy + gvo;
		vboitem[i].v.x = px[i];
		vboitem[i].v.y = py[i];
		vboitem[i].v.z = 0.f;
	}
	draw->indexcount = n;
	draw->elementcount = n;
	draw->elementvbo = vboitem;
	polymost_drawpoly_glcall(GL_TRIANGLE_FAN, draw);
	draw->elementvbo = NULL;
}

static void tessectrap (float *px, float *py, int *point2, int numpoints,
	struct polymostdrawpolycall *draw)
{
	float x0, x1, m0, m1;
	int i, j, k, z, i0, i1, i2, i3, npoints, gap, numrst;

	static int allocpoints = 0, *slist = 0, *npoint2 = 0;
	typedef struct { float x, y, xi; int i; } raster;
	static raster *rst = 0;
	static struct polymostvboitem *vboitem = NULL;
	if (numpoints+16 > allocpoints) //16 for safety
	{
		allocpoints = numpoints+16;
		rst = (raster*)realloc(rst,allocpoints*sizeof(raster));
		slist = (int*)realloc(slist,allocpoints*sizeof(int));
		npoint2 = (int*)realloc(npoint2,allocpoints*sizeof(int));
		vboitem = (struct polymostvboitem *)realloc(vboitem, allocpoints*sizeof(struct polymostvboitem));
	}

		//Remove unnecessary collinear points:
	for(i=0;i<numpoints;i++) npoint2[i] = point2[i];
	npoints = numpoints; z = 0;
	for(i=0;i<numpoints;i++)
	{
		j = npoint2[i]; if ((point2[i] < i) && (i < numpoints-1)) z = 3;
		if (j < 0) continue;
		k = npoint2[j];
		m0 = (px[j]-px[i])*(py[k]-py[j]);
		m1 = (py[j]-py[i])*(px[k]-px[j]);
		if (m0 < m1) { z |= 1; continue; }
		if (m0 > m1) { z |= 2; continue; }
		npoint2[i] = k; npoint2[j] = -1; npoints--; i--; //collinear
	}
	if (!z) return;
	trapextx[0] = trapextx[1] = px[0];
	for(i=j=0;i<numpoints;i++)
	{
		if (npoint2[i] < 0) continue;
		if (px[i] < trapextx[0]) trapextx[0] = px[i];
		if (px[i] > trapextx[1]) trapextx[1] = px[i];
		slist[j++] = i;
	}
	if (z != 3) //Simple polygon... early out
	{
		for(i=0;i<npoints;i++)
		{
			j = slist[i];
			vboitem[i].t.s = px[j]*gux + py[j]*guy + guo;
			vboitem[i].t.t = px[j]*gvx + py[j]*gvy + gvo;
			vboitem[i].v.x = px[j];
			vboitem[i].v.y = py[j];
			vboitem[i].v.z = 0.f;
		}
		draw->indexcount = npoints;
		draw->elementcount = npoints;
		draw->elementvbo = vboitem;
		polymost_drawpoly_glcall(GL_TRIANGLE_FAN, draw);
		return;
	}

		//Sort points by y's
	for(gap=(npoints>>1);gap;gap>>=1)
		for(i=0;i<npoints-gap;i++)
			for(j=i;j>=0;j-=gap)
			{
				if (py[npoint2[slist[j]]] <= py[npoint2[slist[j+gap]]]) break;
				k = slist[j]; slist[j] = slist[j+gap]; slist[j+gap] = k;
			}

	numrst = 0;
	for(z=0;z<npoints;z++)
	{
		i0 = slist[z]; i1 = npoint2[i0]; if (py[i0] == py[i1]) continue;
		i2 = i1; i3 = npoint2[i1];
		if (py[i1] == py[i3]) { i2 = i3; i3 = npoint2[i3]; }

			//i0        i3
			//  \      /
			//   i1--i2
			//  /      \ ~
			//i0        i3

		if ((py[i1] < py[i0]) && (py[i2] < py[i3])) //Insert raster
		{
			for(i=numrst;i>0;i--)
			{
				if (rst[i-1].xi*(py[i1]-rst[i-1].y) + rst[i-1].x < px[i1]) break;
				rst[i+1] = rst[i-1];
			}
			numrst += 2;

			if (i&1) //split inside area
			{
				j = i-1;

				x0 = (py[i1] - rst[j  ].y)*rst[j  ].xi + rst[j  ].x;
				x1 = (py[i1] - rst[j+1].y)*rst[j+1].xi + rst[j+1].x;
				drawtrap(rst[j].x,rst[j+1].x,rst[j].y,x0,x1,py[i1],draw);
				rst[j  ].x = x0; rst[j  ].y = py[i1];
				rst[j+3].x = x1; rst[j+3].y = py[i1];
			}

			m0 = (px[i0]-px[i1]) / (py[i0]-py[i1]);
			m1 = (px[i3]-px[i2]) / (py[i3]-py[i2]);
			j = ((px[i1] > px[i2]) || ((i1 == i2) && (m0 >= m1))) + i;
			k = (i<<1)+1 - j;
			rst[j].i = i0; rst[j].xi = m0; rst[j].x = px[i1]; rst[j].y = py[i1];
			rst[k].i = i3; rst[k].xi = m1; rst[k].x = px[i2]; rst[k].y = py[i2];
		}
		else
		{                  //NOTE:don't count backwards!
			if (i1 == i2) { for(i=0;i<numrst;i++) if (rst[i].i == i1) break; }
						else { for(i=0;i<numrst;i++) if ((rst[i].i == i1) || (rst[i].i == i2)) break; }
			j = i&~1;

			if ((py[i1] > py[i0]) && (py[i2] > py[i3])) //Delete raster
			{
				for(;j<=i+1;j+=2)
				{
					x0 = (py[i1] - rst[j  ].y)*rst[j  ].xi + rst[j  ].x;
					if ((i == j) && (i1 == i2)) x1 = x0; else x1 = (py[i1] - rst[j+1].y)*rst[j+1].xi + rst[j+1].x;
					drawtrap(rst[j].x,rst[j+1].x,rst[j].y,x0,x1,py[i1],draw);
					rst[j  ].x = x0; rst[j  ].y = py[i1];
					rst[j+1].x = x1; rst[j+1].y = py[i1];
				}
				numrst -= 2; for(;i<numrst;i++) rst[i] = rst[i+2];
			}
			else
			{
				x0 = (py[i1] - rst[j  ].y)*rst[j  ].xi + rst[j  ].x;
				x1 = (py[i1] - rst[j+1].y)*rst[j+1].xi + rst[j+1].x;
				drawtrap(rst[j].x,rst[j+1].x,rst[j].y,x0,x1,py[i1],draw);
				rst[j  ].x = x0; rst[j  ].y = py[i1];
				rst[j+1].x = x1; rst[j+1].y = py[i1];

				if (py[i0] < py[i3]) { rst[i].x = px[i2]; rst[i].y = py[i2]; rst[i].i = i3; }
									 else { rst[i].x = px[i1]; rst[i].y = py[i1]; rst[i].i = i0; }
				rst[i].xi = (px[rst[i].i] - rst[i].x) / (py[rst[i].i] - py[i1]);
			}
		}
	}
}

void polymost_fillpolygon (int npoints)
{
	PTHead *pth;
	float alphac=0.0;
	int i, j, k;
	unsigned short ptflags = 0;
	struct polymostdrawpolycall draw;

	globalx1 = mulscale16(globalx1,xyaspect);
	globaly2 = mulscale16(globaly2,xyaspect);
	gux = ((double)asm1)*(1.0/4294967296.0);
	gvx = ((double)asm2)*(1.0/4294967296.0);
	guy = ((double)globalx1)*(1.0/4294967296.0);
	gvy = ((double)globaly2)*(-1.0/4294967296.0);
	guo = (((double)xdim)*gux + ((double)ydim)*guy)*-.5 + ((double)globalposx)*(1.0/4294967296.0);
	gvo = (((double)xdim)*gvx + ((double)ydim)*gvy)*-.5 - ((double)globalposy)*(1.0/4294967296.0);

		//Convert int to float (in-place)
	for(i=npoints-1;i>=0;i--)
	{
		((float *)rx1)[i] = ((float)rx1[i])/4096.0;
		((float *)ry1)[i] = ((float)ry1[i])/4096.0;
	}

	if ((unsigned int)globalpicnum >= MAXTILES) globalpicnum = 0;
	if (!palookup[globalpal]) globalpal = 0;

	if (usehightile) ptflags |= PTH_HIGHTILE;

	draw.texture0 = 0;
	pth = PT_GetHead(globalpicnum, globalpal, ptflags, 0);
	if (pth && pth->pic[PTHPIC_BASE]) {
		draw.texture0 = pth->pic[ PTHPIC_BASE ]->glpic;
	}
	draw.texture1 = nulltexture;
	draw.alphacut = 0.f;
	draw.fogdensity = 0.f;

	draw.colour.r = draw.colour.g = draw.colour.b =
		((float)(numpalookups-min(max(globalshade,0),numpalookups)))/((float)numpalookups);
	switch ((globalorientation>>7)&3) {
		case 0:
		case 1: draw.colour.a = 1.0; glfunc.glDisable(GL_BLEND); break;
		case 2: draw.colour.a = 0.66; glfunc.glEnable(GL_BLEND); break;
		case 3: draw.colour.a = 0.33; glfunc.glEnable(GL_BLEND); break;
	}
	if (pth && (pth->flags & PTH_HIGHTILE) && (globalpal != pth->repldef->palnum)) {
		// apply tinting for replaced textures
		draw.colour.r *= (float)hictinting[globalpal].r / 255.0;
		draw.colour.g *= (float)hictinting[globalpal].g / 255.0;
		draw.colour.b *= (float)hictinting[globalpal].b / 255.0;
	}

	draw.modelview = &gidentitymat[0][0];
	draw.projection = &gorthoprojmat[0][0];

	draw.indexbuffer = 0;
	draw.elementbuffer = 0;
	tessectrap((float *)rx1,(float *)ry1,xb1,npoints,&draw);
}

int polymost_drawtilescreen (int tilex, int tiley, int wallnum, int dimen)
{
	float xdime, ydime, xdimepad, ydimepad, scx, scy;
	int i;
	PTHead *pth;
	palette_t bgcolour;
	struct polymostdrawauxcall draw;
	struct polymostvboitem vboitem[4];

	if ((rendmode != 3) || (qsetmode != 200)) return(-1);

	xdime = (float)tilesizx[wallnum];
	ydime = (float)tilesizy[wallnum];

	if ((xdime <= dimen) && (ydime <= dimen)) {
		scx = xdime;
		scy = ydime;
	} else {
		scx = (float)dimen;
		scy = (float)dimen;
		if (xdime < ydime) {
			scx *= xdime/ydime;
		} else {
			scy *= ydime/xdime;
		}
	}

	pth = PT_GetHead(wallnum, 0, (usehightile ? PTH_HIGHTILE : 0) | PTH_CLAMPED, 0);

	if (pth) {
		xdimepad = (float)pth->pic[PTHPIC_BASE]->tsizx / (float)pth->pic[PTHPIC_BASE]->sizx;
		ydimepad = (float)pth->pic[PTHPIC_BASE]->tsizy / (float)pth->pic[PTHPIC_BASE]->sizy;
	} else {
		xdimepad = 1.0;
		ydimepad = 1.0;
	}

	bgcolour = curpalette[255];
	if (!gammabrightness) {
		bgcolour.r = britable[curbrightness][bgcolour.r];
		bgcolour.g = britable[curbrightness][bgcolour.g];
		bgcolour.b = britable[curbrightness][bgcolour.b];
	}

	draw.mode = 1;	// Tile.

	draw.texture0 = nulltexture;
	if (pth) {
		if (pth->pic[PTHPIC_BASE]) {
			draw.texture0 = pth->pic[PTHPIC_BASE]->glpic;
		}
	}

	draw.bgcolour.r = bgcolour.r / 255.f;
	draw.bgcolour.g = bgcolour.g / 255.f;
	draw.bgcolour.b = bgcolour.b / 255.f;
	draw.bgcolour.a = 1.f;

	vboitem[0].v.x = (GLfloat)tilex;
	vboitem[0].v.y = (GLfloat)tiley;
	vboitem[0].v.z = 0.f;
	vboitem[0].t.s = 0.f;
	vboitem[0].t.t = 0.f;

	vboitem[1].v.x = (GLfloat)tilex+scx;
	vboitem[1].v.y = (GLfloat)tiley;
	vboitem[1].v.z = 0.f;
	vboitem[1].t.s = xdimepad;
	vboitem[1].t.t = 0.f;

	vboitem[2].v.x = (GLfloat)tilex+scx;
	vboitem[2].v.y = (GLfloat)tiley+scy;
	vboitem[2].v.z = 0.f;
	vboitem[2].t.s = xdimepad;
	vboitem[2].t.t = ydimepad;

	vboitem[3].v.x = (GLfloat)tilex;
	vboitem[3].v.y = (GLfloat)tiley+scy;
	vboitem[3].v.z = 0.f;
	vboitem[3].t.s = 0.f;
	vboitem[3].t.t = ydimepad;

	draw.indexcount = 4;
	draw.indexes = NULL;
	draw.elementcount = 4;
	draw.elementvbo = vboitem;

	polymost_drawaux_glcall(GL_TRIANGLE_FAN, &draw);

	return(0);
}

int polymost_printext256(int xpos, int ypos, short col, short backcol, const  char *name, char fontsize)
{
	GLfloat tx, ty, txc, tyc, tyoff, cx, cy;
	int c, indexcnt, vbocnt;
	palette_t colour;
	struct polymostdrawauxcall draw;
	struct polymostvboitem vboitem[80*4];
	GLushort vboindexes[80*6];

	if ((rendmode != 3) || (qsetmode != 200)) return(-1);

	polymost_preparetext();
	setpolymost2dview();	// disables blending, texturing, and depth testing
	glfunc.glDepthMask(GL_FALSE);	// disable writing to the z-buffer
	glfunc.glEnable(GL_BLEND);

	draw.mode = 0;	// Text.

	draw.texture0 = texttexture;

	colour = curpalette[col];
	if (!gammabrightness) {
		colour.r = britable[curbrightness][ colour.r ];
		colour.g = britable[curbrightness][ colour.g ];
		colour.b = britable[curbrightness][ colour.b ];
	}
	draw.colour.r = colour.r / 255.f;
	draw.colour.g = colour.g / 255.f;
	draw.colour.b = colour.b / 255.f;
	draw.colour.a = 1.f;

	colour = curpalette[min(0, backcol)];
	if (!gammabrightness) {
		colour.r = britable[curbrightness][ colour.r ];
		colour.g = britable[curbrightness][ colour.g ];
		colour.b = britable[curbrightness][ colour.b ];
	}
	draw.bgcolour.r = colour.r / 255.f;
	draw.bgcolour.g = colour.g / 255.f;
	draw.bgcolour.b = colour.b / 255.f;
	if (backcol >= 0) {
		draw.bgcolour.a = 1.f;
	} else {
		draw.bgcolour.a = 0.f;
	}

	if (fontsize) {
		tyoff = 8.f;
		cx = 4.f;
		cy = 6.f;
	} else {
		tyoff = 0.f;
		cx = 8.f;
		cy = 8.f;
	}
	txc = cx/256.f;
	tyc = cy/128.f;

	draw.indexes = vboindexes;
	draw.elementvbo = vboitem;

	c = 0;
	indexcnt = vbocnt = 0;
	while (name[c]) {
		for (; name[c] && indexcnt < 80*6; c++) {
			tx = (GLfloat)(name[c]%32)/32.0;
			ty = ((GLfloat)(name[c]/32) + tyoff)/16.0;

			vboindexes[indexcnt + 0] = vbocnt+0;
			vboindexes[indexcnt + 1] = vbocnt+1;
			vboindexes[indexcnt + 2] = vbocnt+2;
			vboindexes[indexcnt + 3] = vbocnt+0;
			vboindexes[indexcnt + 4] = vbocnt+2;
			vboindexes[indexcnt + 5] = vbocnt+3;

			vboitem[vbocnt + 0].v.x = (GLfloat)xpos;
			vboitem[vbocnt + 0].v.y = (GLfloat)ypos;
			vboitem[vbocnt + 0].v.z = 0.f;
			vboitem[vbocnt + 0].t.s = tx;
			vboitem[vbocnt + 0].t.t = ty;

			vboitem[vbocnt + 1].v.x = (GLfloat)xpos+cx;
			vboitem[vbocnt + 1].v.y = (GLfloat)ypos;
			vboitem[vbocnt + 1].v.z = 0.f;
			vboitem[vbocnt + 1].t.s = tx+txc;
			vboitem[vbocnt + 1].t.t = ty;

			vboitem[vbocnt + 2].v.x = (GLfloat)xpos+cx;
			vboitem[vbocnt + 2].v.y = (GLfloat)ypos+cy;
			vboitem[vbocnt + 2].v.z = 0.f;
			vboitem[vbocnt + 2].t.s = tx+txc;
			vboitem[vbocnt + 2].t.t = ty+tyc;

			vboitem[vbocnt + 3].v.x = (GLfloat)xpos;
			vboitem[vbocnt + 3].v.y = (GLfloat)ypos+cy;
			vboitem[vbocnt + 3].v.z = 0.f;
			vboitem[vbocnt + 3].t.s = tx;
			vboitem[vbocnt + 3].t.t = ty+tyc;

			indexcnt += 6;
			vbocnt += 4;
			xpos += (8>>fontsize);
		}

		draw.indexcount = indexcnt;
		draw.elementcount = vbocnt;

		polymost_drawaux_glcall(GL_TRIANGLES, &draw);

		indexcnt = vbocnt = 0;
	}

	glfunc.glDepthMask(GL_TRUE);	// re-enable writing to the z-buffer

	return 0;
}

int polymost_drawline256(int x1, int y1, int x2, int y2, unsigned char col)
{
	palette_t colour;
	struct polymostdrawauxcall draw;
	struct polymostvboitem vboitem[2];

	if ((rendmode != 3) || (qsetmode != 200)) return(-1);

	polymost_preparetext();
	setpolymost2dview();	// disables blending, texturing, and depth testing
	glfunc.glDepthMask(GL_FALSE);	// disable writing to the z-buffer
	glfunc.glEnable(GL_BLEND);

	draw.mode = 2;	// Solid colour.

	colour = curpalette[col];
	if (!gammabrightness) {
		colour.r = britable[curbrightness][ colour.r ];
		colour.g = britable[curbrightness][ colour.g ];
		colour.b = britable[curbrightness][ colour.b ];
	}
	draw.colour.r = colour.r / 255.f;
	draw.colour.g = colour.g / 255.f;
	draw.colour.b = colour.b / 255.f;
	draw.colour.a = 1.f;

	vboitem[0].v.x = (GLfloat)(x1+2048)/4096.f;
	vboitem[0].v.y = (GLfloat)(y1+2048)/4096.f;
	vboitem[0].v.z = 0.f;

	vboitem[1].v.x = (GLfloat)(x2+2048)/4096.f;
	vboitem[1].v.y = (GLfloat)(y2+2048)/4096.f;
	vboitem[1].v.z = 0.f;

	draw.indexcount = 2;
	draw.indexes = NULL;
	draw.elementcount = 2;
	draw.elementvbo = vboitem;

	polymost_drawaux_glcall(GL_LINES, &draw);

	glfunc.glDepthMask(GL_TRUE);	// re-enable writing to the z-buffer

	return 0;
}

int polymost_plotpixel(int x, int y, unsigned char col)
{
	palette_t colour;
	struct polymostdrawauxcall draw;
	struct polymostvboitem vboitem[1];

	if ((rendmode != 3) || (qsetmode != 200)) return(-1);

	setpolymost2dview();	// disables blending, texturing, and depth testing
	glfunc.glDepthMask(GL_FALSE);	// disable writing to the z-buffer
	glfunc.glEnable(GL_BLEND);

	draw.mode = 2;	// Solid colour.

	colour = curpalette[col];
	if (!gammabrightness) {
		colour.r = britable[curbrightness][ colour.r ];
		colour.g = britable[curbrightness][ colour.g ];
		colour.b = britable[curbrightness][ colour.b ];
	}
	draw.colour.r = colour.r / 255.f;
	draw.colour.g = colour.g / 255.f;
	draw.colour.b = colour.b / 255.f;
	draw.colour.a = 1.f;

	vboitem[0].v.x = (GLfloat)x;
	vboitem[0].v.y = (GLfloat)y;
	vboitem[0].v.z = 0.f;

	draw.indexcount = 1;
	draw.indexes = NULL;
	draw.elementcount = 1;
	draw.elementvbo = vboitem;

	polymost_drawaux_glcall(GL_POINTS, &draw);

	glfunc.glDepthMask(GL_TRUE);	// re-enable writing to the z-buffer

	return 0;
}

static int polymost_preparetext(void)
{
	unsigned char *cptr;
	unsigned int *tbuf, *tptr;
	int h,i,j,l;

	if (texttexture) {
		return 0;
	}

	// construct a 256x128 rgba texture for the font glyph matrix
	glfunc.glGenTextures(1,&texttexture);
	if (!texttexture) return -1;

	tbuf = (unsigned int *)Bcalloc(256*128, sizeof(unsigned int));
	if (!tbuf) {
		glfunc.glDeleteTextures(1,&texttexture);
		texttexture = 0;
		return -1;
	}

	cptr = (unsigned char*)textfont;
	for (h=0;h<256;h++) {
		tptr = tbuf + (h%32)*8 + (h/32)*256*8;
		for (i=0;i<8;i++) {
			for (j=0;j<8;j++) {
				if (cptr[h*8+i] & pow2char[7-j]) tptr[j] = 0xffffffff;
			}
			tptr += 256;
		}
	}

	cptr = (unsigned char*)smalltextfont;
	for (h=0;h<256;h++) {
		tptr = tbuf + 256*64 + (h%32)*8 + (h/32)*256*8;
		for (i=1;i<7;i++) {
			for (j=2;j<6;j++) {
				if (cptr[h*8+i] & pow2char[7-j]) tptr[j-2] = 0xffffffff;
			}
			tptr += 256;
		}
	}

	glfunc.glActiveTexture(GL_TEXTURE0);
	glfunc.glBindTexture(GL_TEXTURE_2D, texttexture);
	glfunc.glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,256,128,0,GL_RGBA,GL_UNSIGNED_BYTE,(GLvoid*)tbuf);
	glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
	glfunc.glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
	free(tbuf);

	return 0;
}

void polymost_precache_begin()
{
	PTBeginPriming();
}

void polymost_precache(int dapicnum, int dapalnum, int datype)
{
	// dapicnum and dapalnum are like you'd expect
	// datype is 0 for a wall/floor/ceiling and 1 for a sprite
	//    basically this just means walls are repeating
	//    while sprites are clamped
	int mid;
	unsigned short flags;

	if (rendmode < 3) return;

	if (!palookup[dapalnum]) return;//dapalnum = 0;

		//FIXME
	//buildprintf("precached %d %d type %d\n", dapicnum, dapalnum, datype);
	flags = (datype & 1) ? PTH_CLAMPED :0;
	if (usehightile) flags |= PTH_HIGHTILE;
	PTMarkPrime(dapicnum, dapalnum, flags);

	if (datype == 0) return;

	mid = md_tilehasmodel(dapicnum);
	if (mid < 0 || models[mid]->mdnum < 2) return;

	{
		int i,j=0;

		if (models[mid]->mdnum == 3)
			j = ((md3model *)models[mid])->head.numsurfs;

		for (i=0;i<=j;i++)
			mdloadskin((md2model*)models[mid], 0, dapalnum, i);
	}
}

int polymost_precache_run(int* done, int* total)
{
	return PTDoPrime(done, total);
}

#ifdef DEBUGGINGAIDS
// because I'm lazy
static int osdcmd_debugdumptexturedefs(const osdfuncparm_t * UNUSED(parm))
{
	hicreplctyp *hr;
	int i;

	if (!hicfirstinit) return OSDCMD_OK;

	buildprintf("// Begin Texture Dump\n");
	for (i=0;i<MAXTILES;i++) {
		hr = hicreplc[i];
		if (!hr) continue;
		buildprintf("texture %d {\n", i);
		for (; hr; hr = hr->next) {
			if (!hr->filename) continue;
			buildprintf("    pal %d { name \"%s\" ", hr->palnum, hr->filename);
			if (hr->alphacut >= 0.0) buildprintf("alphacut %g ", hr->alphacut);
			buildprintf("}\n");
		}
		buildprintf("}\n");
	}
	buildprintf("// End Texture Dump\n");

	return OSDCMD_OK;	// no replacement found
}

static int osdcmd_debugtexturehash(const osdfuncparm_t * UNUSED(parm))
{
	PTIter iter;
	PTHead * pth;
	int i;

	if (!hicfirstinit) {
		return OSDCMD_OK;
	}

	buildprintf("// Begin texture hash dump\n");
	iter = PTIterNew();
	while ((pth = PTIterNext(iter)) != 0) {
		buildprintf(" picnum:%d palnum:%d flags:%04X repldef:%p\n",
			   pth->picnum, pth->palnum, pth->flags,
			   pth->repldef);
		for (i=0; i<6; i++) {
			if (pth->pic[i]) {
				buildprintf("   pic[%d]: %p => glpic:%d flags:%x sizx/y:%d/%d tsizx/y:%d/%d\n",
					   i, pth->pic[i], pth->pic[i]->glpic, pth->pic[i]->flags,
					   pth->pic[i]->sizx, pth->pic[i]->sizy,
					   pth->pic[i]->tsizx, pth->pic[i]->tsizy);
			}
		}
	}
	PTIterFree(iter);
	buildprintf("// End texture hash dump\n");

	return OSDCMD_OK;	// no replacement found
}
#endif

#ifdef SHADERDEV
static int osdcmd_debugreloadshaders(const osdfuncparm_t *UNUSED(parm))
{
	polymost_loadshaders();
	return OSDCMD_OK;
}
#endif

static int osdcmd_gltexturemode(const osdfuncparm_t *parm)
{
	int m;
	const char *p;

	if (parm->numparms != 1) {
		buildprintf("Current texturing mode is %s\n", glfiltermodes[gltexfiltermode].name);
		buildprintf("  Vaild modes are:\n");
		for (m = 0; m < (int)numglfiltermodes; m++)
			buildprintf("     %d - %s\n",m,glfiltermodes[m].name);

		return OSDCMD_OK;
	}

	m = Bstrtoul(parm->parms[0], (char **)&p, 10);
	if (p == parm->parms[0]) {
		// string
		for (m = 0; m < (int)numglfiltermodes; m++) {
			if (!Bstrcasecmp(parm->parms[0], glfiltermodes[m].name)) break;
		}
		if (m == numglfiltermodes) m = gltexfiltermode;   // no change
	} else {
		if (m < 0) m = 0;
		else if (m >= (int)numglfiltermodes) m = numglfiltermodes - 1;
	}

	if (m != gltexfiltermode) {
		gltexfiltermode = m;
		gltexapplyprops();
	}

	buildprintf("Texture filtering mode changed to %s\n", glfiltermodes[gltexfiltermode].name );

	return OSDCMD_OK;
}

static int osdcmd_gltextureanisotropy(const osdfuncparm_t *parm)
{
	int l;
	const char *p;

	if (parm->numparms != 1) {
		buildprintf("Current texture anisotropy is %d\n", glanisotropy);
		buildprintf("  Maximum is %f\n", glinfo.maxanisotropy);

		return OSDCMD_OK;
	}

	l = Bstrtoul(parm->parms[0], (char **)&p, 10);
	if (l < 0 || l > glinfo.maxanisotropy) l = 0;

	if (l != gltexfiltermode) {
		glanisotropy = l;
		gltexapplyprops();
	}

	buildprintf("Texture anisotropy changed to %d\n", glanisotropy );

	return OSDCMD_OK;
}

static int osdcmd_forcetexcacherebuild(const osdfuncparm_t *UNUSED(parm))
{
	PTCacheForceRebuild();
	buildprintf("Compressed texture cache invalidated. Use 'restartvid' to reinitialise it.\n");
	return OSDCMD_OK;
}

#endif //USE_OPENGL

static int osdcmd_polymostvars(const osdfuncparm_t *parm)
{
	int showval = (parm->numparms < 1), val = 0;

	if (!showval) val = atoi(parm->parms[0]);
#if USE_OPENGL
	if (!Bstrcasecmp(parm->name, "usemodels")) {
		if (showval) { buildprintf("usemodels is %d\n", usemodels); }
		else usemodels = (val != 0);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "usehightile")) {
		if (showval) { buildprintf("usehightile is %d\n", usehightile); }
		else usehightile = (val != 0);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "glusetexcompr")) {
		if (showval) { buildprintf("glusetexcompr is %d\n", glusetexcompr); }
		else glusetexcompr = (val != 0);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "gltexcomprquality")) {
		if (showval) { buildprintf("gltexcomprquality is %d\n", gltexcomprquality); }
		else {
			if (val < 0 || val > 2) val = 0;
			gltexcomprquality = val;
		}
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "glredbluemode")) {
		if (showval) { buildprintf("glredbluemode is %d\n", glredbluemode); }
		else glredbluemode = (val != 0);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "gltexturemaxsize")) {
		if (showval) { buildprintf("gltexturemaxsize is %d\n", gltexmaxsize); }
		else gltexmaxsize = val;
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "gltexturemiplevel")) {
		if (showval) { buildprintf("gltexturemiplevel is %d\n", gltexmiplevel); }
		else gltexmiplevel = val;
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "usegoodalpha")) {
		if (showval) { buildprintf("usegoodalpha is %d\n", usegoodalpha); }
		else usegoodalpha = (val != 0);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "glpolygonmode")) {
		if (showval) { buildprintf("glpolygonmode is %d\n", glpolygonmode); }
		else glpolygonmode = val;
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "glusetexcache")) {
		if (showval) { buildprintf("glusetexcache is %d\n", glusetexcache); }
		else glusetexcache = (val != 0);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "glmultisample")) {
		if (showval) { buildprintf("glmultisample is %d\n", glmultisample); }
		else glmultisample = max(0,val);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "glnvmultisamplehint")) {
		if (showval) { buildprintf("glnvmultisamplehint is %d\n", glnvmultisamplehint); }
		else glnvmultisamplehint = (val != 0);
		return OSDCMD_OK;
	}
	else if (!Bstrcasecmp(parm->name, "polymosttexverbosity")) {
		if (showval) { buildprintf("polymosttexverbosity is %d\n", polymosttexverbosity); }
		else {
			if (val < 0 || val > 2) val = 1;
			polymosttexverbosity = val;
		}
		return OSDCMD_OK;
	}
#endif //USE_OPENGL
#ifdef DEBUGGINGAIDS
	if (!Bstrcasecmp(parm->name, "debugshowcallcounts")) {
		if (showval) { buildprintf("debugshowcallcounts is %d\n", polymostshowcallcounts); }
		else polymostshowcallcounts = (val != 0);
		return OSDCMD_OK;
	}
#endif
	return OSDCMD_SHOWHELP;
}

void polymost_initosdfuncs(void)
{
#if USE_OPENGL
	OSD_RegisterFunction("usemodels","usemodels: enable/disable model rendering in >8-bit mode",osdcmd_polymostvars);
	OSD_RegisterFunction("usehightile","usehightile: enable/disable hightile texture rendering in >8-bit mode",osdcmd_polymostvars);
	OSD_RegisterFunction("glusetexcompr","glusetexcompr: enable/disable OpenGL texture compression",osdcmd_polymostvars);
	OSD_RegisterFunction("gltexcomprquality","gltexcomprquality: sets texture compression quality. 0 = fast (default), 1 = slow, 2 = very slow",osdcmd_polymostvars);
	OSD_RegisterFunction("glredbluemode","glredbluemode: enable/disable experimental OpenGL red-blue glasses mode",osdcmd_polymostvars);
	OSD_RegisterFunction("gltexturemode", "gltexturemode: changes the texture filtering settings", osdcmd_gltexturemode);
	OSD_RegisterFunction("gltextureanisotropy", "gltextureanisotropy: changes the OpenGL texture anisotropy setting", osdcmd_gltextureanisotropy);
	OSD_RegisterFunction("gltexturemaxsize","gltexturemaxsize: changes the maximum OpenGL texture size limit",osdcmd_polymostvars);
	OSD_RegisterFunction("gltexturemiplevel","gltexturemiplevel: changes the highest OpenGL mipmap level used",osdcmd_polymostvars);
	OSD_RegisterFunction("usegoodalpha","usegoodalpha: enable/disable better looking OpenGL alpha hack",osdcmd_polymostvars);
	OSD_RegisterFunction("glpolygonmode","glpolygonmode: debugging feature. 0 = normal, 1 = edges, 2 = points, 3 = clear each frame",osdcmd_polymostvars);
	OSD_RegisterFunction("glusetexcache","glusetexcache: enable/disable OpenGL compressed texture cache",osdcmd_polymostvars);
	OSD_RegisterFunction("glmultisample","glmultisample: sets the number of samples used for antialiasing (0 = off)",osdcmd_polymostvars);
	OSD_RegisterFunction("glnvmultisamplehint","glnvmultisamplehint: enable/disable Nvidia multisampling hinting",osdcmd_polymostvars);
	OSD_RegisterFunction("polymosttexverbosity","polymosttexverbosity: sets the level of chatter during texture loading. 0 = none, 1 = errors (default), 2 = all",osdcmd_polymostvars);
	OSD_RegisterFunction("forcetexcacherebuild","forcetexcacherebuild: invalidates the compressed texture cache", osdcmd_forcetexcacherebuild);
#ifdef SHADERDEV
	OSD_RegisterFunction("debugreloadshaders","debugreloadshaders: reloads the OpenGL shaders",osdcmd_debugreloadshaders);
#endif
#ifdef DEBUGGINGAIDS
	OSD_RegisterFunction("debugdumptexturedefs","dumptexturedefs: dumps all texture definitions in the new style",osdcmd_debugdumptexturedefs);
	OSD_RegisterFunction("debugtexturehash","debugtexturehash: dumps all the entries in the texture hash",osdcmd_debugtexturehash);
	OSD_RegisterFunction("debugshowcallcounts","debugshowcallcounts: display rendering call counts",osdcmd_polymostvars);
#endif
#endif	//USE_OPENGL
}

#endif	//USE_POLYMOST

// vim:ts=4:sw=4: