1 
2 //**************************************************************************
3 //**
4 //** r_plane.c : Heretic 2 : Raven Software, Corp.
5 //**
6 //** $RCSfile: r_plane.c,v $
7 //** $Revision: 1.5 $
8 //** $Date: 95/07/13 15:17:12 $
9 //** $Author: cjr $
10 //**
11 //**************************************************************************
12 
13 // HEADER FILES ------------------------------------------------------------
14 
15 #include "h2def.h"
16 #include "r_local.h"
17 
18 // MACROS ------------------------------------------------------------------
19 
20 // TYPES -------------------------------------------------------------------
21 
22 // EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
23 
24 // PUBLIC FUNCTION PROTOTYPES ----------------------------------------------
25 
26 // PRIVATE FUNCTION PROTOTYPES ---------------------------------------------
27 
28 // EXTERNAL DATA DECLARATIONS ----------------------------------------------
29 
30 extern fixed_t Sky1ScrollDelta;
31 extern fixed_t Sky2ScrollDelta;
32 
33 // PUBLIC DATA DEFINITIONS -------------------------------------------------
34 
35 int Sky1Texture;
36 int Sky2Texture;
37 fixed_t Sky1ColumnOffset;
38 fixed_t Sky2ColumnOffset;
39 int skyflatnum;
40 int skytexturemid;
41 fixed_t skyiscale;
42 boolean DoubleSky;
43 planefunction_t floorfunc, ceilingfunc;
44 
45 // Opening
46 visplane_t visplanes[MAXVISPLANES], *lastvisplane;
47 visplane_t *floorplane, *ceilingplane;
48 short openings[MAXOPENINGS], *lastopening;
49 
50 // Clip values are the solid pixel bounding the range.
51 // floorclip start out SCREENHEIGHT
52 // ceilingclip starts out -1
53 short floorclip[SCREENWIDTH];
54 short ceilingclip[SCREENWIDTH];
55 
56 // spanstart holds the start of a plane span, initialized to 0
57 int spanstart[SCREENHEIGHT];
58 int spanstop[SCREENHEIGHT];
59 
60 // Texture mapping
61 lighttable_t **planezlight;
62 fixed_t planeheight;
63 fixed_t yslope[SCREENHEIGHT];
64 fixed_t distscale[SCREENWIDTH];
65 fixed_t basexscale, baseyscale;
66 fixed_t cachedheight[SCREENHEIGHT];
67 fixed_t cacheddistance[SCREENHEIGHT];
68 fixed_t cachedxstep[SCREENHEIGHT];
69 fixed_t cachedystep[SCREENHEIGHT];
70 
71 // PRIVATE DATA DEFINITIONS ------------------------------------------------
72 
73 // CODE --------------------------------------------------------------------
74 
75 //==========================================================================
76 //
77 // R_InitSky
78 //
79 // Called at level load.
80 //
81 //==========================================================================
82 
R_InitSky(int map)83 void R_InitSky(int map)
84 {
85 	Sky1Texture = P_GetMapSky1Texture(map);
86 	Sky2Texture = P_GetMapSky2Texture(map);
87 	Sky1ScrollDelta = P_GetMapSky1ScrollDelta(map);
88 	Sky2ScrollDelta = P_GetMapSky2ScrollDelta(map);
89 	Sky1ColumnOffset = 0;
90 	Sky2ColumnOffset = 0;
91 	DoubleSky = P_GetMapDoubleSky(map);
92 }
93 
94 //==========================================================================
95 //
96 // R_InitSkyMap
97 //
98 // Called whenever the view size changes.
99 //
100 //==========================================================================
101 
R_InitSkyMap(void)102 void R_InitSkyMap(void)
103 {
104 	skyflatnum = R_FlatNumForName("F_SKY");
105 	skytexturemid = 200*FRACUNIT;
106 	skyiscale = FRACUNIT;
107 }
108 
109 //==========================================================================
110 //
111 // R_InitPlanes
112 //
113 // Called at game startup.
114 //
115 //==========================================================================
116 
R_InitPlanes(void)117 void R_InitPlanes(void)
118 {
119 }
120 
121 //==========================================================================
122 //
123 // R_MapPlane
124 //
125 // Globals used: planeheight, ds_source, basexscale, baseyscale,
126 // viewx, viewy.
127 //
128 //==========================================================================
129 
R_MapPlane(int y,int x1,int x2)130 void R_MapPlane(int y, int x1, int x2)
131 {
132 	angle_t angle;
133 	fixed_t distance, length;
134 	unsigned index;
135 
136 #ifdef RANGECHECK
137 	if(x2 < x1 || x1 < 0 || x2 >= viewwidth || (unsigned)y > viewheight)
138 	{
139 		I_Error("R_MapPlane: %i, %i at %i", x1, x2, y);
140 	}
141 #endif
142 
143 	if(planeheight != cachedheight[y])
144 	{
145 		cachedheight[y] = planeheight;
146 		distance = cacheddistance[y] = FixedMul(planeheight, yslope[y]);
147 		ds_xstep = cachedxstep[y] = FixedMul(distance, basexscale);
148 		ds_ystep = cachedystep[y] = FixedMul(distance, baseyscale);
149 	}
150 	else
151 	{
152 		distance = cacheddistance[y];
153 		ds_xstep = cachedxstep[y];
154 		ds_ystep = cachedystep[y];
155 	}
156 
157 	length = FixedMul(distance, distscale[x1]);
158 	angle = (viewangle+xtoviewangle[x1])>>ANGLETOFINESHIFT;
159 	ds_xfrac = viewx+FixedMul(finecosine[angle], length);
160 	ds_yfrac = -viewy-FixedMul(finesine[angle], length);
161 
162 	if(fixedcolormap)
163 	{
164 		ds_colormap = fixedcolormap;
165 	}
166 	else
167 	{
168 		index = distance >> LIGHTZSHIFT;
169 		if(index >= MAXLIGHTZ )
170 		{
171 			index = MAXLIGHTZ-1;
172 		}
173 		ds_colormap = planezlight[index];
174 	}
175 
176 	ds_y = y;
177 	ds_x1 = x1;
178 	ds_x2 = x2;
179 
180 	spanfunc(); // High or low detail
181 }
182 
183 //==========================================================================
184 //
185 // R_ClearPlanes
186 //
187 // Called at the beginning of each frame.
188 //
189 //==========================================================================
190 
R_ClearPlanes(void)191 void R_ClearPlanes(void)
192 {
193 	int i;
194 	angle_t angle;
195 
196 	// Opening / clipping determination
197 	for(i = 0; i < viewwidth; i++)
198 	{
199 		floorclip[i] = viewheight;
200 		ceilingclip[i] = -1;
201 	}
202 
203 	lastvisplane = visplanes;
204 	lastopening = openings;
205 
206 	// Texture calculation
207 	memset(cachedheight, 0, sizeof(cachedheight));
208 	angle = (viewangle-ANG90)>>ANGLETOFINESHIFT; // left to right mapping
209 	// Scale will be unit scale at SCREENWIDTH/2 distance
210 	basexscale = FixedDiv(finecosine[angle], centerxfrac);
211 	baseyscale = -FixedDiv(finesine[angle], centerxfrac);
212 }
213 
214 //==========================================================================
215 //
216 // R_FindPlane
217 //
218 //==========================================================================
219 
R_FindPlane(fixed_t height,int picnum,int lightlevel,int special)220 visplane_t *R_FindPlane(fixed_t height, int picnum,
221 	int lightlevel, int special)
222 {
223 	visplane_t *check;
224 
225 	if(special < 150)
226 	{ // Don't let low specials affect search
227 		special = 0;
228 	}
229 
230 	if(picnum == skyflatnum)
231 	{ // All skies map together
232 		height = 0;
233 		lightlevel = 0;
234 	}
235 
236 	for(check = visplanes; check < lastvisplane; check++)
237 	{
238 		if(height == check->height
239 		&& picnum == check->picnum
240 		&& lightlevel == check->lightlevel
241 		&& special == check->special)
242 			break;
243 	}
244 
245 	if(check < lastvisplane)
246 	{
247 		return(check);
248 	}
249 
250 	if(lastvisplane-visplanes == MAXVISPLANES)
251 	{
252 		I_Error("R_FindPlane: no more visplanes");
253 	}
254 
255 	lastvisplane++;
256 	check->height = height;
257 	check->picnum = picnum;
258 	check->lightlevel = lightlevel;
259 	check->special = special;
260 	check->minx = SCREENWIDTH;
261 	check->maxx = -1;
262 	memset(check->top, 0xff, sizeof(check->top));
263 	return(check);
264 }
265 
266 //==========================================================================
267 //
268 // R_CheckPlane
269 //
270 //==========================================================================
271 
R_CheckPlane(visplane_t * pl,int start,int stop)272 visplane_t *R_CheckPlane(visplane_t *pl, int start, int stop)
273 {
274 	int intrl, intrh;
275 	int unionl, unionh;
276 	int x;
277 
278 	if(start < pl->minx)
279 	{
280 		intrl = pl->minx;
281 		unionl = start;
282 	}
283 	else
284 	{
285 		unionl = pl->minx;
286 		intrl = start;
287 	}
288 	if(stop > pl->maxx)
289 	{
290 		intrh = pl->maxx;
291 		unionh = stop;
292 	}
293 	else
294 	{
295 		unionh = pl->maxx;
296 		intrh = stop;
297 	}
298 
299 	for(x = intrl; x <= intrh; x++)
300 	{
301 		if(pl->top[x] != 0xff)
302 		{
303 			break;
304 		}
305 	}
306 
307 	if(x > intrh)
308 	{
309 		pl->minx = unionl;
310 		pl->maxx = unionh;
311 		return pl; // use the same visplane
312 	}
313 
314 	// Make a new visplane
315 	lastvisplane->height = pl->height;
316 	lastvisplane->picnum = pl->picnum;
317 	lastvisplane->lightlevel = pl->lightlevel;
318 	lastvisplane->special = pl->special;
319 	pl = lastvisplane++;
320 	pl->minx = start;
321 	pl->maxx = stop;
322 	memset(pl->top, 0xff, sizeof(pl->top));
323 
324 	return pl;
325 }
326 
327 //==========================================================================
328 //
329 // R_MakeSpans
330 //
331 //==========================================================================
332 
R_MakeSpans(int x,int t1,int b1,int t2,int b2)333 void R_MakeSpans(int x, int t1, int b1, int t2, int b2)
334 {
335 	while(t1 < t2 && t1 <= b1)
336 	{
337 		R_MapPlane(t1, spanstart[t1], x-1);
338 		t1++;
339 	}
340 	while(b1 > b2 && b1 >= t1)
341 	{
342 		R_MapPlane(b1, spanstart[b1], x-1);
343 		b1--;
344 	}
345 	while(t2 < t1 && t2 <= b2)
346 	{
347 		spanstart[t2] = x;
348 		t2++;
349 	}
350 	while(b2 > b1 && b2 >= t2)
351 	{
352 		spanstart[b2] = x;
353 		b2--;
354 	}
355 }
356 
357 //==========================================================================
358 //
359 // R_DrawPlanes
360 //
361 //==========================================================================
362 
363 #define SKYTEXTUREMIDSHIFTED 200
364 
R_DrawPlanes(void)365 void R_DrawPlanes(void)
366 {
367 	visplane_t *pl;
368 	int light;
369 	int x, stop;
370 	int angle;
371 	byte *tempSource;
372 	byte *source;
373 	byte *source2;
374 	byte *dest;
375 	int count;
376 	int offset;
377 	int skyTexture;
378 	int offset2;
379 	int skyTexture2;
380 	int scrollOffset;
381 
382 	extern byte *ylookup[MAXHEIGHT];
383 	extern int columnofs[MAXWIDTH];
384 
385 #ifdef RANGECHECK
386 	if(ds_p-drawsegs > MAXDRAWSEGS)
387 	{
388 		I_Error("R_DrawPlanes: drawsegs overflow (%i)", ds_p-drawsegs);
389 	}
390 	if(lastvisplane-visplanes > MAXVISPLANES)
391 	{
392 		I_Error("R_DrawPlanes: visplane overflow (%i)",
393 			lastvisplane-visplanes);
394 	}
395 	if(lastopening-openings > MAXOPENINGS)
396 	{
397 		I_Error("R_DrawPlanes: opening overflow (%i)",
398 			lastopening-openings);
399 	}
400 #endif
401 
402 	for(pl = visplanes; pl < lastvisplane; pl++)
403 	{
404 		if(pl->minx > pl->maxx)
405 		{
406 			continue;
407 		}
408 		if(pl->picnum == skyflatnum)
409 		{ // Sky flat
410 			if(DoubleSky)
411 			{ // Render 2 layers, sky 1 in front
412 				offset = Sky1ColumnOffset>>16;
413 				skyTexture = texturetranslation[Sky1Texture];
414 				offset2 = Sky2ColumnOffset>>16;
415 				skyTexture2 = texturetranslation[Sky2Texture];
416 				for(x = pl->minx; x <= pl->maxx; x++)
417 				{
418 					dc_yl = pl->top[x];
419 					dc_yh = pl->bottom[x];
420 					if(dc_yl <= dc_yh)
421 					{
422 						count = dc_yh-dc_yl;
423 						if(count < 0)
424 						{
425 							return;
426 						}
427 						angle = (viewangle+xtoviewangle[x])
428 							>>ANGLETOSKYSHIFT;
429 						source = R_GetColumn(skyTexture, angle+offset)
430 							+SKYTEXTUREMIDSHIFTED+(dc_yl-centery);
431 						source2 = R_GetColumn(skyTexture2, angle+offset2)
432 							+SKYTEXTUREMIDSHIFTED+(dc_yl-centery);
433 						dest = ylookup[dc_yl]+columnofs[x];
434 						do
435 						{
436 							if(*source)
437 							{
438 								*dest = *source++;
439 								source2++;
440 							}
441 							else
442 							{
443 								*dest = *source2++;
444 								source++;
445 							}
446 							dest += SCREENWIDTH;
447 						} while(count--);
448 					}
449 				}
450 				continue; // Next visplane
451 			}
452 			else
453 			{ // Render single layer
454 				if(pl->special == 200)
455 				{ // Use sky 2
456 					offset = Sky2ColumnOffset>>16;
457 					skyTexture = texturetranslation[Sky2Texture];
458 				}
459 				else
460 				{ // Use sky 1
461 					offset = Sky1ColumnOffset>>16;
462 					skyTexture = texturetranslation[Sky1Texture];
463 				}
464 				for(x = pl->minx; x <= pl->maxx; x++)
465 				{
466 					dc_yl = pl->top[x];
467 					dc_yh = pl->bottom[x];
468 					if(dc_yl <= dc_yh)
469 					{
470 						count = dc_yh-dc_yl;
471 						if(count < 0)
472 						{
473 							return;
474 						}
475 						angle = (viewangle+xtoviewangle[x])
476 							>>ANGLETOSKYSHIFT;
477 						source = R_GetColumn(skyTexture, angle+offset)
478 							+SKYTEXTUREMIDSHIFTED+(dc_yl-centery);
479 						dest = ylookup[dc_yl]+columnofs[x];
480 						do
481 						{
482 							*dest = *source++;
483 							dest += SCREENWIDTH;
484 						} while(count--);
485 					}
486 				}
487 				continue; // Next visplane
488 			}
489 		}
490 		// Regular flat
491 		tempSource = W_CacheLumpNum(firstflat+
492 			flattranslation[pl->picnum], PU_STATIC);
493 		scrollOffset = leveltime>>1&63;
494 		switch(pl->special)
495 		{ // Handle scrolling flats
496 			case 201: case 202: case 203: // Scroll_North_xxx
497 				ds_source = tempSource+((scrollOffset
498 					<<(pl->special-201)&63)<<6);
499 				break;
500 			case 204: case 205: case 206: // Scroll_East_xxx
501 				ds_source = tempSource+((63-scrollOffset)
502 					<<(pl->special-204)&63);
503 				break;
504 			case 207: case 208: case 209: // Scroll_South_xxx
505 				ds_source = tempSource+(((63-scrollOffset)
506 					<<(pl->special-207)&63)<<6);
507 				break;
508 			case 210: case 211: case 212: // Scroll_West_xxx
509 				ds_source = tempSource+(scrollOffset
510 					<<(pl->special-210)&63);
511 				break;
512 			case 213: case 214: case 215: // Scroll_NorthWest_xxx
513 				ds_source = tempSource+(scrollOffset
514 					<<(pl->special-213)&63)+((scrollOffset
515 					<<(pl->special-213)&63)<<6);
516 				break;
517 			case 216: case 217: case 218: // Scroll_NorthEast_xxx
518 				ds_source = tempSource+((63-scrollOffset)
519 					<<(pl->special-216)&63)+((scrollOffset
520 					<<(pl->special-216)&63)<<6);
521 				break;
522 			case 219: case 220: case 221: // Scroll_SouthEast_xxx
523 				ds_source = tempSource+((63-scrollOffset)
524 					<<(pl->special-219)&63)+(((63-scrollOffset)
525 					<<(pl->special-219)&63)<<6);
526 				break;
527 			case 222: case 223: case 224: // Scroll_SouthWest_xxx
528 				ds_source = tempSource+(scrollOffset
529 					<<(pl->special-222)&63)+(((63-scrollOffset)
530 					<<(pl->special-222)&63)<<6);
531 				break;
532 			default:
533 				ds_source = tempSource;
534 				break;
535 		}
536 		planeheight = abs(pl->height-viewz);
537 		light = (pl->lightlevel >> LIGHTSEGSHIFT)+extralight;
538 		if(light >= LIGHTLEVELS)
539 		{
540 			light = LIGHTLEVELS-1;
541 		}
542 		if(light < 0)
543 		{
544 			light = 0;
545 		}
546 		planezlight = zlight[light];
547 
548 		pl->top[pl->maxx+1] = 0xff;
549 		pl->top[pl->minx-1] = 0xff;
550 
551 		stop = pl->maxx+1;
552 		for(x = pl->minx; x <= stop; x++)
553 		{
554 			R_MakeSpans(x, pl->top[x-1], pl->bottom[x-1],
555 				pl->top[x], pl->bottom[x]);
556 		}
557 		Z_ChangeTag(tempSource, PU_CACHE);
558 	}
559 }
560