xref: /reactos/dll/opengl/mesa/rastpos.c (revision 98e8827a)
1 /* $Id: rastpos.c,v 1.5 1997/07/24 01:23:44 brianp Exp $ */
2 
3 /*
4  * Mesa 3-D graphics library
5  * Version:  2.4
6  * Copyright (C) 1995-1997  Brian Paul
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Library General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Library General Public License for more details.
17  *
18  * You should have received a copy of the GNU Library General Public
19  * License along with this library; if not, write to the Free
20  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 
24 /*
25  * $Log: rastpos.c,v $
26  * Revision 1.5  1997/07/24 01:23:44  brianp
27  * changed precompiled header symbol from PCH to PC_HEADER
28  *
29  * Revision 1.4  1997/06/20 02:25:54  brianp
30  * replaced Current.IntColor with Current.ByteColor
31  *
32  * Revision 1.3  1997/05/28 03:26:18  brianp
33  * added precompiled header (PCH) support
34  *
35  * Revision 1.2  1997/05/01 01:39:59  brianp
36  * replaced sqrt() with GL_SQRT()
37  *
38  * Revision 1.1  1997/04/01 04:17:13  brianp
39  * Initial revision
40  *
41  */
42 
43 
44 #ifdef PC_HEADER
45 #include "all.h"
46 #else
47 #include "clip.h"
48 #include "feedback.h"
49 #include "light.h"
50 #include "macros.h"
51 #include "matrix.h"
52 #include "mmath.h"
53 #include "shade.h"
54 #include "types.h"
55 #include "xform.h"
56 #endif
57 
58 
59 /*
60  * Caller:  context->API.RasterPos4f
61  */
62 void gl_RasterPos4f( GLcontext *ctx,
63                      GLfloat x, GLfloat y, GLfloat z, GLfloat w )
64 {
65    GLfloat v[4], eye[4], clip[4], ndc[3], d;
66 
67    ASSIGN_4V( v, x, y, z, w );
68 
69    if (ctx->NewModelViewMatrix) {
70       gl_analyze_modelview_matrix(ctx);
71    }
72    if (ctx->NewProjectionMatrix) {
73       gl_analyze_projection_matrix(ctx);
74    }
75    if (ctx->NewTextureMatrix) {
76       gl_analyze_texture_matrix(ctx);
77    }
78 
79    /* transform v to eye coords:  eye = ModelView * v */
80    TRANSFORM_POINT( eye, ctx->ModelViewMatrix, v );
81 
82    /* raster color */
83    if (ctx->Light.Enabled) {
84       GLfloat eyenorm[3];
85       TRANSFORM_NORMAL( eyenorm[0], eyenorm[1], eyenorm[2], ctx->Current.Normal,
86                         ctx->ModelViewInv );
87       if (ctx->Visual->RGBAflag) {
88          GLubyte color[4];
89          gl_color_shade_vertices( ctx, 0, 1, &eye, &eyenorm, &color );
90          ctx->Current.RasterColor[0] = color[0] * ctx->Visual->InvRedScale;
91          ctx->Current.RasterColor[1] = color[1] * ctx->Visual->InvGreenScale;
92          ctx->Current.RasterColor[2] = color[2] * ctx->Visual->InvBlueScale;
93          ctx->Current.RasterColor[3] = color[3] * ctx->Visual->InvAlphaScale;
94       }
95       else {
96 	 gl_index_shade_vertices( ctx, 0, 1, &eye, &eyenorm,
97                                   &ctx->Current.RasterIndex );
98       }
99    }
100    else {
101       /* use current color or index */
102       if (ctx->Visual->RGBAflag) {
103          GLfloat *rc = ctx->Current.RasterColor;
104          rc[0] = ctx->Current.ByteColor[0] * ctx->Visual->InvRedScale;
105          rc[1] = ctx->Current.ByteColor[1] * ctx->Visual->InvGreenScale;
106          rc[2] = ctx->Current.ByteColor[2] * ctx->Visual->InvBlueScale;
107          rc[3] = ctx->Current.ByteColor[3] * ctx->Visual->InvAlphaScale;
108       }
109       else {
110 	 ctx->Current.RasterIndex = ctx->Current.Index;
111       }
112    }
113 
114    /* clip to user clipping planes */
115    if (gl_userclip_point(ctx, eye)==0) {
116       ctx->Current.RasterPosValid = GL_FALSE;
117       return;
118    }
119 
120    /* compute raster distance */
121    ctx->Current.RasterDistance =
122                       GL_SQRT( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
123 
124    /* apply projection matrix:  clip = Proj * eye */
125    TRANSFORM_POINT( clip, ctx->ProjectionMatrix, eye );
126 
127    /* clip to view volume */
128    if (gl_viewclip_point( clip )==0) {
129       ctx->Current.RasterPosValid = GL_FALSE;
130       return;
131    }
132 
133    /* ndc = clip / W */
134    ASSERT( clip[3]!=0.0 );
135    d = 1.0F / clip[3];
136    ndc[0] = clip[0] * d;
137    ndc[1] = clip[1] * d;
138    ndc[2] = clip[2] * d;
139 
140    ctx->Current.RasterPos[0] = ndc[0] * ctx->Viewport.Sx + ctx->Viewport.Tx;
141    ctx->Current.RasterPos[1] = ndc[1] * ctx->Viewport.Sy + ctx->Viewport.Ty;
142    ctx->Current.RasterPos[2] = (ndc[2] * ctx->Viewport.Sz + ctx->Viewport.Tz)
143                                / DEPTH_SCALE;
144    ctx->Current.RasterPos[3] = clip[3];
145    ctx->Current.RasterPosValid = GL_TRUE;
146 
147    /* FOG??? */
148 
149    if (ctx->Texture.Enabled) {
150       COPY_4V( ctx->Current.RasterTexCoord, ctx->Current.TexCoord );
151    }
152 
153    if (ctx->RenderMode==GL_SELECT) {
154       gl_update_hitflag( ctx, ctx->Current.RasterPos[2] );
155    }
156 
157 }
158 
159 
160 
161 /*
162  * This is a MESA extension function.  Pretty much just like glRasterPos
163  * except we don't apply the modelview or projection matrices; specify a
164  * window coordinate directly.
165  * Caller:  context->API.WindowPos4fMESA pointer.
166  */
167 void gl_windowpos( GLcontext *ctx, GLfloat x, GLfloat y, GLfloat z, GLfloat w )
168 {
169    /* set raster position */
170    ctx->Current.RasterPos[0] = x;
171    ctx->Current.RasterPos[1] = y;
172    ctx->Current.RasterPos[2] = CLAMP( z, 0.0F, 1.0F );
173    ctx->Current.RasterPos[3] = w;
174 
175    ctx->Current.RasterPosValid = GL_TRUE;
176 
177    /* raster color */
178    if (ctx->Light.Enabled) {
179       GLfloat eye[4];
180       GLfloat eyenorm[3];
181       COPY_4V( eye, ctx->Current.RasterPos );
182       if (ctx->NewModelViewMatrix) {
183 	 gl_analyze_modelview_matrix(ctx);
184       }
185       TRANSFORM_NORMAL( eyenorm[0], eyenorm[1], eyenorm[2],
186                         ctx->Current.Normal,
187                         ctx->ModelViewInv );
188       if (ctx->Visual->RGBAflag) {
189          GLubyte color[4];
190          gl_color_shade_vertices( ctx, 0, 1, &eye, &eyenorm, &color );
191          ASSIGN_4V( ctx->Current.RasterColor,
192                     (GLfloat) color[0] * ctx->Visual->InvRedScale,
193                     (GLfloat) color[1] * ctx->Visual->InvGreenScale,
194                     (GLfloat) color[2] * ctx->Visual->InvBlueScale,
195                     (GLfloat) color[3] * ctx->Visual->InvAlphaScale );
196       }
197       else {
198 	 gl_index_shade_vertices( ctx, 0, 1, &eye, &eyenorm,
199                                   &ctx->Current.RasterIndex );
200       }
201    }
202    else {
203       /* use current color or index */
204       if (ctx->Visual->RGBAflag) {
205          ASSIGN_4V( ctx->Current.RasterColor,
206                     ctx->Current.ByteColor[0] * ctx->Visual->InvRedScale,
207                     ctx->Current.ByteColor[1] * ctx->Visual->InvGreenScale,
208                     ctx->Current.ByteColor[2] * ctx->Visual->InvBlueScale,
209                     ctx->Current.ByteColor[3] * ctx->Visual->InvAlphaScale );
210       }
211       else {
212 	 ctx->Current.RasterIndex = ctx->Current.Index;
213       }
214    }
215 
216    ctx->Current.RasterDistance = 0.0;
217 
218    if (ctx->Texture.Enabled) {
219       COPY_4V( ctx->Current.RasterTexCoord, ctx->Current.TexCoord );
220    }
221 
222    if (ctx->RenderMode==GL_SELECT) {
223       gl_update_hitflag( ctx, ctx->Current.RasterPos[2] );
224    }
225 }
226