s_texcombine.c revision c1f859d4
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.5.1
4 *
5 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26#include "main/glheader.h"
27#include "main/context.h"
28#include "main/colormac.h"
29#include "main/image.h"
30#include "main/imports.h"
31#include "main/macros.h"
32#include "main/pixel.h"
33
34#include "s_context.h"
35#include "s_texcombine.h"
36
37
38#define PROD(A,B)   ( (GLuint)(A) * ((GLuint)(B)+1) )
39#define S_PROD(A,B) ( (GLint)(A) * ((GLint)(B)+1) )
40#if CHAN_BITS == 32
41typedef GLfloat ChanTemp;
42#else
43typedef GLuint ChanTemp;
44#endif
45
46
47/**
48 * Do texture application for GL_ARB/EXT_texture_env_combine.
49 * This function also supports GL_{EXT,ARB}_texture_env_dot3 and
50 * GL_ATI_texture_env_combine3.  Since "classic" texture environments are
51 * implemented using GL_ARB_texture_env_combine-like state, this same function
52 * is used for classic texture environment application as well.
53 *
54 * \param ctx          rendering context
55 * \param textureUnit  the texture unit to apply
56 * \param n            number of fragments to process (span width)
57 * \param primary_rgba incoming fragment color array
58 * \param texelBuffer  pointer to texel colors for all texture units
59 *
60 * \param rgba         incoming colors, which get modified here
61 */
62static void
63texture_combine( const GLcontext *ctx, GLuint unit, GLuint n,
64                 CONST GLchan (*primary_rgba)[4],
65                 CONST GLchan *texelBuffer,
66                 GLchan (*rgba)[4] )
67{
68   const struct gl_texture_unit *textureUnit = &(ctx->Texture.Unit[unit]);
69   const GLchan (*argRGB [3])[4];
70   const GLchan (*argA [3])[4];
71   const GLuint RGBshift = textureUnit->_CurrentCombine->ScaleShiftRGB;
72   const GLuint Ashift   = textureUnit->_CurrentCombine->ScaleShiftA;
73#if CHAN_TYPE == GL_FLOAT
74   const GLchan RGBmult = (GLfloat) (1 << RGBshift);
75   const GLchan Amult = (GLfloat) (1 << Ashift);
76#else
77   const GLint half = (CHAN_MAX + 1) / 2;
78#endif
79   static const GLchan one[4] = { CHAN_MAX, CHAN_MAX, CHAN_MAX, CHAN_MAX };
80   static const GLchan zero[4] = { 0, 0, 0, 0 };
81   const GLuint numColorArgs = textureUnit->_CurrentCombine->_NumArgsRGB;
82   const GLuint numAlphaArgs = textureUnit->_CurrentCombine->_NumArgsA;
83   GLchan ccolor[3][MAX_WIDTH][4];
84   GLuint i, j;
85
86   ASSERT(ctx->Extensions.EXT_texture_env_combine ||
87          ctx->Extensions.ARB_texture_env_combine);
88   ASSERT(SWRAST_CONTEXT(ctx)->_AnyTextureCombine);
89
90   /*
91   printf("modeRGB 0x%x  modeA 0x%x  srcRGB1 0x%x  srcA1 0x%x  srcRGB2 0x%x  srcA2 0x%x\n",
92          textureUnit->_CurrentCombine->ModeRGB,
93          textureUnit->_CurrentCombine->ModeA,
94          textureUnit->_CurrentCombine->SourceRGB[0],
95          textureUnit->_CurrentCombine->SourceA[0],
96          textureUnit->_CurrentCombine->SourceRGB[1],
97          textureUnit->_CurrentCombine->SourceA[1]);
98   */
99
100   /*
101    * Do operand setup for up to 3 operands.  Loop over the terms.
102    */
103   for (j = 0; j < numColorArgs; j++) {
104      const GLenum srcRGB = textureUnit->_CurrentCombine->SourceRGB[j];
105
106      switch (srcRGB) {
107         case GL_TEXTURE:
108            argRGB[j] = (const GLchan (*)[4])
109               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
110            break;
111         case GL_PRIMARY_COLOR:
112            argRGB[j] = primary_rgba;
113            break;
114         case GL_PREVIOUS:
115            argRGB[j] = (const GLchan (*)[4]) rgba;
116            break;
117         case GL_CONSTANT:
118            {
119               GLchan (*c)[4] = ccolor[j];
120               GLchan red, green, blue, alpha;
121               UNCLAMPED_FLOAT_TO_CHAN(red,   textureUnit->EnvColor[0]);
122               UNCLAMPED_FLOAT_TO_CHAN(green, textureUnit->EnvColor[1]);
123               UNCLAMPED_FLOAT_TO_CHAN(blue,  textureUnit->EnvColor[2]);
124               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
125               for (i = 0; i < n; i++) {
126                  c[i][RCOMP] = red;
127                  c[i][GCOMP] = green;
128                  c[i][BCOMP] = blue;
129                  c[i][ACOMP] = alpha;
130               }
131               argRGB[j] = (const GLchan (*)[4]) ccolor[j];
132            }
133            break;
134	 /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
135	  */
136	 case GL_ZERO:
137            argRGB[j] = & zero;
138            break;
139	 case GL_ONE:
140            argRGB[j] = & one;
141            break;
142         default:
143            /* ARB_texture_env_crossbar source */
144            {
145               const GLuint srcUnit = srcRGB - GL_TEXTURE0;
146               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
147               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
148                  return;
149               argRGB[j] = (const GLchan (*)[4])
150                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
151            }
152      }
153
154      if (textureUnit->_CurrentCombine->OperandRGB[j] != GL_SRC_COLOR) {
155         const GLchan (*src)[4] = argRGB[j];
156         GLchan (*dst)[4] = ccolor[j];
157
158         /* point to new arg[j] storage */
159         argRGB[j] = (const GLchan (*)[4]) ccolor[j];
160
161         if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_ONE_MINUS_SRC_COLOR) {
162            for (i = 0; i < n; i++) {
163               dst[i][RCOMP] = CHAN_MAX - src[i][RCOMP];
164               dst[i][GCOMP] = CHAN_MAX - src[i][GCOMP];
165               dst[i][BCOMP] = CHAN_MAX - src[i][BCOMP];
166            }
167         }
168         else if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_SRC_ALPHA) {
169            for (i = 0; i < n; i++) {
170               dst[i][RCOMP] = src[i][ACOMP];
171               dst[i][GCOMP] = src[i][ACOMP];
172               dst[i][BCOMP] = src[i][ACOMP];
173            }
174         }
175         else {
176            ASSERT(textureUnit->_CurrentCombine->OperandRGB[j] ==GL_ONE_MINUS_SRC_ALPHA);
177            for (i = 0; i < n; i++) {
178               dst[i][RCOMP] = CHAN_MAX - src[i][ACOMP];
179               dst[i][GCOMP] = CHAN_MAX - src[i][ACOMP];
180               dst[i][BCOMP] = CHAN_MAX - src[i][ACOMP];
181            }
182         }
183      }
184   }
185
186   /*
187    * Set up the argA[i] pointers
188    */
189   for (j = 0; j < numAlphaArgs; j++) {
190      const GLenum srcA = textureUnit->_CurrentCombine->SourceA[j];
191
192      switch (srcA) {
193         case GL_TEXTURE:
194            argA[j] = (const GLchan (*)[4])
195               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
196            break;
197         case GL_PRIMARY_COLOR:
198            argA[j] = primary_rgba;
199            break;
200         case GL_PREVIOUS:
201            argA[j] = (const GLchan (*)[4]) rgba;
202            break;
203         case GL_CONSTANT:
204            {
205               GLchan alpha, (*c)[4] = ccolor[j];
206               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
207               for (i = 0; i < n; i++)
208                  c[i][ACOMP] = alpha;
209               argA[j] = (const GLchan (*)[4]) ccolor[j];
210            }
211            break;
212	 /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
213	  */
214	 case GL_ZERO:
215            argA[j] = & zero;
216            break;
217	 case GL_ONE:
218            argA[j] = & one;
219            break;
220         default:
221            /* ARB_texture_env_crossbar source */
222            {
223               const GLuint srcUnit = srcA - GL_TEXTURE0;
224               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
225               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
226                  return;
227               argA[j] = (const GLchan (*)[4])
228                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
229            }
230      }
231
232      if (textureUnit->_CurrentCombine->OperandA[j] == GL_ONE_MINUS_SRC_ALPHA) {
233         const GLchan (*src)[4] = argA[j];
234         GLchan (*dst)[4] = ccolor[j];
235         argA[j] = (const GLchan (*)[4]) ccolor[j];
236         for (i = 0; i < n; i++) {
237            dst[i][ACOMP] = CHAN_MAX - src[i][ACOMP];
238         }
239      }
240   }
241
242   /*
243    * Do the texture combine.
244    */
245   switch (textureUnit->_CurrentCombine->ModeRGB) {
246      case GL_REPLACE:
247         {
248            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
249            if (RGBshift) {
250               for (i = 0; i < n; i++) {
251#if CHAN_TYPE == GL_FLOAT
252                  rgba[i][RCOMP] = arg0[i][RCOMP] * RGBmult;
253                  rgba[i][GCOMP] = arg0[i][GCOMP] * RGBmult;
254                  rgba[i][BCOMP] = arg0[i][BCOMP] * RGBmult;
255#else
256                  GLuint r = (GLuint) arg0[i][RCOMP] << RGBshift;
257                  GLuint g = (GLuint) arg0[i][GCOMP] << RGBshift;
258                  GLuint b = (GLuint) arg0[i][BCOMP] << RGBshift;
259                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
260                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
261                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
262#endif
263               }
264            }
265            else {
266               for (i = 0; i < n; i++) {
267                  rgba[i][RCOMP] = arg0[i][RCOMP];
268                  rgba[i][GCOMP] = arg0[i][GCOMP];
269                  rgba[i][BCOMP] = arg0[i][BCOMP];
270               }
271            }
272         }
273         break;
274      case GL_MODULATE:
275         {
276            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
277            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
278#if CHAN_TYPE != GL_FLOAT
279            const GLint shift = CHAN_BITS - RGBshift;
280#endif
281            for (i = 0; i < n; i++) {
282#if CHAN_TYPE == GL_FLOAT
283               rgba[i][RCOMP] = arg0[i][RCOMP] * arg1[i][RCOMP] * RGBmult;
284               rgba[i][GCOMP] = arg0[i][GCOMP] * arg1[i][GCOMP] * RGBmult;
285               rgba[i][BCOMP] = arg0[i][BCOMP] * arg1[i][BCOMP] * RGBmult;
286#else
287               GLuint r = PROD(arg0[i][RCOMP], arg1[i][RCOMP]) >> shift;
288               GLuint g = PROD(arg0[i][GCOMP], arg1[i][GCOMP]) >> shift;
289               GLuint b = PROD(arg0[i][BCOMP], arg1[i][BCOMP]) >> shift;
290               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
291               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
292               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
293#endif
294            }
295         }
296         break;
297      case GL_ADD:
298         {
299            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
300            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
301            for (i = 0; i < n; i++) {
302#if CHAN_TYPE == GL_FLOAT
303               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP]) * RGBmult;
304               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP]) * RGBmult;
305               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP]) * RGBmult;
306#else
307               GLint r = ((GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP]) << RGBshift;
308               GLint g = ((GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP]) << RGBshift;
309               GLint b = ((GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP]) << RGBshift;
310               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
311               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
312               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
313#endif
314            }
315         }
316         break;
317      case GL_ADD_SIGNED:
318         {
319            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
320            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
321            for (i = 0; i < n; i++) {
322#if CHAN_TYPE == GL_FLOAT
323               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP] - 0.5) * RGBmult;
324               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP] - 0.5) * RGBmult;
325               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP] - 0.5) * RGBmult;
326#else
327               GLint r = (GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP] -half;
328               GLint g = (GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP] -half;
329               GLint b = (GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP] -half;
330               r = (r < 0) ? 0 : r << RGBshift;
331               g = (g < 0) ? 0 : g << RGBshift;
332               b = (b < 0) ? 0 : b << RGBshift;
333               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
334               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
335               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
336#endif
337            }
338         }
339         break;
340      case GL_INTERPOLATE:
341         {
342            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
343            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
344            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
345#if CHAN_TYPE != GL_FLOAT
346            const GLint shift = CHAN_BITS - RGBshift;
347#endif
348            for (i = 0; i < n; i++) {
349#if CHAN_TYPE == GL_FLOAT
350               rgba[i][RCOMP] = (arg0[i][RCOMP] * arg2[i][RCOMP] +
351                      arg1[i][RCOMP] * (CHAN_MAXF - arg2[i][RCOMP])) * RGBmult;
352               rgba[i][GCOMP] = (arg0[i][GCOMP] * arg2[i][GCOMP] +
353                      arg1[i][GCOMP] * (CHAN_MAXF - arg2[i][GCOMP])) * RGBmult;
354               rgba[i][BCOMP] = (arg0[i][BCOMP] * arg2[i][BCOMP] +
355                      arg1[i][BCOMP] * (CHAN_MAXF - arg2[i][BCOMP])) * RGBmult;
356#else
357               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
358                           + PROD(arg1[i][RCOMP], CHAN_MAX - arg2[i][RCOMP]))
359                              >> shift;
360               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
361                           + PROD(arg1[i][GCOMP], CHAN_MAX - arg2[i][GCOMP]))
362                              >> shift;
363               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
364                           + PROD(arg1[i][BCOMP], CHAN_MAX - arg2[i][BCOMP]))
365                              >> shift;
366               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
367               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
368               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
369#endif
370            }
371         }
372         break;
373      case GL_SUBTRACT:
374         {
375            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
376            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
377            for (i = 0; i < n; i++) {
378#if CHAN_TYPE == GL_FLOAT
379               rgba[i][RCOMP] = (arg0[i][RCOMP] - arg1[i][RCOMP]) * RGBmult;
380               rgba[i][GCOMP] = (arg0[i][GCOMP] - arg1[i][GCOMP]) * RGBmult;
381               rgba[i][BCOMP] = (arg0[i][BCOMP] - arg1[i][BCOMP]) * RGBmult;
382#else
383               GLint r = ((GLint) arg0[i][RCOMP] - (GLint) arg1[i][RCOMP]) << RGBshift;
384               GLint g = ((GLint) arg0[i][GCOMP] - (GLint) arg1[i][GCOMP]) << RGBshift;
385               GLint b = ((GLint) arg0[i][BCOMP] - (GLint) arg1[i][BCOMP]) << RGBshift;
386               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
387               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
388               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
389#endif
390            }
391         }
392         break;
393      case GL_DOT3_RGB_EXT:
394      case GL_DOT3_RGBA_EXT:
395         {
396            /* Do not scale the result by 1 2 or 4 */
397            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
398            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
399            for (i = 0; i < n; i++) {
400#if CHAN_TYPE == GL_FLOAT
401               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
402                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
403                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
404                            * 4.0F;
405               dot = CLAMP(dot, 0.0F, CHAN_MAXF);
406#else
407               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
408				   (GLint)arg1[i][RCOMP] - half) +
409			    S_PROD((GLint)arg0[i][GCOMP] - half,
410				   (GLint)arg1[i][GCOMP] - half) +
411			    S_PROD((GLint)arg0[i][BCOMP] - half,
412				   (GLint)arg1[i][BCOMP] - half)) >> 6;
413               dot = CLAMP(dot, 0, CHAN_MAX);
414#endif
415               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
416            }
417         }
418         break;
419      case GL_DOT3_RGB:
420      case GL_DOT3_RGBA:
421         {
422            /* DO scale the result by 1 2 or 4 */
423            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
424            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
425            for (i = 0; i < n; i++) {
426#if CHAN_TYPE == GL_FLOAT
427               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
428                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
429                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
430                            * 4.0F * RGBmult;
431               dot = CLAMP(dot, 0.0, CHAN_MAXF);
432#else
433               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
434				   (GLint)arg1[i][RCOMP] - half) +
435			    S_PROD((GLint)arg0[i][GCOMP] - half,
436				   (GLint)arg1[i][GCOMP] - half) +
437			    S_PROD((GLint)arg0[i][BCOMP] - half,
438				   (GLint)arg1[i][BCOMP] - half)) >> 6;
439               dot <<= RGBshift;
440               dot = CLAMP(dot, 0, CHAN_MAX);
441#endif
442               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
443            }
444         }
445         break;
446      case GL_MODULATE_ADD_ATI:
447         {
448            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
449            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
450            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
451#if CHAN_TYPE != GL_FLOAT
452            const GLint shift = CHAN_BITS - RGBshift;
453#endif
454            for (i = 0; i < n; i++) {
455#if CHAN_TYPE == GL_FLOAT
456               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP]) * RGBmult;
457               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP]) * RGBmult;
458               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP]) * RGBmult;
459#else
460               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
461                           + ((GLuint) arg1[i][RCOMP] << CHAN_BITS)) >> shift;
462               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
463                           + ((GLuint) arg1[i][GCOMP] << CHAN_BITS)) >> shift;
464               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
465                           + ((GLuint) arg1[i][BCOMP] << CHAN_BITS)) >> shift;
466               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
467               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
468               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
469#endif
470            }
471	 }
472         break;
473      case GL_MODULATE_SIGNED_ADD_ATI:
474         {
475            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
476            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
477            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
478#if CHAN_TYPE != GL_FLOAT
479            const GLint shift = CHAN_BITS - RGBshift;
480#endif
481            for (i = 0; i < n; i++) {
482#if CHAN_TYPE == GL_FLOAT
483               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP] - 0.5) * RGBmult;
484               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP] - 0.5) * RGBmult;
485               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP] - 0.5) * RGBmult;
486#else
487               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
488			  + (((GLint) arg1[i][RCOMP] - half) << CHAN_BITS))
489		    >> shift;
490               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
491			  + (((GLint) arg1[i][GCOMP] - half) << CHAN_BITS))
492		    >> shift;
493               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
494			  + (((GLint) arg1[i][BCOMP] - half) << CHAN_BITS))
495		    >> shift;
496               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
497               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
498               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
499#endif
500            }
501	 }
502         break;
503      case GL_MODULATE_SUBTRACT_ATI:
504         {
505            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
506            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
507            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
508#if CHAN_TYPE != GL_FLOAT
509            const GLint shift = CHAN_BITS - RGBshift;
510#endif
511            for (i = 0; i < n; i++) {
512#if CHAN_TYPE == GL_FLOAT
513               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) - arg1[i][RCOMP]) * RGBmult;
514               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) - arg1[i][GCOMP]) * RGBmult;
515               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) - arg1[i][BCOMP]) * RGBmult;
516#else
517               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
518			  - ((GLint) arg1[i][RCOMP] << CHAN_BITS))
519		    >> shift;
520               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
521			  - ((GLint) arg1[i][GCOMP] << CHAN_BITS))
522		    >> shift;
523               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
524			  - ((GLint) arg1[i][BCOMP] << CHAN_BITS))
525		    >> shift;
526               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
527               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
528               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
529#endif
530            }
531	 }
532         break;
533      default:
534         _mesa_problem(ctx, "invalid combine mode");
535   }
536
537   switch (textureUnit->_CurrentCombine->ModeA) {
538      case GL_REPLACE:
539         {
540            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
541            if (Ashift) {
542               for (i = 0; i < n; i++) {
543#if CHAN_TYPE == GL_FLOAT
544                  GLchan a = arg0[i][ACOMP] * Amult;
545#else
546                  GLuint a = (GLuint) arg0[i][ACOMP] << Ashift;
547#endif
548                  rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
549               }
550            }
551            else {
552               for (i = 0; i < n; i++) {
553                  rgba[i][ACOMP] = arg0[i][ACOMP];
554               }
555            }
556         }
557         break;
558      case GL_MODULATE:
559         {
560            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
561            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
562#if CHAN_TYPE != GL_FLOAT
563            const GLint shift = CHAN_BITS - Ashift;
564#endif
565            for (i = 0; i < n; i++) {
566#if CHAN_TYPE == GL_FLOAT
567               rgba[i][ACOMP] = arg0[i][ACOMP] * arg1[i][ACOMP] * Amult;
568#else
569               GLuint a = (PROD(arg0[i][ACOMP], arg1[i][ACOMP]) >> shift);
570               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
571#endif
572            }
573         }
574         break;
575      case GL_ADD:
576         {
577            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
578            const GLchan  (*arg1)[4] = (const GLchan (*)[4]) argA[1];
579            for (i = 0; i < n; i++) {
580#if CHAN_TYPE == GL_FLOAT
581               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP]) * Amult;
582#else
583               GLint a = ((GLint) arg0[i][ACOMP] + arg1[i][ACOMP]) << Ashift;
584               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
585#endif
586            }
587         }
588         break;
589      case GL_ADD_SIGNED:
590         {
591            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
592            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
593            for (i = 0; i < n; i++) {
594#if CHAN_TYPE == GL_FLOAT
595               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP] - 0.5F) * Amult;
596#else
597               GLint a = (GLint) arg0[i][ACOMP] + (GLint) arg1[i][ACOMP] -half;
598               a = (a < 0) ? 0 : a << Ashift;
599               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
600#endif
601            }
602         }
603         break;
604      case GL_INTERPOLATE:
605         {
606            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
607            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
608            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
609#if CHAN_TYPE != GL_FLOAT
610            const GLint shift = CHAN_BITS - Ashift;
611#endif
612            for (i=0; i<n; i++) {
613#if CHAN_TYPE == GL_FLOAT
614               rgba[i][ACOMP] = (arg0[i][ACOMP] * arg2[i][ACOMP] +
615                                 arg1[i][ACOMP] * (CHAN_MAXF - arg2[i][ACOMP]))
616                                * Amult;
617#else
618               GLuint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
619                           + PROD(arg1[i][ACOMP], CHAN_MAX - arg2[i][ACOMP]))
620                              >> shift;
621               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
622#endif
623            }
624         }
625         break;
626      case GL_SUBTRACT:
627         {
628            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
629            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
630            for (i = 0; i < n; i++) {
631#if CHAN_TYPE == GL_FLOAT
632               rgba[i][ACOMP] = (arg0[i][ACOMP] - arg1[i][ACOMP]) * Amult;
633#else
634               GLint a = ((GLint) arg0[i][ACOMP] - (GLint) arg1[i][ACOMP]) << Ashift;
635               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
636#endif
637            }
638         }
639         break;
640      case GL_MODULATE_ADD_ATI:
641         {
642            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
643            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
644            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
645#if CHAN_TYPE != GL_FLOAT
646            const GLint shift = CHAN_BITS - Ashift;
647#endif
648            for (i = 0; i < n; i++) {
649#if CHAN_TYPE == GL_FLOAT
650               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP]) * Amult;
651#else
652               GLint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
653			   + ((GLuint) arg1[i][ACOMP] << CHAN_BITS))
654		    >> shift;
655               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
656#endif
657            }
658         }
659         break;
660      case GL_MODULATE_SIGNED_ADD_ATI:
661         {
662            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
663            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
664            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
665#if CHAN_TYPE != GL_FLOAT
666            const GLint shift = CHAN_BITS - Ashift;
667#endif
668            for (i = 0; i < n; i++) {
669#if CHAN_TYPE == GL_FLOAT
670               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP] - 0.5F) * Amult;
671#else
672               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP])
673			  + (((GLint) arg1[i][ACOMP] - half) << CHAN_BITS))
674		    >> shift;
675               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
676#endif
677            }
678         }
679         break;
680      case GL_MODULATE_SUBTRACT_ATI:
681         {
682            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
683            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
684            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
685#if CHAN_TYPE != GL_FLOAT
686            const GLint shift = CHAN_BITS - Ashift;
687#endif
688            for (i = 0; i < n; i++) {
689#if CHAN_TYPE == GL_FLOAT
690               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) - arg1[i][ACOMP]) * Amult;
691#else
692               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP])
693			  - ((GLint) arg1[i][ACOMP] << CHAN_BITS))
694		    >> shift;
695               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
696#endif
697            }
698         }
699         break;
700      default:
701         _mesa_problem(ctx, "invalid combine mode");
702   }
703
704   /* Fix the alpha component for GL_DOT3_RGBA_EXT/ARB combining.
705    * This is kind of a kludge.  It would have been better if the spec
706    * were written such that the GL_COMBINE_ALPHA value could be set to
707    * GL_DOT3.
708    */
709   if (textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA_EXT ||
710       textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA) {
711      for (i = 0; i < n; i++) {
712	 rgba[i][ACOMP] = rgba[i][RCOMP];
713      }
714   }
715}
716#undef PROD
717
718
719/**
720 * Apply a conventional OpenGL texture env mode (REPLACE, ADD, BLEND,
721 * MODULATE, or DECAL) to an array of fragments.
722 * Input:  textureUnit - pointer to texture unit to apply
723 *         format - base internal texture format
724 *         n - number of fragments
725 *         primary_rgba - primary colors (may alias rgba for single texture)
726 *         texels - array of texel colors
727 * InOut:  rgba - incoming fragment colors modified by texel colors
728 *                according to the texture environment mode.
729 */
730static void
731texture_apply( const GLcontext *ctx,
732               const struct gl_texture_unit *texUnit,
733               GLuint n,
734               CONST GLchan primary_rgba[][4], CONST GLchan texel[][4],
735               GLchan rgba[][4] )
736{
737   GLint baseLevel;
738   GLuint i;
739   GLchan Rc, Gc, Bc, Ac;
740   GLenum format;
741   (void) primary_rgba;
742
743   ASSERT(texUnit);
744   ASSERT(texUnit->_Current);
745
746   baseLevel = texUnit->_Current->BaseLevel;
747   ASSERT(texUnit->_Current->Image[0][baseLevel]);
748
749   format = texUnit->_Current->Image[0][baseLevel]->_BaseFormat;
750
751   if (format == GL_COLOR_INDEX || format == GL_YCBCR_MESA) {
752      format = GL_RGBA;  /* a bit of a hack */
753   }
754   else if (format == GL_DEPTH_COMPONENT || format == GL_DEPTH_STENCIL_EXT) {
755      format = texUnit->_Current->DepthMode;
756   }
757
758   switch (texUnit->EnvMode) {
759      case GL_REPLACE:
760	 switch (format) {
761	    case GL_ALPHA:
762	       for (i=0;i<n;i++) {
763		  /* Cv = Cf */
764                  /* Av = At */
765                  rgba[i][ACOMP] = texel[i][ACOMP];
766	       }
767	       break;
768	    case GL_LUMINANCE:
769	       for (i=0;i<n;i++) {
770		  /* Cv = Lt */
771                  GLchan Lt = texel[i][RCOMP];
772                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
773                  /* Av = Af */
774	       }
775	       break;
776	    case GL_LUMINANCE_ALPHA:
777	       for (i=0;i<n;i++) {
778                  GLchan Lt = texel[i][RCOMP];
779		  /* Cv = Lt */
780		  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
781		  /* Av = At */
782		  rgba[i][ACOMP] = texel[i][ACOMP];
783	       }
784	       break;
785	    case GL_INTENSITY:
786	       for (i=0;i<n;i++) {
787		  /* Cv = It */
788                  GLchan It = texel[i][RCOMP];
789                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = It;
790                  /* Av = It */
791                  rgba[i][ACOMP] = It;
792	       }
793	       break;
794	    case GL_RGB:
795	       for (i=0;i<n;i++) {
796		  /* Cv = Ct */
797		  rgba[i][RCOMP] = texel[i][RCOMP];
798		  rgba[i][GCOMP] = texel[i][GCOMP];
799		  rgba[i][BCOMP] = texel[i][BCOMP];
800		  /* Av = Af */
801	       }
802	       break;
803	    case GL_RGBA:
804	       for (i=0;i<n;i++) {
805		  /* Cv = Ct */
806		  rgba[i][RCOMP] = texel[i][RCOMP];
807		  rgba[i][GCOMP] = texel[i][GCOMP];
808		  rgba[i][BCOMP] = texel[i][BCOMP];
809		  /* Av = At */
810		  rgba[i][ACOMP] = texel[i][ACOMP];
811	       }
812	       break;
813            default:
814               _mesa_problem(ctx, "Bad format (GL_REPLACE) in texture_apply");
815               return;
816	 }
817	 break;
818
819      case GL_MODULATE:
820         switch (format) {
821	    case GL_ALPHA:
822	       for (i=0;i<n;i++) {
823		  /* Cv = Cf */
824		  /* Av = AfAt */
825		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
826	       }
827	       break;
828	    case GL_LUMINANCE:
829	       for (i=0;i<n;i++) {
830		  /* Cv = LtCf */
831                  GLchan Lt = texel[i][RCOMP];
832		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
833		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
834		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
835		  /* Av = Af */
836	       }
837	       break;
838	    case GL_LUMINANCE_ALPHA:
839	       for (i=0;i<n;i++) {
840		  /* Cv = CfLt */
841                  GLchan Lt = texel[i][RCOMP];
842		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
843		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
844		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
845		  /* Av = AfAt */
846		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
847	       }
848	       break;
849	    case GL_INTENSITY:
850	       for (i=0;i<n;i++) {
851		  /* Cv = CfIt */
852                  GLchan It = texel[i][RCOMP];
853		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], It );
854		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], It );
855		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], It );
856		  /* Av = AfIt */
857		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], It );
858	       }
859	       break;
860	    case GL_RGB:
861	       for (i=0;i<n;i++) {
862		  /* Cv = CfCt */
863		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
864		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
865		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
866		  /* Av = Af */
867	       }
868	       break;
869	    case GL_RGBA:
870	       for (i=0;i<n;i++) {
871		  /* Cv = CfCt */
872		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
873		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
874		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
875		  /* Av = AfAt */
876		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
877	       }
878	       break;
879            default:
880               _mesa_problem(ctx, "Bad format (GL_MODULATE) in texture_apply");
881               return;
882	 }
883	 break;
884
885      case GL_DECAL:
886         switch (format) {
887            case GL_ALPHA:
888            case GL_LUMINANCE:
889            case GL_LUMINANCE_ALPHA:
890            case GL_INTENSITY:
891               /* undefined */
892               break;
893	    case GL_RGB:
894	       for (i=0;i<n;i++) {
895		  /* Cv = Ct */
896		  rgba[i][RCOMP] = texel[i][RCOMP];
897		  rgba[i][GCOMP] = texel[i][GCOMP];
898		  rgba[i][BCOMP] = texel[i][BCOMP];
899		  /* Av = Af */
900	       }
901	       break;
902	    case GL_RGBA:
903	       for (i=0;i<n;i++) {
904		  /* Cv = Cf(1-At) + CtAt */
905		  GLchan t = texel[i][ACOMP], s = CHAN_MAX - t;
906		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(texel[i][RCOMP],t);
907		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(texel[i][GCOMP],t);
908		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(texel[i][BCOMP],t);
909		  /* Av = Af */
910	       }
911	       break;
912            default:
913               _mesa_problem(ctx, "Bad format (GL_DECAL) in texture_apply");
914               return;
915	 }
916	 break;
917
918      case GL_BLEND:
919         UNCLAMPED_FLOAT_TO_CHAN(Rc, texUnit->EnvColor[0]);
920         UNCLAMPED_FLOAT_TO_CHAN(Gc, texUnit->EnvColor[1]);
921         UNCLAMPED_FLOAT_TO_CHAN(Bc, texUnit->EnvColor[2]);
922         UNCLAMPED_FLOAT_TO_CHAN(Ac, texUnit->EnvColor[3]);
923	 switch (format) {
924	    case GL_ALPHA:
925	       for (i=0;i<n;i++) {
926		  /* Cv = Cf */
927		  /* Av = AfAt */
928                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
929	       }
930	       break;
931            case GL_LUMINANCE:
932	       for (i=0;i<n;i++) {
933		  /* Cv = Cf(1-Lt) + CcLt */
934		  GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
935		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
936		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
937		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
938		  /* Av = Af */
939	       }
940	       break;
941	    case GL_LUMINANCE_ALPHA:
942	       for (i=0;i<n;i++) {
943		  /* Cv = Cf(1-Lt) + CcLt */
944		  GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
945		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
946		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
947		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
948		  /* Av = AfAt */
949		  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
950	       }
951	       break;
952            case GL_INTENSITY:
953	       for (i=0;i<n;i++) {
954		  /* Cv = Cf(1-It) + CcIt */
955		  GLchan It = texel[i][RCOMP], s = CHAN_MAX - It;
956		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, It);
957		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, It);
958		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, It);
959                  /* Av = Af(1-It) + Ac*It */
960                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], s) + CHAN_PRODUCT(Ac, It);
961               }
962               break;
963	    case GL_RGB:
964	       for (i=0;i<n;i++) {
965		  /* Cv = Cf(1-Ct) + CcCt */
966		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
967		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
968		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
969		  /* Av = Af */
970	       }
971	       break;
972	    case GL_RGBA:
973	       for (i=0;i<n;i++) {
974		  /* Cv = Cf(1-Ct) + CcCt */
975		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
976		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
977		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
978		  /* Av = AfAt */
979		  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
980	       }
981	       break;
982            default:
983               _mesa_problem(ctx, "Bad format (GL_BLEND) in texture_apply");
984               return;
985	 }
986	 break;
987
988     /* XXX don't clamp results if GLchan is float??? */
989
990      case GL_ADD:  /* GL_EXT_texture_add_env */
991         switch (format) {
992            case GL_ALPHA:
993               for (i=0;i<n;i++) {
994                  /* Rv = Rf */
995                  /* Gv = Gf */
996                  /* Bv = Bf */
997                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
998               }
999               break;
1000            case GL_LUMINANCE:
1001               for (i=0;i<n;i++) {
1002                  ChanTemp Lt = texel[i][RCOMP];
1003                  ChanTemp r = rgba[i][RCOMP] + Lt;
1004                  ChanTemp g = rgba[i][GCOMP] + Lt;
1005                  ChanTemp b = rgba[i][BCOMP] + Lt;
1006                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
1007                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
1008                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
1009                  /* Av = Af */
1010               }
1011               break;
1012            case GL_LUMINANCE_ALPHA:
1013               for (i=0;i<n;i++) {
1014                  ChanTemp Lt = texel[i][RCOMP];
1015                  ChanTemp r = rgba[i][RCOMP] + Lt;
1016                  ChanTemp g = rgba[i][GCOMP] + Lt;
1017                  ChanTemp b = rgba[i][BCOMP] + Lt;
1018                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
1019                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
1020                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
1021                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
1022               }
1023               break;
1024            case GL_INTENSITY:
1025               for (i=0;i<n;i++) {
1026                  GLchan It = texel[i][RCOMP];
1027                  ChanTemp r = rgba[i][RCOMP] + It;
1028                  ChanTemp g = rgba[i][GCOMP] + It;
1029                  ChanTemp b = rgba[i][BCOMP] + It;
1030                  ChanTemp a = rgba[i][ACOMP] + It;
1031                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
1032                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
1033                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
1034                  rgba[i][ACOMP] = MIN2(a, CHAN_MAX);
1035               }
1036               break;
1037	    case GL_RGB:
1038	       for (i=0;i<n;i++) {
1039                  ChanTemp r = rgba[i][RCOMP] + texel[i][RCOMP];
1040                  ChanTemp g = rgba[i][GCOMP] + texel[i][GCOMP];
1041                  ChanTemp b = rgba[i][BCOMP] + texel[i][BCOMP];
1042		  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
1043		  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
1044		  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
1045		  /* Av = Af */
1046	       }
1047	       break;
1048	    case GL_RGBA:
1049	       for (i=0;i<n;i++) {
1050                  ChanTemp r = rgba[i][RCOMP] + texel[i][RCOMP];
1051                  ChanTemp g = rgba[i][GCOMP] + texel[i][GCOMP];
1052                  ChanTemp b = rgba[i][BCOMP] + texel[i][BCOMP];
1053		  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
1054		  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
1055		  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
1056                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
1057               }
1058               break;
1059            default:
1060               _mesa_problem(ctx, "Bad format (GL_ADD) in texture_apply");
1061               return;
1062	 }
1063	 break;
1064
1065      default:
1066         _mesa_problem(ctx, "Bad env mode in texture_apply");
1067         return;
1068   }
1069}
1070
1071
1072
1073/**
1074 * Apply texture mapping to a span of fragments.
1075 */
1076void
1077_swrast_texture_span( GLcontext *ctx, SWspan *span )
1078{
1079   SWcontext *swrast = SWRAST_CONTEXT(ctx);
1080   GLchan primary_rgba[MAX_WIDTH][4];
1081   GLuint unit;
1082
1083   ASSERT(span->end < MAX_WIDTH);
1084
1085   /*
1086    * Save copy of the incoming fragment colors (the GL_PRIMARY_COLOR)
1087    */
1088   if (swrast->_AnyTextureCombine)
1089      MEMCPY(primary_rgba, span->array->rgba, 4 * span->end * sizeof(GLchan));
1090
1091   /*
1092    * Must do all texture sampling before combining in order to
1093    * accomodate GL_ARB_texture_env_crossbar.
1094    */
1095   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
1096      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
1097         const GLfloat (*texcoords)[4]
1098            = (const GLfloat (*)[4])
1099            span->array->attribs[FRAG_ATTRIB_TEX0 + unit];
1100         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
1101         const struct gl_texture_object *curObj = texUnit->_Current;
1102         GLfloat *lambda = span->array->lambda[unit];
1103         GLchan (*texels)[4] = (GLchan (*)[4])
1104            (swrast->TexelBuffer + unit * (span->end * 4 * sizeof(GLchan)));
1105
1106         /* adjust texture lod (lambda) */
1107         if (span->arrayMask & SPAN_LAMBDA) {
1108            if (texUnit->LodBias + curObj->LodBias != 0.0F) {
1109               /* apply LOD bias, but don't clamp yet */
1110               const GLfloat bias = CLAMP(texUnit->LodBias + curObj->LodBias,
1111                                          -ctx->Const.MaxTextureLodBias,
1112                                          ctx->Const.MaxTextureLodBias);
1113               GLuint i;
1114               for (i = 0; i < span->end; i++) {
1115                  lambda[i] += bias;
1116               }
1117            }
1118
1119            if (curObj->MinLod != -1000.0 || curObj->MaxLod != 1000.0) {
1120               /* apply LOD clamping to lambda */
1121               const GLfloat min = curObj->MinLod;
1122               const GLfloat max = curObj->MaxLod;
1123               GLuint i;
1124               for (i = 0; i < span->end; i++) {
1125                  GLfloat l = lambda[i];
1126                  lambda[i] = CLAMP(l, min, max);
1127               }
1128            }
1129         }
1130
1131         /* Sample the texture (span->end = number of fragments) */
1132         swrast->TextureSample[unit]( ctx, texUnit->_Current, span->end,
1133                                      texcoords, lambda, texels );
1134
1135         /* GL_SGI_texture_color_table */
1136         if (texUnit->ColorTableEnabled) {
1137#if CHAN_TYPE == GL_UNSIGNED_BYTE
1138            _mesa_lookup_rgba_ubyte(&texUnit->ColorTable, span->end, texels);
1139#elif CHAN_TYPE == GL_UNSIGNED_SHORT
1140            _mesa_lookup_rgba_ubyte(&texUnit->ColorTable, span->end, texels);
1141#else
1142            _mesa_lookup_rgba_float(&texUnit->ColorTable, span->end, texels);
1143#endif
1144         }
1145      }
1146   }
1147
1148   /*
1149    * OK, now apply the texture (aka texture combine/blend).
1150    * We modify the span->color.rgba values.
1151    */
1152   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
1153      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
1154         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
1155         if (texUnit->_CurrentCombine != &texUnit->_EnvMode ) {
1156            texture_combine( ctx, unit, span->end,
1157                             (CONST GLchan (*)[4]) primary_rgba,
1158                             swrast->TexelBuffer,
1159                             span->array->rgba );
1160         }
1161         else {
1162            /* conventional texture blend */
1163            const GLchan (*texels)[4] = (const GLchan (*)[4])
1164               (swrast->TexelBuffer + unit *
1165                (span->end * 4 * sizeof(GLchan)));
1166            texture_apply( ctx, texUnit, span->end,
1167                           (CONST GLchan (*)[4]) primary_rgba, texels,
1168                           span->array->rgba );
1169         }
1170      }
1171   }
1172}
1173