Split the s_texture.c file into two new files:

  s_texcombine.c - for texture combining/application
  s_texfilter.c - for texture sampling/filtering

1 files changed, 1162 insertions, 0 deletions

diff --git a/src/mesa/swrast/s_texcombine.c b/src/mesa/swrast/s_texcombine.c
new file mode 100644
index 00000000000..65eccad2e91
--- /dev/null
+++ b/src/mesa/swrast/s_texcombine.c
@@ -0,0 +1,1162 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.5
+ *
+ * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#include "glheader.h"
+#include "context.h"
+#include "colormac.h"
+#include "imports.h"
+#include "macros.h"
+#include "pixel.h"
+
+#include "s_context.h"
+#include "s_texcombine.h"
+
+
+#define PROD(A,B)   ( (GLuint)(A) * ((GLuint)(B)+1) )
+#define S_PROD(A,B) ( (GLint)(A) * ((GLint)(B)+1) )
+
+
+/**
+ * Do texture application for GL_ARB/EXT_texture_env_combine.
+ * This function also supports GL_{EXT,ARB}_texture_env_dot3 and
+ * GL_ATI_texture_env_combine3.  Since "classic" texture environments are
+ * implemented using GL_ARB_texture_env_combine-like state, this same function
+ * is used for classic texture environment application as well.
+ *
+ * \param ctx          rendering context
+ * \param textureUnit  the texture unit to apply
+ * \param n            number of fragments to process (span width)
+ * \param primary_rgba incoming fragment color array
+ * \param texelBuffer  pointer to texel colors for all texture units
+ * 
+ * \param rgba         incoming colors, which get modified here
+ */
+static void
+texture_combine( const GLcontext *ctx, GLuint unit, GLuint n,
+                 CONST GLchan (*primary_rgba)[4],
+                 CONST GLchan *texelBuffer,
+                 GLchan (*rgba)[4] )
+{
+   const struct gl_texture_unit *textureUnit = &(ctx->Texture.Unit[unit]);
+   const GLchan (*argRGB [3])[4];
+   const GLchan (*argA [3])[4];
+   const GLuint RGBshift = textureUnit->_CurrentCombine->ScaleShiftRGB;
+   const GLuint Ashift   = textureUnit->_CurrentCombine->ScaleShiftA;
+#if CHAN_TYPE == GL_FLOAT
+   const GLchan RGBmult = (GLfloat) (1 << RGBshift);
+   const GLchan Amult = (GLfloat) (1 << Ashift);
+   static const GLchan one[4] = { 1.0, 1.0, 1.0, 1.0 };
+   static const GLchan zero[4] = { 0.0, 0.0, 0.0, 0.0 };
+#else
+   const GLint half = (CHAN_MAX + 1) / 2;
+   static const GLchan one[4] = { CHAN_MAX, CHAN_MAX, CHAN_MAX, CHAN_MAX };
+   static const GLchan zero[4] = { 0, 0, 0, 0 };
+#endif
+   const GLuint numColorArgs = textureUnit->_CurrentCombine->_NumArgsRGB;
+   const GLuint numAlphaArgs = textureUnit->_CurrentCombine->_NumArgsA;
+   GLchan ccolor[3][MAX_WIDTH][4];
+   GLuint i, j;
+
+   ASSERT(ctx->Extensions.EXT_texture_env_combine ||
+          ctx->Extensions.ARB_texture_env_combine);
+   ASSERT(SWRAST_CONTEXT(ctx)->_AnyTextureCombine);
+
+   /*
+   printf("modeRGB 0x%x  modeA 0x%x  srcRGB1 0x%x  srcA1 0x%x  srcRGB2 0x%x  srcA2 0x%x\n",
+          textureUnit->_CurrentCombine->ModeRGB,
+          textureUnit->_CurrentCombine->ModeA,
+          textureUnit->_CurrentCombine->SourceRGB[0],
+          textureUnit->_CurrentCombine->SourceA[0],
+          textureUnit->_CurrentCombine->SourceRGB[1],
+          textureUnit->_CurrentCombine->SourceA[1]);
+   */
+
+   /*
+    * Do operand setup for up to 3 operands.  Loop over the terms.
+    */
+   for (j = 0; j < numColorArgs; j++) {
+      const GLenum srcRGB = textureUnit->_CurrentCombine->SourceRGB[j];
+
+
+      switch (srcRGB) {
+         case GL_TEXTURE:
+            argRGB[j] = (const GLchan (*)[4])
+               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
+            break;
+         case GL_PRIMARY_COLOR:
+            argRGB[j] = primary_rgba;
+            break;
+         case GL_PREVIOUS:
+            argRGB[j] = (const GLchan (*)[4]) rgba;
+            break;
+         case GL_CONSTANT:
+            {
+               GLchan (*c)[4] = ccolor[j];
+               GLchan red, green, blue, alpha;
+               UNCLAMPED_FLOAT_TO_CHAN(red,   textureUnit->EnvColor[0]);
+               UNCLAMPED_FLOAT_TO_CHAN(green, textureUnit->EnvColor[1]);
+               UNCLAMPED_FLOAT_TO_CHAN(blue,  textureUnit->EnvColor[2]);
+               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
+               for (i = 0; i < n; i++) {
+                  c[i][RCOMP] = red;
+                  c[i][GCOMP] = green;
+                  c[i][BCOMP] = blue;
+                  c[i][ACOMP] = alpha;
+               }
+               argRGB[j] = (const GLchan (*)[4]) ccolor[j];
+            }
+            break;
+	 /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
+	  */
+	 case GL_ZERO:
+            argRGB[j] = & zero;
+            break;
+	 case GL_ONE:
+            argRGB[j] = & one;
+            break;
+         default:
+            /* ARB_texture_env_crossbar source */
+            {
+               const GLuint srcUnit = srcRGB - GL_TEXTURE0;
+               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
+               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
+                  return;
+               argRGB[j] = (const GLchan (*)[4])
+                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
+            }
+      }
+
+      if (textureUnit->_CurrentCombine->OperandRGB[j] != GL_SRC_COLOR) {
+         const GLchan (*src)[4] = argRGB[j];
+         GLchan (*dst)[4] = ccolor[j];
+
+         /* point to new arg[j] storage */
+         argRGB[j] = (const GLchan (*)[4]) ccolor[j];
+
+         if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_ONE_MINUS_SRC_COLOR) {
+            for (i = 0; i < n; i++) {
+               dst[i][RCOMP] = CHAN_MAX - src[i][RCOMP];
+               dst[i][GCOMP] = CHAN_MAX - src[i][GCOMP];
+               dst[i][BCOMP] = CHAN_MAX - src[i][BCOMP];
+            }
+         }
+         else if (textureUnit->_CurrentCombine->OperandRGB[j] == GL_SRC_ALPHA) {
+            for (i = 0; i < n; i++) {
+               dst[i][RCOMP] = src[i][ACOMP];
+               dst[i][GCOMP] = src[i][ACOMP];
+               dst[i][BCOMP] = src[i][ACOMP];
+            }
+         }
+         else {
+            ASSERT(textureUnit->_CurrentCombine->OperandRGB[j] ==GL_ONE_MINUS_SRC_ALPHA);
+            for (i = 0; i < n; i++) {
+               dst[i][RCOMP] = CHAN_MAX - src[i][ACOMP];
+               dst[i][GCOMP] = CHAN_MAX - src[i][ACOMP];
+               dst[i][BCOMP] = CHAN_MAX - src[i][ACOMP];
+            }
+         }
+      }
+   }
+
+   /*
+    * Set up the argA[i] pointers
+    */
+   for (j = 0; j < numAlphaArgs; j++) {
+      const GLenum srcA = textureUnit->_CurrentCombine->SourceA[j];
+
+      switch (srcA) {
+         case GL_TEXTURE:
+            argA[j] = (const GLchan (*)[4])
+               (texelBuffer + unit * (n * 4 * sizeof(GLchan)));
+            break;
+         case GL_PRIMARY_COLOR:
+            argA[j] = primary_rgba;
+            break;
+         case GL_PREVIOUS:
+            argA[j] = (const GLchan (*)[4]) rgba;
+            break;
+         case GL_CONSTANT:
+            {
+               GLchan alpha, (*c)[4] = ccolor[j];
+               UNCLAMPED_FLOAT_TO_CHAN(alpha, textureUnit->EnvColor[3]);
+               for (i = 0; i < n; i++)
+                  c[i][ACOMP] = alpha;
+               argA[j] = (const GLchan (*)[4]) ccolor[j];
+            }
+            break;
+	 /* GL_ATI_texture_env_combine3 allows GL_ZERO & GL_ONE as sources.
+	  */
+	 case GL_ZERO:
+            argA[j] = & zero;
+            break;
+	 case GL_ONE:
+            argA[j] = & one;
+            break;
+         default:
+            /* ARB_texture_env_crossbar source */
+            {
+               const GLuint srcUnit = srcA - GL_TEXTURE0;
+               ASSERT(srcUnit < ctx->Const.MaxTextureUnits);
+               if (!ctx->Texture.Unit[srcUnit]._ReallyEnabled)
+                  return;
+               argA[j] = (const GLchan (*)[4])
+                  (texelBuffer + srcUnit * (n * 4 * sizeof(GLchan)));
+            }
+      }
+
+      if (textureUnit->_CurrentCombine->OperandA[j] == GL_ONE_MINUS_SRC_ALPHA) {
+         const GLchan (*src)[4] = argA[j];
+         GLchan (*dst)[4] = ccolor[j];
+         argA[j] = (const GLchan (*)[4]) ccolor[j];
+         for (i = 0; i < n; i++) {
+            dst[i][ACOMP] = CHAN_MAX - src[i][ACOMP];
+         }
+      }
+   }
+
+   /*
+    * Do the texture combine.
+    */
+   switch (textureUnit->_CurrentCombine->ModeRGB) {
+      case GL_REPLACE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            if (RGBshift) {
+               for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+                  rgba[i][RCOMP] = arg0[i][RCOMP] * RGBmult;
+                  rgba[i][GCOMP] = arg0[i][GCOMP] * RGBmult;
+                  rgba[i][BCOMP] = arg0[i][BCOMP] * RGBmult;
+#else
+                  GLuint r = (GLuint) arg0[i][RCOMP] << RGBshift;
+                  GLuint g = (GLuint) arg0[i][GCOMP] << RGBshift;
+                  GLuint b = (GLuint) arg0[i][BCOMP] << RGBshift;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+#endif
+               }
+            }
+            else {
+               for (i = 0; i < n; i++) {
+                  rgba[i][RCOMP] = arg0[i][RCOMP];
+                  rgba[i][GCOMP] = arg0[i][GCOMP];
+                  rgba[i][BCOMP] = arg0[i][BCOMP];
+               }
+            }
+         }
+         break;
+      case GL_MODULATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = arg0[i][RCOMP] * arg1[i][RCOMP] * RGBmult;
+               rgba[i][GCOMP] = arg0[i][GCOMP] * arg1[i][GCOMP] * RGBmult;
+               rgba[i][BCOMP] = arg0[i][BCOMP] * arg1[i][BCOMP] * RGBmult;
+#else
+               GLuint r = PROD(arg0[i][RCOMP], arg1[i][RCOMP]) >> shift;
+               GLuint g = PROD(arg0[i][GCOMP], arg1[i][GCOMP]) >> shift;
+               GLuint b = PROD(arg0[i][BCOMP], arg1[i][BCOMP]) >> shift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP]) * RGBmult;
+#else
+               GLint r = ((GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP]) << RGBshift;
+               GLint g = ((GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP]) << RGBshift;
+               GLint b = ((GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP]) << RGBshift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD_SIGNED:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] + arg1[i][RCOMP] - 0.5) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] + arg1[i][GCOMP] - 0.5) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] + arg1[i][BCOMP] - 0.5) * RGBmult;
+#else
+               GLint r = (GLint) arg0[i][RCOMP] + (GLint) arg1[i][RCOMP] -half;
+               GLint g = (GLint) arg0[i][GCOMP] + (GLint) arg1[i][GCOMP] -half;
+               GLint b = (GLint) arg0[i][BCOMP] + (GLint) arg1[i][BCOMP] -half;
+               r = (r < 0) ? 0 : r << RGBshift;
+               g = (g < 0) ? 0 : g << RGBshift;
+               b = (b < 0) ? 0 : b << RGBshift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_INTERPOLATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] * arg2[i][RCOMP] +
+                      arg1[i][RCOMP] * (CHAN_MAXF - arg2[i][RCOMP])) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] * arg2[i][GCOMP] +
+                      arg1[i][GCOMP] * (CHAN_MAXF - arg2[i][GCOMP])) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] * arg2[i][BCOMP] +
+                      arg1[i][BCOMP] * (CHAN_MAXF - arg2[i][BCOMP])) * RGBmult;
+#else
+               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+                           + PROD(arg1[i][RCOMP], CHAN_MAX - arg2[i][RCOMP]))
+                              >> shift;
+               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+                           + PROD(arg1[i][GCOMP], CHAN_MAX - arg2[i][GCOMP]))
+                              >> shift;
+               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+                           + PROD(arg1[i][BCOMP], CHAN_MAX - arg2[i][BCOMP]))
+                              >> shift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_SUBTRACT:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = (arg0[i][RCOMP] - arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = (arg0[i][GCOMP] - arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = (arg0[i][BCOMP] - arg1[i][BCOMP]) * RGBmult;
+#else
+               GLint r = ((GLint) arg0[i][RCOMP] - (GLint) arg1[i][RCOMP]) << RGBshift;
+               GLint g = ((GLint) arg0[i][GCOMP] - (GLint) arg1[i][GCOMP]) << RGBshift;
+               GLint b = ((GLint) arg0[i][BCOMP] - (GLint) arg1[i][BCOMP]) << RGBshift;
+               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_DOT3_RGB_EXT:
+      case GL_DOT3_RGBA_EXT:
+         {
+            /* Do not scale the result by 1 2 or 4 */
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
+                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
+                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
+                            * 4.0F;
+               dot = CLAMP(dot, 0.0F, CHAN_MAXF);
+#else
+               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
+				   (GLint)arg1[i][RCOMP] - half) +
+			    S_PROD((GLint)arg0[i][GCOMP] - half,
+				   (GLint)arg1[i][GCOMP] - half) +
+			    S_PROD((GLint)arg0[i][BCOMP] - half,
+				   (GLint)arg1[i][BCOMP] - half)) >> 6;
+               dot = CLAMP(dot, 0, CHAN_MAX);
+#endif
+               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
+            }
+         }
+         break;
+      case GL_DOT3_RGB:
+      case GL_DOT3_RGBA:
+         {
+            /* DO scale the result by 1 2 or 4 */
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               GLchan dot = ((arg0[i][RCOMP]-0.5F) * (arg1[i][RCOMP]-0.5F) +
+                             (arg0[i][GCOMP]-0.5F) * (arg1[i][GCOMP]-0.5F) +
+                             (arg0[i][BCOMP]-0.5F) * (arg1[i][BCOMP]-0.5F))
+                            * 4.0F * RGBmult;
+               dot = CLAMP(dot, 0.0, CHAN_MAXF);
+#else
+               GLint dot = (S_PROD((GLint)arg0[i][RCOMP] - half,
+				   (GLint)arg1[i][RCOMP] - half) +
+			    S_PROD((GLint)arg0[i][GCOMP] - half,
+				   (GLint)arg1[i][GCOMP] - half) +
+			    S_PROD((GLint)arg0[i][BCOMP] - half,
+				   (GLint)arg1[i][BCOMP] - half)) >> 6;
+               dot <<= RGBshift;
+               dot = CLAMP(dot, 0, CHAN_MAX);
+#endif
+               rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = (GLchan) dot;
+            }
+         }
+         break;
+      case GL_MODULATE_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP]) * RGBmult;
+#else
+               GLuint r = (PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+                           + ((GLuint) arg1[i][RCOMP] << CHAN_BITS)) >> shift;
+               GLuint g = (PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+                           + ((GLuint) arg1[i][GCOMP] << CHAN_BITS)) >> shift;
+               GLuint b = (PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+                           + ((GLuint) arg1[i][BCOMP] << CHAN_BITS)) >> shift;
+               rgba[i][RCOMP] = (GLchan) MIN2(r, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) MIN2(g, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) MIN2(b, CHAN_MAX);
+#endif
+            }
+	 }
+         break;
+      case GL_MODULATE_SIGNED_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) + arg1[i][RCOMP] - 0.5) * RGBmult;
+               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) + arg1[i][GCOMP] - 0.5) * RGBmult;
+               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) + arg1[i][BCOMP] - 0.5) * RGBmult;
+#else
+               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+			  + (((GLint) arg1[i][RCOMP] - half) << CHAN_BITS))
+		    >> shift;
+               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+			  + (((GLint) arg1[i][GCOMP] - half) << CHAN_BITS))
+		    >> shift;
+               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+			  + (((GLint) arg1[i][BCOMP] - half) << CHAN_BITS))
+		    >> shift;
+               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
+#endif
+            }
+	 }
+         break;
+      case GL_MODULATE_SUBTRACT_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argRGB[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argRGB[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argRGB[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - RGBshift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][RCOMP] = ((arg0[i][RCOMP] * arg2[i][RCOMP]) - arg1[i][RCOMP]) * RGBmult;
+               rgba[i][GCOMP] = ((arg0[i][GCOMP] * arg2[i][GCOMP]) - arg1[i][GCOMP]) * RGBmult;
+               rgba[i][BCOMP] = ((arg0[i][BCOMP] * arg2[i][BCOMP]) - arg1[i][BCOMP]) * RGBmult;
+#else
+               GLint r = (S_PROD(arg0[i][RCOMP], arg2[i][RCOMP])
+			  - ((GLint) arg1[i][RCOMP] << CHAN_BITS))
+		    >> shift;
+               GLint g = (S_PROD(arg0[i][GCOMP], arg2[i][GCOMP])
+			  - ((GLint) arg1[i][GCOMP] << CHAN_BITS))
+		    >> shift;
+               GLint b = (S_PROD(arg0[i][BCOMP], arg2[i][BCOMP])
+			  - ((GLint) arg1[i][BCOMP] << CHAN_BITS))
+		    >> shift;
+               rgba[i][RCOMP] = (GLchan) CLAMP(r, 0, CHAN_MAX);
+               rgba[i][GCOMP] = (GLchan) CLAMP(g, 0, CHAN_MAX);
+               rgba[i][BCOMP] = (GLchan) CLAMP(b, 0, CHAN_MAX);
+#endif
+            }
+	 }
+         break;
+      default:
+         _mesa_problem(ctx, "invalid combine mode");
+   }
+
+   switch (textureUnit->_CurrentCombine->ModeA) {
+      case GL_REPLACE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            if (Ashift) {
+               for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+                  GLchan a = arg0[i][ACOMP] * Amult;
+#else
+                  GLuint a = (GLuint) arg0[i][ACOMP] << Ashift;
+#endif
+                  rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+               }
+            }
+            else {
+               for (i = 0; i < n; i++) {
+                  rgba[i][ACOMP] = arg0[i][ACOMP];
+               }
+            }
+         }
+         break;
+      case GL_MODULATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = arg0[i][ACOMP] * arg1[i][ACOMP] * Amult;
+#else
+               GLuint a = (PROD(arg0[i][ACOMP], arg1[i][ACOMP]) >> shift);
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan  (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = ((GLint) arg0[i][ACOMP] + arg1[i][ACOMP]) << Ashift;
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_ADD_SIGNED:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] + arg1[i][ACOMP] - 0.5F) * Amult;
+#else
+               GLint a = (GLint) arg0[i][ACOMP] + (GLint) arg1[i][ACOMP] -half;
+               a = (a < 0) ? 0 : a << Ashift;
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_INTERPOLATE:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i=0; i<n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] * arg2[i][ACOMP] +
+                                 arg1[i][ACOMP] * (CHAN_MAXF - arg2[i][ACOMP]))
+                                * Amult;
+#else
+               GLuint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
+                           + PROD(arg1[i][ACOMP], CHAN_MAX - arg2[i][ACOMP]))
+                              >> shift;
+               rgba[i][ACOMP] = (GLchan) MIN2(a, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_SUBTRACT:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = (arg0[i][ACOMP] - arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = ((GLint) arg0[i][ACOMP] - (GLint) arg1[i][ACOMP]) << Ashift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_MODULATE_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = (PROD(arg0[i][ACOMP], arg2[i][ACOMP])
+			   + ((GLuint) arg1[i][ACOMP] << CHAN_BITS))
+		    >> shift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_MODULATE_SIGNED_ADD_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) + arg1[i][ACOMP] - 0.5F) * Amult;
+#else
+               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP])
+			  + (((GLint) arg1[i][ACOMP] - half) << CHAN_BITS))
+		    >> shift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      case GL_MODULATE_SUBTRACT_ATI:
+         {
+            const GLchan (*arg0)[4] = (const GLchan (*)[4]) argA[0];
+            const GLchan (*arg1)[4] = (const GLchan (*)[4]) argA[1];
+            const GLchan (*arg2)[4] = (const GLchan (*)[4]) argA[2];
+#if CHAN_TYPE != GL_FLOAT
+            const GLint shift = CHAN_BITS - Ashift;
+#endif
+            for (i = 0; i < n; i++) {
+#if CHAN_TYPE == GL_FLOAT
+               rgba[i][ACOMP] = ((arg0[i][ACOMP] * arg2[i][ACOMP]) - arg1[i][ACOMP]) * Amult;
+#else
+               GLint a = (S_PROD(arg0[i][ACOMP], arg2[i][ACOMP]) 
+			  - ((GLint) arg1[i][ACOMP] << CHAN_BITS))
+		    >> shift;
+               rgba[i][ACOMP] = (GLchan) CLAMP(a, 0, CHAN_MAX);
+#endif
+            }
+         }
+         break;
+      default:
+         _mesa_problem(ctx, "invalid combine mode");
+   }
+
+   /* Fix the alpha component for GL_DOT3_RGBA_EXT/ARB combining.
+    * This is kind of a kludge.  It would have been better if the spec
+    * were written such that the GL_COMBINE_ALPHA value could be set to
+    * GL_DOT3.
+    */
+   if (textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA_EXT ||
+       textureUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA) {
+      for (i = 0; i < n; i++) {
+	 rgba[i][ACOMP] = rgba[i][RCOMP];
+      }
+   }
+}
+#undef PROD
+
+
+/**
+ * Apply a conventional OpenGL texture env mode (REPLACE, ADD, BLEND,
+ * MODULATE, or DECAL) to an array of fragments.
+ * Input:  textureUnit - pointer to texture unit to apply
+ *         format - base internal texture format
+ *         n - number of fragments
+ *         primary_rgba - primary colors (may alias rgba for single texture)
+ *         texels - array of texel colors
+ * InOut:  rgba - incoming fragment colors modified by texel colors
+ *                according to the texture environment mode.
+ */
+static void
+texture_apply( const GLcontext *ctx,
+               const struct gl_texture_unit *texUnit,
+               GLuint n,
+               CONST GLchan primary_rgba[][4], CONST GLchan texel[][4],
+               GLchan rgba[][4] )
+{
+   GLint baseLevel;
+   GLuint i;
+   GLint Rc, Gc, Bc, Ac;
+   GLenum format;
+   (void) primary_rgba;
+
+   ASSERT(texUnit);
+   ASSERT(texUnit->_Current);
+
+   baseLevel = texUnit->_Current->BaseLevel;
+   ASSERT(texUnit->_Current->Image[0][baseLevel]);
+
+   format = texUnit->_Current->Image[0][baseLevel]->Format;
+
+   if (format == GL_COLOR_INDEX || format == GL_YCBCR_MESA) {
+      format = GL_RGBA;  /* a bit of a hack */
+   }
+   else if (format == GL_DEPTH_COMPONENT) {
+      format = texUnit->_Current->DepthMode;
+   }
+
+   switch (texUnit->EnvMode) {
+      case GL_REPLACE:
+	 switch (format) {
+	    case GL_ALPHA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf */
+                  /* Av = At */
+                  rgba[i][ACOMP] = texel[i][ACOMP];
+	       }
+	       break;
+	    case GL_LUMINANCE:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Lt */
+                  GLchan Lt = texel[i][RCOMP];
+                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
+                  /* Av = Af */
+	       }
+	       break;
+	    case GL_LUMINANCE_ALPHA:
+	       for (i=0;i<n;i++) {
+                  GLchan Lt = texel[i][RCOMP];
+		  /* Cv = Lt */
+		  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = Lt;
+		  /* Av = At */
+		  rgba[i][ACOMP] = texel[i][ACOMP];
+	       }
+	       break;
+	    case GL_INTENSITY:
+	       for (i=0;i<n;i++) {
+		  /* Cv = It */
+                  GLchan It = texel[i][RCOMP];
+                  rgba[i][RCOMP] = rgba[i][GCOMP] = rgba[i][BCOMP] = It;
+                  /* Av = It */
+                  rgba[i][ACOMP] = It;
+	       }
+	       break;
+	    case GL_RGB:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Ct */
+		  rgba[i][RCOMP] = texel[i][RCOMP];
+		  rgba[i][GCOMP] = texel[i][GCOMP];
+		  rgba[i][BCOMP] = texel[i][BCOMP];
+		  /* Av = Af */
+	       }
+	       break;
+	    case GL_RGBA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Ct */
+		  rgba[i][RCOMP] = texel[i][RCOMP];
+		  rgba[i][GCOMP] = texel[i][GCOMP];
+		  rgba[i][BCOMP] = texel[i][BCOMP];
+		  /* Av = At */
+		  rgba[i][ACOMP] = texel[i][ACOMP];
+	       }
+	       break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_REPLACE) in texture_apply");
+               return;
+	 }
+	 break;
+
+      case GL_MODULATE:
+         switch (format) {
+	    case GL_ALPHA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf */
+		  /* Av = AfAt */
+		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
+	       }
+	       break;
+	    case GL_LUMINANCE:
+	       for (i=0;i<n;i++) {
+		  /* Cv = LtCf */
+                  GLchan Lt = texel[i][RCOMP];
+		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
+		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
+		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
+		  /* Av = Af */
+	       }
+	       break;
+	    case GL_LUMINANCE_ALPHA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = CfLt */
+                  GLchan Lt = texel[i][RCOMP];
+		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], Lt );
+		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], Lt );
+		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], Lt );
+		  /* Av = AfAt */
+		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
+	       }
+	       break;
+	    case GL_INTENSITY:
+	       for (i=0;i<n;i++) {
+		  /* Cv = CfIt */
+                  GLchan It = texel[i][RCOMP];
+		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], It );
+		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], It );
+		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], It );
+		  /* Av = AfIt */
+		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], It );
+	       }
+	       break;
+	    case GL_RGB:
+	       for (i=0;i<n;i++) {
+		  /* Cv = CfCt */
+		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
+		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
+		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
+		  /* Av = Af */
+	       }
+	       break;
+	    case GL_RGBA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = CfCt */
+		  rgba[i][RCOMP] = CHAN_PRODUCT( rgba[i][RCOMP], texel[i][RCOMP] );
+		  rgba[i][GCOMP] = CHAN_PRODUCT( rgba[i][GCOMP], texel[i][GCOMP] );
+		  rgba[i][BCOMP] = CHAN_PRODUCT( rgba[i][BCOMP], texel[i][BCOMP] );
+		  /* Av = AfAt */
+		  rgba[i][ACOMP] = CHAN_PRODUCT( rgba[i][ACOMP], texel[i][ACOMP] );
+	       }
+	       break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_MODULATE) in texture_apply");
+               return;
+	 }
+	 break;
+
+      case GL_DECAL:
+         switch (format) {
+            case GL_ALPHA:
+            case GL_LUMINANCE:
+            case GL_LUMINANCE_ALPHA:
+            case GL_INTENSITY:
+               /* undefined */
+               break;
+	    case GL_RGB:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Ct */
+		  rgba[i][RCOMP] = texel[i][RCOMP];
+		  rgba[i][GCOMP] = texel[i][GCOMP];
+		  rgba[i][BCOMP] = texel[i][BCOMP];
+		  /* Av = Af */
+	       }
+	       break;
+	    case GL_RGBA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf(1-At) + CtAt */
+		  GLint t = texel[i][ACOMP], s = CHAN_MAX - t;
+		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(texel[i][RCOMP],t);
+		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(texel[i][GCOMP],t);
+		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(texel[i][BCOMP],t);
+		  /* Av = Af */
+	       }
+	       break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_DECAL) in texture_apply");
+               return;
+	 }
+	 break;
+
+      case GL_BLEND:
+         Rc = (GLint) (texUnit->EnvColor[0] * CHAN_MAXF);
+         Gc = (GLint) (texUnit->EnvColor[1] * CHAN_MAXF);
+         Bc = (GLint) (texUnit->EnvColor[2] * CHAN_MAXF);
+         Ac = (GLint) (texUnit->EnvColor[3] * CHAN_MAXF);
+	 switch (format) {
+	    case GL_ALPHA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf */
+		  /* Av = AfAt */
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+	       }
+	       break;
+            case GL_LUMINANCE:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf(1-Lt) + CcLt */
+		  GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
+		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
+		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
+		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
+		  /* Av = Af */
+	       }
+	       break;
+	    case GL_LUMINANCE_ALPHA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf(1-Lt) + CcLt */
+		  GLchan Lt = texel[i][RCOMP], s = CHAN_MAX - Lt;
+		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, Lt);
+		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, Lt);
+		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, Lt);
+		  /* Av = AfAt */
+		  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
+	       }
+	       break;
+            case GL_INTENSITY:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf(1-It) + CcIt */
+		  GLchan It = texel[i][RCOMP], s = CHAN_MAX - It;
+		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], s) + CHAN_PRODUCT(Rc, It);
+		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], s) + CHAN_PRODUCT(Gc, It);
+		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], s) + CHAN_PRODUCT(Bc, It);
+                  /* Av = Af(1-It) + Ac*It */
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], s) + CHAN_PRODUCT(Ac, It);
+               }
+               break;
+	    case GL_RGB:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf(1-Ct) + CcCt */
+		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
+		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
+		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
+		  /* Av = Af */
+	       }
+	       break;
+	    case GL_RGBA:
+	       for (i=0;i<n;i++) {
+		  /* Cv = Cf(1-Ct) + CcCt */
+		  rgba[i][RCOMP] = CHAN_PRODUCT(rgba[i][RCOMP], (CHAN_MAX-texel[i][RCOMP])) + CHAN_PRODUCT(Rc,texel[i][RCOMP]);
+		  rgba[i][GCOMP] = CHAN_PRODUCT(rgba[i][GCOMP], (CHAN_MAX-texel[i][GCOMP])) + CHAN_PRODUCT(Gc,texel[i][GCOMP]);
+		  rgba[i][BCOMP] = CHAN_PRODUCT(rgba[i][BCOMP], (CHAN_MAX-texel[i][BCOMP])) + CHAN_PRODUCT(Bc,texel[i][BCOMP]);
+		  /* Av = AfAt */
+		  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP],texel[i][ACOMP]);
+	       }
+	       break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_BLEND) in texture_apply");
+               return;
+	 }
+	 break;
+
+     /* XXX don't clamp results if GLchan is float??? */
+
+      case GL_ADD:  /* GL_EXT_texture_add_env */
+         switch (format) {
+            case GL_ALPHA:
+               for (i=0;i<n;i++) {
+                  /* Rv = Rf */
+                  /* Gv = Gf */
+                  /* Bv = Bf */
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+               }
+               break;
+            case GL_LUMINANCE:
+               for (i=0;i<n;i++) {
+                  GLuint Lt = texel[i][RCOMP];
+                  GLuint r = rgba[i][RCOMP] + Lt;
+                  GLuint g = rgba[i][GCOMP] + Lt;
+                  GLuint b = rgba[i][BCOMP] + Lt;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  /* Av = Af */
+               }
+               break;
+            case GL_LUMINANCE_ALPHA:
+               for (i=0;i<n;i++) {
+                  GLuint Lt = texel[i][RCOMP];
+                  GLuint r = rgba[i][RCOMP] + Lt;
+                  GLuint g = rgba[i][GCOMP] + Lt;
+                  GLuint b = rgba[i][BCOMP] + Lt;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+               }
+               break;
+            case GL_INTENSITY:
+               for (i=0;i<n;i++) {
+                  GLchan It = texel[i][RCOMP];
+                  GLuint r = rgba[i][RCOMP] + It;
+                  GLuint g = rgba[i][GCOMP] + It;
+                  GLuint b = rgba[i][BCOMP] + It;
+                  GLuint a = rgba[i][ACOMP] + It;
+                  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+                  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+                  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  rgba[i][ACOMP] = MIN2(a, CHAN_MAX);
+               }
+               break;
+	    case GL_RGB:
+	       for (i=0;i<n;i++) {
+                  GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
+                  GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
+                  GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
+		  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+		  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+		  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+		  /* Av = Af */
+	       }
+	       break;
+	    case GL_RGBA:
+	       for (i=0;i<n;i++) {
+                  GLuint r = rgba[i][RCOMP] + texel[i][RCOMP];
+                  GLuint g = rgba[i][GCOMP] + texel[i][GCOMP];
+                  GLuint b = rgba[i][BCOMP] + texel[i][BCOMP];
+		  rgba[i][RCOMP] = MIN2(r, CHAN_MAX);
+		  rgba[i][GCOMP] = MIN2(g, CHAN_MAX);
+		  rgba[i][BCOMP] = MIN2(b, CHAN_MAX);
+                  rgba[i][ACOMP] = CHAN_PRODUCT(rgba[i][ACOMP], texel[i][ACOMP]);
+               }
+               break;
+            default:
+               _mesa_problem(ctx, "Bad format (GL_ADD) in texture_apply");
+               return;
+	 }
+	 break;
+
+      default:
+         _mesa_problem(ctx, "Bad env mode in texture_apply");
+         return;
+   }
+}
+
+
+
+/**
+ * Apply texture mapping to a span of fragments.
+ */
+void
+_swrast_texture_span( GLcontext *ctx, struct sw_span *span )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   GLchan primary_rgba[MAX_WIDTH][4];
+   GLuint unit;
+
+   ASSERT(span->end < MAX_WIDTH);
+   ASSERT(span->arrayMask & SPAN_TEXTURE);
+
+   /*
+    * Save copy of the incoming fragment colors (the GL_PRIMARY_COLOR)
+    */
+   if (swrast->_AnyTextureCombine)
+      MEMCPY(primary_rgba, span->array->rgba, 4 * span->end * sizeof(GLchan));
+
+   /*
+    * Must do all texture sampling before combining in order to
+    * accomodate GL_ARB_texture_env_crossbar.
+    */
+   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
+      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
+         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
+         const struct gl_texture_object *curObj = texUnit->_Current;
+         GLfloat *lambda = span->array->lambda[unit];
+         GLchan (*texels)[4] = (GLchan (*)[4])
+            (swrast->TexelBuffer + unit * (span->end * 4 * sizeof(GLchan)));
+
+         /* adjust texture lod (lambda) */
+         if (span->arrayMask & SPAN_LAMBDA) {
+            if (texUnit->LodBias + curObj->LodBias != 0.0F) {
+               /* apply LOD bias, but don't clamp yet */
+               const GLfloat bias = CLAMP(texUnit->LodBias + curObj->LodBias,
+                                          -ctx->Const.MaxTextureLodBias,
+                                          ctx->Const.MaxTextureLodBias);
+               GLuint i;
+               for (i = 0; i < span->end; i++) {
+                  lambda[i] += bias;
+               }
+            }
+
+            if (curObj->MinLod != -1000.0 || curObj->MaxLod != 1000.0) {
+               /* apply LOD clamping to lambda */
+               const GLfloat min = curObj->MinLod;
+               const GLfloat max = curObj->MaxLod;
+               GLuint i;
+               for (i = 0; i < span->end; i++) {
+                  GLfloat l = lambda[i];
+                  lambda[i] = CLAMP(l, min, max);
+               }
+            }
+         }
+
+         /* Sample the texture (span->end fragments) */
+         swrast->TextureSample[unit]( ctx, unit, texUnit->_Current, span->end,
+                         (const GLfloat (*)[4]) span->array->texcoords[unit],
+                         lambda, texels );
+
+         /* GL_SGI_texture_color_table */
+         if (texUnit->ColorTableEnabled) {
+            _mesa_lookup_rgba_chan(&texUnit->ColorTable, span->end, texels);
+         }
+      }
+   }
+
+   /*
+    * OK, now apply the texture (aka texture combine/blend).
+    * We modify the span->color.rgba values.
+    */
+   for (unit = 0; unit < ctx->Const.MaxTextureUnits; unit++) {
+      if (ctx->Texture.Unit[unit]._ReallyEnabled) {
+         const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
+         if (texUnit->_CurrentCombine != &texUnit->_EnvMode ) {
+            texture_combine( ctx, unit, span->end,
+                             (CONST GLchan (*)[4]) primary_rgba,
+                             swrast->TexelBuffer,
+                             span->array->rgba );
+         }
+         else {
+            /* conventional texture blend */
+            const GLchan (*texels)[4] = (const GLchan (*)[4])
+               (swrast->TexelBuffer + unit *
+                (span->end * 4 * sizeof(GLchan)));
+            texture_apply( ctx, texUnit, span->end,
+                           (CONST GLchan (*)[4]) primary_rgba, texels,
+                           span->array->rgba );
+         }
+      }
+   }
+}