s_texcombine.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

      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;
   GLchan 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]->_BaseFormat;

   if (format == GL_COLOR_INDEX || format == GL_YCBCR_MESA) {
      format = GL_RGBA;  /* a bit of a hack */
   }
   else if (format == GL_DEPTH_COMPONENT || format == GL_DEPTH_STENCIL_EXT) {
      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];
	       }