static GLboolean link_uniform_vars	(	GLcontext *	ctx,
		struct gl_shader_program *	shProg,
		struct gl_program *	prog,
		GLuint *	numSamplers
	)		`[static]`

Build the shProg->Uniforms list. This is basically a list/index of all uniforms found in either/both of the vertex and fragment shaders.

About uniforms: Each uniform has two indexes, one that points into the vertex program's parameter array and another that points into the fragment program's parameter array. When the user changes a uniform's value we have to change the value in the vertex and/or fragment program's parameter array.

This function will be called twice to set up the two uniform->parameter mappings.

If a uniform is only present in the vertex program OR fragment program then the fragment/vertex parameter index, respectively, will be -1.

Definition at line 225 of file slang_link.c.

Referenced by _slang_link().

{
   GLuint samplerMap[200]; /* max number of samplers declared, not used */
   GLuint i;

   for (i = 0; i < prog->Parameters->NumParameters; i++) {
      const struct gl_program_parameter *p = prog->Parameters->Parameters + i;

      /*
       * XXX FIX NEEDED HERE
       * We should also be adding a uniform if p->Type == PROGRAM_STATE_VAR.
       * For example, modelview matrix, light pos, etc.
       * Also, we need to update the state-var name-generator code to
       * generate GLSL-style names, like "gl_LightSource[0].position".
       * Furthermore, we'll need to fix the state-var's size/datatype info.
       */

      if ((p->Type == PROGRAM_UNIFORM || p->Type == PROGRAM_SAMPLER)
          && p->Used) {
         /* add this uniform, indexing into the target's Parameters list */
         struct gl_uniform *uniform =
            _mesa_append_uniform(shProg->Uniforms, p->Name, prog->Target, i);
         if (uniform)
            uniform->Initialized = p->Initialized;
      }

      /* The samplerMap[] table we build here is used to remap/re-index
       * sampler references by TEX instructions.
       */
      if (p->Type == PROGRAM_SAMPLER && p->Used) {
         /* Allocate a new sampler index */
         GLuint oldSampNum = (GLuint) prog->Parameters->ParameterValues[i][0];
         GLuint newSampNum = *numSamplers;
         if (newSampNum >= ctx->Const.MaxTextureImageUnits) {
            char s[100];
            _mesa_sprintf(s, "Too many texture samplers (%u, max is %u)",
                          newSampNum, ctx->Const.MaxTextureImageUnits);
            link_error(shProg, s);
            return GL_FALSE;
         }
         /* save old->new mapping in the table */
         if (oldSampNum < Elements(samplerMap))
            samplerMap[oldSampNum] = newSampNum;
         /* update parameter's sampler index */
         prog->Parameters->ParameterValues[i][0] = (GLfloat) newSampNum;
         (*numSamplers)++;
      }
   }

   /* OK, now scan the program/shader instructions looking for texture
    * instructions using sampler vars.  Replace old sampler indexes with
    * new ones.
    */
   prog->SamplersUsed = 0x0;
   for (i = 0; i < prog->NumInstructions; i++) {
      struct prog_instruction *inst = prog->Instructions + i;
      if (_mesa_is_tex_instruction(inst->Opcode)) {
         const GLint oldSampNum = inst->TexSrcUnit;

#if 0
         printf("====== remap sampler from %d to %d\n",
                inst->TexSrcUnit, samplerMap[ inst->TexSrcUnit ]);
#endif

         /* here, texUnit is really samplerUnit */
         if (oldSampNum < Elements(samplerMap)) {
            const GLuint newSampNum = samplerMap[oldSampNum];
            inst->TexSrcUnit = newSampNum;
            prog->SamplerTargets[newSampNum] = inst->TexSrcTarget;
            prog->SamplersUsed |= (1 << newSampNum);
         }
      }
   }

   return GL_TRUE;
}

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