mesa: fix another "out of samplers" problem

Now only the samplers that are actually used by texture() functions are
saved in the uniform variable list.  Before, we could run out of samplers
if too many were declared while only some of them were actually used.

1 files changed, 41 insertions, 16 deletions

diff --git a/src/mesa/shader/slang/slang_link.c b/src/mesa/shader/slang/slang_link.c
index b49fd0e99d3..b2fd9554a66 100644
--- a/src/mesa/shader/slang/slang_link.c
+++ b/src/mesa/shader/slang/slang_link.c
@@ -1,8 +1,9 @@
 /*
  * Mesa 3-D graphics library
- * Version:  7.2
+ * Version:  7.3
  *
  * Copyright (C) 2008  Brian Paul   All Rights Reserved.
+ * Copyright (C) 2009  VMware, Inc.  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"),
@@ -206,6 +207,19 @@ link_varying_vars(struct gl_shader_program *shProg, struct gl_program *prog)
  * 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.
  */
 static GLboolean
 link_uniform_vars(GLcontext *ctx,
@@ -213,7 +227,7 @@ link_uniform_vars(GLcontext *ctx,
                   struct gl_program *prog,
                   GLuint *numSamplers)
 {
-   GLuint samplerMap[MAX_SAMPLERS];
+   GLuint samplerMap[200]; /* max number of samplers declared, not used */
    GLuint i;
 
    for (i = 0; i < prog->Parameters->NumParameters; i++) {
@@ -228,33 +242,41 @@ link_uniform_vars(GLcontext *ctx,
        * Furthermore, we'll need to fix the state-var's size/datatype info.
        */
 
-      if ((p->Type == PROGRAM_UNIFORM && p->Used) ||
-          p->Type == PROGRAM_SAMPLER) {
+      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;
       }
 
-      if (p->Type == PROGRAM_SAMPLER) {
+      /* 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 sampNum = *numSamplers;
          GLuint oldSampNum = (GLuint) prog->Parameters->ParameterValues[i][0];
-         if (oldSampNum >= ctx->Const.MaxTextureImageUnits) {
+         GLuint newSampNum = *numSamplers;
+         if (newSampNum >= ctx->Const.MaxTextureImageUnits) {
             char s[100];
             sprintf(s, "Too many texture samplers (%u, max is %u)",
-                    oldSampNum + 1, ctx->Const.MaxTextureImageUnits);
+                    newSampNum, ctx->Const.MaxTextureImageUnits);
             link_error(shProg, s);
             return GL_FALSE;
          }
-         samplerMap[oldSampNum] = sampNum;
+         /* 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 sampler vars,
-    * replacing the old index with the new index.
+   /* 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++) {
@@ -265,10 +287,13 @@ link_uniform_vars(GLcontext *ctx,
                 inst->Sampler, map[ inst->Sampler ]);
          */
          /* here, texUnit is really samplerUnit */
-         assert(inst->TexSrcUnit < MAX_SAMPLERS);
-         inst->TexSrcUnit = samplerMap[inst->TexSrcUnit];
-         prog->SamplerTargets[inst->TexSrcUnit] = inst->TexSrcTarget;
-         prog->SamplersUsed |= (1 << inst->TexSrcUnit);
+         const GLint oldSampNum = inst->TexSrcUnit;
+         if (oldSampNum < Elements(samplerMap)) {
+            const GLuint newSampNum = samplerMap[oldSampNum];
+            inst->TexSrcUnit = newSampNum;
+            prog->SamplerTargets[newSampNum] = inst->TexSrcTarget;
+            prog->SamplersUsed |= (1 << newSampNum);
+         }
       }
    }