1 files changed, 22 insertions, 18 deletions

diff --git a/src/mesa/shader/shader_api.c b/src/mesa/shader/shader_api.c
index 1b604f0713..54a25dfaf0 100644
--- a/src/mesa/shader/shader_api.c
+++ b/src/mesa/shader/shader_api.c
@@ -1612,10 +1612,8 @@ set_program_uniform(GLcontext *ctx, struct gl_program *program,
                     GLenum type, GLsizei count, GLint elems,
                     const void *values)
 {
-   struct gl_program_parameter *param =
+   const struct gl_program_parameter *param =
       &program->Parameters->Parameters[index];
-   const GLboolean isUniformBool = is_boolean_type(param->DataType);
-   const GLboolean areIntValues = is_integer_type(type);
 
    assert(offset >= 0);
    assert(elems >= 1);
@@ -1633,19 +1631,13 @@ set_program_uniform(GLcontext *ctx, struct gl_program *program,
 
    if (param->Type == PROGRAM_SAMPLER) {
       /* This controls which texture unit which is used by a sampler */
+      GLboolean changed = GL_FALSE;
       GLint i;
 
-      /* data type for setting samplers must be int */
-      if (type != GL_INT) {
-         _mesa_error(ctx, GL_INVALID_OPERATION,
-                     "glUniform(only glUniform1i can be used "
-                     "to set sampler uniforms)");
-         return;
-      }
+      /* this should have been caught by the compatible_types() check */
+      ASSERT(type == GL_INT);
 
-      /* XXX arrays of samplers haven't been tested much, but it's not a
-       * common thing...
-       */
+      /* loop over number of samplers to change */
       for (i = 0; i < count; i++) {
          GLuint sampler =
             (GLuint) program->Parameters->ParameterValues[index + offset + i][0];
@@ -1664,19 +1656,31 @@ set_program_uniform(GLcontext *ctx, struct gl_program *program,
             _mesa_printf("Set program %p sampler %d '%s' to unit %u\n",
                          program, sampler, param->Name, texUnit);
 #endif
-            program->SamplerUnits[sampler] = texUnit;
+            if (program->SamplerUnits[sampler] != texUnit) {
+               program->SamplerUnits[sampler] = texUnit;
+               changed = GL_TRUE;
+            }
          }
       }
 
-      _mesa_update_shader_textures_used(program);
-
-      FLUSH_VERTICES(ctx, _NEW_TEXTURE);
+      if (changed) {
+         /* When a sampler's value changes it usually requires rewriting
+          * a GPU program's TEX instructions since there may not be a
+          * sampler->texture lookup table.  We signal this with the
+          * ProgramStringNotify() callback.
+          */
+         FLUSH_VERTICES(ctx, _NEW_TEXTURE | _NEW_PROGRAM);
+         _mesa_update_shader_textures_used(program);
+         ctx->Driver.ProgramStringNotify(ctx, program->Target, program);
+      }
    }
    else {
       /* ordinary uniform variable */
-      GLsizei k, i;
+      const GLboolean isUniformBool = is_boolean_type(param->DataType);
+      const GLboolean areIntValues = is_integer_type(type);
       const GLint slots = (param->Size + 3) / 4;
       const GLint typeSize = sizeof_glsl_type(param->DataType);
+      GLsizei k, i;
 
       if (param->Size > typeSize) {
          /* an array */