1 files changed, 58 insertions, 0 deletions
diff --git a/mesalib/src/mesa/main/transformfeedback.c b/mesalib/src/mesa/main/transformfeedback.c
index 3f8a7f48d..bc9b52ab9 100644
--- a/mesalib/src/mesa/main/transformfeedback.c
+++ b/mesalib/src/mesa/main/transformfeedback.c
@@ -44,6 +44,41 @@
 
 #include "program/prog_parameter.h"
 
+struct using_program_tuple
+{
+   struct gl_shader_program *shProg;
+   bool found;
+};
+
+static void
+active_xfb_object_references_program(GLuint key, void *data, void *user_data)
+{
+   struct using_program_tuple *callback_data = user_data;
+   struct gl_transform_feedback_object *obj = data;
+   if (obj->Active && obj->shader_program == callback_data->shProg)
+      callback_data->found = true;
+}
+
+/**
+ * Return true if any active transform feedback object is using a program.
+ */
+bool
+_mesa_transform_feedback_is_using_program(struct gl_context *ctx,
+                                          struct gl_shader_program *shProg)
+{
+   struct using_program_tuple callback_data;
+   callback_data.shProg = shProg;
+   callback_data.found = false;
+
+   _mesa_HashWalk(ctx->TransformFeedback.Objects,
+                  active_xfb_object_references_program, &callback_data);
+
+   /* Also check DefaultObject, as it's not in the Objects hash table. */
+   active_xfb_object_references_program(0, ctx->TransformFeedback.DefaultObject,
+                                        &callback_data);
+
+   return callback_data.found;
+}
 
 /**
  * Do reference counting of transform feedback buffers.
@@ -406,6 +441,8 @@ _mesa_BeginTransformFeedback(GLenum mode)
       obj->GlesRemainingPrims = max_vertices / vertices_per_prim;
    }
 
+   obj->shader_program = ctx->Shader.CurrentVertexProgram;
+
    assert(ctx->Driver.BeginTransformFeedback);
    ctx->Driver.BeginTransformFeedback(ctx, mode, obj);
 }
@@ -611,6 +648,16 @@ _mesa_TransformFeedbackVaryings(GLuint program, GLsizei count,
    GLint i;
    GET_CURRENT_CONTEXT(ctx);
 
+   /* From the ARB_transform_feedback2 specification:
+    * "The error INVALID_OPERATION is generated by TransformFeedbackVaryings
+    *  if the current transform feedback object is active, even if paused."
+    */
+   if (ctx->TransformFeedback.CurrentObject->Active) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+               "glTransformFeedbackVaryings(current object is active)");
+      return;
+   }
+
    switch (bufferMode) {
    case GL_INTERLEAVED_ATTRIBS:
       break;
@@ -931,6 +978,17 @@ _mesa_ResumeTransformFeedback(void)
       return;
    }
 
+   /* From the ARB_transform_feedback2 specification:
+    * "The error INVALID_OPERATION is generated by ResumeTransformFeedback if
+    *  the program object being used by the current transform feedback object
+    *  is not active."
+    */
+   if (obj->shader_program != ctx->Shader.CurrentVertexProgram) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glResumeTransformFeedback(wrong vertex program bound)");
+      return;
+   }
+
    FLUSH_VERTICES(ctx, 0);
    ctx->NewDriverState |= ctx->DriverFlags.NewTransformFeedback;