[Mesa-dev] [PATCH 3/5] mesa/gles3: Generate error on DrawElements* calls if transform feedback active.

[Ian Romanick]

On 12/14/2012 01:01 PM, Paul Berry wrote:
> In GLES3, only glDrawArrays() and glDrawArraysInstanced() calls are
> allowed when transform feedback is active.
> ---
>   src/mesa/main/api_validate.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 45 insertions(+)
>
> diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
> index e47db23..355a93c 100644
> --- a/src/mesa/main/api_validate.c
> +++ b/src/mesa/main/api_validate.c
> @@ -313,9 +313,24 @@ _mesa_validate_DrawElements(struct gl_context *ctx,
>   			    GLenum mode, GLsizei count, GLenum type,
>   			    const GLvoid *indices, GLint basevertex)
>   {
> +   struct gl_transform_feedback_object *xfb_obj
> +      = ctx->TransformFeedback.CurrentObject;
>      ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
>      FLUSH_CURRENT(ctx, 0);
>
> +   /* From the GLES3 specification, section 2.14.2 (Transform Feedback
> +    * Primitive Capture):
> +    *
> +    *   The error INVALID_OPERATION is also generated by DrawElements,
> +    *   DrawElementsInstanced, and DrawRangeElements while transform feedback
> +    *   is active and not paused, regardless of mode.
> +    */
> +   if (_mesa_is_gles3(ctx) && xfb_obj->Active && !xfb_obj->Paused) {
                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

It seems like this predicate appears in a bunch of places.  May be an 
is_active() macro to wrap it would be nice?

> +      _mesa_error(ctx, GL_INVALID_OPERATION,
> +                  "glDrawElements(transform feedback active)");
> +      return GL_FALSE;
> +   }
> +
>      if (count <= 0) {
>         if (count < 0)
>   	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawElements(count)" );
> @@ -431,9 +446,24 @@ _mesa_validate_DrawRangeElements(struct gl_context *ctx, GLenum mode,
>   				 GLsizei count, GLenum type,
>   				 const GLvoid *indices, GLint basevertex)
>   {
> +   struct gl_transform_feedback_object *xfb_obj
> +      = ctx->TransformFeedback.CurrentObject;
>      ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
>      FLUSH_CURRENT(ctx, 0);
>
> +   /* From the GLES3 specification, section 2.14.2 (Transform Feedback
> +    * Primitive Capture):
> +    *
> +    *   The error INVALID_OPERATION is also generated by DrawElements,
> +    *   DrawElementsInstanced, and DrawRangeElements while transform feedback
> +    *   is active and not paused, regardless of mode.
> +    */
> +   if (_mesa_is_gles3(ctx) && xfb_obj->Active && !xfb_obj->Paused) {
> +      _mesa_error(ctx, GL_INVALID_OPERATION,
> +                  "glDrawElements(transform feedback active)");
> +      return GL_FALSE;
> +   }
> +
>      if (count <= 0) {
>         if (count < 0)
>   	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(count)" );
> @@ -560,9 +590,24 @@ _mesa_validate_DrawElementsInstanced(struct gl_context *ctx,
>                                        const GLvoid *indices, GLsizei numInstances,
>                                        GLint basevertex)
>   {
> +   struct gl_transform_feedback_object *xfb_obj
> +      = ctx->TransformFeedback.CurrentObject;
>      ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
>      FLUSH_CURRENT(ctx, 0);
>
> +   /* From the GLES3 specification, section 2.14.2 (Transform Feedback
> +    * Primitive Capture):
> +    *
> +    *   The error INVALID_OPERATION is also generated by DrawElements,
> +    *   DrawElementsInstanced, and DrawRangeElements while transform feedback
> +    *   is active and not paused, regardless of mode.
> +    */
> +   if (_mesa_is_gles3(ctx) && xfb_obj->Active && !xfb_obj->Paused) {
> +      _mesa_error(ctx, GL_INVALID_OPERATION,
> +                  "glDrawElements(transform feedback active)");
> +      return GL_FALSE;
> +   }
> +
>      if (count <= 0) {
>         if (count < 0)
>   	 _mesa_error(ctx, GL_INVALID_VALUE,
>