[Mesa-dev] [PATCH 2/2] st/mesa: fix DDY opcode for FBOs

[Brian Paul]

On 07/22/2012 05:37 PM, Marek Olšák wrote:
> This fixes piglit/fbo-deriv.
> ---
>   src/mesa/state_tracker/st_glsl_to_tgsi.cpp |   24 ++++++++++++++++++++++--
>   1 file changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> index 45136de..fcd69b1 100644
> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> @@ -1448,9 +1448,29 @@ glsl_to_tgsi_visitor::visit(ir_expression *ir)
>         emit(ir, TGSI_OPCODE_DDX, result_dst, op[0]);
>         break;
>      case ir_unop_dFdy:
> -      op[0].negate = ~op[0].negate;
> -      emit(ir, TGSI_OPCODE_DDY, result_dst, op[0]);
> +   {
> +      /* The X component contains 1 or -1 depending on whether the framebuffer
> +       * is a FBO or the window system buffer, respectively.
> +       * It is then multiplied with the source operand of DDY.
> +       */
> +      static const gl_state_index transform_y_state[STATE_LENGTH]
> +         = { STATE_INTERNAL, STATE_FB_WPOS_Y_TRANSFORM };
> +
> +      unsigned transform_y_index =
> +         _mesa_add_state_reference(this->prog->Parameters,
> +                                   transform_y_state);
> +
> +      st_src_reg transform_y = st_src_reg(PROGRAM_STATE_VAR,
> +                                          transform_y_index,
> +                                          glsl_type::vec4_type);
> +      transform_y.swizzle = SWIZZLE_XXXX;
> +
> +      st_src_reg temp = get_temp(glsl_type::vec4_type);
> +
> +      emit(ir, TGSI_OPCODE_MUL, st_dst_reg(temp), transform_y, op[0]);
> +      emit(ir, TGSI_OPCODE_DDY, result_dst, temp);
>         break;
> +   }
>
>      case ir_unop_noise: {
>         /* At some point, a motivated person could add a better

This was on my list of things to check/test too.  Thanks.

Reviewed-by: Brian Paul <brianp at vmware.com>