[Mesa-dev] [PATCH] i965: Use GL_RED for DEPTH_TEXTURE_MODE in ES 3.0 for unsized formats.

[Ian Romanick]

On 01/23/2013 06:27 PM, Kenneth Graunke wrote:
> Khronos has apparently decided that depth textures with sized formats
> (allowed with ARB_internalformat_query or ES 3.0) should be treated as
> GL_RED, while unsized formats (an existing feature) should be treated
> as GL_INTENSITY for compatibility with ES 2.0.
>
> Ian is proposing changes to ARB_internalformat_query which will make
> this actually legal and consistent.
>
> A similar problem exists with GL 4.2, but we're going to ignore that
> for the time being.
>
> Tested on Ivybridge: no Piglit regressions; fixes 4 es3conform tests:
> - depth_texture_fbo
> - depth_texture_fbo_clear
> - depth_texture_teximage
> - depth_texture_texsubimage
>
> Cc: Ian Romanick <idr at freedesktop.org>

We probably could have done this in core Mesa, but I think this is okay 
for now.  I pushed a version of this patch with my R-b to the gles3 branch.

> ---
>   src/mesa/drivers/dri/i965/brw_state.h             |  3 ++-
>   src/mesa/drivers/dri/i965/brw_wm.c                |  2 +-
>   src/mesa/drivers/dri/i965/brw_wm_surface_state.c  | 18 ++++++++++++++++--
>   src/mesa/drivers/dri/i965/gen7_wm_surface_state.c |  5 ++---
>   4 files changed, 21 insertions(+), 7 deletions(-)
>
> Please NAK and revert
>
>    mesa: Use GL_RED for DEPTH_TEXTURE_MODE for everything but legacy GL.
>    mesa: Use GL_RED for DEPTH_TEXTURE_MODE for #version 300 es shaders.
>
> before applying this patch.  Otherwise, you'll get failures.
>
> diff --git a/src/mesa/drivers/dri/i965/brw_state.h b/src/mesa/drivers/dri/i965/brw_state.h
> index c6b8219..d9708c1 100644
> --- a/src/mesa/drivers/dri/i965/brw_state.h
> +++ b/src/mesa/drivers/dri/i965/brw_state.h
> @@ -202,7 +202,8 @@ GLuint translate_tex_format(gl_format mesa_format,
>   			    GLenum depth_mode,
>   			    GLenum srgb_decode);
>
> -int brw_get_texture_swizzle(const struct gl_texture_object *t);
> +int brw_get_texture_swizzle(const struct gl_context *ctx,
> +                            const struct gl_texture_object *t);
>
>   /* gen7_wm_surface_state.c */
>   uint32_t gen7_surface_tiling_mode(uint32_t tiling);
> diff --git a/src/mesa/drivers/dri/i965/brw_wm.c b/src/mesa/drivers/dri/i965/brw_wm.c
> index 2891567..4b04465 100644
> --- a/src/mesa/drivers/dri/i965/brw_wm.c
> +++ b/src/mesa/drivers/dri/i965/brw_wm.c
> @@ -316,7 +316,7 @@ brw_populate_sampler_prog_key_data(struct gl_context *ctx,
>             * (except for GL_ALPHA); all other platforms need MOVs in the shader.
>             */
>            if (!intel->is_haswell || alpha_depth)
> -            key->swizzles[s] = brw_get_texture_swizzle(t);
> +            key->swizzles[s] = brw_get_texture_swizzle(ctx, t);
>
>   	 if (img->InternalFormat == GL_YCBCR_MESA) {
>   	    key->yuvtex_mask |= 1 << s;
> diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
> index 5e99592..87a69d6 100644
> --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
> +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
> @@ -30,6 +30,7 @@
>     */
>
>
> +#include "main/context.h"
>   #include "main/mtypes.h"
>   #include "main/samplerobj.h"
>   #include "program/prog_parameter.h"
> @@ -685,7 +686,8 @@ brw_get_surface_num_multisamples(unsigned num_samples)
>    * swizzling.
>    */
>   int
> -brw_get_texture_swizzle(const struct gl_texture_object *t)
> +brw_get_texture_swizzle(const struct gl_context *ctx,
> +                        const struct gl_texture_object *t)
>   {
>      const struct gl_texture_image *img = t->Image[0][t->BaseLevel];
>
> @@ -701,7 +703,19 @@ brw_get_texture_swizzle(const struct gl_texture_object *t)
>
>      if (img->_BaseFormat == GL_DEPTH_COMPONENT ||
>          img->_BaseFormat == GL_DEPTH_STENCIL) {
> -      switch (t->DepthMode) {
> +      GLenum depth_mode = t->DepthMode;
> +
> +      /* In ES 3.0, DEPTH_TEXTURE_MODE is expected to be GL_RED for textures
> +       * with depth component data specified with a sized internal format.
> +       * Otherwise, it's left at the old default, GL_LUMINANCE.
> +       */
> +      if (_mesa_is_gles3(ctx) &&
> +          img->InternalFormat != GL_DEPTH_COMPONENT &&
> +          img->InternalFormat != GL_DEPTH_STENCIL) {
> +         depth_mode = GL_RED;
> +      }
> +
> +      switch (depth_mode) {
>         case GL_ALPHA:
>            swizzles[0] = SWIZZLE_ZERO;
>            swizzles[1] = SWIZZLE_ZERO;
> diff --git a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
> index 05e9e75..236d50c 100644
> --- a/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
> +++ b/src/mesa/drivers/dri/i965/gen7_wm_surface_state.c
> @@ -344,9 +344,8 @@ gen7_update_texture_surface(struct gl_context *ctx,
>            (firstImage->_BaseFormat == GL_DEPTH_COMPONENT ||
>             firstImage->_BaseFormat == GL_DEPTH_STENCIL);
>
> -      const int swizzle =
> -         unlikely(alpha_depth) ? SWIZZLE_XYZW : brw_get_texture_swizzle(tObj);
> -
> +      const int swizzle = unlikely(alpha_depth)
> +         ? SWIZZLE_XYZW : brw_get_texture_swizzle(ctx, tObj);
>
>         surf[7] =
>            SET_FIELD(swizzle_to_scs(GET_SWZ(swizzle, 0)), GEN7_SURFACE_SCS_R) |
>