[Mesa-dev] [PATCH] mesa: add NV_read_{depth, stencil, depth_stencil} extensions

[Marek Olšák]

On Mon, Aug 10, 2015 at 1:02 PM, Rob Clark <robdclark at gmail.com> wrote:
> From: Rob Clark <robclark at freedesktop.org>
>
> These extensions allow reading depth/stencil for GLES contexts, which is
> useful for tools like apitrace.
>
> Signed-off-by: Rob Clark <robclark at freedesktop.org>
> ---
> I have a patch, which I will send out after some cleanup, that makes
> apitrace able to dump depth/stencil buffers with GLES, thanks to this
> extension.
>
>  src/mesa/main/extensions.c |  3 +++
>  src/mesa/main/readpix.c    | 25 +++++++++++++++++++------
>  2 files changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
> index 2dbfabd..d934d19 100644
> --- a/src/mesa/main/extensions.c
> +++ b/src/mesa/main/extensions.c
> @@ -385,6 +385,9 @@ static const struct extension extension_table[] = {
>     { "GL_NV_point_sprite",                         o(NV_point_sprite),                         GL,             2001 },
>     { "GL_NV_primitive_restart",                    o(NV_primitive_restart),                    GLL,            2002 },
>     { "GL_NV_read_buffer",                          o(dummy_true),                              ES2,            2011 },
> +   { "GL_NV_read_depth",                           o(dummy_true),                              ES2,            2011 },
> +   { "GL_NV_read_depth_stencil",                   o(dummy_true),                              ES2,            2011 },
> +   { "GL_NV_read_stencil",                         o(dummy_true),                              ES2,            2011 },
>     { "GL_NV_texgen_reflection",                    o(dummy_true),                              GLL,            1999 },
>     { "GL_NV_texture_barrier",                      o(NV_texture_barrier),                      GL,             2009 },
>     { "GL_NV_texture_env_combine4",                 o(NV_texture_env_combine4),                 GLL,            1999 },
> diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
> index 2744232..65751aa 100644
> --- a/src/mesa/main/readpix.c
> +++ b/src/mesa/main/readpix.c
> @@ -917,7 +917,9 @@ read_pixels_es3_error_check(GLenum format, GLenum type,
>     GLboolean is_unsigned_int = GL_FALSE;
>     GLboolean is_signed_int = GL_FALSE;
>
> -   if (!_mesa_is_color_format(internalFormat)) {
> +   /* TODO just drop the check?  Are there any formats to filter out? */

Yes, please drop it.

> +   if (!(_mesa_is_color_format(internalFormat) ||
> +         _mesa_is_depth_or_stencil_format(internalFormat))) {
>        return GL_INVALID_OPERATION;
>     }
>
> @@ -950,6 +952,22 @@ read_pixels_es3_error_check(GLenum format, GLenum type,
>            (is_unsigned_int && type == GL_UNSIGNED_INT))
>           return GL_NO_ERROR;
>        break;
> +   case GL_DEPTH_STENCIL:
> +      if ((internalFormat == GL_DEPTH24_STENCIL8) &&
> +          (type == GL_UNSIGNED_INT_24_8))
> +         return GL_NO_ERROR;
> +      if ((internalFormat == GL_DEPTH32F_STENCIL8) &&
> +          (type == GL_FLOAT_32_UNSIGNED_INT_24_8_REV))
> +         return GL_NO_ERROR;
> +      break;
> +   case GL_DEPTH_COMPONENT:
> +      if ((internalFormat == GL_DEPTH_COMPONENT32F) &&
> +          (type == GL_FLOAT))
> +         return GL_NO_ERROR;
> +      if ((internalFormat == GL_DEPTH_COMPONENT24) &&
> +          (type == GL_UNSIGNED_INT))
> +         return GL_NO_ERROR;
> +      break;

What about GL_STENCIL_INDEX? Mesa does support GL_OES_stencil8.

Marek