[Mesa-dev] [PATCH 04/25] mesa: Reset image unit state to the default values when a bound image is deleted.

[Tapani Pälli]

On 08/17/2015 07:45 PM, Francisco Jerez wrote:
> The ES31-CTS.shader_image_load_store.basic-api-bind conformance test
> expects the whole image unit state to be reset when the bound texture
> object is deleted.  The ARB_shader_image_load_store extension is
> rather vague regarding what should happen with image unit state other
> than the texture object in that case -- In any case it shouldn't make

FWIW this seems to be specified in the desktop GL (and ES 3.1) spec in 
section "Automatic Unbinding of Deleted Objects".

Reviewed-by: Tapani Pälli <tapani.palli at intel.com>

> any practical difference because one cannot sensibly use an image unit
> not bound to any texture object without re-specifying its state, so
> just make the test happy.
> ---
>   src/mesa/main/shaderimage.c | 19 +++++++++++++------
>   src/mesa/main/shaderimage.h |  6 ++++++
>   src/mesa/main/texobj.c      |  5 ++++-
>   3 files changed, 23 insertions(+), 7 deletions(-)
>
> diff --git a/src/mesa/main/shaderimage.c b/src/mesa/main/shaderimage.c
> index 2d86931..48e3e09 100644
> --- a/src/mesa/main/shaderimage.c
> +++ b/src/mesa/main/shaderimage.c
> @@ -394,17 +394,24 @@ is_image_format_supported(const struct gl_context *ctx, GLenum format)
>      }
>   }
>
> +struct gl_image_unit
> +_mesa_default_image_unit(struct gl_context *ctx)
> +{
> +   const struct gl_image_unit u = {
> +      .Access = GL_READ_ONLY,
> +      .Format = GL_R8,
> +      ._ActualFormat = _mesa_get_shader_image_format(GL_R8)
> +   };
> +   return u;
> +}
> +
>   void
>   _mesa_init_image_units(struct gl_context *ctx)
>   {
>      unsigned i;
>
> -   for (i = 0; i < ARRAY_SIZE(ctx->ImageUnits); ++i) {
> -      struct gl_image_unit *u = &ctx->ImageUnits[i];
> -      u->Access = GL_READ_ONLY;
> -      u->Format = GL_R8;
> -      u->_ActualFormat = _mesa_get_shader_image_format(u->Format);
> -   }
> +   for (i = 0; i < ARRAY_SIZE(ctx->ImageUnits); ++i)
> +      ctx->ImageUnits[i] = _mesa_default_image_unit(ctx);
>   }
>
>   static GLboolean
> diff --git a/src/mesa/main/shaderimage.h b/src/mesa/main/shaderimage.h
> index d08ece8..bbe088a 100644
> --- a/src/mesa/main/shaderimage.h
> +++ b/src/mesa/main/shaderimage.h
> @@ -43,6 +43,12 @@ mesa_format
>   _mesa_get_shader_image_format(GLenum format);
>
>   /**
> + * Get a single image unit struct with the default state.
> + */
> +struct gl_image_unit
> +_mesa_default_image_unit(struct gl_context *ctx);
> +
> +/**
>    * Initialize a context's shader image units to the default state.
>    */
>   void
> diff --git a/src/mesa/main/texobj.c b/src/mesa/main/texobj.c
> index cd7cfd6..395e4d3 100644
> --- a/src/mesa/main/texobj.c
> +++ b/src/mesa/main/texobj.c
> @@ -37,6 +37,7 @@
>   #include "hash.h"
>   #include "imports.h"
>   #include "macros.h"
> +#include "shaderimage.h"
>   #include "teximage.h"
>   #include "texobj.h"
>   #include "texstate.h"
> @@ -1411,8 +1412,10 @@ unbind_texobj_from_image_units(struct gl_context *ctx,
>      for (i = 0; i < ctx->Const.MaxImageUnits; i++) {
>         struct gl_image_unit *unit = &ctx->ImageUnits[i];
>
> -      if (texObj == unit->TexObj)
> +      if (texObj == unit->TexObj) {
>            _mesa_reference_texobj(&unit->TexObj, NULL);
> +         *unit = _mesa_default_image_unit(ctx);
> +      }
>      }
>   }
>
>