[Mesa-stable] [PATCH 1/4] mesa: Expose function to calculate whether a shader image unit is valid.

[Ian Romanick]

On 09/03/2015 06:53 AM, Francisco Jerez wrote:
> A future commit will remove all texture object-dependent derived state
> from the image unit struct to make validation unnecessary on texture
> state changes.  Instead of checking gl_image_unit::_Valid drivers will
> be required to call this function when needed to find out whether an
> image unit is in a valid state and whether access from the shader is
> allowed.
> 
> Tested-by: Ye Tian <yex.tian at intel.com>
> CC: "11.0" <mesa-stable at lists.freedesktop.org>
> ---
>  src/mesa/main/shaderimage.c |  8 ++++----
>  src/mesa/main/shaderimage.h | 11 +++++++++++
>  2 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/src/mesa/main/shaderimage.c b/src/mesa/main/shaderimage.c
> index c4bba84..a0a3b7b 100644
> --- a/src/mesa/main/shaderimage.c
> +++ b/src/mesa/main/shaderimage.c
> @@ -415,8 +415,8 @@ _mesa_init_image_units(struct gl_context *ctx)
>        ctx->ImageUnits[i] = _mesa_default_image_unit(ctx);
>  }
>  
> -static GLboolean
> -validate_image_unit(struct gl_context *ctx, struct gl_image_unit *u)
> +GLboolean
> +_mesa_is_image_unit_valid(struct gl_context *ctx, struct gl_image_unit *u)

The series is

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

I'd also support a follow-up patch that changes this function to use
stdbool types and names.

>  {
>     struct gl_texture_object *t = u->TexObj;
>     mesa_format tex_format;
> @@ -567,7 +567,7 @@ _mesa_BindImageTexture(GLuint unit, GLuint texture, GLint level,
>     u->Access = access;
>     u->Format = format;
>     u->_ActualFormat = _mesa_get_shader_image_format(format);
> -   u->_Valid = validate_image_unit(ctx, u);
> +   u->_Valid = _mesa_is_image_unit_valid(ctx, u);
>  
>     if (u->TexObj && _mesa_tex_target_is_layered(u->TexObj->Target)) {
>        u->Layered = layered;
> @@ -707,7 +707,7 @@ _mesa_BindImageTextures(GLuint first, GLsizei count, const GLuint *textures)
>           u->Access = GL_READ_WRITE;
>           u->Format = tex_format;
>           u->_ActualFormat = _mesa_get_shader_image_format(tex_format);
> -         u->_Valid = validate_image_unit(ctx, u);
> +         u->_Valid = _mesa_is_image_unit_valid(ctx, u);
>        } else {
>           /* Unbind the texture from the unit */
>           _mesa_reference_texobj(&u->TexObj, NULL);
> diff --git a/src/mesa/main/shaderimage.h b/src/mesa/main/shaderimage.h
> index bbe088a..14a544f 100644
> --- a/src/mesa/main/shaderimage.h
> +++ b/src/mesa/main/shaderimage.h
> @@ -55,6 +55,17 @@ void
>  _mesa_init_image_units(struct gl_context *ctx);
>  
>  /**
> + * Return GL_TRUE if the state of the image unit passed as argument is valid
> + * and access from the shader is allowed.  Otherwise loads from this unit
> + * should return zero and stores should have no effect.
> + *
> + * The result depends on context state other than the passed image unit, part
> + * of the _NEW_TEXTURE set.
> + */
> +GLboolean
> +_mesa_is_image_unit_valid(struct gl_context *ctx, struct gl_image_unit *u);
> +
> +/**
>   * Recalculate the \c _Valid flag of a context's shader image units.
>   *
>   * To be called when the state of any texture bound to an image unit
>