[Mesa-dev] [PATCH 1/3] gallium: add expand_resource interface

[Roland Scheidegger]

I don't quite understand what this should do, at first sight it looks
like a ugly hack (which should really not be part of gallium interface)
to make fast color clearing work better with window framebuffers.
Seems to go against the idea of resources (which are immutable, well not
the contents but the properties).
(If anything I wanted an interface to change bind flags for resources
after initialization, because they are near impossible to guarantee with
OpenGL's (or d3d9 for that matter) distinct texture/fb model, but that
would also be quite a hack.)
Could you elaborate with some example what that's supposed to do in
practice?

Roland


Am 10.07.2013 18:20, schrieb Grigori Goronzy:
> This interface is used to expand fast-cleared window system
> colorbuffers.
> ---
>  src/gallium/include/pipe/p_context.h                 | 8 ++++++++
>  src/gallium/state_trackers/dri/common/dri_drawable.c | 4 ++++
>  src/gallium/state_trackers/dri/drm/dri2.c            | 8 ++++++--
>  3 files changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
> index aa18cbf..38d5ee6 100644
> --- a/src/gallium/include/pipe/p_context.h
> +++ b/src/gallium/include/pipe/p_context.h
> @@ -354,6 +354,14 @@ struct pipe_context {
>                                 unsigned dstx, unsigned dsty,
>                                 unsigned width, unsigned height);
>  
> +   /**
> +    * Expand a color resource in-place.
> +    *
> +    * \return TRUE if resource was expanded, FALSE otherwise
> +    */
> +   boolean (*expand_resource)(struct pipe_context *pipe,
> +                              struct pipe_resource *dst);
> +
>     /** Flush draw commands
>      *
>      * \param flags  bitfield of enum pipe_flush_flags values.
> diff --git a/src/gallium/state_trackers/dri/common/dri_drawable.c b/src/gallium/state_trackers/dri/common/dri_drawable.c
> index 18d8d89..b67a497 100644
> --- a/src/gallium/state_trackers/dri/common/dri_drawable.c
> +++ b/src/gallium/state_trackers/dri/common/dri_drawable.c
> @@ -448,6 +448,10 @@ dri_flush(__DRIcontext *cPriv,
>           }
>  
>           /* FRONT_LEFT is resolved in drawable->flush_frontbuffer. */
> +      } else if (ctx->st->pipe->expand_resource) {
> +         /* Expand fast-cleared framebuffer */
> +         ctx->st->pipe->expand_resource(ctx->st->pipe,
> +               drawable->textures[ST_ATTACHMENT_BACK_LEFT]);
>        }
>  
>        dri_postprocessing(ctx, drawable, ST_ATTACHMENT_BACK_LEFT);
> diff --git a/src/gallium/state_trackers/dri/drm/dri2.c b/src/gallium/state_trackers/dri/drm/dri2.c
> index 1dcc1f7..97784ec 100644
> --- a/src/gallium/state_trackers/dri/drm/dri2.c
> +++ b/src/gallium/state_trackers/dri/drm/dri2.c
> @@ -490,18 +490,22 @@ dri2_flush_frontbuffer(struct dri_context *ctx,
>  {
>     __DRIdrawable *dri_drawable = drawable->dPriv;
>     struct __DRIdri2LoaderExtensionRec *loader = drawable->sPriv->dri2.loader;
> +   struct pipe_context *pipe = ctx->st->pipe;
>  
>     if (statt != ST_ATTACHMENT_FRONT_LEFT)
>        return;
>  
>     if (drawable->stvis.samples > 1) {
> -      struct pipe_context *pipe = ctx->st->pipe;
> -
>        /* Resolve the front buffer. */
>        dri_pipe_blit(ctx->st->pipe,
>                      drawable->textures[ST_ATTACHMENT_FRONT_LEFT],
>                      drawable->msaa_textures[ST_ATTACHMENT_FRONT_LEFT]);
>        pipe->flush(pipe, NULL, 0);
> +   } else if (pipe->expand_resource && drawable->textures[ST_ATTACHMENT_FRONT_LEFT]) {
> +      /* Expand fast-cleared framebuffer */
> +      if (pipe->expand_resource(pipe, drawable->textures[ST_ATTACHMENT_FRONT_LEFT])) {
> +         pipe->flush(pipe, NULL, 0);
> +      }
>     }
>  
>     if (loader->flushFrontBuffer) {
>