[Mesa-dev] [PATCH 5/6][RFC] Gallium/dri2: implement blitImage

[Axel Davy]

On 06/01/2014, Marek Olšák wrote :
> On Sun, Jan 5, 2014 at 10:26 PM, Axel Davy <axel.davy at ens.fr> wrote:
>> Signed-off-by: Axel Davy <axel.davy at ens.fr>
>> ---
>>   src/gallium/state_trackers/dri/drm/dri2.c | 49 +++++++++++++++++++++++++++++--
>>   1 file changed, 47 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/gallium/state_trackers/dri/drm/dri2.c b/src/gallium/state_trackers/dri/drm/dri2.c
>> index 2a5b7b4..89d9040 100644
>> --- a/src/gallium/state_trackers/dri/drm/dri2.c
>> +++ b/src/gallium/state_trackers/dri/drm/dri2.c
>> @@ -985,6 +985,49 @@ dri2_from_fds(__DRIscreen *screen, int width, int height, int fourcc,
>>   }
>>
>>   static void
>> +dri2_blit_image(__DRIcontext *context, __DRIimage *dst, __DRIimage *src,
>> +                    int dstx0, int dsty0, int dstwidth, int dstheight,
>> +                    int srcx0, int srcy0, int srcwidth, int srcheight,
>> +                    int flags)
>> +{
>> +   struct dri_context *ctx = dri_context(context);
>> +   struct pipe_context *pipe = ctx->st->pipe;
>> +   struct pipe_screen* screen = dri_screen(ctx->sPriv)->base.screen;
>> +   struct pipe_fence_handle *fence;
>> +   struct pipe_blit_info blit;
>> +
>> +   if (!dst || !src)
>> +      return;
>> +
>> +   memset(&blit, 0, sizeof(blit));
>> +   blit.dst.resource = dst->texture;
>> +   blit.dst.box.x = dstx0;
>> +   blit.dst.box.y = dsty0;
>> +   blit.dst.box.width = dstwidth;
>> +   blit.dst.box.height = dstheight;
>> +   blit.dst.box.depth = 1;
>> +   blit.dst.format = dst->texture->format;
>> +   blit.src.resource = src->texture;
>> +   blit.src.box.x = srcx0;
>> +   blit.src.box.y = srcy0;
>> +   blit.src.box.width = srcwidth;
>> +   blit.src.box.height = srcheight;
>> +   blit.src.box.depth = 1;
>> +   blit.src.format = src->texture->format;
>> +   blit.mask = PIPE_MASK_RGBA;
>> +   blit.filter = PIPE_TEX_FILTER_NEAREST;
>> +
>> +   pipe->blit(pipe, &blit);
>> +
>> +   pipe->flush_resource(pipe, dst->texture);
>> +
>> +   ctx->st->flush(ctx->st, 0, &fence);
>> +
>> +   if (flags & __BLIT_FLAG_FINISH)
>> +      (void) screen->fence_finish(screen, fence, PIPE_TIMEOUT_INFINITE);
>> +   screen->fence_reference(screen, &fence, NULL);
> Fences might not be implemented by some drivers. I recommend setting
> the fence pointer to NULL, then calling flush and then checking if
> it's not NULL. Also, getting a fence incurs some overhead, so if
> __BLIT_FLAG_FINISH is not set, the last parameter of st->flush should
> be NULL.
>
> Who can call this function? The X server?
>
> Marek
>
Thanks for the comment.

the __BLIT_FLAG_FINISH flag is to glFinish before exporting the buffer 
when rendering on a different card than the compositor. This use case 
will disappear with dma-buf fences.
I'm hesitating to remove this flag, and bet that dma-buf fences will 
land soon.

The blitImage function would be called for Wayland when on a different 
device than the Wayland compositor,
but it can be used fro X dri3 too (when on the dedicated device).
The work done for prime support for Wayland can be taken for X dri3.

About the flush done in the function: do you think it is ok to flush 
here, or that it sould be optional to flush?

Axel Davy