[Mesa-dev] ARB_copy_image support in Gallium

[Ilia Mirkin]

Let me put this another way... if anyone is strongly opposed to this
plan, please speak up now. Otherwise I'll push this before the
branchpoint (again, without actually enabling the ext).

On Wed, Aug 12, 2015 at 3:17 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> As I'm guessing that it's unlikely that the VMWare implementation will
> get upstreamed before the Mesa 11.0 branch point, how do people feel
> about including the below implementation *without* the extension
> enable? That way people will still be able to run bioshock infinite
> without resorting to patching (by adding the ext override) while we
> wait for a proper implementation.
>
> Thoughts?
>
>   -ilia
>
>
> On Mon, Jul 20, 2015 at 3:19 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> On Mon, Jul 20, 2015 at 2:44 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>> Hi Brian,
>>>
>>> You marked off ARB_copy_image (and ARB_clear_texture) as in-progress
>>> by VMware some months ago -- has there been any movement on that? It
>>> appears that Bioshock Infinite requires ARB_copy_image so might be
>>> nice to get that added in.
>>>
>>> The complication in implementing ARB_copy_image was that st/mesa will
>>> pick potentially different PIPE_FORMAT enums for the same internal
>>> format, depending on the parameters to the glTexImage call. A
>>> developer (irc handle Leftmost, I forget his real name, sorry) tried
>>> to wrestle with the issues this presents, but as I recall ended up
>>> coming up short.
>>>
>>> The final implementation probably needs some combination of
>>> resource_copy_region and blit. I think resource_copy_region currently
>>> is spec'd to require identical formats in src and dst, but that could
>>> be relaxed.
>>>
>>> Anyways, would be interested in hearing whether you guys have made any
>>> progress, or if you had thoughts on proper implementation.
>>>
>>> Cheers,
>>>
>>>   -ilia
>>
>> As an aside, here's a very naive implementation of the ext, which
>> fails for lots of reasons not the least of which is that we default to
>> BGRA instead of RGBA. Perhaps we could create a resource_copy_region
>> version that also takes (or knows about) swizzles... that should also
>> cover many (all?) of the situations I think.
>>
>>   -ilia
>>
>> diff --git a/src/mesa/state_tracker/st_cb_texture.c
>> b/src/mesa/state_tracker/st_cb_texture.c
>> index 7ea3846..b6b0081 100644
>> --- a/src/mesa/state_tracker/st_cb_texture.c
>> +++ b/src/mesa/state_tracker/st_cb_texture.c
>> @@ -1864,6 +1864,28 @@ st_TextureView(struct gl_context *ctx,
>>     return GL_TRUE;
>>  }
>>
>> +static void
>> +st_CopyImageSubData(struct gl_context *ctx,
>> +                    struct gl_texture_image *src_image,
>> +                    int src_x, int src_y, int src_z,
>> +                    struct gl_texture_image *dst_image,
>> +                    int dst_x, int dst_y, int dst_z,
>> +                    int src_width, int src_height)
>> +{
>> +   struct st_context *st = st_context(ctx);
>> +   struct pipe_context *pipe = st->pipe;
>> +   struct st_texture_image *src = st_texture_image(src_image);
>> +   struct st_texture_image *dst = st_texture_image(dst_image);
>> +
>> +   struct pipe_box box;
>> +
>> +   u_box_2d_zslice(src_x, src_y, src_z, src_width, src_height, &box);
>> +   pipe->resource_copy_region(pipe, dst->pt, dst_image->Level,
>> +                              dst_x, dst_y, dst_z,
>> +                              src->pt, src_image->Level,
>> +                              &box);
>> +}
>> +
>>
>>  void
>>  st_init_texture_functions(struct dd_function_table *functions)
>> @@ -1896,4 +1918,6 @@ st_init_texture_functions(struct
>> dd_function_table *functions)
>>
>>     functions->AllocTextureStorage = st_AllocTextureStorage;
>>     functions->TextureView = st_TextureView;
>> +
>> +   functions->CopyImageSubData = st_CopyImageSubData;
>>  }
>> diff --git a/src/mesa/state_tracker/st_extensions.c
>> b/src/mesa/state_tracker/st_extensions.c
>> index b1057f3..9bff7b4 100644
>> --- a/src/mesa/state_tracker/st_extensions.c
>> +++ b/src/mesa/state_tracker/st_extensions.c
>> @@ -589,6 +589,7 @@ void st_init_extensions(struct pipe_screen *screen,
>>      * Extensions that are supported by all Gallium drivers:
>>      */
>>     extensions->ARB_ES2_compatibility = GL_TRUE;
>> +   extensions->ARB_copy_image = GL_TRUE;
>>     extensions->ARB_draw_elements_base_vertex = GL_TRUE;
>>     extensions->ARB_explicit_attrib_location = GL_TRUE;
>>     extensions->ARB_explicit_uniform_location = GL_TRUE;