Re: [Mesa3d-dev] RFC: allow resource_copy_region between different (yet compatabile) formats

[José F. <jfo...@vm...>]

On Mon, 2010-09-06 at 10:41 -0700, Luca Barbieri wrote:
> How about dropping the idea that "resource_copy_region must be just a
> memcpy" and have the driver instruct the hardware 2D blitter to write
> 1s in the alpha channel if supported by hw or have u_blitter do this
> in the shader?

It's really different functionality. You're asking for a cast, as in

   b = (type)a;

as in (int)1.0f = 1.

Another thing is

  b = *(type *)&a;

as *(int *)&1.0f = 0x3f800000. This is my understanding of
region_copy_region (previously known as surface_copy). And Roland
provided a compelling argument for that.

Both these functionality are exposed by APIs, and neither is a superset
of the other.

Jose