[Scummvm-devel] Bitdepth/pixel format API concerns

[Andre Heider]

On Tue, Jun 9, 2009 at 8:43 PM, Max Horn<max at quendi.de> wrote:
>> Max Horn <max at quendi.de> writes:
>>
>>> -> survey: which backends support which modes natively, anyway? Again
>>> something that I would recommend collecting in a table on the wiki
>>> for
>>> future reference!

A little late to the party, but the relevant texture formats on the
Gamecube/Wii (big endian) are:

RGB565
RGB5A3 (MSB = 1 -> RGB555, MSB = 0 -> RGBA4443)
RGBA8 (ARGB)

The port is currently using RGB565.

The fun thing is the texture tiling:

RGB565: 4x4 tiles of 16bit RGB
ARGB: 2 * 4x4 tiles of 16bit, one time AR and one time GB

Those tiled textures are assembled on every frame by the CPU, and then
scaled by the GPU to the framebuffer, which uses YCbCr/YUV4:2:2.

Regards,
Andre