On Mon, 2017-06-19 at 13:35 +0100, Daniel Stone wrote: > On 13 June 2017 at 21:43, Adam Jackson <[email protected]> wrote: > > On Thu, 2017-06-08 at 19:43 +0100, Daniel Stone wrote: > > > > > > +typedef struct { > > > + [...] > > > + CARD32 stride0 B32; > > > + CARD32 offset0 B32; > > > + CARD32 stride1 B32; > > > + CARD32 offset1 B32; > > > + CARD32 stride2 B32; > > > + CARD32 offset2 B32; > > > + CARD32 stride3 B32; > > > + CARD32 offset3 B32; > > > + [...] > > > +} xDRI3PixmapFromBuffersReq; > > > +#define sz_xDRI3PixmapFromBuffersReq 64 > > > > Why exactly four strides/offsets? > > Because that's what KMS takes for AddFB2, and (not coincidentally) > what EGL_EXT_image_dma_buf_import_modifiers also defines tokens for. I > don't even know of anyone using four, which would be tri-planar Y/U/V > with an auxiliary plane. But seemed prudent to line up with the > external APIs.
Aux plane for alpha or transparency key maybe? But thanks, that clarifies the intent for me. I wasn't sure whether the multiple buffers were for front/back and left/right for stereo or something. If they're for planar color then 4 is plenty unless someone wants like CMYKA or something silly like that. - ajax _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel
