On Fri, Sep 2, 2011 at 4:03 AM, Eric Anholt <e...@anholt.net> wrote: > On Wed, 31 Aug 2011 13:46:34 +0800, Chia-I Wu <olva...@gmail.com> wrote: >> From: Chia-I Wu <o...@lunarg.com> >> >> Add a new format token, __DRI_IMAGE_FORMAT_RGBA8888_REV, to __DRI_IMAGE. >> It maps to MESA_FORMAT_RGBA8888_REV in core mesa or >> PIPE_FORMAT_R8G8B8A8_UNORM in gallium. It is the format of translucent >> surfaces on Android. > > This could use some explanation: Why can't android use the existing > format with alpha? Does the GL get no input into the hardware formats > chosen? Who chooses the format? Would it work if we just didn't report > HAL_PIXEL_FORMAT_RGBA_8888 for configs? Android defines both
HAL_PIXEL_FORMAT_RGBA_8888 (maps to MESA_FORMAT_RGBA8888_REV) HAL_PIXEL_FORMAT_BGRA_8888 (maps to MESA_FORMAT_ARGB8888) among others. The 2D graphics toolkit and the reference (software) OpenGL renderer only support the former format. With i915/i965, on the other hand, EGLConfig's reported by Mesa never use the former format but the latter one. Now this is on the app side. GL gets a say about the formats it wants. But as both formats above may be used by apps, the compositor, which is also a GL user, have to support sampling from buffers in either format. That is the reason for this new __DRI_IMAGE format. > Also, I'd prefer to see the name ABGR8888 to the ridiculous _REV naming, > if we do need a new format. I am fine with changing the naming. -- o...@lunarg.com _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
