[Mesa-dev] [PATCHv2 0/3] st/mesa: make winsys framebuffer sRGB-capable

[Chia-I Wu]

Hi,

Until now, we do not support sRGB write for winsys framebuffers.  This series
changes that so that winsys framebuffers are marked sRGB-capable when the pipe
driver supports it.

This is not to be confused with GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB.  The
attribute guarantees the created winsys framebuffers to be sRGB-capable.  This
series is just a prerequisite if we ever want to export fbconfigs that are
sRGB-capable.

And we mark winsys framebuffers to be sRGB-capable only for desktop GL
contexts.  In GLES, sRGB capability implies sRGB write.  There is no
GL_FRAMEBUFFER_SRGB to control whether sRGB write is enabled or not.  We do
not want to surprise applications that do not expect sRGB.  This could change
when EGL_KHR_gl_colorspace is supported.

v2:
 - add MESA_FORMAT_B8G8R8X8_SRGB
 - never mark winsys framebuffer sRGB-capable for GLES contexts