EGL_GAMMA_SRGB_BIT should be changed to a boolean EGL config attribute so it can be optionally sorted by eglChooseConfig. It should be sorted after EGL_COLOR_BUFFER_TYPE and true values would be preferred. This sorting should be optional and is done so compositing window managers can sample the framebuffer as an sRGB texture. EGL_GAMMA_SRGB_BIT could also optionally be disabled when the format is not supported as an sRGB texture by the hardware.
On Wed, Sep 26, 2012 at 10:19 AM, John Kåre Alsaker <john.kare.alsa...@gmail.com> wrote: > The way this would interact with ARB_framebuffer_sRGB is that the > EGL's surface EGL_GAMMA attribute would be ignored. If a EGL config > has the EGL_GAMMA_SRGB_BIT, it is required to support sRGB for the > default OpenGL framebuffer. > > On Tue, Sep 25, 2012 at 5:58 PM, John Kåre Alsaker > <john.kare.alsa...@gmail.com> wrote: >> Hello, >> >> I would like add support for sRGB framebuffers to EGL. Here are my >> proposed changes to EGL: >> >> A new EGL_SURFACE_TYPE bit: >> EGL_GAMMA_SRGB_BIT - This format supports sRGB framebuffers. This also >> means that ARB_framebuffer_sRGB is supported for this format. >> >> New values: >> EGL_GAMMA_LINEAR - The gamma is linear. >> EGL_GAMMA_SRGB - The gamma is as defined by the sRGB standard. >> >> New EGL surface attribute: >> EGL_GAMMA - The gamma of the surface's framebuffer. The default value >> is EGL_GAMMA_LINEAR. >> >> When the surface's EGL_GAMMA attribute's value is EGL_GAMMA_SRGB and >> this is supported by >> the format, reads from this framebuffer will be converted from sRGB >> gamma and writes will >> be converted to sRGB gamma. This may not apply to all functions in the >> client API. >> >> There may be something related to the ARB_framebuffer_sRGB extension >> in EGL already, in >> which case someone should link me to it. >> >> There's two assumptions behind this proposal. One is that you won't >> support sRGB only >> formats. The other is that linear gamma and sRGB gamma format support >> is the same. >> This means that window systems can't add a new linear gamma format >> without adding an sRGB >> format and the other way around. >> >> I'd like some comments on this proposal and tips on how it could be >> implemented in the >> mess that is DRI. >> >> Thanks, >> John Kåre _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
