[Mesa-dev] [PATCH] i965: handle stencil_bits parameter for MESA_FORMAT_B8G8R8X8_UNORM format.

[Deve]

This patch indeed seems to not have a sense. I just added it to the bug 
report as a suggestion that it works for me after this modification. 
Emil Velikov said that I should send it to the mailing list.

Here is how it works in Supertuxkart:
We create rtt with following parameters:

DepthStencilTexture = generateRTT(res, GL_DEPTH24_STENCIL8, 
GL_DEPTH_STENCIL, GL_UNSIGNED_INT_24_8);

Then, during rendering scene, we do:

     glEnable(GL_FRAMEBUFFER_SRGB);
     glBindFramebuffer(GL_FRAMEBUFFER, 0);
     (...)
     render();
     (...)
     glDisable(GL_FRAMEBUFFER_SRGB);

It looks that glEnable(GL_FRAMEBUFFER_SRGB) doesn't work anymore. It's 
because of following lines in intel_screen.c in intelCreateBuffer() 
function:

    if (mesaVis->redBits == 5)
       rgbFormat = MESA_FORMAT_B5G6R5_UNORM;
    else if (mesaVis->sRGBCapable)
       rgbFormat = MESA_FORMAT_B8G8R8A8_SRGB;
    else if (mesaVis->alphaBits == 0)
       rgbFormat = MESA_FORMAT_B8G8R8X8_UNORM;
    else {
       rgbFormat = MESA_FORMAT_B8G8R8A8_SRGB;
       fb->Visual.sRGBCapable = true;
    }

Previously MESA_FORMAT_B8G8R8X8_UNORM was not available, and thus 
MESA_FORMAT_B8G8R8A8_UNORM was handled as last case (using 
MESA_FORMAT_B8G8R8A8_SRGB format). Now it uses 
MESA_FORMAT_B8G8R8X8_UNORM format.

Any ideas how it should be handled?

Regards,
Deve

W dniu 09.12.2015 o 03:00, Ilia Mirkin pisze:
> On Mon, Dec 7, 2015 at 5:32 PM, Dawid Gan <deveee at gmail.com> wrote:
>> This format has been added in commit:
>> 28090b30dd6b5977de085f48c620574214b6b4ba
>> But it was handled in the same way as MESA_FORMAT_B8G8R8A8_UNORM format.
>> It was causing the screen in Supertuxkart to be darker than expected, see:
>> https://bugs.freedesktop.org/show_bug.cgi?id=92759
>>
>> Cc: Boyan Ding <boyan.j.ding at gmail.com>
>> Cc: "11.0 11.1" <mesa-stable at lists.freedesktop.org>
>> Fixes: 28090b30dd6 "i965: Add XRGB8888 format to intel_screen_make_configs"
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92759
>> ---
>>   src/mesa/drivers/dri/i965/intel_screen.c | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
>> index cc90efe..75d5a65 100644
>> --- a/src/mesa/drivers/dri/i965/intel_screen.c
>> +++ b/src/mesa/drivers/dri/i965/intel_screen.c
>> @@ -1237,6 +1237,9 @@ intel_screen_make_configs(__DRIscreen *dri_screen)
>>                stencil_bits[2] = 8;
>>                num_depth_stencil_bits = 3;
>>            }
>> +      } else if (formats[i] == MESA_FORMAT_B8G8R8X8_UNORM) {
>> +         depth_bits[1] = 24;
>> +         stencil_bits[1] = 0;
>
> Why would you want depth without stencil when using BGRX? I don't see
> how the two are connected... Are you sure you're picking the right
> visual?
>
>    -ilia
>