[Mesa-dev] Check the compilation problems in mesa-user

[Brian Paul]

On 07/25/2012 10:57 AM, Eric Anholt wrote:
> Brian Paul<brianp at vmware.com>  writes:
>
>> On 07/25/2012 09:01 AM, Matt Turner wrote:
>>> On Wed, Jul 25, 2012 at 6:57 AM, Brian Paul<brianp at vmware.com>   wrote:
>>>>> Several days passed and no software renderer.
>>>>> I rather would like to test the llvmpipe
>>>>> than fix the compiler...
>>>>>
>>>>> What is the status with OSMesa and llvmpipe?
>>>>
>>>>
>>>> OSMesa only works with the legacy swrast driver, not llvmpipe.  One thing on
>>>> my to-do list is to write a gallium state tracker to implement OSMesa for
>>>> gallium drivers.  But I don't know when I'll get to that.
>>>
>>> OSMesa does software offscreen rendering? Why wouldn't developers just
>>> use FBOs these days? Beyond not depending on OSMesa, they'd have
>>> hardware acceleration.
>>
>> I think it's mostly legacay apps that use OSMesa.  But some OSMesa
>> apps do unusual things like directly touching the color/depth buffer
>> values to avoid glRead/DrawPixels (see the
>> OSMesaGetDepth/ColorBuffer() functions).
>
> Even for hardware drivers, people want to be able to directly map
> renderbuffers (wine, ported DX apps, chromium at least I've hard of).
> If someone writes an extension for that, we might be able to stop having
> a custom GL library just for that purpose.

I've actually thought about prototyping a GL extension which would 
allow the user to map renderbuffers and texture images for direct 
access.  One messy part is the need to completely describe the 
format/layout of the memory since OpenGL doesn't normally let you know 
those exact details.

-Brian