[Mesa-dev] dd_function_table::Clear()

[Dee Sharpe]

On 1/18/2012 11:19 AM, Brian Paul wrote:
> On 01/18/2012 09:01 AM, Dee Sharpe wrote:
>> While implementing Clear() for a platform, which buffers in GLContext 
>> need to be cleared out of the list of:
>>
>> DrawBuffer
>> ReadBuffer
>> WinSysDrawBuffer
>> WinSysReadBuffer
>>
>> Or do they all need to be cleared?
>
> Clearing effects "draw" buffers, not "read" buffers.
>
> Unless a user-created FBO is bound, ctx->WinSysDrawBuffer == 
> ctx->DrawBuffer.
>
> You need to clear the color buffers attached to ctx->DrawBuffer.  The 
> number of buffers to clear is ctx->DrawBuffer->_NumColorDrawBuffers 
> and the indexes/pointers to the renderbuffers is in 
> _ColorDrawBufferIndexes[] and _ColorDrawBuffers[].
>
> I may actually get rid of the later (redundant) array and just write a 
> helper function that returns a pointer to a renderbuffer given a 
> buffer index.

Thanks for the quick reply. So, if I want to directly access the 
renderbuffer that I designated as the front left buffer, then I need to 
use _ColorDrawBuffers[BUFFER_FRONT_LEFT], correct?

-- 

Dee Sharpe

The difference between what IS done
&  what COULD be done is relational to
what you ARE doing&  what you COULD be doing!