brianp at vmware.com
Thu Jan 19 09:07:53 PST 2012
On 01/19/2012 09:58 AM, Dee Sharpe wrote:
> 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:
>>> Or do they all need to be cleared?
>> Clearing effects "draw" buffers, not "read" buffers.
>> Unless a user-created FBO is bound, ctx->WinSysDrawBuffer ==
>> 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?
No. The _ColorDrawBuffers array is indexed by an integer between 0
and _NumColorDrawBuffers-1. The contents of the array is updated by
calls to glDrawBuffer() or glDrawBuffersARB().
If you specifically want the front-left buffer you'd use:
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