Clearing FrameBuffer when setRenderTarget is used

[Klaudiusz]

Hi Egon,

FrameBuffer.clear() method clears the whole FrameBuffer no matter how small texture is used in setRenderTarget.

Little step in the optimalisation process:)

[EgonOlsen]

Yes, but only when FBOs are not used or not available. I wouldn't consider this to be a bug. "Optimizing" this process makes no sense, because clearing the buffer is drop dead cheap nowadays.