dispose method
void
dispose()
Implementation
void dispose(){
if(_didDispose) return;
_didDispose = true;
emptyTextures.clear();
equationToGL.clear();
factorToGL.clear();
buffers.clear();
enabledCapabilities.clear();
currentBoundFramebuffers.clear();
defaultDrawbuffers.clear();
currentBoundTextures.clear();
extensions.dispose();
currentDrawbuffers.dispose();
}