tdf#93529 - move to a Mac-like double-buffered OpenGL model. private/mmeeks/opengl-backbuffer2

This moves us to always rendering to an off-screen texture, and then
(at idle) blitting this to the screen & swapping buffers. Ideally we
should never see any rendering, or flicker again with this approach.

Several fixes are included:
+ avoid multiple OpenGL contexts being created for the same window,
created excessive flicker problems.
+ de-virtualize UseContext - which context we use is less critical.
+ kill 'mbOffscreen' distinction - all VCL rendering is offscreen.
+ implement 'doFlush' and high priority idle flushing.
+ bind stencil buffer for clipping vs. textures - fixing complex
clopping when rendering to virtual-devices, and off-screen.
+ document environment. variables.
+ use white as default background glClear color, but red for debug.

Change-Id: I6be08595b6c8deb7e6db0dbd81308b2c97d2b4ff

0 files changed, 0 insertions, 0 deletions