Documentation

Obtain new Sync with or without timeout in nanoseconds. Fence sync objects are used to wait for partial completion of the GL command stream, as a more flexible form of glFinish.

-- Sync objects can be used many times
sync1 <- getSync (Just 16000)
sync2 <- getSync Nothing

For each frame:

glFence sync1 $ \isTimedOut -> do
  {- modify buffers, textures, etc -}
glFence sync2 $ \isTimedOut -> do
  {- modify buffers, textures, etc -}
endFrameGL

Block and wait for GPU commands issued here complete. Better glFinish for ES 3+. Block and wait for a Sync object to become signaled, then run specified block.

Blocks on GPU until GL commands issued here complete. Better glFlush for ES 3+. Sync timeout is ignored. Instruct the GL server to block (on the GPU) until the previous call of glFence* with specified Sync object becomes finished on the GL server, then run specified block.

Same as glFlush. This operation is expensive, so frequent use should be avoided as far as possible.

Same as glFinish. This operation is expensive, so frequent use should be avoided as far as possible.