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CompositeViewer support: Difference between revisions
→Swap Buffers
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=== Swap Buffers === | === Swap Buffers === | ||
OpenGL drivers have a FIFO, your app fills the fifo with tokens and | |||
data, at the end of the frame you send in a swap buffers token and | |||
this goes into the FIFO with everything else. Normally the swap | |||
buffers call itself doesn't block (although some implementations do | |||
this), but the FIFO itself can only be cleared at the rate for one | |||
swap buffers call per frame so it'll fill and once filled up it will | |||
effectively block until previous frame was begun dispatching. The | |||
driver may allow several frames worth data in the fifo before block, | |||
this is driver dependent, and also dependent on just how data you have | |||
to pass to OpenGL- if you have massive models the CPU will be block on | |||
the FIFO right on the same frame rather than more than one frame begin | |||
backed in the FIFO. | |||
The end result of this is simpler though - put vsync on, and your | |||
frame loop will block and should iddle while its waiting for the FIFO | |||
to begin accepting new data. <ref>https://www.mail-archive.com/osg-users@lists.openscenegraph.org/msg04323.html</ref> | |||
The driver will be queuing up multiple frames in the FIFO, something it | The driver will be queuing up multiple frames in the FIFO, something it | ||
does to help improve the framerate, but increases frame latency. | does to help improve the framerate, but increases frame latency. | ||