Asynchronous (i.e. fast) readback from a framebuffer in OpenGL into a Jitter matrix.


The jit.gl.asyncread object uses Pixel Buffer Objects (PBOs) to perform asynchronous reads of the OpenGL context a high framerates. The performance gain comes from using two pixel buffer objects in tandem to amortize the cost of the read operation over time without blocking other rendering commands from executing as is typically the case when naive methods are used.

Information for Jitter 3D Object (OB3D) messages and attributes to this object




Name Type g/s Description
matrixoutput int Output a copy of the frame buffer (OpenGL render context). The output matrix dimensions adapt to the size of the window.
mode symbol Sets the reading mode. The available modes are:

split: Split reads a single frame in two passes and the output is concurrent.
interleaved: Interleaved reads an entire frame into each internal buffer, switching buffers every other frame. In interleaved mode, the readback is delayed for one frame.
out_name symbol (get) Returns the name of the internal frame buffer (OpenGL render context).

Information for box attributes common to all objects


See Also

Name Description
jit.gl.slab Performs a GL accelerated grid-based evaluation
jit.gl.videoplane GL accelerated video plane