glFinish3x
Block until all gl execution is complete
C specification
void glFinish( void )
Overview
glFinish does not return until the effects of all previously called GL commands are complete. Such effects include all changes to GL state, all changes to connection state, and all changes to the frame buffer contents.
Notes
glFinish requires a round trip to the server.
Errors
GL_INVALID_OPERATION is generated if glFinish is executed between the execution of glBegin and the corresponding execution of glEnd.