/ comp / gb.opengl / gl / flush
Gl.Flush (gb.opengl)
Syntax

    STATIC SUB Flush ( )

### Force execution of GL commands in finite time

#### Description

Different GL implementations buffer commands in several different locations, including network buffers and the graphics accelerator itself. Gl.Flush empties all of these buffers, causing all issued commands to be executed as quickly as they are accepted by the actual rendering engine. Though this execution may not be completed in any particular time period, it does complete in finite time.

Because any GL program might be executed over a network, or on an accelerator that buffers commands, all programs should call Gl.Flush whenever they count on having all of their previously issued commands completed. For example, call Gl.Flush before waiting for user input that depends on the generated image.

| Gl.Flush can return at any time. It does not wait until the execution of all previously issued OpenGL commands is complete.

#### Errors

Gl.GL_INVALID_OPERATION is generated if Gl.Flush is called between a call to Gl.Begin and the corresponding call to Gl.End.

### See also

Gl.Finish