STATIC SUB ClearAccum ( Red AS Float, Green AS Float, Blue AS Float, Alpha AS Float )
Gl.ClearAccum specifies the red, green, blue, and alpha values used by Gl.Clear to clear the accumulation buffer. Values specified by Gl.ClearAccum are clamped to the range [-1,1].
Gl.GL_INVALID_OPERATION is generated if Gl.ClearAccum is called between a call to Gl.Begin and the corresponding call to Gl.End.