Specifies a rectangular clipping area for all subsequent drawing operations.
Any drawing commands that extend outside the rectangle will be clipped so that only the portion inside the rectangle will be displayed. The rectangle dimensions are not transformed by the current model-view matrix.
The rectangle is intersected with the current clip region. To undo the effect of this function, call clip_pop.
left edge of the clip rectangle in window coordinates
top edge of the clip rectangle in window coordinates
width of the clip rectangle
height of the clip rectangle