CanvasOpen ( n, w, h, viewport_x, viewport_y, viewport_w, viewport_h,
mode)
Opens a canvas for drawing.
n - the canvas index; there is a max of 8 ( 0 to 7 )
w, h - the total size of the drawing surface
viewport_x, viewport_y - where on the window to draw the canvas
viewport_w, viewport_h - size of the canvas area to be shown
Mode 0 - Solid
Mode 1 - Transparent
Example:
CanvasOpen ( 0, 640,
480, 0, 0, 640,
480, 1 )