NAME

scrmask − defines a clipping mask for the screen

SPECIFICATION

C
scrmask(left, right, bottom, top)
Screencoord left, right, bottom, top;

FORTRAN
subroutine scrmas(left, right, bottom, top)
integer*4 left, right, bottom, top

Pascal
procedure scrmask(left, right, bottom, top: Screencoord);

DESCRIPTION

scrmask provides fine character clipping.  viewport sets the same area for both the viewport and the screenmask, which left, right, bottom, and top defines.  scrmask sets only the screenmask, which must be placed entirely within the viewport. 

Strings that begin outside the viewport are clipped out; this is called gross clipping.  Strings that begin inside the viewport but outside the screenmask are clipped to the pixel boundaries of the screenmask; this is called fine clipping.  All drawing routines are also clipped to the viewport, but it is only useful for characters; gross clipping is sufficient for all other primitives. 

SEE ALSO

getscrmask, viewport IRIS Graphics Programming, Section 4.4, Viewports
 

Version 2.5r1  —  October 29, 1986