NAME

viewport − allocates an area of the window for an image

SPECIFICATION

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

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

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

DESCRIPTION

viewport specifies, in pixels, the area of the window that displays an image.  Specifying the viewport is the first step in mapping world coordinates to screen coordinates.  The portion of world space that window, ortho, or perspective describes is mapped into the viewport.  left, right, bottom, top coordinates define a rectangular area on the screen. 

viewport also loads the screenmask. 

SEE ALSO

scrmask, getviewport, popviewport, pushviewport Programming Guide, Section 4.4, Viewports

Version 3.6  —  December 20, 1987