NAME

viewport - allocate an area of the screen for an image

SYNOPSIS

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

FORTRAN
subroutine viewpo(left, right, bottom, top)
integer*2 left, right, bottom, top

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

DESCRIPTION

The first step in defining the mapping from world coordinates to screen coordinates is to choose an area of the screen to display an image.  This area is called the viewport and is specified in screen coordinates.  The arguments to the viewport command define a rectangular area on the screen by the left, right, bottom, and top coordinates.  This command also loads the screen mask. 

SEE ALSO

scrmask, getviewport, popviewport, pushviewport

Version 2.3  —  July 04, 1985