screenspace(3G)

NAME
     screenspace - map world space to absolute screen coordinates

C SPECIFICATION
     void screenspace()

PARAMETERS
     none

DESCRIPTION
     screenspace sets the projection matrix and viewport of the current window
     so as to map world space to absolute screen coordinates (instead of to
     the more usual window-relative screen coordinates).  This provides a
     convenient coordinate system for operations that are not constrained to a
     window, e.g. reading pixels.

     screenspace is equivalent to:

          long xmin, ymin;

          getorigin(&xmin, &ymin);
          viewport(-xmin, getgdesc(GD_XPMAX)-xmin,
                   -ymin, getgdesc(GD_YPMAX)-ymin);
          ortho2(-0.5, getgdesc(GD_XPMAX)+0.5,
                 -0.5, getgdesc(GD_YPMAX)+0.5);


SEE ALSO
     fullscrn, getgdesc, getorigin, viewport, ortho2

NOTE
     This routine is available only in immediate mode.