screen(3G)

NAME
     screen - map world space to absolute screen coordinates

FORTRAN SPECIFICATION
     subroutine screen

PARAMETERS
     none

DESCRIPTION
     screen 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.

     screen is equivalent to:

           integer*4 xmin, ymin

           call getorg(xmin, ymin)
           call viewpo(-xmin, getgde(GDXPMA)-xmin,
          +            -ymin, getgde(GDYPMA)-ymin)
           call ortho2(-0.5, getgde(GDXPMA)+0.5,
          +            -0.5, getgde(GDYPMA)+0.5)


SEE ALSO
     fullsc, getgde, getori, viewpo, ortho2

NOTE
     This routine is available only in immediate mode.