[comp.graphics] Question about GKS viewport clipping.

sgcpal@watdcsu.waterloo.edu (Paul Layman) (06/04/88)

I am having trouble getting GKS to clip at the viewport boundary on my
VAX-Station II using an X-Window (X-10, Ultrix2.0/BSD4.3).

I execute the folloing commands:

call gswn(1,0.0,10.0,0.0,10.0)
call gsvp(1,0.4,0.6,0.4,0.6)
call gsclip(1)
call gselnt (1)

and the image doesn't get clipped at to 0.4, 0.6, 0.4, 0.6, (NDC) although
it does get sized properly.

call gqclip(errind,clip)

returns errind=0 and clip=1

if I call the c routine to which gqclip is bound, gks$inq_clip
it returns error=0, clipsw=1, cliprect=(0.0,1.0,0.0,0.0)
which seems to indicate the clipping rectangle is a straight line.

I wouldn't care if it didn't clip if I could keep the X server from
crashing if I try to draw outside the workstation window.

Any ideas or comments?
-- 
Paul A. Layman (playman@phonon.waterloo.edu)

University of Waterloo, Electrical Engineering,
Silicon Devices and Integrated Circuits Research Group (SiDIC)