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From: bdiscoe@tybalt.caltech.edu (Ben W. Discoe)
Newsgroups: comp.sys.amiga.tech
Subject: Automatic window clipping
Summary: What are the limits to window clipping?
Message-ID: <12540@cit-vax.Caltech.Edu>
Date: 7 Nov 89 07:07:10 GMT
Sender: news@cit-vax.Caltech.Edu
Reply-To: bdiscoe@tybalt.caltech.edu.UUCP (Ben W. Discoe)
Distribution: usa
Organization: California Institute of Technology
Lines: 23


    I'm writing a structed graphics program that allows unlimited zoom
(simply changing scaling factors) and until recently could count on the
automatic clipping the graphics library does using the Layer limits.
However, when I start to draw line WAY off the screen (>several thousand
pixels) two things start happening:

	1) the lines become jagged when they appear on the screen
	2) eventually the machine dies or the program freezes in a state
	   of intense CPU usage.

    I realize what I should do is test the endpoints of each line I draw
and not draw the ones too far off, however, I'd like to know a few things:

	1) What are the exact limits to the gfx lib clipping?
	2) Does is make a difference if the number you pass "Draw()"
	   is great than a WORD variable will allow?
	3) Why does the machine die?  Does it have to do with the line
	   drawing being done in hardware?

I couldn't find anything in the RKMs about this and I hope it isn't a
case of RTFM.   Thanks much,
		Ben "struggling starving student stereotype"