Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!cis.ohio-state.edu!ucbvax!bloom-beacon!dont-send-mail-to-path-lines
From: tomt@maui.coral.COM (Tom Tulinsky)
Newsgroups: comp.windows.x
Subject: how to XDrawLines > MaxRequestSize
Message-ID: <9106142040.AA25972@maui.coral.com>
Date: 14 Jun 91 20:40:04 GMT
References: <9106122314.AA17431@lightning.McRCIM.McGill.EDU>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 33


) 
) > I hadn't realized that there was a limit to the size of the lists
) > that the X poly requests like XDrawLines can handle until recently,
) > when I read Kenton Lee's article 'Behind Curtain X' in June's Unix
) > Review.  Here's some code which will draw lines with an arbitrary
) > length array of points.
) 
) [code omitted; simply breaks up the list of points, calling XDrawLines
)  multiple times.]
) 
) > A couple of pointed questions:
) > - If it's so simple, why can't the Xlib do it for you?
) 
) Because it's *not* so simple.  Read the protocol spec for the PolyLine
) request.  In particular, pay close attention to joins and the semantics
) of overlapping lines.  Your "solution" produces at least the following
) violations:
) . . .

Good point, correction accepted.  I believe that my for loop will
satisfy the protocol when the GC function is GXCopy because multiple
drawing of pixels does not matter in this common case.


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