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Article #5579Re: A QuickDraw bug.
From: Greg
Date: Sat, 10 May 1986 20:19
Date: Sat, 10 May 1986 20:19
15 lines
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1460 bytes
In article <932@harvard.UUCP> greg@harvard.UUCP (Greg) writes: >Apparently, a region is stored as a linked-list of horizontal scan lines. When >you move a window on the screen, the Window Manager calls CopyBits to copy the >window contents. Normally CopyBits runs from top to bottom, using the >scanlines of the region in order. However, if you are copying from a grafport, >like the screen, to itself, then CopyBits may have to copy the image from >bottom to top so that it won't lose information during the transfer. Someone at General Computer who actually poked around in the ROM has pointed out to me that a region is not stored as a linked list of horizontal scan lines, but simply as a consecutive list of horizontal scan lines. However, since the scan lines have variable length, the problem persists. The rest of my article is correct. -- gregregreg
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!burl!ulysses!allegra!princeton!orsvax1!pyrnj!caip!topaz!uwvax!harvard!greg From: greg@harvard.UUCP (Greg) Newsgroups: net.micro.mac Subject: Re: A QuickDraw bug. Message-ID: <941@harvard.UUCP> Date: Sat, 10-May-86 16:19:47 EDT Article-I.D.: harvard.941 Posted: Sat May 10 16:19:47 1986 Date-Received: Tue, 13-May-86 03:22:16 EDT References: <932@harvard.UUCP> Reply-To: greg@harvard.UUCP (Greg) Organization: Harvard Lines: 15 Keywords: regions CopyBits Summary: small correction.