Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!eos!aurora!labrea!polya!ali
From: ali@polya.STANFORD.EDU (Ali Ozer)
Newsgroups: comp.sys.amiga
Subject: Re: BltBitMap() problems.
Message-ID: <2073@polya.STANFORD.EDU>
Date: 23 Feb 88 22:08:24 GMT
References: <1081@percival.UUCP> <961@radio.toronto.edu>
Reply-To: ali@polya.UUCP (Ali Ozer)
Organization: Stanford University
Lines: 18
Keywords: Help!

In article <961@radio.toronto.edu> cks@radio.UUCP (Chris Siebenmann) writes:
> While this isn't your problem, everyone should be aware of a
>BltBitMap() bug I stumbled across a while back. One of BltBitMap()'s
>parameters is a temporary memory buffer for overlapping copies (tempA,
>the last parameter). In 1.1, you had to allocate this yourself; in 1.2
>the OS is supposed to do this for you. ...  But they never deallocate it
>afterwards ...

The same bug bit me while using The Director; I had text flying around
(different words on different bit planes, each bit plane blitting
in different direction; oh what power!) and I noticed that once in
a while my chip memory would go down in bursts of several K. Finally
I tracked it down to using the BLIT command to blit stuff directly to the
right --- that's the only time it'll lose stuff. So if you're a Director
user, be aware of this bug.

Ali Ozer, ali@polya.stanford.edu