Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!bu-cs!dartvax!eleazar.dartmouth.edu!xxiaoye
From: xxiaoye@eleazar.dartmouth.edu (Xiaoxia Ye)
Newsgroups: comp.sys.mac.programmer
Subject: Integer Size problem
Message-ID: <15141@dartvax.Dartmouth.EDU>
Date: 21 Aug 89 21:55:47 GMT
Sender: news@dartvax.Dartmouth.EDU
Reply-To: xxiaoye@eleazar.dartmouth.edu (Xiaoxia Ye)
Organization: Dartmouth College, Hanover, NH
Lines: 45

Would someone explain the following weirdness?

the WIND resource' first 8 bytes are its positions on the screen: top,
left, bottom and right.  I tried to save the window postions and so to
write to the first 8 bytes of the WIND resource.

I have my rectange declared as (it's in THINK C):
Rect myRect;
and I get a handle to the WIND resource:
myHandle=GetResource('WIND',MY_WIND_RES_ID);

after I lock the Handle and do the following to assignment to the
resource:
**myHandle=myRect.top;
**myHandle+=2;
**myHandle=myRect.left
... blah blah and did this for all four coordinates.
and do a ChangedResource, and UpdateResFile, etc ...

What happened was:
say that I have the following eight bytes in my WIND resource (in Hex):
0044 0043 0056 0098
and say that myRect.top = 0x60, myRect.left=0x60, myRect.bottom=0x80 and
myRect.right=0x80.

and when I examined what was written to the resource, I found out that
first 8 bytes of WIND resource became:
6044 6043 8056 8098

in another words, if I just do an integer assignment, I don't get 00
padding and have the proper alignment.  Why??

And if I write a 0x132 to '0044', those two bytes will become '1324'
instead of '0132'.  Why ??

Well, eventually, I gave up and wrote a little routine to copy the bytes
myself (actually the THINK C inline assembly would do the job).

Much thanks.



________________________________________________________________________
Xiaoxia  Ye          INTERNET/BITNET/UUCP: xxiaoye@eleazar.dartmouth.edu
Dartmouth College    For more info: finger xxiaoye@eleazar.dartmouth.edu