Path: utzoo!attcan!uunet!aplcen!haven!decuac!decwrl!elroy.jpl.nasa.gov!ames!dftsrv!amarna.gsfc.nasa.gov!seiler
From: seiler@amarna.gsfc.nasa.gov (Ed Seiler)
Newsgroups: comp.sys.mac.programmer
Subject: Still need help creating a QuickDraw picture
Message-ID: <2223@dftsrv.gsfc.nasa.gov>
Date: 2 Jun 90 08:50:17 GMT
Sender: news@dftsrv.gsfc.nasa.gov
Reply-To: seiler@amarna.gsfc.nasa.gov
Organization: NASA Goddard Space Flight Center - Greenbelt, MD, USA
Lines: 44
News-Software: VAX/VMS VNEWS 1.3-4

I still don't get it. Let me give a bit more detail. I have an image file, 512
lines by 512 pixels per line. I create a pixMap and read the image data,
storing at the location starting at the baseAddr of the pixMap. The high bit of
the rowBytes field is set. I create a color window via NewCWindow (windPtr is
the pointer to it), and also open a color GrafPort via OpenCPort (myCGrafPtr is
the pointer to it). The baseAddr, rowBytes, and bounds of the portPixMap of the
cGrafPort are assigned the corresponding values of the pixMap. When I do

CopyBits((BitMap *) *(*myCGrafPtr).portPixMap, &(windPtr->portBits),
        &(*pixMapHndl)->bounds,(windPtr->portRect), srcCopy, NULL);

the image appears in the window.

So far so good. Now I would like to creat a QuickDraw picture. If I do

SetPort(windPtr);
picHndl = OpenPicture(&(windPtr->portRect));
CopyBits(&(windPtr->portBits), &(windPtr->portBits),
         &(windPtr->portRect), &(windPtr->portRect), srcCopy, NULL);
ClosePicture();

no copybits opcode shows up, but the sequence: version op, version, header op,
size, fBBox, <4 bytes reserved>, DefHilite, Clip, opEndPic occurs.
If I try

SetPort(myCGrafPtr);
picHndl = OpenPicture(&(windPtr->portRect));
CopyBits((BitMap *) *(*myCGrafPtr).portPixMap,
         (BitMap *) *(*myCGrafPtr).portPixMap, 
         &(myCGrafPtr->portRect), &(myCGrafPtr->portRect),
         srcCopy, NULL);
ClosePicture();

then after the version opcode of 0011, the 4 following bytes are 0000, DD50,
rather than 02FF, 0C00. After that it looks like a picture, with a copybits
opcode. This doesn't seem to qualify as a picture, and a call to DrawPicture
doesn't draw anything. Just what is the correct way to create the picture?

Edward Seiler                           seiler@dftnic.gsfc.nasa.gov
Mail Code 635                           seiler@chrpserv.gsfc.nasa.gov
Goddard Space Flight Center             (301) 286-9421
Greenbelt, MD 20771

"Against stupidity, the gods themselves contend in vain"