Imagedata row order

J. Landman Gay jacque at hyperactivesw.com
Fri Jul 21 20:54:58 EDT 2006


Dar Scott wrote:
 >
 > On Jul 21, 2006, at 4:07 PM, J. Landman Gay wrote:
 >
 >> But now I'm curious. My first attempt created an incomplete set of
 >> pixels that didn't fill the image completely, but how come it wrapped
 >> by itself? That got me to wondering how imagedata gets applied. Is it
 >> supposed to just go along in rows until it hits the edge of the image
 >> object and then wrap itself around? If so, what I saw wasn't doing that.
 >
 > I assume you are using 4 bytes per pixel with no lf or spaces in between.

Right.

 > You might want to check the height & width and formattedHeight &
 > formattedWidth.

I got tired of crashing, but if I get brave again I'll do that. Hadn't 
thought of it, but it would be interesting to know.

 > Also, I have seen cases when funny things happen when the total size is
 > not as expected.  It goes completely wacko.

That's the word I was looking for. :)

 >
 > That may be why I clear the image and set the height and width before
 > setting the imageData.  Or is it set height & width, then clear the
 > data?  Or maybe...

Do you use imageData a lot? I know the crashes I had were because the 
imageData was wrong, but in your experience is this generally a stable 
technique for repeated use?

-- 
Jacqueline Landman Gay         |     jacque at hyperactivesw.com
HyperActive Software           |     http://www.hyperactivesw.com



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