Re: CGBitmapContextCreate hates me
Re: CGBitmapContextCreate hates me
- Subject: Re: CGBitmapContextCreate hates me
- From: Scott Thompson <email@hidden>
- Date: Mon, 20 Mar 2006 18:57:31 -0600
data = malloc( dataLength );
memset( data, 0, dataLength );
newImgSetup = CGBitmapContextCreate( data, width, height,
bitsPerComponent,
bytesPerRow, colorSpace, alphaInfo );
Core Graphics doesn't support RGB Bitmap contexts (i.e. ones with
no storage for alpha channel). Set your components to 4 and use
kCGImageAlphaNoneSkipFirst or kCGImageAlphaNoneSkipLast.
(depending on your desires).
see also:
<http://developer.apple.com/qa/qa2001/qa1037.html>
Scott
Bah, you know as soon as I read that, it clicked what I had read
about 24 bit bitmaps not being supported. I just didn’t see that I
was asking CG for a 24bit context. It works now (albeit I get a
solid black image for output... hrm).
Well, that's what you ask for :-) memset(data, 0, dataLength) sets
XRGB (or RGBX) pixels to an opaque black.
Scott
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