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POConvert raw RGBA to UIImage
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  1. POConvert raw RGBA to UIImage
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    copied!<p>Yes, I know this sounds like a duplicate... but I've tried lots of examples and even Apple's official code on their developer page and this is resulting in a white image on iPhone 4S &amp; iPad 3. Works great on iPad 1 and the iPhone Simulator though.</p> <p>width and height passed to convertBitmapRGBA8ToUIImage is in actual pixels, not UIKit 'points'. I.e., on iPad 1, it would be 1024, 768. On iPad 3, it's 2048, 1536.</p> <p>The raw data buffer is RGBA data read from glReadPixels and flipped manually before passing to tweetMessage().</p> <pre><code>- (UIImage *) convertBitmapRGBA8ToUIImage:(unsigned char *) buffer withWidth:(int) width withHeight:(int) height { CGDataProviderRef ref = CGDataProviderCreateWithData(NULL, buffer, width * height * 4, NULL); CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB(); CGImageRef iref = CGImageCreate(width, height, 8, 32, width * 4, colorspace, kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast, ref, NULL, true, kCGRenderingIntentDefault); float scale = 1.0f; if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) { scale = [[UIScreen mainScreen] scale]; } UIGraphicsBeginImageContextWithOptions(CGSizeMake(width/scale, height/scale), NO, scale); CGContextRef cgcontext = UIGraphicsGetCurrentContext(); CGContextSetBlendMode(cgcontext, kCGBlendModeCopy); // Image needs to be flipped BACK for CG CGContextTranslateCTM(cgcontext, 0, height/scale); CGContextScaleCTM(cgcontext, 1, -1); CGContextDrawImage(cgcontext, CGRectMake(0.0, 0.0, width/scale, height/scale), iref); UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); CFRelease(ref); CFRelease(colorspace); CGImageRelease(iref); return image; } - (void)tweetMessage:(const char *)message withURL:(const char *)url withImage:(unsigned char*)rawRGBAImage withWidth:(unsigned int)imageWidth withHeight:(unsigned int)imageHeight { UIImage *tweetImage = nil; if (rawRGBAImage != nil) { // Convert raw data to UIImage tweetImage = [self convertBitmapRGBA8ToUIImage:rawRGBAImage withWidth:imageWidth withHeight:imageHeight]; } } </code></pre>
 

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