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copied!<p>After a few days I finally got a working solution to this. There is code provided by Apple which produces an UIImage from an EAGLView. Then you simply need to flip the image vertically since UIKit is upside down. The link to the documentation where I found this method doesn't exist anymore.</p> <p>Method to capture EAGLView:</p> <pre><code>-(UIImage *)drawableToCGImage { GLint backingWidth2, backingHeight2; //Bind the color renderbuffer used to render the OpenGL ES view // If your application only creates a single color renderbuffer which is already bound at this point, // this call is redundant, but it is needed if you're dealing with multiple renderbuffers. // Note, replace "_colorRenderbuffer" with the actual name of the renderbuffer object defined in your class. glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer); // Get the size of the backing CAEAGLLayer glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth2); glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight2); NSInteger x = 0, y = 0, width2 = backingWidth2, height2 = backingHeight2; NSInteger dataLength = width2 * height2 * 4; GLubyte *data = (GLubyte*)malloc(dataLength * sizeof(GLubyte)); // Read pixel data from the framebuffer glPixelStorei(GL_PACK_ALIGNMENT, 4); glReadPixels(x, y, width2, height2, GL_RGBA, GL_UNSIGNED_BYTE, data); // Create a CGImage with the pixel data // If your OpenGL ES content is opaque, use kCGImageAlphaNoneSkipLast to ignore the alpha channel // otherwise, use kCGImageAlphaPremultipliedLast CGDataProviderRef ref = CGDataProviderCreateWithData(NULL, data, dataLength, NULL); CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB(); CGImageRef iref = CGImageCreate(width2, height2, 8, 32, width2 * 4, colorspace, kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast, ref, NULL, true, kCGRenderingIntentDefault); // OpenGL ES measures data in PIXELS // Create a graphics context with the target size measured in POINTS NSInteger widthInPoints, heightInPoints; if (NULL != UIGraphicsBeginImageContextWithOptions) { // On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration // Set the scale parameter to your OpenGL ES view's contentScaleFactor // so that you get a high-resolution snapshot when its value is greater than 1.0 CGFloat scale = self.contentScaleFactor; widthInPoints = width2 / scale; heightInPoints = height2 / scale; UIGraphicsBeginImageContextWithOptions(CGSizeMake(widthInPoints, heightInPoints), NO, scale); } else { // On iOS prior to 4, fall back to use UIGraphicsBeginImageContext widthInPoints = width2; heightInPoints = height2; UIGraphicsBeginImageContext(CGSizeMake(widthInPoints, heightInPoints)); } CGContextRef cgcontext = UIGraphicsGetCurrentContext(); // UIKit coordinate system is upside down to GL/Quartz coordinate system // Flip the CGImage by rendering it to the flipped bitmap context // The size of the destination area is measured in POINTS CGContextSetBlendMode(cgcontext, kCGBlendModeCopy); CGContextDrawImage(cgcontext, CGRectMake(0.0, 0.0, widthInPoints, heightInPoints), iref); // Retrieve the UIImage from the current context UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); // Clean up free(data); CFRelease(ref); CFRelease(colorspace); CGImageRelease(iref); return image; } </code></pre> <p>Method to flip the image vertically:</p> <pre><code>- (UIImage *)flipImageVertically:(UIImage *)originalImage { UIImageView *tempImageView = [[UIImageView alloc] initWithImage:originalImage]; UIGraphicsBeginImageContext(tempImageView.frame.size); CGContextRef context = UIGraphicsGetCurrentContext(); CGAffineTransform flipVertical = CGAffineTransformMake( 1, 0, 0, -1, 0, tempImageView.frame.size.height ); CGContextConcatCTM(context, flipVertical); [tempImageView.layer renderInContext:context]; UIImage *flippedImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); //[tempImageView release]; return flippedImage; } </code></pre>

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