Nate n8r0n

steipete / UIImage+PSPDFKitAdditions.m

Created August 13, 2011 20:52

Preload UIImage for super-smooth interaction. especially great if you use JPGs, which otherwise produce a noticeable lag on the main thread.

	- (UIImage *)pspdf_preloadedImage {
	CGImageRef image = self.CGImage;

	// make a bitmap context of a suitable size to draw to, forcing decode
	size_t width = CGImageGetWidth(image);
	size_t height = CGImageGetHeight(image);

	CGColorSpaceRef colourSpace = CGColorSpaceCreateDeviceRGB();
	CGContextRef imageContext = CGBitmapContextCreate(NULL, width, height, 8, width*4, colourSpace,
	kCGImageAlphaPremultipliedFirst \| kCGBitmapByteOrder32Little);