UIImage by selecting part of another UIImage

Question

I have an UIImage and a CGPoint which tells me in what direction I should move it to create another image. The backgrou

Answer 1

You can use CGImageCreateWithImageInRect(). You can get a CGImage from a UIImage with the property of the same name.

Basically what you end up doing is apply masks to the existing image to extract the portions you need. Like so -

myImageArea = CGRectMake(xOrigin, yOrigin, myWidth, myHeight);//newImage
mySubimage  = CGImageCreateWithImageInRect(oldImage, myImageArea);
myRect      = CGRectMake(0, 0, myWidth*2, myHeight*2);
CGContextDrawImage(context, myRect, mySubimage);

This post gives a good idea of how to use this property.