CGRect change origin in Swift

Question

https://drive.google.com/file/d/1Nd6q9OmDppJrxjZIRODzffVDiBXKnB_e/view?usp=sharing

I'd like to change the position of the 'origin' like a picture for compose the watermark.

Bellow is my code.

var watermark = UIImage(named: "logo.png")
var newHeight = filteredImage.image?.size.height
var newWidth = filteredImage.image?.size.width

UIGraphicsBeginImageContext(CGSize(width:newWidth!, height:newHeight!))

watermark.draw(in: CGRect(x:-0, y:-0, width:400, height:300))

let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()

watermark = newImage!

filter = CIFilter(name: "CISourceOverCompositing")
filter!.setValue(CIImage(image: watermark), forKey: "inputImage")
filter!.setValue(coreImage1, forKey: "inputBackgroundImage")

How should I change my code?

Answer 1

If you want to place watermark to right bottom corner, use:

var watermark = UIImage(named: "logo.png")!
var newSize = filteredImage.image.size

UIGraphicsBeginImageContext(newSize)

watermark.draw(in: CGRect(
    x: newSize.width - watermark.image.width,
    y: newSize.height - watermark.image.height,
    width: watermark.image.width,
    height: watermark.image.height
))

...

Changing the origin is possible but impractical in this case.