Get Size of UImage when in UIImageView when ContentMode = AspectFill

Question

Im currently editing an UIImage with core graphics

The UIImage content mode is set to .aspectFill

When I draw on the image I want to keep the scale / ratio of the image.

Ive tried the following code but it returns .aspectFit values rather then .AspectFill

let imageSize = AVMakeRect(aspectRatio: (mainImageView.image?.size)!, insideRect: mainImageView.frame)

Any help would be greatly appreciated

Thomas

Answer 1

That function can only do an aspect fit.

Here is a function that will do an aspect fill:

func makeFillRect(aspectRatio: CGSize, insideRect: CGRect) -> CGRect {
    let aspectRatioFraction = aspectRatio.width / aspectRatio.height
    let insideRectFraction = insideRect.size.width / insideRect.size.height
    let r: CGRect
    if (aspectRatioFraction > insideRectFraction) {
        let w = insideRect.size.height * aspectRatioFraction
        r = CGRect(x: (insideRect.size.width - w)/2, y: 0, width: w, height: insideRect.size.height)
    } else {
        let h = insideRect.size.width / aspectRatioFraction
        r = CGRect(x: 0, y: (insideRect.size.height - h)/2, width: insideRect.size.width, height: h)
    }
    return r
}