I've created Swift
version of this class: https://github.com/bennythemink/ZoomRotatePanImageView/blob/master/ZoomRotatePanImageView.m Works nice. Now I want to save modified image to file. The thing is I want to save it in full resolution and also I want to save area which is only visible to user.
Let me show you simple example:
This is how it looks in my app. Image is one a few samples in iOS simulator. Most of it is out of screen. I want only visible part.
After saving without cropping it looks like this:
So far so good after clipping it'd be nice.
But now let's make some changes:
After saving:
Looks like it's transformed by wrong pivot. How can I fix it?
Here's my code for saving:
UIGraphicsBeginImageContextWithOptions(image.size, false, 0)
let context = UIGraphicsGetCurrentContext()
let transform = imageView.transform
let imageRect = CGRectMake(0, 0, image.size.width, image.size.height)
CGContextSetFillColorWithColor(context, UIColor.blueColor().CGColor) //for debugging
CGContextFillRect(context, imageRect)
CGContextConcatCTM(context, transform)
image.drawInRect(imageRect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
There's a simpler method to achieve it:
UIGraphicsBeginImageContextWithOptions(imageContainer.bounds.size, false, 0)
self.imageContainer.drawViewHierarchyInRect(imageContainer.bounds, afterScreenUpdates: true)
let screenshot = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
However output image has size of the view not an actual image and I want it in full resolution.
Updated code to work with image of any size :
let boundsScale = imageView.bounds.size.width / imageView.bounds.size.height
let imageScale = image!.size.width / image!.size.height
let size = (image?.size)!
var canvasSize = size
if boundsScale > imageScale {
canvasSize.width = canvasSize.height * boundsScale
}else{
canvasSize.height = canvasSize.width / boundsScale
}
let xScale = canvasSize.width / imageView.bounds.width
let yScale = canvasSize.height / imageView.bounds.height
let center = CGPointApplyAffineTransform(imageView.center, CGAffineTransformScale(CGAffineTransformIdentity, xScale, yScale))
let xCenter = center.x
let yCenter = center.y
UIGraphicsBeginImageContextWithOptions(canvasSize, false, 0);
let context = UIGraphicsGetCurrentContext()!
//Apply transformation
CGContextTranslateCTM(context, xCenter, yCenter)
CGContextConcatCTM(context, imageView.transform)
CGContextTranslateCTM(context, -xCenter, -yCenter)
var drawingRect : CGRect = CGRectZero
drawingRect.size = canvasSize
//Transaltion
drawingRect.origin.x = (xCenter - size.width*0.5)
drawingRect.origin.y = (yCenter - size.height*0.5)
//Aspectfit calculation
if boundsScale > imageScale {
drawingRect.size.width = drawingRect.size.height * imageScale
}else{
drawingRect.size.height = drawingRect.size.width / imageScale
}
image!.drawInRect(drawingRect)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
Simulator screen shot
Saved image
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