LeadKit/Sources/Extensions/Drawing/CGSize/CGSize+Resize.swift

76 lines
2.7 KiB
Swift

//
// Copyright (c) 2017 Touch Instinct
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the Software), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
import CoreGraphics.CGGeometry
public extension CGSize {
/// Calculates rect "inside" CGSize to match requested size with accordance to resize mode.
///
/// - Parameters:
/// - newSize: Requested new size.
/// - resizeMode: Resize mode to use.
/// - Returns: A new CGRect instance matching request parameters.
func resizeRect(forNewSize newSize: CGSize, resizeMode: ResizeMode) -> CGRect {
let horizontalRatio = newSize.width / width
let verticalRatio = newSize.height / height
let ratio: CGFloat
switch resizeMode {
case .scaleToFill:
ratio = 1
case .scaleAspectFill:
ratio = max(horizontalRatio, verticalRatio)
case .scaleAspectFit:
ratio = min(horizontalRatio, verticalRatio)
}
let newWidth = resizeMode == .scaleToFill ? newSize.width : width * ratio
let newHeight = resizeMode == .scaleToFill ? newSize.height : height * ratio
let originX: CGFloat
let originY: CGFloat
if newWidth > newSize.width {
originX = (newSize.width - newWidth) / 2
} else if newWidth < newSize.width {
originX = newSize.width / 2 - newWidth / 2
} else {
originX = 0
}
if newHeight > newSize.height {
originY = (newSize.height - newHeight) / 2
} else if newHeight < newSize.height {
originY = newSize.height / 2 - newHeight / 2
} else {
originY = 0
}
return CGRect(origin: CGPoint(x: originX, y: originY),
size: CGSize(width: newWidth, height: newHeight))
}
}