swift: Geometric Utility

ZGeoUtils.swift

//
//  ZGeoUtils.swift
//  ZKit
//
//  Created by Kaz Yoshikawa on 2015/02/08.
//  Copyright (c) 2015 Electricwoods LLC. All rights reserved.
//

import Foundation
import CoreGraphics

func DegreesToRadians(value:Double) -> Double {
	return value * M_PI / 180.0
}
 
func RadiansToDegrees (value:Double) -> Double {
	return value * 180.0 / M_PI
}

func CGRectMakeAspectFill(size: CGSize, bounds: CGRect) -> CGRect {

	let horizontalRatioToFit = bounds.size.width / size.width
	let verticalRatioToFit = bounds.size.height / size.height

	let imageHeightWhenItFitsHorizontally = horizontalRatioToFit * size.height
	let imageWidthWhenItFitsVertically = verticalRatioToFit * size.width

	let minX = CGRectGetMinX(bounds)
	let minY = CGRectGetMinY(bounds)

	if imageHeightWhenItFitsHorizontally > bounds.size.height {
		let margin = (imageHeightWhenItFitsHorizontally - bounds.size.height) * 0.5;
		return CGRectMake(minX, minY - margin, size.width * horizontalRatioToFit, size.height * horizontalRatioToFit)
	}
	else {
		let margin = (imageWidthWhenItFitsVertically - bounds.size.width) * 0.5;
		return CGRectMake(minX - margin, minY, size.width * verticalRatioToFit, size.height * verticalRatioToFit);
	}
}

func CGRectMakeAspectFit(size: CGSize, bounds: CGRect) -> CGRect {
	let minX = CGRectGetMinX(bounds)
	let minY = CGRectGetMinY(bounds)
	let widthRatio = bounds.size.width / size.width
	let heightRatio = bounds.size.height / size.height
	let ratio = (widthRatio < heightRatio) ? widthRatio : heightRatio
	let width = size.width * ratio
	let height = size.height * ratio
	let marginX = (bounds.size.width - width) / 2.0
	let marginY = (bounds.size.height - height) / 2.0
	return CGRectMake(minX + marginX, minY + marginY, width, height)
}

func CGSizeMakeAspectFit(imageSize: CGSize, frameSize: CGSize) -> CGSize {
	let widthRatio = frameSize.width / imageSize.width
	let heightRatio = frameSize.height / imageSize.height
	let ratio = (widthRatio < heightRatio) ? widthRatio : heightRatio
	let width = imageSize.width * ratio
	let height = imageSize.height * ratio
	return CGSizeMake(width, height)
}

func CGRectGetMidXMidYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect))
}

func CGRectGetMinXMinYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMinX(rect), CGRectGetMinY(rect))
}

func CGRectGetMaxXMaxYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMaxX(rect), CGRectGetMaxY(rect))
}

func CGRectGetMinXMaxYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMinX(rect), CGRectGetMaxY(rect))
}

func CGRectGetMaxXMinYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMaxX(rect), CGRectGetMinY(rect))
}

func CGRectGetMinXMidYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMinX(rect), CGRectGetMidY(rect))
}

func CGRectGetMaxXMidYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMaxX(rect), CGRectGetMidY(rect))
}

func CGRectGetMidXMinYPoint(rect: CGRect) -> CGPoint {
	return CGPointMake(CGRectGetMidX(rect), CGRectGetMinY(rect))
}

func CGRectGetMidXMaxYPoint(rect: CGRect) -> CGPoint
{
	return CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect))
}

func CGRectByExtendingWidth(rect: CGRect, width: CGFloat) -> CGRect
{
	return CGRectMake(rect.origin.x, rect.origin.y, rect.size.width + width, rect.size.height)
}

func CGRectByExtendingHeight_(rect: CGRect, height: CGFloat) -> CGRect
{
	return CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height + height)
}

// MARK: -

func CGPointOffset(point: CGPoint, offset: CGPoint) -> CGPoint
{
	return CGPointMake(point.x + offset.x, point.y + offset.y);
}

func CGRectMakeWithPoints(point1: CGPoint, point2: CGPoint) -> CGRect
{
	let minX = min(point1.x, point2.x)
	let minY = min(point1.y, point2.y)
	let maxX = max(point1.x, point2.x)
	let maxY = max(point1.y, point2.y)
	return CGRectMake(minX, minY, maxX - minX, maxY - minY)
}

// MARK: -

func CGPathCreateRoundRect(rect: CGRect, radius: CGFloat) -> CGPathRef
{
	assert(CGRectGetWidth(rect) >= radius * 2.0, "invalid radius")
	assert(CGRectGetHeight(rect) >= radius * 2.0, "invalid radius")

	let t = CGRectGetMinY(rect)
	let b = CGRectGetMaxY(rect)
	let l = CGRectGetMinX(rect)
	let r = CGRectGetMaxX(rect)

	let pathRef = CGPathCreateMutable()
	CGPathMoveToPoint(pathRef, nil, l+radius, t)
	CGPathAddArcToPoint(pathRef, nil, l, t, l, t+radius, radius)
	CGPathAddArcToPoint(pathRef, nil, l, b, l+radius, b, radius)
	CGPathAddArcToPoint(pathRef, nil, r, b, r, b-radius, radius)
	CGPathAddArcToPoint(pathRef, nil, r, t, r-radius, t, radius)
	CGPathCloseSubpath(pathRef);
	return pathRef
}