版本记录
| 版本号 | 时间 |
|---|---|
| V1.0 | 2021.03.15 星期一 |
前言
quartz是一个通用的术语，用于描述在iOS和MAC OS X中整个媒体层用到的多种技术 包括图形、动画、音频、适配。Quart 2D是一组二维绘图和渲染API，Core Graphic会使用到这组API，Quartz Core专指Core Animation用到的动画相关的库、API和类。CoreGraphics是UIKit下的主要绘图系统，频繁的用于绘制自定义视图。Core Graphics是高度集成于UIView和其他UIKit部分的。Core Graphics数据结构和函数可以通过前缀CG来识别。在app中很多时候绘图等操作我们要利用CoreGraphic框架，它能绘制字符串、图形、渐变色等等，是一个很强大的工具。感兴趣的可以看我另外几篇。
1. CoreGraphic框架解析（一）—— 基本概览
2. CoreGraphic框架解析（二）—— 基本使用
3. CoreGraphic框架解析（三）—— 类波浪线的实现
4. CoreGraphic框架解析（四）—— 基本架构补充
5. CoreGraphic框架解析 （五）—— 基于CoreGraphic的一个简单绘制示例 （一）
6. CoreGraphic框架解析 （六）—— 基于CoreGraphic的一个简单绘制示例 （二）
7. CoreGraphic框架解析 （七）—— 基于CoreGraphic的一个简单绘制示例 （三）
8. CoreGraphic框架解析 （八）—— 基于CoreGraphic的一个简单绘制示例 （四）
9. CoreGraphic框架解析 （九）—— 一个简单小游戏 （一）
10. CoreGraphic框架解析 （十）—— 一个简单小游戏 （二）
11. CoreGraphic框架解析 （十一）—— 一个简单小游戏 （三）
12. CoreGraphic框架解析 （十二）—— Shadows 和 Gloss （一）
13. CoreGraphic框架解析 （十三）—— Shadows 和 Gloss （二）
14. CoreGraphic框架解析 （十四）—— Arcs 和 Paths （一）
15. CoreGraphic框架解析 （十五）—— Arcs 和 Paths （二）
16. CoreGraphic框架解析 （十六）—— Lines, Rectangles 和 Gradients （一）
17. CoreGraphic框架解析 （十七）—— Lines, Rectangles 和 Gradients （二）
18. CoreGraphic框架解析 （十八） —— 如何制作Glossy效果的按钮（一）
19. CoreGraphic框架解析 （十九） —— 如何制作Glossy效果的按钮（二）
20. CoreGraphic框架解析 （二十） —— Curves and Layers（一）
21. CoreGraphic框架解析 （二十一） —— Curves and Layers（二）
22. CoreGraphic框架解析 （二十二） —— Gradients 和 Contexts的简单示例（一）
23. CoreGraphic框架解析 （二十三） —— Gradients 和 Contexts的简单示例（二）
24. CoreGraphic框架解析 （二十四） —— 基于Core Graphic的重复图案的绘制（一）
源码
1. Swift
首先看下工程组织结构
下面就是源码了
1. MedalDrawing.playground
import UIKit
let size = CGSize(width: 120, height: 200)
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
guard let context = UIGraphicsGetCurrentContext() else {
fatalError("\(#function):\(#line) Failed to get current context.")
}
// Gold colors
let darkGoldColor = UIColor(red: 0.6, green: 0.5, blue: 0.15, alpha: 1.0)
let midGoldColor = UIColor(red: 0.86, green: 0.73, blue: 0.3, alpha: 1.0)
let lightGoldColor = UIColor(red: 1.0, green: 0.98, blue: 0.9, alpha: 1.0)
//// Add shadow
// let shadow = UIColor.black.withAlphaComponent(0.80)
// let shadowOffset = CGSize(width: 2.0, height: 2.0)
// let shadowBlurRadius: CGFloat = 5
//
// context.setShadow(offset: shadowOffset, blur: shadowBlurRadius, color: shadow.cgColor)
//
// context.beginTransparencyLayer(auxiliaryInfo: nil)
// Lower ribbon
let lowerRibbonPath = UIBezierPath()
lowerRibbonPath.move(to: CGPoint(x: 0, y: 0))
lowerRibbonPath.addLine(to: CGPoint(x: 40, y: 0))
lowerRibbonPath.addLine(to: CGPoint(x: 78, y: 70))
lowerRibbonPath.addLine(to: CGPoint(x: 38, y: 70))
lowerRibbonPath.close()
UIColor.red.setFill()
lowerRibbonPath.fill()
// Clasp
let claspPath = UIBezierPath(roundedRect: CGRect(x: 36, y: 62, width: 43, height: 20), cornerRadius: 5)
claspPath.lineWidth = 5
darkGoldColor.setStroke()
claspPath.stroke()
//// Medallion
// let medallionPath = UIBezierPath(ovalIn: CGRect(x: 8, y: 72, width: 100, height: 100))
// context.saveGState()
// medallionPath.addClip()
//
// let colors = [darkGoldColor.cgColor, midGoldColor.cgColor, lightGoldColor.cgColor] as CFArray
// guard let gradient = CGGradient(
// colorsSpace: CGColorSpaceCreateDeviceRGB(),
// colors: colors,
// locations: [0, 0.51, 1]
// ) else {
// fatalError("Failed to instantiate an instance of \(String(describing: CGGradient.self))")
// }
// context.drawLinearGradient(gradient, start: CGPoint(x: 40, y: 40), end: CGPoint(x: 100, y: 160), options: [])
// context.restoreGState()
//
//// Create a transform
//// Scale it, and translate it right and down
// var transform = CGAffineTransform(scaleX: 0.8, y: 0.8)
// transform = transform.translatedBy(x: 15, y: 30)
// medallionPath.lineWidth = 2.0
//
//// Apply the transform to the path
// medallionPath.apply(transform)
// medallionPath.stroke()
//
//// Upper ribbon
// let upperRibbonPath = UIBezierPath()
// upperRibbonPath.move(to: CGPoint(x: 68, y: 0))
// upperRibbonPath.addLine(to: CGPoint(x: 108, y: 0))
// upperRibbonPath.addLine(to: CGPoint(x: 78, y: 70))
// upperRibbonPath.addLine(to: CGPoint(x: 38, y: 70))
// upperRibbonPath.close()
//
// UIColor.blue.setFill()
// upperRibbonPath.fill()
//
//// Number One
//
//// Must be NSString to be able to use draw(in:)
// let numberOne = "1" as NSString
// let numberOneRect = CGRect(x: 47, y: 100, width: 50, height: 50)
// guard let font = UIFont(name: "Academy Engraved LET", size: 60) else {
// fatalError("\(#function):\(#line) Failed to instantiate font with name \"Academy Engraved LET\"")
// }
// let numberOneAttributes = [
// NSAttributedString.Key.font: font,
// NSAttributedString.Key.foregroundColor: darkGoldColor
// ]
// numberOne.draw(in: numberOneRect, withAttributes: numberOneAttributes)
//
// context.endTransparencyLayer()
// This code must always be at the end of the playground
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
2. AppDelegate.swift
import UIKit
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
}
3. ViewController.swift
import UIKit
class ViewController: UIViewController {
// Counter outlets
@IBOutlet weak var counterView: CounterView!
@IBOutlet weak var counterLabel: UILabel!
@IBOutlet weak var containerView: UIView!
@IBOutlet weak var graphView: GraphView!
// Label outlets
@IBOutlet weak var averageWaterDrunk: UILabel!
@IBOutlet weak var maxLabel: UILabel!
@IBOutlet weak var stackView: UIStackView!
@IBOutlet weak var medalView: MedalView!
var isGraphViewShowing = false
@IBAction func pushButtonPressed(_ button: PushButton) {
if button.isAddButton {
counterView.counter += 1
} else {
if counterView.counter > 0 {
counterView.counter -= 1
}
}
counterLabel.text = String(counterView.counter)
if isGraphViewShowing {
counterViewTap(nil)
}
checkTotal()
rotateButton(button)
}
private func rotateButton(_ button: UIButton) {
let layer = button.layer
let rotationAnimation = CAKeyframeAnimation(keyPath: "transform.rotation")
rotationAnimation.keyTimes = [0, 1]
rotationAnimation.values = [0, CGFloat.pi]
rotationAnimation.duration = 0.25
layer.add(rotationAnimation, forKey: "transform.rotation")
}
@IBAction func counterViewTap(_ gesture: UITapGestureRecognizer?) {
if isGraphViewShowing {
UIView.transition(
from: graphView,
to: counterView,
duration: 1.0,
options: [.transitionFlipFromLeft, .showHideTransitionViews],
completion: nil
)
} else {
setupGraphDisplay()
UIView.transition(
from: counterView,
to: graphView,
duration: 1.0,
options: [.transitionFlipFromRight, .showHideTransitionViews],
completion: nil
)
}
isGraphViewShowing.toggle()
}
override func viewDidLoad() {
super.viewDidLoad()
counterLabel.text = String(counterView.counter)
checkTotal()
}
func setupGraphDisplay() {
let maxDayIndex = stackView.arrangedSubviews.count - 1
// 1 - replace last day with today's actual data
graphView.graphPoints[graphView.graphPoints.count - 1] = counterView.counter
// 2 - indicate that the graph needs to be redrawn
graphView.setNeedsDisplay()
maxLabel.text = "\(graphView.graphPoints.max() ?? 0)"
// 3 - calculate average from graphPoints
let average = graphView.graphPoints.reduce(0, +) / graphView.graphPoints.count
averageWaterDrunk.text = "\(average)"
// 4 - setup date formatter and calendar
let today = Date()
let calendar = Calendar.current
let formatter = DateFormatter()
formatter.setLocalizedDateFormatFromTemplate("EEEEE")
// 5 - set up the day name labels with correct day
for i in (0...maxDayIndex) {
if let date = calendar.date(byAdding: .day, value: -i, to: today),
let label = stackView.arrangedSubviews[maxDayIndex - i] as? UILabel {
label.text = formatter.string(from: date)
}
}
}
func checkTotal() {
if counterView.counter >= 8 {
medalView.showMedal(show: true)
} else {
medalView.showMedal(show: false)
}
}
}
4. PushButton.swift
import UIKit
@IBDesignable
class PushButton: UIButton {
private enum Constants {
static let plusLineWidth: CGFloat = 3.0
static let plusButtonScale: CGFloat = 0.6
static let halfPointShift: CGFloat = 0.5
}
private var halfWidth: CGFloat {
return bounds.width / 2
}
private var halfHeight: CGFloat {
return bounds.height / 2
}
@IBInspectable var fillColor: UIColor = .green
@IBInspectable var isAddButton: Bool = true
override func draw(_ rect: CGRect) {
let path = UIBezierPath(ovalIn: rect)
fillColor.setFill()
path.fill()
let plusWidth = min(bounds.width, bounds.height) * Constants.plusButtonScale
let halfPlusWidth = plusWidth / 2
let plusPath = UIBezierPath()
plusPath.lineWidth = Constants.plusLineWidth
plusPath.move(to: CGPoint(
x: halfWidth - halfPlusWidth + Constants.halfPointShift,
y: halfHeight + Constants.halfPointShift))
plusPath.addLine(to: CGPoint(
x: halfWidth + halfPlusWidth + Constants.halfPointShift,
y: halfHeight + Constants.halfPointShift))
if isAddButton {
plusPath.move(to: CGPoint(
x: halfWidth + Constants.halfPointShift,
y: halfHeight - halfPlusWidth + Constants.halfPointShift))
plusPath.addLine(to: CGPoint(
x: halfWidth + Constants.halfPointShift,
y: halfHeight + halfPlusWidth + Constants.halfPointShift))
}
UIColor.white.setStroke()
plusPath.stroke()
}
}
5. CounterView.swift
import UIKit
@IBDesignable
class CounterView: UIView {
private enum Constants {
static let numberOfGlasses = 8
static let lineWidth: CGFloat = 5.0
static let arcWidth: CGFloat = 76
static var halfOfLineWidth: CGFloat {
return lineWidth / 2
}
}
@IBInspectable var counter: Int = 5 {
didSet {
if counter <= Constants.numberOfGlasses {
setNeedsDisplay()
}
}
}
@IBInspectable var outlineColor: UIColor = UIColor.blue
@IBInspectable var counterColor: UIColor = UIColor.orange
override func draw(_ rect: CGRect) {
let center = CGPoint(x: bounds.width / 2, y: bounds.height / 2)
let radius = max(bounds.width, bounds.height)
let startAngle: CGFloat = 3 * .pi / 4
let endAngle: CGFloat = .pi / 4
let path = UIBezierPath(
arcCenter: center,
radius: radius / 2 - Constants.arcWidth / 2,
startAngle: startAngle,
endAngle: endAngle,
clockwise: true)
path.lineWidth = Constants.arcWidth
counterColor.setStroke()
path.stroke()
let angleDifference: CGFloat = 2 * .pi - startAngle + endAngle
let arcLengthPerGlass = angleDifference / CGFloat(Constants.numberOfGlasses)
let outlineEndAngle = arcLengthPerGlass * CGFloat(counter) + startAngle
let outerArcRadius = bounds.width / 2 - Constants.halfOfLineWidth
let outlinePath = UIBezierPath(
arcCenter: center,
radius: outerArcRadius,
startAngle: startAngle,
endAngle: outlineEndAngle,
clockwise: true)
let innerArcRadius = bounds.width / 2 - Constants.arcWidth + Constants.halfOfLineWidth
outlinePath.addArc(
withCenter: center,
radius: innerArcRadius,
startAngle: outlineEndAngle,
endAngle: startAngle,
clockwise: false)
outlinePath.close()
outlineColor.setStroke()
outlinePath.lineWidth = Constants.lineWidth
outlinePath.stroke()
// Counter View markers
guard let context = UIGraphicsGetCurrentContext() else {
return
}
context.saveGState()
outlineColor.setFill()
let markerWidth: CGFloat = 5.0
let markerSize: CGFloat = 10.0
let markerPath = UIBezierPath(rect: CGRect(x: -markerWidth / 2, y: 0, width: markerWidth, height: markerSize))
context.translateBy(x: rect.width / 2, y: rect.height / 2)
for i in 1...Constants.numberOfGlasses {
context.saveGState()
let angle = arcLengthPerGlass * CGFloat(i) + startAngle - .pi / 2
context.rotate(by: angle)
context.translateBy(x: 0, y: rect.height / 2 - markerSize)
markerPath.fill()
context.restoreGState()
}
context.restoreGState()
}
}
6. GraphView.swift
import UIKit
@IBDesignable
class GraphView: UIView {
private enum Constants {
static let cornerRadiusSize = CGSize(width: 8.0, height: 8.0)
static let margin: CGFloat = 20.0
static let topBorder: CGFloat = 60
static let bottomBorder: CGFloat = 50
static let colorAlpha: CGFloat = 0.3
static let circleDiameter: CGFloat = 5.0
}
@IBInspectable var startColor: UIColor = .red
@IBInspectable var endColor: UIColor = .green
var graphPoints: [Int] = [4, 2, 6, 4, 5, 8, 3]
// swiftlint:disable:next function_body_length
override func draw(_ rect: CGRect) {
let width = rect.width
let height = rect.height
let path = UIBezierPath(
roundedRect: rect,
byRoundingCorners: UIRectCorner.allCorners,
cornerRadii: Constants.cornerRadiusSize
)
path.addClip()
guard let context = UIGraphicsGetCurrentContext() else {
return
}
let colors = [startColor.cgColor, endColor.cgColor]
let colorSpace = CGColorSpaceCreateDeviceRGB()
let colorLocations: [CGFloat] = [0.0, 1.0]
guard let gradient = CGGradient(
colorsSpace: colorSpace,
colors: colors as CFArray,
locations: colorLocations
) else {
return
}
var startPoint = CGPoint.zero
var endPoint = CGPoint(x: 0, y: self.bounds.height)
context.drawLinearGradient(
gradient,
start: startPoint,
end: endPoint,
options: []
)
let margin = Constants.margin
let columnXPoint = { (column: Int) -> CGFloat in
let spacing = (width - margin * 2 - 4) / CGFloat((self.graphPoints.count - 1))
return CGFloat(column) * spacing + margin + 2
}
let topBorder: CGFloat = Constants.topBorder
let bottomBorder: CGFloat = Constants.bottomBorder
let graphHeight = height - topBorder - bottomBorder
guard let maxValue = graphPoints.max() else {
return
}
let columnYPoint = { (graphPoint: Int) -> CGFloat in
let yPoint = CGFloat(graphPoint) / CGFloat(maxValue) * graphHeight
return graphHeight + topBorder - yPoint
}
UIColor.white.setFill()
UIColor.white.setStroke()
let graphPath = UIBezierPath()
graphPath.move(to: CGPoint(x: columnXPoint(0), y: columnYPoint(graphPoints[0])))
for i in 1..<graphPoints.count {
let nextPoint = CGPoint(x: columnXPoint(i), y: columnYPoint(graphPoints[i]))
graphPath.addLine(to: nextPoint)
}
context.saveGState()
guard let clippingPath = graphPath.copy() as? UIBezierPath else {
return
}
clippingPath.addLine(to: CGPoint(x: columnXPoint(graphPoints.count - 1), y: height))
clippingPath.addLine(to: CGPoint(x: columnXPoint(0), y: height))
clippingPath.close()
clippingPath.addClip()
let highestYPoint = columnYPoint(maxValue)
startPoint = CGPoint(x: margin, y: highestYPoint)
endPoint = CGPoint(x: margin, y: self.bounds.height)
context.drawLinearGradient(
gradient,
start: startPoint,
end: endPoint,
options: CGGradientDrawingOptions(rawValue: 0)
)
context.restoreGState()
graphPath.lineWidth = 2.0
graphPath.stroke()
for i in 0..<graphPoints.count {
var point = CGPoint(x: columnXPoint(i), y: columnYPoint(graphPoints[i]))
point.x -= Constants.circleDiameter / 2
point.y -= Constants.circleDiameter / 2
let circle = UIBezierPath(
ovalIn: CGRect(
origin: point,
size: CGSize(width: Constants.circleDiameter, height: Constants.circleDiameter)
)
)
circle.fill()
}
let linePath = UIBezierPath()
linePath.move(to: CGPoint(x: margin, y: topBorder))
linePath.addLine(to: CGPoint(x: width - margin, y: topBorder))
linePath.move(to: CGPoint(x: margin, y: graphHeight / 2 + topBorder))
linePath.addLine(to: CGPoint(x: width - margin, y: graphHeight / 2 + topBorder))
linePath.move(to: CGPoint(x: margin, y: height - bottomBorder))
linePath.addLine(to: CGPoint(x: width - margin, y: height - bottomBorder))
let color = UIColor(white: 1.0, alpha: Constants.colorAlpha)
color.setStroke()
linePath.lineWidth = 1.0
linePath.stroke()
}
}
7. BackgroundView.swift
import UIKit
@IBDesignable
class BackgroundView: UIView {
// 1
@IBInspectable var lightColor: UIColor = .orange
@IBInspectable var darkColor: UIColor = .yellow
@IBInspectable var patternSize: CGFloat = 200
override func draw(_ rect: CGRect) {
// 2
guard let context = UIGraphicsGetCurrentContext() else {
fatalError("\(#function):\(#line) Failed to get current context.")
}
// 3
context.setFillColor(darkColor.cgColor)
// 4
context.fill(rect)
let drawSize = CGSize(width: patternSize, height: patternSize)
UIGraphicsBeginImageContextWithOptions(drawSize, true, 0.0)
guard let drawingContext = UIGraphicsGetCurrentContext() else {
fatalError("\(#function):\(#line) Failed to get current context.")
}
// Set the fill color for the new context
darkColor.setFill()
drawingContext.fill(CGRect(x: 0, y: 0, width: drawSize.width, height: drawSize.height))
let trianglePath = UIBezierPath()
// 1
trianglePath.move(to: CGPoint(x: drawSize.width / 2, y: 0))
// 2
trianglePath.addLine(to: CGPoint(x: 0, y: drawSize.height / 2))
// 3
trianglePath.addLine(to: CGPoint(x: drawSize.width, y: drawSize.height / 2))
// 4
trianglePath.move(to: CGPoint(x: 0, y: drawSize.height / 2))
// 5
trianglePath.addLine(to: CGPoint(x: drawSize.width / 2, y: drawSize.height))
// 6
trianglePath.addLine(to: CGPoint(x: 0, y: drawSize.height))
// 7
trianglePath.move(to: CGPoint(x: drawSize.width, y: drawSize.height / 2))
// 8
trianglePath.addLine(to: CGPoint(x: drawSize.width / 2, y: drawSize.height))
// 9
trianglePath.addLine(to: CGPoint(x: drawSize.width, y: drawSize.height))
lightColor.setFill()
trianglePath.fill()
guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
fatalError("\(#function):\(#line) Failed to get an image from current context.")
}
UIGraphicsEndImageContext()
UIColor(patternImage: image).setFill()
context.fill(rect)
}
}
8. MedalView.swift
import UIKit
class MedalView: UIImageView {
lazy var medalImage = self.createMedalImage()
// swiftlint:disable function_body_length
func createMedalImage() -> UIImage {
debugPrint("creating Medal Image")
let size = CGSize(width: 120, height: 200)
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
guard let context = UIGraphicsGetCurrentContext() else {
fatalError("\(#function):\(#line) Failed to get current context.")
}
// Gold colors
let darkGoldColor = UIColor(red: 0.6, green: 0.5, blue: 0.15, alpha: 1.0)
let midGoldColor = UIColor(red: 0.86, green: 0.73, blue: 0.3, alpha: 1.0)
let lightGoldColor = UIColor(red: 1.0, green: 0.98, blue: 0.9, alpha: 1.0)
// Add shadow
let shadow = UIColor.black.withAlphaComponent(0.80)
let shadowOffset = CGSize(width: 2.0, height: 2.0)
let shadowBlurRadius: CGFloat = 5
context.setShadow(offset: shadowOffset, blur: shadowBlurRadius, color: shadow.cgColor)
context.beginTransparencyLayer(auxiliaryInfo: nil)
// Lower ribbon
let lowerRibbonPath = UIBezierPath()
lowerRibbonPath.move(to: CGPoint(x: 0, y: 0))
lowerRibbonPath.addLine(to: CGPoint(x: 40, y: 0))
lowerRibbonPath.addLine(to: CGPoint(x: 78, y: 70))
lowerRibbonPath.addLine(to: CGPoint(x: 38, y: 70))
lowerRibbonPath.close()
UIColor.red.setFill()
lowerRibbonPath.fill()
// Clasp
let claspPath = UIBezierPath(roundedRect: CGRect(x: 36, y: 62, width: 43, height: 20), cornerRadius: 5)
claspPath.lineWidth = 5
darkGoldColor.setStroke()
claspPath.stroke()
// Medallion
let medallionPath = UIBezierPath(ovalIn: CGRect(x: 8, y: 72, width: 100, height: 100))
context.saveGState()
medallionPath.addClip()
let colors = [darkGoldColor.cgColor, midGoldColor.cgColor, lightGoldColor.cgColor] as CFArray
guard let gradient = CGGradient(
colorsSpace: CGColorSpaceCreateDeviceRGB(),
colors: colors,
locations: [0, 0.51, 1]
) else {
fatalError("Failed to instantiate an instance of \(String(describing: CGGradient.self))")
}
context.drawLinearGradient(gradient, start: CGPoint(x: 40, y: 40), end: CGPoint(x: 100, y: 160), options: [])
context.restoreGState()
// Create a transform
// Scale it, and translate it right and down
var transform = CGAffineTransform(scaleX: 0.8, y: 0.8)
transform = transform.translatedBy(x: 15, y: 30)
medallionPath.lineWidth = 2.0
// apply the transform to the path
medallionPath.apply(transform)
medallionPath.stroke()
// Upper ribbon
let upperRibbonPath = UIBezierPath()
upperRibbonPath.move(to: CGPoint(x: 68, y: 0))
upperRibbonPath.addLine(to: CGPoint(x: 108, y: 0))
upperRibbonPath.addLine(to: CGPoint(x: 78, y: 70))
upperRibbonPath.addLine(to: CGPoint(x: 38, y: 70))
upperRibbonPath.close()
UIColor.blue.setFill()
upperRibbonPath.fill()
// Number One
// Must be NSString to be able to use draw(in:)
let numberOne = "1" as NSString
let numberOneRect = CGRect(x: 47, y: 100, width: 50, height: 50)
guard let font = UIFont(name: "Academy Engraved LET", size: 60) else {
fatalError("\(#function):\(#line) Failed to instantiate font with name \"Academy Engraved LET\"")
}
let numberOneAttributes = [
NSAttributedString.Key.font: font,
NSAttributedString.Key.foregroundColor: darkGoldColor
]
numberOne.draw(in: numberOneRect, withAttributes: numberOneAttributes)
context.endTransparencyLayer()
// This code must always be at the end of the playground
guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
fatalError("\(#function):\(#line) Failed to get an image from current context.")
}
UIGraphicsEndImageContext()
return image
}
func showMedal(show: Bool) {
image = show == true ? medalImage : nil
}
}
后记
本篇主要讲述了基于
Core Graphic的重复图案的绘制，感兴趣的给个赞或者关注~~~
