Quartz 2D是2D绘图引擎，适用iOS和Mac OS X程序。它提供底层轻量级的接口，并且会根据输出显示设备提供不匹配的逼真的画面。
Quartz 2D是与分辨率和设备无关的一个引擎。你不需要关注最终成像目标位置如何。非常容易使用，提供大量强大的功能，例如透明度，画线，视角距离效果渲染，颜色管理，反锯齿渲染，PDF文档创建，显示，解析。
Quartz 2D是Core Graphics框架的一部分，所以看到CG开头，别奇怪，就是Core Graphic的简写。
#import "DrawView.h"
@interface DrawView ()
{
CGPoint _startPoint;
CGPoint _endPoint;
}
@property(nonatomic,strong)NSMutableArray *pathArray;
@end
@implementation DrawView
- (NSMutableArray *)pathArray{
if (!_pathArray) {
self.pathArray = [NSMutableArray array];
}
return _pathArray;
}
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
// //获取路径
// UIBezierPath *path = [UIBezierPath bezierPath];
// [path moveToPoint:_startPoint];
// [path addLineToPoint:_endPoint];
// [path stroke];
for (UIBezierPath *path in self.pathArray) {
[[UIColor redColor] set];
path.lineWidth = 10;
[path stroke];
}
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
_startPoint = [[touches anyObject] locationInView:self];
//创建贝瑟尔路径
UIBezierPath *path = [UIBezierPath bezierPath];
//起点
[path moveToPoint:_startPoint];
//添加到数组
[self.pathArray addObject:path];
}
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
_endPoint = [[touches anyObject] locationInView:self];
//终点
UIBezierPath *path = [self.pathArray lastObject];
[path addLineToPoint:_endPoint];
[self setNeedsDisplay];
}
/** 第一种画线方式 */
- (void)line1{
// 1.获取上下文（绘图环境 画布）
CGContextRef cxt = UIGraphicsGetCurrentContext();
// 2. 描绘路径
CGMutablePathRef path = CGPathCreateMutable();
// 起点
CGPathMoveToPoint(path, NULL, 50, 50);
// 终点
CGPathAddLineToPoint(path, NULL, 1000, 1000);
//3. 把路径放到图形上下文
CGContextAddPath(cxt, path);
//4. 渲染上下文
CGContextStrokePath(cxt);
}
/** 第二种画线方式 */
- (void)line2{
//BezierPath(贝瑟尔路径)
UIBezierPath *path = [UIBezierPath bezierPath];
//设置起点
[path moveToPoint:CGPointMake(50, 50)];
//设置终点
[path addLineToPoint:CGPointMake(200, 200)];
//改变颜色
[[UIColor redColor] set];
//设置宽度
path.lineWidth = 10;
//渲染
[path stroke];
//第二条线
UIBezierPath *path1 = [UIBezierPath bezierPath];
[path1 moveToPoint:CGPointMake(200, 200)];
[path1 addLineToPoint:CGPointMake(200, 400)];
[[UIColor blueColor] set];
path1.lineWidth = 10;
[path1 stroke];
}
- (void)line3{
//绘制曲线
CGContextRef cxt = UIGraphicsGetCurrentContext();
//描述路径
CGContextMoveToPoint(cxt, 50, 50);
CGContextAddQuadCurveToPoint(cxt,150, 100, 250, 50);
//渲染
CGContextStrokePath(cxt);
}
@end
