//shapeLayer
[self matchPeople];
//圆角
[self cornerRadiusTest];
//CATextLayer
[self textLayerTest];
//富文本
[self attributedStringTest];
//transformLayer
[self transformLayerTest];
//gradientLayer
[self gradientLayerTest];
[self gradientLayerLocationsTest];
//replicatorLayer
[self replicatorLayerTest];
//反射
[self reflectionViewTest];
//scrollLayer
[self scrollViewTest];
//tiledLayer
[self tiledLayerTest];
//CAEmitterLayer
[self emitterLayerTest];
//CAEAGLLayer
[self EAGLLayerTest];
//AVPlayerLayer
[self AVPlayerLayerTest];
//CAShapeLayer:是一个通过矢量图形而不是bitmap来绘制的图层子类。CAShapeLayer属性是CGPathRef类型
//创建一个CGPath
//lineWith（线宽，用点表示单位），lineCap（线条结尾的样子），和lineJoin（线条之间的结合点的样子）;但是在图层层面你只有一次机会设置这些属性。如果你想用不同颜色或风格来绘制多个形状，就不得不为每个形状准备一个图层了。
- (void)matchPeople {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(20.f, 20.f, 300.0f, 300.0f);
[self.view addSubview:containerView];
//create path
UIBezierPath *path = [[UIBezierPath alloc] init];
[path moveToPoint:CGPointMake(175.0f, 100.0f)];
[path addArcWithCenter:CGPointMake(150.0f, 100.0f) radius:25 startAngle:0 endAngle:2*M_PI clockwise:YES];
[path moveToPoint:CGPointMake(150, 125)];
[path addLineToPoint:CGPointMake(150, 175)];
[path addLineToPoint:CGPointMake(125, 225)];
[path moveToPoint:CGPointMake(150, 175)];
[path addLineToPoint:CGPointMake(175, 225)];
[path moveToPoint:CGPointMake(100, 150)];
[path addLineToPoint:CGPointMake(200, 150)];
//create shape layer
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.strokeColor = [UIColor redColor].CGColor;
shapeLayer.fillColor = [UIColor clearColor].CGColor;
shapeLayer.lineWidth = 5;
shapeLayer.lineJoin = kCALineJoinRound;
shapeLayer.lineCap = kCALineCapRound;
shapeLayer.path = path.CGPath;
//add it to our view
[containerView.layer addSublayer:shapeLayer];
}
圆角
- (void)cornerRadiusTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(20.f, 20.f, 300.0f, 300.0f);
[self.view addSubview:containerView];
//define path parameters
CGRect rect = CGRectMake(50, 50, 100, 100);
CGSize radii = CGSizeMake(20, 20);
UIRectCorner corners = UIRectCornerTopLeft|UIRectCornerBottomRight|UIRectCornerTopRight|UIRectCornerBottomLeft;
//create path
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect byRoundingCorners:corners cornerRadii:radii];
//create shape layer
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
shapeLayer.strokeColor = [UIColor redColor].CGColor;
shapeLayer.fillColor = [UIColor clearColor].CGColor;
shapeLayer.lineWidth = 5;
shapeLayer.lineJoin = kCALineJoinRound;
shapeLayer.lineCap = kCALineCapRound;
shapeLayer.path = path.CGPath;
//add it to our view
[containerView.layer addSublayer:shapeLayer];
}
CATextLayer
//Core Animation提供了一个CALayer的子类CATextLayer，它以图层的形式包含了UILabel几乎所有的绘制特性，并且额外提供了一些新的特性。
- (void)textLayerTest {
UIView *lableView = [[UIView alloc] init];
lableView.frame = CGRectMake(20.0, 20.0, 300, 300);
[self.view addSubview:lableView];
//create a text layer
CATextLayer *textLayer = [CATextLayer layer];
textLayer.frame = lableView.bounds;
[lableView.layer addSublayer:textLayer];
//set text attributes
textLayer.foregroundColor = [UIColor blackColor].CGColor;
textLayer.alignmentMode = kCAAlignmentJustified;
textLayer.wrapped = YES;
//choose a font
UIFont *font = [UIFont systemFontOfSize:15];
//set layer font
CFStringRef fontName = (__bridge CFStringRef)font.fontName;
CGFontRef fontRef = CGFontCreateWithFontName(fontName);//CGFontRef类型还是CTFontRef类型（Core Text字体）
textLayer.font = fontRef;//CFTypeRef
textLayer.fontSize = font.pointSize;
CGFontRelease(fontRef);
//choose some text
NSString *text = @"Lorem ipsum dolor sit amet, consectetur adipiscing \ elit. Quisque massa arcu, eleifend vel varius in, facilisis pulvinar \ leo. Nunc quis nunc at mauris pharetra condimentum ut ac neque. Nunc elementum, libero ut porttitor dictum, diam odio congue lacus, vel \ fringilla sapien diam at purus. Etiam suscipit pretium nunc sit amet \ lobortis";
//set layer text
textLayer.string = text;//id类型 可以用NSString也可以用NSAttributedString来指定文本了
//contentsScale并不关心屏幕的拉伸因素而总是默认为1.0。
textLayer.contentsScale = [UIScreen mainScreen].scale;
}
富文本
//NSAttributedString.iOS 6及以上可以用新的NSTextAttributeName实例来设置我们的字符串属性，在iOS 5及以下，用Core Text，也就是需要把Core Text framework添加到项目中。
- (void)attributedStringTest {
UIView *lableView = [[UIView alloc] init];
lableView.frame = CGRectMake(20.0, 20.0, 300, 300);
[self.view addSubview:lableView];
//create a text layer
CATextLayer *textLayer = [CATextLayer layer];
textLayer.frame = lableView.bounds;
textLayer.contentsScale = [UIScreen mainScreen].scale;
[lableView.layer addSublayer:textLayer];
//set text attributes
textLayer.alignmentMode = kCAAlignmentJustified;
textLayer.wrapped = YES;
//choose a font
UIFont *font = [UIFont systemFontOfSize:15];
//choose some text
NSString *text = @"Lorem ipsum dolor sit amet, consectetur adipiscing \ elit. Quisque massa arcu, eleifend vel varius in, facilisis pulvinar \ leo. Nunc quis nunc at mauris pharetra condimentum ut ac neque. Nunc elementum, libero ut porttitor dictum, diam odio congue lacus, vel \ fringilla sapien diam at purus. Etiam suscipit pretium nunc sit amet \ lobortis";
//create attributed string
NSMutableAttributedString *string = nil;
string = [[NSMutableAttributedString alloc] initWithString:text];
//convert UIFont to a CTFont
CFStringRef fontName = (__bridge CFStringRef)font.fontName;
CGFloat fontSize = font.pointSize;
CTFontRef fontRef = CTFontCreateWithName(fontName, fontSize, NULL);
//set text attributes
NSDictionary *attributes = @{(__bridge id)kCTForegroundColorAttributeName:(__bridge id)[UIColor blackColor].CGColor, (__bridge id)kCTFontAttributeName:(__bridge id)fontRef};
[string setAttributes:attributes range:NSMakeRange(0, [text length])];
attributes = @{
(__bridge id)kCTForegroundColorAttributeName:(__bridge id)[UIColor redColor].CGColor,
(__bridge id)kCTUnderlineStyleAttributeName:@(kCTUnderlineStyleSingle),
(__bridge id)kCTFontAttributeName:(__bridge id)fontRef
};
[string setAttributes:attributes range:NSMakeRange(6, 5)];
//release the CTFont we created earlier
CFRelease(fontRef);
//set layer text
textLayer.string = string;
}
行距和字距
//由于绘制的实现机制不同（Core Text和WebKit），用CATextLayer渲染和用UILabel渲染出的文本行距和字距也不是不尽相同的。
UILabel的替代品
//继承UILabel，然后添加一个子图层CATextLayer并重写显示文本的方法。
//我们继承了UIView，那我们就可以重写+layerClass方法使得在创建的时候能返回一个不同的图层子类。UIView会在初始化的时候调用+layerClass方法，然后用它的返回类型来创建宿主图层。
//例子：LayerLabel.h
CATransformLayer
//CATransformLayer不同于普通的CALayer，因为它不能显示它自己的内容。只有当存在了一个能作用域子图层的变换它才真正存在。CATransformLayer并不平面化它的子图层，所以它能够用于构造一个层级的3D结构，比如我的手臂示例。
- (CALayer *)faceWithTransform:(CATransform3D)transform {
//create cube face layer
CALayer *face = [CALayer layer];
face.frame = CGRectMake(-50, -50, 100, 100);
//apply a random color
CGFloat red = (rand() / (double)INT_MAX);
CGFloat green = (rand() / (double)INT_MAX);
CGFloat blue = (rand() / (double)INT_MAX);
face.backgroundColor = [UIColor colorWithRed:red green:green blue:blue alpha:1.0f].CGColor;
//apply the transform and return
face.transform = transform;
return face;
}
- (CALayer *)cubeWithTransform:(CATransform3D)transform {
//create cube layer
CATransformLayer *cube = [CATransformLayer layer];
//add cube face 1
CATransform3D ct = CATransform3DMakeTranslation(0, 0, 50);
[cube addSublayer:[self faceWithTransform:ct]];
//add cube face 2
ct = CATransform3DMakeTranslation(50, 0, 0);
ct = CATransform3DRotate(ct, M_PI_2, 0, 1, 0);
[cube addSublayer:[self faceWithTransform:ct]];
//add cube face 3
ct = CATransform3DMakeTranslation(0, -50, 0);
ct = CATransform3DRotate(ct, M_PI_2, 1, 0, 0);
[cube addSublayer:[self faceWithTransform:ct]];
//add cube face 4
ct = CATransform3DMakeTranslation(0, 50, 0);
ct = CATransform3DRotate(ct, -M_PI_2, 1, 0, 0);
[cube addSublayer:[self faceWithTransform:ct]];
//add cube face 5
ct = CATransform3DMakeTranslation(-50, 0, 0);
ct = CATransform3DRotate(ct, -M_PI_2, 0, 1, 0);
[cube addSublayer:[self faceWithTransform:ct]];
//add cube face 6
ct = CATransform3DMakeTranslation(0, 0, -50);
ct = CATransform3DRotate(ct, M_PI, 0, 1, 0);
[cube addSublayer:[self faceWithTransform:ct]];
//center the cube layer within the container
CGSize containerSize = containerView.bounds.size;
cube.position = CGPointMake(containerSize.width/2.0, containerSize.height/2.0 );
//apply the transform and return
cube.transform = transform;
return cube;
}
- (void)transformLayerTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[self.view addSubview:containerView];
//set up the perspective transform
CATransform3D pt = CATransform3DIdentity;
pt.m34 = -1.0/500.0f;
containerView.layer.sublayerTransform = pt;
//set up the transform for cube 1 and add it
CATransform3D c1t = CATransform3DIdentity;
c1t = CATransform3DTranslate(c1t, -100, 0, 0);
CALayer *cube1 = [self cubeWithTransform:c1t];
[containerView.layer addSublayer:cube1];
//set up the transform for cube 2 and add it
CATransform3D c2t = CATransform3DIdentity;
c2t = CATransform3DTranslate(c2t, 100, 0, 0);
c2t = CATransform3DRotate(c2t, -M_PI_4, 1, 0, 0);
c2t = CATransform3DRotate(c2t, -M_PI_4, 0, 1, 0);
CALayer *cube2 = [self cubeWithTransform:c2t];
[containerView.layer addSublayer:cube2];
}
//CAGradientLayer:是用来生成两种或更多颜色平滑渐变的。
基础渐变
//colors属性:数组成员接受CGColorRef类型的值
//startPoint和endPoint属性，他们决定了渐变的方向。这两个参数是以单位坐标系进行的定义，所以左上角坐标是{0, 0}，右下角坐标是{1, 1}
- (void)gradientLayerTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[self.view addSubview:containerView];
//create gradient layer and add it to our container view
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = containerView.bounds;
[containerView.layer addSublayer:gradientLayer];
//set gradient colors
gradientLayer.colors = @[(__bridge id)[UIColor redColor].CGColor, (__bridge id)[UIColor blueColor].CGColor];
//set gradient start and end points
gradientLayer.startPoint = CGPointMake(0, 0);
gradientLayer.endPoint = CGPointMake(1, 1);
}
多重渐变
//locations属性是一个浮点数值的数组（以NSNumber包装）。这些浮点数定义了colors属性中每个不同颜色的位置，同样的，也是以单位坐标系进行标定。0.0代表着渐变的开始，1.0代表着结束。
- (void)gradientLayerLocationsTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[self.view addSubview:containerView];
//create gradient layer and add it to our container view
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = containerView.bounds;
[containerView.layer addSublayer:gradientLayer];
//set gradient colors
gradientLayer.colors = @[(__bridge id)[UIColor redColor].CGColor, (__bridge id)[UIColor blueColor].CGColor, (__bridge id)[UIColor greenColor].CGColor ];
//set locations
gradientLayer.locations = @[@0.0, @0.25, @0.5];
//set gradient start and end points
gradientLayer.startPoint = CGPointMake(0, 1);
gradientLayer.endPoint = CGPointMake(1, 1);
}
//CAReplicatorLayer:的目的是为了高效生成许多相似的图层。它会绘制一个或多个图层的子图层，并在每个复制体上应用不同的变换。
重复图层（Repeating Layers）
- (void)replicatorLayerTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(20, 20, 300, 300);
containerView.backgroundColor = [UIColor blackColor];
[self.view addSubview:containerView];
//create a replicator layer and add it to our view
CAReplicatorLayer *replicator = [CAReplicatorLayer layer];
replicator.frame = containerView.bounds;
[containerView.layer addSublayer:replicator];
//configure the replicator
replicator.instanceCount = 10;
//apply a transform for each instance
CATransform3D transform = CATransform3DIdentity;
transform = CATransform3DTranslate(transform, 0, 25, 0);
transform = CATransform3DRotate(transform, M_PI/5.0f, 0, 0, 1);
transform = CATransform3DTranslate(transform, 0, -25, 0);
replicator.instanceTransform = transform;
// apply a color shift for each instance
replicator.instanceBlueOffset = -0.1;
replicator.instanceGreenOffset = -0.1;
//create a sublayer and place it inside the replicator
CALayer *layer = [CALayer layer];
layer.frame = CGRectMake(50, 50, 50.0f, 50.0f);
layer.backgroundColor = [UIColor whiteColor].CGColor;
[replicator addSublayer:layer];
}
反射
- (void)reflectionViewTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(20, 20, 300, 300);
[self.view addSubview:containerView];
ReflectionView *reflectionView = [[ReflectionView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
UIImage *image = [UIImage imageNamed:@"Meal"];
CALayer *layer = [CALayer layer];
layer.frame = CGRectMake(0, 0, 100, 100);
layer.contents = (__bridge id)image.CGImage;
[reflectionView.layer addSublayer:layer];
[containerView addSubview:reflectionView];
}
CAScrollLayer
//frame属性是由bounds属性自动计算而出的，所以更改任意一个值都会更新其他值。
//-scrollToPoint:它自动适应bounds的原点以便图层内容出现在滑动的地方
//- (void)scrollPoint:(CGPoint)p;
//- (void)scrollRectToVisible:(CGRect)r;
//@property(readonly) CGRect visibleRect;
- (void)scrollViewTest {
ScrollView *scrollView = [[ScrollView alloc] initWithFrame:CGRectMake(20.0, 20.0f, 300, 300)];
UIImage *image = [UIImage imageNamed:@"Meal"];
CALayer *layer = [CALayer layer];
layer.frame = CGRectMake(0, 0, 100, 100);
layer.contents = (__bridge id)image.CGImage;
[scrollView.layer addSublayer:layer];
[self.view addSubview:scrollView];
}
CATiledLayer
//CATiledLayer为载入大图造成的性能问题提供了一个解决方案：将大图分解成小片然后将他们单独按需载入
//小片裁剪
- (void)tiledLayerTest {
scrollView = [[UIScrollView alloc] init];
scrollView.frame = CGRectMake(0, 0, 300, 300);
[self.view addSubview:scrollView];
//add the tiled layer
CATiledLayer *tileLayer = [CATiledLayer layer];
tileLayer.frame = CGRectMake(0, 0, 2048, 2048);
tileLayer.delegate = self;
//Retina小图
tileLayer.contentsScale = [UIScreen mainScreen].scale;
[scrollView.layer addSublayer:tileLayer];
//configure the scroll view
scrollView.contentSize = tileLayer.frame.size;
//draw layer
[tileLayer setNeedsDisplay];
}
#pragma mark CALayerDelegate
- (void)drawLayer:(CATiledLayer *)layer inContext:(CGContextRef)ctx {
//determine title coordinate
CGRect bounds = CGContextGetClipBoundingBox(ctx);
NSInteger x = floor(bounds.origin.x / layer.tileSize.width);
NSInteger y = floor(bounds.origin.y / layer.tileSize.height);
//Retina小图
//tileSize是以像素为单位
//determine tile coordinate 适应小图渲染代码以对应安排scale的变化
// CGRect bounds = CGContextGetClipBoundingBox(ctx);
// CGFloat scale = [UIScreen mainScreen].scale;
// NSInteger x = floor(bounds.origin.x / layer.tileSize.width * scale);
// NSInteger y = floor(bounds.origin.y / layer.tileSize.height * scale);
//load tile image
// NSString *imageName = [NSString stringWithFormat: @"Meal_%02i_%02i", x, y];
// NSString *imagePath = [[NSBundle mainBundle] pathForResource:imageName ofType:@"jpg"];
// UIImage *tileImage = [UIImage imageWithContentsOfFile:imagePath];
UIImage *tileImage = [UIImage imageNamed:@"Meal"];
//draw tile
UIGraphicsPushContext(ctx);
[tileImage drawInRect:bounds];
UIGraphicsPopContext();
}
烟雾，火，雨等等这些效果
//CAEmitterLayer:是一个高性能的粒子引擎，被用来创建实时例子动画如：烟雾，火，雨等等这些效果
//CAEmitterCell:一个CAEmitterCell类似于一个CALayer：它有一个contents属性可以定义为一个CGImage
- (void)emitterLayerTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(20, 20, 300, 300);
containerView.backgroundColor = [UIColor blackColor];
[self.view addSubview:containerView];
//create particle emitter layer
CAEmitterLayer *emitter = [CAEmitterLayer layer];
emitter.frame = containerView.bounds;
[containerView.layer addSublayer:emitter];
//configure emitter
emitter.renderMode = kCAEmitterLayerAdditive;
emitter.emitterPosition = CGPointMake(emitter.frame.size.width / 2.0, emitter.frame.size.height / 2.0);
//create a particle template
CAEmitterCell *cell = [[CAEmitterCell alloc] init];
cell.contents = (__bridge id)[UIImage imageNamed:@"Star"].CGImage;
cell.birthRate = 150;
cell.lifetime = 5.0;
cell.color = [UIColor colorWithRed:1 green:0.5 blue:0.1 alpha:1.0].CGColor;
cell.alphaSpeed = -0.4;
cell.velocity = 50;
cell.velocityRange = 50;
cell.emissionRange = M_PI * 2.0;
//add particle template to emitter
emitter.emitterCells = @[cell];
}
CAEMitterCell
//这种粒子的某一属性的初始值。比如，color属性指定了一个可以混合图片内容颜色的混合色。在示例中，我们将它设置为桔色。
//例子某一属性的变化范围。比如emissionRange属性的值是2π，这意味着例子可以从360度任意位置反射出来。如果指定一个小一些的值，就可以创造出一个圆锥形
//指定值在时间线上的变化。比如，在示例中，我们将alphaSpeed设置为-0.4，就是说例子的透明度每过一秒就是减少0.4，这样就有发射出去之后逐渐小时的效果。
CAEAGLLayer
//当iOS要处理高性能图形绘制，必要时就是OpenGL。
//OpenGL提供了Core Animation的基础，它是底层的C接口，直接和iPhone，iPad的硬件通信，极少地抽象出来的方法。OpenGL没有对象或是图层的继承概念。它只是简单地处理三角形。OpenGL中所有东西都是3D空间中有颜色和纹理的三角形。用起来非常复杂和强大，但是用OpenGL绘制iOS用户界面就需要很多很多的工作了
//在iOS 5中，苹果引入了一个新的框架叫做GLKit，它去掉了一些设置OpenGL的复杂性，提供了一个叫做CLKView的UIView的子类，帮你处理大部分的设置和绘制工作。前提是各种各样的OpenGL绘图缓冲的底层可配置项仍然需要你用CAEAGLLayer完成，它是CALayer的一个子类，用来显示任意的OpenGL图形。
- (void)EAGLLayerTest {
glView = [[UIView alloc] init];
glView.frame = CGRectMake(0, 0, 300, 300);
glView.backgroundColor = [UIColor blackColor];
[self.view addSubview:glView];
//set up context
glContext = [[EAGLContext alloc] initWithAPI: kEAGLRenderingAPIOpenGLES2];
[EAGLContext setCurrentContext:glContext];
//set up layer
glLayer = [CAEAGLLayer layer];
glLayer.frame = glView.bounds;
[glView.layer addSublayer:glLayer];
glLayer.drawableProperties = @{kEAGLDrawablePropertyRetainedBacking:@NO, kEAGLDrawablePropertyColorFormat: kEAGLColorFormatRGBA8};
//set up base effect
effect = [[GLKBaseEffect alloc] init];
//set up buffers
[self setUpBuffers];
//draw frame
[self drawFrame];
}
- (void)setUpBuffers {
//set up frame buffer
glGenFramebuffers(1, &framebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
//set up color render buffer
glGenRenderbuffers(1, &colorRenderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, colorRenderbuffer);
[glContext renderbufferStorage:GL_RENDERBUFFER fromDrawable:glLayer];
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &framebufferWidth);
glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &framebufferHeight);
//check success
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
NSLog(@"Failed to make complete framebuffer object:%i", glCheckFramebufferStatus(GL_FRAMEBUFFER));
}
}
- (void)drawFrame {
//bind framebuffer & set viewport
glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
glViewport(0, 0, framebufferWidth, framebufferHeight);
//bind shader program
[effect prepareToDraw];
//clear the screen
glClear(GL_COLOR_BUFFER_BIT);
glClearColor(0.0, 0.0, 0.0, 1.0f);
//set up vertices
GLfloat vertices[] = {
-0.5f, -0.5f, -1.0f, 0.0f, 0.5f, -1.0f, 0.5f, -0.5f, -1.0f,
};
//set up colors
GLfloat colors[] = {
0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
};
//draw triangle
glEnableVertexAttribArray(GLKVertexAttribPosition);
glEnableVertexAttribArray(GLKVertexAttribColor);
glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 0, vertices);
glVertexAttribPointer(GLKVertexAttribColor,4, GL_FLOAT, GL_FALSE, 0, colors);
glDrawArrays(GL_TRIANGLES, 0, 3);
//present render buffer
glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
[glContext presentRenderbuffer:GL_RENDERBUFFER];
}
- (void)viewDidDisappear:(BOOL)animated {
[super viewDidDisappear:YES];
[self tearDownBuffers];
}
- (void)dealloc {
[self tearDownBuffers];
[EAGLContext setCurrentContext:nil];
}
- (void)tearDownBuffers {
if (framebuffer) {
//delete framebuffer
glDeleteFramebuffers(1, &framebuffer);
framebuffer = 0;
}
if (colorRenderbuffer) {
//delete color render buffer
glDeleteRenderbuffers(1, &colorRenderbuffer);
colorRenderbuffer = 0;
}
}
AVPlayerLayer
框架（AVFoundation）提供的 它和Core Animation紧密地结合在一起，提供了一个CALayer子类来显示自定义的内容类型。
- (void)AVPlayerLayerTest {
containerView = [[UIView alloc] init];
containerView.frame = CGRectMake(20.0, 20.0, 300, 300);
[self.view addSubview:containerView];
//get video URl
NSURL *url = [[NSBundle mainBundle] URLForResource:@"Vedio" withExtension:@"mp4"];
//create player and layer layer
AVPlayer *player = [AVPlayer playerWithURL:url];
AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
//set player layer frame and attach it to our view
playerLayer.frame = containerView.bounds;
[containerView.layer addSublayer:playerLayer];
//因为AVPlayerLayer是CALayer的子类，它继承了父类的所有特性。
//transform layer
CATransform3D transform = CATransform3DIdentity;
transform.m34 = -1.0 / 500.0;
transform = CATransform3DRotate(transform, M_PI_4, 1, 1, 0);
playerLayer.transform = transform;
//add rounded corners and border
playerLayer.masksToBounds = YES;
playerLayer.cornerRadius = 20.0f;
playerLayer.borderColor = [UIColor redColor].CGColor;
playerLayer.borderWidth = 5.0f;
//play the video
[player play];
}
//我们只是了解到这些图层的皮毛,像CATiledLayer和CAEMitterLayer这些类可以单独写一章的。