Core Animation笔记（特殊图层）

1.shapeLayer: 渲染快速，内存占用小，不会被图层边界裁掉（可以在边界之外绘制），不会像素化（当做3D变化如缩放是不会失真）

   CGRect rect = self.containerView.bounds;

    CAShapeLayer *shaper = [CAShapeLayer new];

    shaper.backgroundColor = [UIColor yellowColor].CGColor;

    shaper.lineWidth = ;

    shaper.strokeColor = [UIColor redColor].CGColor;

    //单独设置左上，右上圆角

    UIRectCorner rcorner = UIRectCornerTopLeft|UIRectCornerTopRight;

    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect byRoundingCorners:rcorner cornerRadii:CGSizeMake(, )];

    //设置路径

    shaper.path = path.CGPath;

//    [self.containerView.layer addSublayer:shaper];

    //定义父图层的可见区域(这里使父图层的圆角单独设置左上,右上)

    self.containerView.layer.mask = shaper;

2.CATextLayer

     CATextLayer *textLayer = [CATextLayer new];

    textLayer.frame = self.containerView.bounds;

    [self.containerView.layer addSublayer:textLayer];

    //设置文本属性

    textLayer.foregroundColor = [UIColor blueColor].CGColor;

    textLayer.alignmentMode = kCAAlignmentJustified;

    textLayer.wrapped = YES;

    //设置字体

    UIFont *font = [UIFont systemFontOfSize:];

    CFStringRef fontStrRef = (__bridge CFStringRef)font.fontName;

    CGFontRef fontRef = CGFontCreateWithFontName(fontStrRef);

    textLayer.font = fontRef;

    CFRelease(fontRef);

    textLayer.fontSize = font.pointSize;

    //设置缩放倍数，防止像素化

    textLayer.contentsScale = [UIScreen mainScreen].scale;

    //这里也可以设置富文本字符串NSMutableString

    textLayer.string = @"on my god we you yao bei rangyizhuier le ma ,zhe me zhen shi de ma ,ai ";

3.CATransformLayer: 不平面化子图层，用于构建3D 形状，如下代码用于构建一个正方体

//产生某个面的子layer

- (CALayer*)faceWithTransform:(CATransform3D)transform{

    CALayer *layer = [CALayer layer];

    layer.frame = CGRectMake(-, -, , );

    layer.backgroundColor = [UIColor colorWithRed:rand()/(double)INT_MAX green:rand()/(double)INT_MAX  blue:rand()/(double)INT_MAX alpha:].CGColor;

    layer.transform = transform;

    return layer;

}

- (CALayer*)cubeWithTransform:(CATransform3D)transform{

    CATransformLayer *cubeLayer = [CATransformLayer layer];

    //

    CATransform3D ct = CATransform3DMakeTranslation(, , );

    [cubeLayer addSublayer:[self faceWithTransform:ct]];

    //

    ct = CATransform3DMakeTranslation(, , );

    ct = CATransform3DRotate(ct, M_PI_2, , , );

    [cubeLayer addSublayer:[self faceWithTransform:ct]];

    //

    ct = CATransform3DMakeTranslation(, -, );

    ct = CATransform3DRotate(ct, -M_PI_2, , , );

    [cubeLayer addSublayer:[self faceWithTransform:ct]];

    //

    ct = CATransform3DMakeTranslation(, , );

    ct = CATransform3DRotate(ct, -M_PI_2, , , );

    [cubeLayer addSublayer:[self faceWithTransform:ct]];

    //

    ct = CATransform3DMakeTranslation(-, , );

    ct = CATransform3DRotate(ct, -M_PI_2, , , );

    [cubeLayer addSublayer:[self faceWithTransform:ct]];

    //

    ct = CATransform3DMakeTranslation(, , -);

    ct = CATransform3DRotate(ct, M_PI, , , );

    [cubeLayer addSublayer:[self faceWithTransform:ct]];

    cubeLayer.position = CGPointMake(self.containerView.bounds.size.width/, self.containerView.bounds.size.height/);

    //运用3D变换

    cubeLayer.transform = transform;

    return cubeLayer;

}

- (void)testTransformLayer{

    CATransform3D tran = CATransform3DIdentity;

    tran.m34 = -1.0/;

//添加透视效果

    self.containerView.layer.sublayerTransform = tran;

    CATransform3D ct2  = CATransform3DIdentity;

    ct2 = CATransform3DTranslate(ct2, , , );

    ct2 = CATransform3DRotate(ct2, -M_PI_4, , , );

    ct2 = CATransform3DRotate(ct2, -M_PI_4, , , );

    [self.containerView.layer addSublayer:[self cubeWithTransform:ct2]];

}

4.CAGradientLayer:渐变图层

 CAGradientLayer *gradientLayer = [CAGradientLayer layer];

    gradientLayer.frame = self.containerView.bounds;

    [self.containerView.layer addSublayer:gradientLayer];

    gradientLayer.colors = @[(__bridge id)[UIColor redColor].CGColor,(__bridge id)[UIColor yellowColor].CGColor,(__bridge id)[UIColor greenColor].CGColor];

    gradientLayer.startPoint = CGPointMake(, );

    gradientLayer.endPoint = CGPointMake(, );

    //各个渐变点开始渐变的位置，和colors数组个数必须一致.

    gradientLayer.locations = @[@0.0,@0.1,@0.2]

5.CAReplicatorLayer，生成重复的子图层，并未每个图层应用变换

    CAReplicatorLayer *replayer = [CAReplicatorLayer layer];

    replayer.frame = self.containerView.bounds;

    [self.containerView.layer addSublayer:replayer];

//复制个数

    replayer.instanceCount = ;

    CATransform3D transform = CATransform3DIdentity;

    transform = CATransform3DTranslate(transform, , , );

    transform = CATransform3DRotate(transform, M_PI/5.0, , , );

    transform = CATransform3DTranslate(transform, , -, );

    //运用变换

    replayer.instanceTransform = transform;

    //改变下一图层的蓝红通道 ,每个复制的图层颜色不一样

    replayer.instanceBlueOffset = -0.1;

    replayer.instanceRedOffset = - 0.1;

//放一个子图层进去

    CALayer *layer = [CALayer layer];

    layer.frame = CGRectMake(, , , );

    layer.backgroundColor = [UIColor whiteColor].CGColor;

    [replayer addSublayer:layer];

产生一个倒影效果(这里自定义一个view用于产生倒影效果)：

自定义view,返回指定的图层

+ (Class)layerClass{

    return [CAReplicatorLayer class];

}

- (instancetype)init{

    if (self = [super init]) {

        [self setUp];

    }

    return self;

}

- (instancetype)initWithFrame:(CGRect)frame{

    if (self = [super initWithFrame:frame]) {

        [self setUp];

    }

    return self;

}

- (void)awakeFromNib{

    [super awakeFromNib];

    [self setUp];

}

- (void)setUp{

    CAReplicatorLayer *layer = (CAReplicatorLayer*)self.layer;

    layer.instanceCount = ;

    CATransform3D transform = CATransform3DIdentity;

    CGSize size = self.bounds.size;

    transform = CATransform3DTranslate(transform, 0, size.height+2, 0);

    /**

        y方向倒转

     */

    transform = CATransform3DScale(transform, , -, );

    layer.instanceTransform = transform;

    layer.instanceAlphaOffset = -0.6;

}

6.CAEmitterLayer:粒子发散效果

 CAEmitterLayer *emmitLayer = [CAEmitterLayer layer];

    emmitLayer.frame = self.containerView.bounds;

    [self.containerView.layer addSublayer:emmitLayer];

    CGSize size = self.containerView.frame.size;

    emmitLayer.masksToBounds = true;

    //重叠部分效果，kCAEmitterLayerAdditive，重叠部分更亮

    emmitLayer.renderMode = kCAEmitterLayerAdditive;

    //发散点

    emmitLayer.emitterPosition = CGPointMake(size.width/, size.height/);

    CAEmitterCell *cell =[ CAEmitterCell emitterCell];

//注意图片大小

    cell.contents = (__bridge id)[UIImage imageNamed:@"spark.jpg"].CGImage;

    cell.birthRate = ;//每秒多少个

    cell.lifetime = ;

    cell.color = [UIColor colorWithRed: green:0.5 blue: alpha:].CGColor;

    cell.alphaSpeed = -0.3;

    cell.velocity = ;

    cell.velocityRange = ;

//发散范围

    cell.emissionRange = M_PI*;

    emmitLayer.emitterCells = @[cell];

7.其他

CAEAGLLayer

CAScrollLayer

CATiledLayer:载入大图

巴特西

Core Animation笔记（特殊图层）

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