仿射变换(CGAffineTransform)使用小结

一、理论基础

请参考CGAffineTransform简单分析

二、效果演示

三、实现代码

3.1：位移变换

-(void)positionAnimation{
    _demoView.transform = CGAffineTransformIdentity;
    [UIView animateWithDuration:1.0f animations:^{
        _demoView.transform = CGAffineTransformMakeTranslation(100, 100);
    }];
}

3.2：缩放变换

-(void)scaleAnimation{
    _demoView.transform = CGAffineTransformIdentity;
    [UIView animateWithDuration:1.0f animations:^{
        _demoView.transform = CGAffineTransformMakeScale(2, 2);
    }];
}

3.3：旋转变换

-(void)rotateAnimation{
    _demoView.transform = CGAffineTransformIdentity;
    [UIView animateWithDuration:1.0f animations:^{
        _demoView.transform = CGAffineTransformMakeRotation(M_PI);
    }];
}

3.4：组合变换

-(void)combinationAnimation{
    //仿射变换的组合使用
    _demoView.transform = CGAffineTransformIdentity;
    [UIView animateWithDuration:1.0f animations:^{
        CGAffineTransform transform1 = CGAffineTransformMakeRotation(M_PI);
        CGAffineTransform transform2 = CGAffineTransformScale(transform1, 0.5, 0.5);
        _demoView.transform = CGAffineTransformTranslate(transform2, 100, 100);
    }];
}

3.5：矩阵的反转

-(void)invertAnimation{
    _demoView.transform = CGAffineTransformIdentity;
    [UIView animateWithDuration:1.0f animations:^{
        //矩阵反转
        _demoView.transform = CGAffineTransformInvert(CGAffineTransformMakeScale(2, 2));
    }];
}

四、补充

• CGAffineTransformIdentity ： 单位矩阵变换，一般用于仿射变换的初始化或者还原。

• CGAffineTransformEqualToTransform(CGAffineTransform t1, 
  CGAffineTransform t2) ： 判断两个变换矩阵是否相等

• CGAffineTransformConcat(CGAffineTransform t1, 
  CGAffineTransform t2) ： 得到两个矩阵相加后得到的最终矩阵

• CGPoint CGPointApplyAffineTransform(CGPoint point, 
  CGAffineTransform t) ： 某点通过矩阵变换之后的点

• CGSize CGSizeApplyAffineTransform(CGSize size, CGAffineTransform t) ： 某个size通过矩阵变换之后的size

• CGRect CGRectApplyAffineTransform(CGRect rect, CGAffineTransform t) ： 某个Rect通过矩阵变换之后的区域

五、Demo下载地址

github下载地址 

 

转自：http://blog.csdn.net/yixiangboy