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IOS开发 CGAffineTransform相关函数

2016-05-18 13:35 399 查看
CoreGraphics.h

CGAffineTransform rotation = CGAffineTransformMakeRotation(M_PI_2);
[xxx setTransform:rotation];
呵呵就这么简单的两行代码就可以实现了!

顺便记录一些常量,以后用的着!

#define M_E 2.71828182845904523536028747135266250 e
#define M_LOG2E 1.44269504088896340735992468100189214 log 2e
#define M_LOG10E 0.434294481903251827651128918916605082 log 10e
#define M_LN2 0.693147180559945309417232121458176568 log
e2
#define M_LN10 2.30258509299404568401799145468436421 log e10
#define M_PI 3.14159265358979323846264338327950288 pi
#define M_PI_2 1.57079632679489661923132169163975144 pi/2
#define M_PI_4 0.785398163397448309615660845819875721 pi/4
#define
M_1_PI 0.318309886183790671537767526745028724 1/pi
#define M_2_PI 0.636619772367581343075535053490057448 2/pi
#define M_2_SQRTPI 1.12837916709551257389615890312154517 2/sqrt(pi)
#define M_SQRT2 1.41421356237309504880168872420969808 sqrt(2)
#define
M_SQRT1_2 0.707106781186547524400844362104849039 1/sqrt(2)

from:http://donbe.blog.163.com/blog/static/138048021201061054243442/

CGAffineTransformMakeTranslation(width, 0.0);是改变位置的,


CGAffineTransformRotate(transform, M_PI);是旋转的。


CGAffineTransformMakeRotation(-M_PI);也是旋转的


transform = CGAffineTransformScale(transform, -1.0, 1.0);是缩放的。


view.transform = CGAffineTransformIdentity;线性代数里面讲的矩阵变换,这个是恒等变换


当 你改变过一个view.transform属性或者view.layer.transform的时候需要恢复默认状态的话,记得先把他们重置可以使用

view.transform = CGAffineTransformIdentity,

或者view.layer.transform = CATransform3DIdentity,

假设你一直不断的改变一个view.transform的属性,而每次改变之前没有重置的话,你会发现后来 的改变和你想要的发生变化了,不是你真正想要的结果



Quartz转换实现的原理:Quartz把绘图分成两个部分,

用户空间,即和设备无关,

设备空间,

用户空间和设备空间中间存在一个转换矩阵 : CTM

本章实质是讲解CTM

Quartz提供的3大功能

移动,旋转,缩放

演示如下,首先加载一张图片

void CGContextDrawImage (

CGContextRef c,

CGRect rect,

CGImageRef image

);

移动函数

CGContextTranslateCTM (myContext, 100, 50);

旋转函数

include <math.h>

static inline double radians (double degrees) {return degrees * M_PI/180;}

CGContextRotateCTM (myContext, radians(–45.));

缩放

CGContextScaleCTM (myContext, .5, .75);

翻转, 两种转换合成后的效果,先把图片移动到右上角,然后旋转180度

CGContextTranslateCTM (myContext, w,h);

CGContextRotateCTM (myContext, radians(-180.));

组合几个动作

CGContextTranslateCTM (myContext, w/4, 0);

CGContextScaleCTM (myContext, .25, .5);

CGContextRotateCTM (myContext, radians ( 22.));

CGContextRotateCTM (myContext, radians ( 22.));

CGContextScaleCTM (myContext, .25, .5);

CGContextTranslateCTM (myContext, w/4, 0);

上面是通过直接修改当前的ctm实现3大效果,下面是通过创建Affine Transforms,然后连接ctm实现同样的3种效果

这样做的好处是可以重用这个Affine Transforms

应用Affine Transforms 到ctm的函数

void CGContextConcatCTM (

CGContextRef c,

CGAffineTransform transform

);

Creating Affine Transforms

移动效果

CGAffineTransform CGAffineTransformMakeTranslation (

CGFloat tx,

CGFloat ty

);

CGAffineTransform CGAffineTransformTranslate (

CGAffineTransform t,

CGFloat tx,

CGFloat ty

);

旋转效果

CGAffineTransform CGAffineTransformMakeRotation (

CGFloat angle

);

CGAffineTransform CGAffineTransformRotate (

CGAffineTransform t,

CGFloat angle

);

缩放效果

CGAffineTransform CGAffineTransformMakeScale (

CGFloat sx,

CGFloat sy

);

CGAffineTransform CGAffineTransformScale (

CGAffineTransform t,

CGFloat sx,

CGFloat sy

);

反转效果

CGAffineTransform CGAffineTransformInvert (

CGAffineTransform t

);

只对局部产生效果

CGRect CGRectApplyAffineTransform (

CGRect rect,

CGAffineTransform t

);

判断两个AffineTrans是否相等

bool CGAffineTransformEqualToTransform (

CGAffineTransform t1,

CGAffineTransform t2

);

获得Affine Transform

CGAffineTransform CGContextGetUserSpaceToDeviceSpaceTransform (

CGContextRef c

);

下面的函数只起到查看的效果,比如看一下这个用户空间的点,转换到设备空间去坐标是多少

CGPoint CGContextConvertPointToDeviceSpace (

CGContextRef c,

CGPoint point

);

CGPoint CGContextConvertPointToUserSpace (

CGContextRef c,

CGPoint point

);

CGSize CGContextConvertSizeToDeviceSpace (

CGContextRef c,

CGSize size

);

CGSize CGContextConvertSizeToUserSpace (

CGContextRef c,

CGSize size

);

CGRect CGContextConvertRectToDeviceSpace (

CGContextRef c,

CGRect rect

);

CGRect CGContextConvertRectToUserSpace (

CGContextRef c,

CGRect rect

);

CTM真正的数学行为

这个转换矩阵其实是一个 3x3的 举证

如下图

下面举例说明几个转换运算的数学实现

x y 是原先点的坐标

下面是从用户坐标转换到设备坐标的计算公式

下面是一个identity matrix,就是输入什么坐标,出来什么坐标,没有转换

最终的计算结果是 x=x,y=y,

可以用函数判断这个矩阵是不是一个 identity matrix

bool CGAffineTransformIsIdentity (

CGAffineTransform t

);

参考:http://developer.apple.com/library/ios/#documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_affine/dq_affine.html

- (void)willAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration

{

if (toInterfaceOrientation == UIInterfaceOrientationPortrait)

{

b=YES;

self.view=mainvv;

self.view.transform = CGAffineTransformIdentity;

self.view.transform = CGAffineTransformMakeRotation(degreesToRadian(0));

self.view.bounds = CGRectMake(0.0, 0.0, 768.0, 1004.0);

}

else if (toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft)

{

b=NO;

self.view = self.vv;

self.view.transform = CGAffineTransformIdentity;

self.view.transform = CGAffineTransformMakeRotation(degreesToRadian(-90));

self.view.bounds = CGRectMake(0.0, 0.0, 1024.0, 748.0);

}

else if (toInterfaceOrientation == UIInterfaceOrientationPortraitUpsideDown)

{

b=YES;

self.view=mainvv;

self.view.transform = CGAffineTransformIdentity;

self.view.transform = CGAffineTransformMakeRotation(degreesToRadian(180));

self.view.bounds = CGRectMake(0.0, 0.0, 768.0, 1004.0);

}

else if (toInterfaceOrientation == UIInterfaceOrientationLandscapeRight)

{

b=NO;

self.view = self.vv;

self.view.transform = CGAffineTransformIdentity;

self.view.transform = CGAffineTransformMakeRotation(degreesToRadian(90));

self.view.bounds = CGRectMake(0.0, 0.0, 1024.0, 748.0);

}

}

3

Quartz转换实现的原理:Quartz把绘图分成两个部分,

用户空间,即和设备无关,

设备空间,

用户空间和设备空间中间存在一个转换矩阵 : CTM

本章实质是讲解CTM

Quartz提供的3大功能

移动,旋转,缩放

演示如下,首先加载一张图片

void CGContextDrawImage (

CGContextRef c,

CGRect rect,

CGImageRef image

);

移动函数

CGContextTranslateCTM (myContext, 100, 50);

旋转函数

include <math.h>

static inline double radians (double degrees) {return degrees * M_PI/180;}

CGContextRotateCTM (myContext, radians(–45.));

缩放

CGContextScaleCTM (myContext, .5, .75);

翻转, 两种转换合成后的效果,先把图片移动到右上角,然后旋转180度

CGContextTranslateCTM (myContext, w,h);

CGContextRotateCTM (myContext, radians(-180.));

组合几个动作

CGContextTranslateCTM (myContext, w/4, 0);

CGContextScaleCTM (myContext, .25, .5);

CGContextRotateCTM (myContext, radians ( 22.));

CGContextRotateCTM (myContext, radians ( 22.));

CGContextScaleCTM (myContext, .25, .5);

CGContextTranslateCTM (myContext, w/4, 0);

上面是通过直接修改当前的ctm实现3大效果,下面是通过创建Affine Transforms,然后连接ctm实现同样的3种效果

这样做的好处是可以重用这个Affine Transforms

应用Affine Transforms 到ctm的函数

void CGContextConcatCTM (

CGContextRef c,

CGAffineTransform transform

);

Creating Affine Transforms

移动效果

CGAffineTransform CGAffineTransformMakeTranslation (

CGFloat tx,

CGFloat ty

);

CGAffineTransform CGAffineTransformTranslate (

CGAffineTransform t,

CGFloat tx,

CGFloat ty

);

旋转效果

CGAffineTransform CGAffineTransformMakeRotation (

CGFloat angle

);

CGAffineTransform CGAffineTransformRotate (

CGAffineTransform t,

CGFloat angle

);

缩放效果

CGAffineTransform CGAffineTransformMakeScale (

CGFloat sx,

CGFloat sy

);

CGAffineTransform CGAffineTransformScale (

CGAffineTransform t,

CGFloat sx,

CGFloat sy

);

反转效果

CGAffineTransform CGAffineTransformInvert (

CGAffineTransform t

);

只对局部产生效果

CGRect CGRectApplyAffineTransform (

CGRect rect,

CGAffineTransform t

);

判断两个AffineTrans是否相等

bool CGAffineTransformEqualToTransform (

CGAffineTransform t1,

CGAffineTransform t2

);

获得Affine Transform

CGAffineTransform CGContextGetUserSpaceToDeviceSpaceTransform (

CGContextRef c

);

下面的函数只起到查看的效果,比如看一下这个用户空间的点,转换到设备空间去坐标是多少

CGPoint CGContextConvertPointToDeviceSpace (

CGContextRef c,

CGPoint point

);

CGPoint CGContextConvertPointToUserSpace (

CGContextRef c,

CGPoint point

);

CGSize CGContextConvertSizeToDeviceSpace (

CGContextRef c,

CGSize size

);

CGSize CGContextConvertSizeToUserSpace (

CGContextRef c,

CGSize size

);

CGRect CGContextConvertRectToDeviceSpace (

CGContextRef c,

CGRect rect

);

CGRect CGContextConvertRectToUserSpace (

CGContextRef c,

CGRect rect

);

CTM真正的数学行为

这个转换矩阵其实是一个 3x3的 举证

如下图

下面举例说明几个转换运算的数学实现

x y 是原先点的坐标

下面是从用户坐标转换到设备坐标的计算公式

下面是一个identity matrix,就是输入什么坐标,出来什么坐标,没有转换

最终的计算结果是 x=x,y=y,

可以用函数判断这个矩阵是不是一个 identity matrix

bool CGAffineTransformIsIdentity (

CGAffineTransform t

);

移动矩阵

缩放矩阵

旋转矩阵

旋转加移动矩阵

//********************************//

layer 动画-(transform.rotation篇)

x轴旋转:
CABasicAnimation *theAnimation;
theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.rotation.x"];
theAnimation.duration=8;
theAnimation.removedOnCompletion = YES;
theAnimation.fromValue = [NSNumber numberWithFloat:0];
theAnimation.toValue = [NSNumber numberWithFloat:3.1415926];
[yourView.layer addAnimation:theAnimation forKey:@"animateTransform"];

y轴旋转:
CABasicAnimation *theAnimation;
theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.rotation.y"];
theAnimation.duration=8;
theAnimation.removedOnCompletion = YES;
theAnimation.fromValue = [NSNumber numberWithFloat:0];
theAnimation.toValue = [NSNumber numberWithFloat:3.1415926];
[yourView.layer addAnimation:theAnimation forKey:@"animateTransform"];

z轴旋转:
CABasicAnimation *theAnimation;
theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
theAnimation.duration=8;
theAnimation.removedOnCompletion = YES;
theAnimation.fromValue = [NSNumber numberWithFloat:0];
theAnimation.toValue = [NSNumber numberWithFloat:3.1415926];
[yourView.layer addAnimation:theAnimation forKey:@"animateTransform"];

以上缩放是以view的中心点为中心缩放的,如果需要自定义缩放点,可以设置卯点:
//中心点
[yourView.layer setAnchorPoint:CGPointMake(0.5, 0.5)];

//左上角
[yourView.layer setAnchorPoint:CGPointMake(0, 0)];

//右下角
[yourView.layer setAnchorPoint:CGPointMake(1, 1)];

可设参数:

theAnimation.repeatCount = 0;
theAnimation.autoreverses = NO;

旋转的另一种实现:(以下代码绕z轴旋转180度)
[self.topViewController.view.layer setAnchorPoint:CGPointMake(0.5, 0.5)];
[self.topViewController.view.layer setTransform:CATransform3DMakeRotation(0, 0, 0, 1)];
[UIView animateWithDuration:8 delay:0.0f options:UIViewAnimationOptionAllowUserInteraction | UIViewAnimationCurveEaseIn animations:^{
[self.topViewController.view.layer setTransform:CATransform3DMakeRotation(3.1415926, 0, 0, 1)];
} completion:^(BOOL finished) {
}];


//获取当前transform
CGAffineTransform transform = self.lblSeg.transform;

//缩放
self.lblSeg.transform = CGAffineTransformMakeScale(.5, .5);

//在一个transform的基础上再缩放
self.lblTest.transform = CGAffineTransformScale(transform, 0.5, 0.5);

//旋转(弧度制)
self.lblSeg.transform = CGAffineTransformMakeRotation(M_2_PI);

//在一个transform的基础上再旋转
self.lblTest.transform = CGAffineTransformRotate(transform,M_2_PI);

//平移
self.lblSeg.transform = CGAffineTransformMakeTranslation(100, 100);

//在一个transform的基础上再平移
self.lblTest.transform = CGAffineTransformTranslate(transform, 100, 100);
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