iOS开发CATransform3D.h属性详解和方法使用

1、CATransform3D简介

　　layer有个属性transform，是CATransform3D类型。可以使其在三维界面作平移、缩放和旋转单独或组合动画！

　　CATransform3D结构体：

/* Homogeneous three-dimensional transforms.
m11：控制x方向上的缩放
m41：控制x方向上的平移

m22：控制y方向上的缩放
m42：控制y方向上的平移
 
m33：控制z方向上的缩放
m43：控制z方向上的平移
 
m21、m31、m12、m32、m13、m23控制旋转
 m21:和m12一起决定z轴的旋转
 m31:和m13一起决定y轴的旋转
 m32:和m23一起决定x轴的旋转
 
m14、m24、m34、m44
m34为透视效果，要操作的这个对象要有旋转的角度，否则没有效果*/
struct CATransform3D
{
    CGFloat m11, m12, m13, m14;
    CGFloat m21, m22, m23, m24;
    CGFloat m31, m32, m33, m34;
    CGFloat m41, m42, m43, m44;
};

2、CATransform3D的简单使用和代码展示

　　2.1、平移

#pragma mark---平移
/* Returns a transform that translates by '(tx, ty, tz)':
 * t' =  [1 0 0 0; 0 1 0 0; 0 0 1 0; tx ty tz 1].
 平移 tx，ty，tz对象x，y和z轴*/
CA_EXTERN CATransform3D CATransform3DMakeTranslation (CGFloat tx,
                                                      CGFloat ty, CGFloat tz);
/* Translate 't' by '(tx, ty, tz)' and return the result:
 * t' = translate(tx, ty, tz) * t.
 在t变换的基础上 进行平移*/
CA_EXTERN CATransform3D CATransform3DTranslate (CATransform3D t, CGFloat tx,
                                                CGFloat ty, CGFloat tz)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

- (void)transform3D{
    CATransform3D transA = CATransform3DIdentity;
    transA               = CATransform3DMakeTranslation(50, 50, 0);
    [UIView animateWithDuration:1
                     animations:^{
                         bgImageView.layer.transform = transA;
                     }
                     completion:^(BOOL finished) {
                         [UIView animateWithDuration:1
                                          animations:^{
                                              bgImageView.layer.transform = CATransform3DTranslate(transA, -50, -50, 0);
                                          } completion:^(BOOL finished) {
                                              bgImageView.layer.transform = CATransform3DIdentity;
                                          }];
                     }];
}

　　2.2、缩放

#pragma mark---缩放
/* Returns a transform that scales by `(sx, sy, sz)':
 * t' = [sx 0 0 0; 0 sy 0 0; 0 0 sz 0; 0 0 0 1].
 缩放tx，ty，tz对象x，y和z轴缩放比例*/
CA_EXTERN CATransform3D CATransform3DMakeScale (CGFloat sx, CGFloat sy,
                                                CGFloat sz);
/* Scale 't' by '(sx, sy, sz)' and return the result:
 * t' = scale(sx, sy, sz) * t.
 在t变换的基础上 进行缩放*/
CA_EXTERN CATransform3D CATransform3DScale (CATransform3D t, CGFloat sx,
                                            CGFloat sy, CGFloat sz)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

- (void)transform3DScale{
//    1、缩放时先设置初始状态CATransform3DMakeScale(1, 1, 0);
//    2、使用CATransform3DScale时，连续缩小或放大（不能缩放后放大、放大后缩小）
//    3、直接使用CATransform3DMakeScale可以随意设置
    CATransform3D transA = CATransform3DIdentity;
    transA  = CATransform3DMakeScale(0.5, 0.5, 0);
    bgImageView.layer.transform       = CATransform3DMakeScale(1, 1, 0);
    [UIView animateWithDuration:1
                     animations:^{
                         bgImageView.layer.transform =transA;
                     }
                     completion:^(BOOL finished) {
                         [UIView animateWithDuration:1
                                          animations:^{
                                              bgImageView.layer.transform =  CATransform3DScale(transA, 0.5, 0.5, 0);
                                          } completion:^(BOOL finished) {
                                              bgImageView.layer.transform = CATransform3DIdentity;
                                          }];
                     }];
}

　　2.3、旋转

#pragma mark---旋转
/* Returns a transform that rotates by 'angle' radians about the vector
 * '(x, y, z)'. If the vector has length zero the identity transform is
 * returned.
 旋转
 angle参数是旋转的角度
 x，y，z决定了旋转围绕的中轴，取值为-1 — 1之间，
 如（1，0，0）,则是绕x轴旋转，（0.5，0.5，0），则是绕x轴与y轴中间45度为轴旋转*/
CA_EXTERN CATransform3D CATransform3DMakeRotation (CGFloat angle, CGFloat x,
                                                   CGFloat y, CGFloat z);
/* Rotate 't' by 'angle' radians about the vector '(x, y, z)' and return
 * the result. If the vector has zero length the behavior is undefined:
 * t' = rotation(angle, x, y, z) * t.
 在t变换的基础上 进行旋转*/
CA_EXTERN CATransform3D CATransform3DRotate (CATransform3D t, CGFloat angle,
                                             CGFloat x, CGFloat y, CGFloat z)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

- (void)transform3DRotation{
//    1、m34实际上影响了z轴方向的translation，m34= -1/D,  默认值是0，我们需要尽可能的让m34这个值尽可能小
    CATransform3D transA = CATransform3DIdentity;
    transA.m34           = - 1.0 / 600;
    transA               = CATransform3DMakeRotation(M_PI_4, 1, 1, 0);
    [UIView animateWithDuration:1
                     animations:^{
                         bgImageView.layer.transform = transA;
                     }
                     completion:^(BOOL finished) {
                         [UIView animateWithDuration:1
                                          animations:^{
                                              bgImageView.layer.transform =  CATransform3DRotate(transA, -M_PI_4, -1, 1, 0);
                                          } completion:^(BOOL finished) {
                                              bgImageView.layer.transform = CATransform3DIdentity;
                                          }];
                     }];
}

3、CATransform3D的其它方法说明

/* The identity transform: [1 0 0 0; 0 1 0 0; 0 0 1 0; 0 0 0 1].
 最初的对象*/
CA_EXTERN const CATransform3D CATransform3DIdentity
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

/* Returns true if 't' is the identity transform.
 判断t是否是最初的对象*/
CA_EXTERN bool CATransform3DIsIdentity (CATransform3D t)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

/* Returns true if 'a' is exactly equal to 'b'.
 判断a和b是否相同*/
CA_EXTERN bool CATransform3DEqualToTransform (CATransform3D a,
                                              CATransform3D b)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);


#pragma mark---other
/* Concatenate 'b' to 'a' and return the result: t' = a * b.
 a和b进行叠加 返回新的对象*/
CA_EXTERN CATransform3D CATransform3DConcat (CATransform3D a, CATransform3D b)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

/* Invert 't' and return the result. Returns the original matrix if 't'
 * has no inverse.
 反向变换*/
CA_EXTERN CATransform3D CATransform3DInvert (CATransform3D t)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

#pragma mark--- 3D和2D转换
/* Return a transform with the same effect as affine transform 'm'.
 将CGAffineTransform转化为CATransform3D*/
CA_EXTERN CATransform3D CATransform3DMakeAffineTransform (CGAffineTransform m)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

/* Returns true if 't' can be represented exactly by an affine transform.
 判断一个CATransform3D是否可以转换为CGAffineTransform*/
CA_EXTERN bool CATransform3DIsAffine (CATransform3D t)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);

/* Returns the affine transform represented by 't'. If 't' can not be
 * represented exactly by an affine transform the returned value is
 * undefined.
 将CATransform3D转换为CGAffineTransform*/
CA_EXTERN CGAffineTransform CATransform3DGetAffineTransform (CATransform3D t)
CA_AVAILABLE_STARTING (10.5, 2.0, 9.0, 2.0);