学习笔记5（CATransform3D-Cube）

1. CATransform3D结构成员的意义。

?

struct CATransform3D

{

CGFloat m11（x缩放）, m12（y切变）, m13（旋转）, m14（）;

CGFloat m21（x切变）, m22（y缩放）, m23（）, m24（）;

CGFloat m31（旋转）, m32（）, m33（）, m34（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。正直/负值都有意义）;

CGFloat m41（x平移）, m42（y平移）, m43（z平移）, m44（）;

};

ps:整体比例变换时，也就是m11==m22时，若m33>1，图形整体缩小，若0<m33<1，图形整体放大，若s<0,发生关于原点的对称等比变换。

（）空的地方以后补充。

2. CATransform3DMakeTranslation

CATransform3DMakeTranslation(0, 0, 0) 创建了一个4*4的单位矩阵。

3. CATransform3DMakeRotation And CATransform3DRotate

CATransform3DMakeRotation()

    _transformedLayer = [CALayer layer];    _transformedLayer.frame = self.bounds;    _transformedLayer.anchorPoint = CGPointMake(0.5f, 0.5f);    CATransform3D sublayerTransform = CATransform3DIdentity;    // Set perspective    sublayerTransform.m34 = kPerspective;    [_transformedLayer setSublayerTransform:sublayerTransform];        [self.layer addSublayer:_transformedLayer];    //init Sublayers    CATransform3D t = CATransform3DMakeTranslation(0, 0, 0);    // take snapshot of the current view    [_transformedLayer addSublayer:[self snapshot:t                                          withView:_contentView                                          isMasked:YES]];    // 暂时先支持一个方向翻转    RotateDirection direction = RotateFromBottom;    if (YES || direction == RotateFromBottom)    {        CGFloat height = self.bounds.size.height;        //CGFloat cubeSize = 100.0f;        t = CATransform3DRotate(t, D2R(90.0), 1, 0, 0);【1】        t = CATransform3DTranslate(t, 0, height, 0);        CALayer *subLayer = [self snapshot:t withView:view isMasked:YES];        [_transformedLayer addSublayer:subLayer];    }    else     {    }        _newContentView = view;        [self animationCubeRotate:direction withDuration:duration];

　　

4. 翻转的动画

- (void)animationCubeRotate:(RotateDirection)direction                withDuration:(float)duration{    [CATransaction flush];    CGFloat height = self.bounds.size.height;    CABasicAnimation *rotation;    // CABasicAnimation *translationX;// 如果沿X轴翻转,则用不到这个变量.    CABasicAnimation *translationY;// 如果沿Y轴翻转,则用不到这个变量.    CABasicAnimation *translationZ;    CAAnimationGroup *animationGroup = [CAAnimationGroup animation];    animationGroup.delegate = self;    animationGroup.duration = duration;        if ( direction == RotateFromBottom )    {        // 创建(某方向)关键帧动画.        translationY = [CABasicAnimation animationWithKeyPath:                        @"sublayerTransform.translation.y"];        translationY.toValue = [NSNumber numberWithFloat:-(height / 2)];【2】        rotation = [CABasicAnimation animationWithKeyPath:                    @"sublayerTransform.rotation.x"];        rotation.toValue = [NSNumber numberWithFloat:D2R(-90.0f)];    }     else if ( direction == RotateFromTop )    {    }        // 处理Z轴    translationZ = [CABasicAnimation animationWithKeyPath:                    @"sublayerTransform.translation.z"];    translationZ.toValue = [NSNumber numberWithFloat:height / 2];【3】    animationGroup.animations =     [NSArray arrayWithObjects: rotation, translationY, translationZ, nil];    animationGroup.fillMode = kCAFillModeForwards;    animationGroup.removedOnCompletion = NO;    [_transformedLayer addAnimation:animationGroup forKey:kAnimationKey];}

made, 我发现这个东西确实很难讲清楚，主要是因为我理论薄弱，

【1】针对X轴旋转，就是1，0，0，针对Y轴旋转，就是0，1，0...下面那行也要进行正确的转换。

【2】此处应该是和 anchorPoint有关系的。

【3】这个值会影响类似于深度的东西，比如说Cube会离我们更近，或者是更远。（但是，似乎不算是透视关系）