ios 圖片倒影投影的原理詳解

最近一直在趕項目好久沒更新自己的部落格了。

就寫一下自己在投影上面學到的東西吧

原始圖片：

       [[[self view] layer] setBackgroundColor:[[UIColor blackColor] CGColor]];         UIImage *balloon = [UIImage imageNamed:@"mj_207.jpg"];        CALayer *reflectionLayer = [[CALayer alloc] init];         [reflectionLayer setBounds:CGRectMake(0.0f, 0.0f, 320.0, 480.0)];         [reflectionLayer setPosition:CGPointMake(160.0f, 220.0f)];        [reflectionLayer setContents:(id)[balloon CGImage]];        [reflectionLayer setValue:[NSNumber numberWithFloat:480.0] forKeyPath:@"-transform.rotation.x"];//-transform.rotation.x 對稱方向        CAGradientLayer *gradientLayer = [[CAGradientLayer alloc] init];         [gradientLayer setBounds:[reflectionLayer bounds]];         [gradientLayer setPosition:CGPointMake([reflectionLayer bounds].size.width/2, [reflectionLayer bounds].size.height/2)];        [gradientLayer setColors:[NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor clearColor] CGColor],(id)[[UIColor clearColor] CGColor],(id)[[UIColor blackColor] CGColor],nil]];//alpha 漸層數組 就是怎麼漸層的        [gradientLayer setStartPoint:CGPointMake(0.0,0.4)]; //開始點        [gradientLayer setEndPoint:CGPointMake(0.0,0.8)];//結束點 與常規有點不一樣        [reflectionLayer setMask:gradientLayer];        [[[self view] layer] addSublayer:reflectionLayer];

：

把-transform.rotation.x改成transform.rotation.x就變成沿x軸的倒影

：

把-transform.rotation.x改成transform.rotation.y就變成沿y軸的倒影

 

[gradientLayersetEndPoint:CGPointMake(0.0,0.8)]改成
[gradientLayer setEndPoint:CGPointMake(1.0,0.8)]

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