iOS transform(2D仿射)

//位移仿射
CGAffineTransformMakeTranslation
CGAffineTransformTranslate
//旋转仿射
CGAffineTransformMakeRotation
CGAffineTransformRotate
//缩放仿射
CGAffineTransformMakeScale
CGAffineTransformScale
//叠加仿射效果
CGAffineTransformConcat
//仿射矩阵方法，可以直接做效果叠加
CGAffineTransformMake (sx,shx,shy,sy,tx,ty)

//仿射矩阵
//A是m×n矩阵和B是n×p矩阵，它们的乘积C是一个m×p矩阵
//1行3列 * 3行3列 = 1行3列
[x,y,1] * [a  b  0] = [x',y',z']
          [c  d  0]
          [tx ty 1]


设a,d=1 c,b = 0 那么
x' = a*x + c*y + tx
y' = b*x + d*y + ty
z' = 0*x + 0*y + 1*1
就变成了
x' = x + tx
y' = y + ty

向右移动300的仿射效果
CGAffineTransform translate = CGAffineTransformMakeTranslation(300, 0)
使用仿射基础方法 
CGAffineTransform translate = CGAffineTransformMake(1,0,0,1,300,0)
//CGAffineTransformMake(CGFloat a,CGFloat b,CGFloat c,CGFloat d,CGFloat tx,CGFloat ty)