iOS开发 ☞ 仿射变换

In English,Affine means 仿射，Transform means 变换，so，you know it.

来看一个常量

/* The identity transform: [ 1 0 0 1 0 0 ]. */

CG_EXTERN const CGAffineTransform CGAffineTransformIdentity
  CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

一般形式

CG_EXTERN CGAffineTransform CGAffineTransformMake(CGFloat a, CGFloat b,
  CGFloat c, CGFloat d, CGFloat tx, CGFloat ty)
  CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);