- CGAffineTransformMake
- CGAffineTransformMakeTranslation
- CGAffineTransformMakeScale
- CGAffineTransformMakeRotation
- CGAffineTransformIsIdentity
- CGAffineTransformTranslate
- CGAffineTransformScale
- CGAffineTransformRotate
- CGAffineTransformInvert
- CGAffineTransformConcat
- CGAffineTransformEqualToTransform
- CGPointApplyAffineTransform
- CGSizeApplyAffineTransform
unlike apple always rotate thing in clockwise, this sdk rotate thing in counter clockwise.