图像，动画，随笔

1.CGAffineTransform 类型表示一个仿射变化CGAffineTransformMake*（）函数返回一个CGAffineTransform类型的对方CGAffineTransform仿射变化是作用在path（路径）上的，而不是作用在context（画板）上的

//平移CGAffineTransform transform = CGAffineTransformMakeTranslation(100.0f, 0.0f);//缩放CGAffineTransform transform = CGAffineTransformMakeScale(0.5f, 0.5f);//旋转CGAffineTransformMakeRotation((45.0f * M_PI) / 180.0f);CGPathAddRect(path, &transform, rectangle);

2.CGContextTranslateCTM（）函数直接把仿射变化作用在context（画板）上

UIGraphicsGetCurrentContext();//平移CGContextTranslateCTM(currentContext, 100.0f, 0);//缩放CGContextScaleCTM(currentContext, 0.5f, 0.5f);//旋转CGContextRotateCTM