CALayer geometryFlipped 的行为如何？

Question

假设我有一个名为 somePath 的 CGPathRef，我正在这样做：

CAShapeLayer *shapeLayer = [[CAShapeLayer alloc] init];
shapeLayer.path = somePath;
shapeLayer.geometryFlipped = YES;

但出于某种原因，我不想翻转几何体——我想做这样的事情：

CAShapeLayer *shapeLayer = [[CAShapeLayer alloc] init];
CGAffineTransform flipTransform = ........;
shapeLayer.path = CGPathApplyAffineTransform(somePath, &flipTransform);
shapeLayer.geometryFlipped = NO;

flipTransform 必须看起来如何才能使图层显示与以前完全相同？

:)

Answer 1

CGAffineTransform flipTransform = CGAffineTransformMakeScale(1, -1);