命中检测

遍历所有绘制对象执行检测：https://searchfox.org/mozilla-central/source/layout/painting/nsDisplayList.cpp#2755

https://www.xarg.org/book/computer-graphics/2d-hittest/

Hit-test: Bezier curve and Point

https://stackoverflow.com/questions/15987966/hit-detection-on-beziercurves-with-tolerance