MaLiang
iOS painting and drawing library based on Metal
...Canvas extends from MetalView, which extends from MTKView. MetalView handles all the logic with MetalKit and hides them from you. MaLiang supports the automatic adjustment of stroke size with painting force. 3D Touch is supported by default, and simulated force will be setup on devices that do not support this. forceSensitive is the property that force affects the stroke size. It should be set between 0 to 1. the smaller the value is, the less sensitive will be. if sets to 0, then force will not affect the stroke size.