Learning glsl shader with help of GlslCanvas. GlslCanvas is JavaScript Library that helps you easily load GLSL Fragment and Vertex Shaders into an HTML canvas. Originally made by Patricio Gonzalez Vivo author of Book of Shaders and glslEditor.

Cross-hatching GLSL shader Based on Microsoft Research "Real-Time Hatching" paper. Shader reference: https://www.clicktorelease.com/code/cross-hatching/