Good resourses - YanLiang1102/Computer_Graphics_OU GitHub Wiki

https://www.cs.mtsu.edu/~jhankins/files/4250/notes/

https://www.tomdalling.com/blog/modern-opengl/explaining-homogenous-coord

http://math.hws.edu/graphicsbook/c3/s3.html

https://www.ntu.edu.sg/home/ehchua/programming/opengl/CG_Examples.html

http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-13-normal-mapping/

https://www.codementor.io/isaib.cicourel/image-manipulation-in-python-du1089j1u

why use homogeneous coordinates

https://www.tomdalling.com/blog/modern-opengl/explaining-homogenous-coordinates-and-projective-geometry/