A Simple Example of Projection Matrix

I’m am aware of how a Orthographic projection matrix is calculated using the arguments passed to the glOrtho() method.
I just wanted to see a working example and a diagram to explain the effect of multiplying a vector with this matrix.

OpenGL Projection Matrix – Orthographic (Ahn)

It’s just a scale and bias in X, Y, and Z. Pretty easy to visualize: just squish or stretch space; then change the origin.