Practical OpenGL and GLSL shaders fundamentals with C++

What is OpenGL?

It is a "state machine" that can be set up to perform rendering

Lets dive into the fundamentals of OpenGL machinery. Actually its easy to get the basic idea - OpenGL is a "server" and you apply C-function calls (as a "client") to "access" and "modify" its state. To setup the scene and the OpenGL renders it

Also in this lecture:

- the "phototable" metaphor

- feeding the OpenGL with the geometry (vertices)

- introduction to shaders

- the "rendering pipeline" concept

- OpenGL screen coordinates

This is summary of the Section 3

I highlight some of the important concepts on the geometry (like CW and CCW directions of vertices, loading of multiple vertex buffer objects, setting up shader variables and varyings, etc)

Hope this help to summarize everything and build the general understanding of how the basic shaders machinery works

How do the shadertoy.com masterpieces work?

They use full-screen rendering from within the shaders.

Lets explore the very basic principle to do so

Want to know more about 4D matrices and why we need them?

Let's explore the homogenous coordinates!

This is an elegant mathematical "trick" to make a uniform stack of 4D matrices - to represent not only rotation and scale but also translation (and concatenate the combined transformations easily!).

In real 2d and 3d games engines this ability gives us amazing boost in performance! Where each child sub-node has its own 4D node transformation defined relative to the parent node.

So we only apply the transformation once

ps. actually for the simplicity I explore 3D homogenous coordinate as we cannot think in 4D

but the same logic is applicable to 4D world as well! So just get the principal idea

Lets enter the 3D space!

3D rendering has its own caveats and tricks.

So lets just start simple and build a rotating cube!

A small lesson of how to add the GLM math library.

It will be neccessary to use it to define the projection transformation later