After weeks of desperate searching on the internet for proper documentation on how to work with shaders in Direct3D 9, I finally grasped the basic concept of it and decided to make a short beginner-friendly tutorial.
DX9 is old, to say the least, but it is also the easiest starting point if you want to learn DX11 or DX12.
There are a few good tutorials out there on how to draw your first triangle, load your first mesh, but I've found none talking about shaders, which is a pretty important part if you wanted to make eye-candy effects or optimize performance.
Even Microsoft's documentation on how to load a shader is very-very confusing.
This tutorial aims for a fast and easy way to learn shaders. The goal is to provide the shortest, most intuitive explanation of shaders. It won't teach you in-depth advanced techniques but rather gives you a basic concept of how everything works.