Book Image

GLSL Essentials

By : Jacobo Rodriguez
Book Image

GLSL Essentials

By: Jacobo Rodriguez

Overview of this book

Shader programming has been the largest revolution in graphics programming. OpenGL Shading Language (abbreviated: GLSL or GLslang), is a high-level shading language based on the syntax of the C programming language.With GLSL you can execute code on your GPU (aka graphics card). More sophisticated effects can be achieved with this technique.Therefore, knowing how OpenGL works and how each shader type interacts with each other, as well as how they are integrated into the system, is imperative for graphic programmers. This knowledge is crucial in order to be familiar with the mechanisms for rendering 3D objects. GLSL Essentials is the only book on the market that teaches you about shaders from the very beginning. It shows you how graphics programming has evolved, in order to understand why you need each stage in the Graphics Rendering Pipeline, and how to manage it in a simple but concise way. This book explains how shaders work in a step-by-step manner, with an explanation of how they interact with the application assets at each stage. This book will take you through the graphics pipeline and will describe each section in an interactive and clear way. You will learn how the OpenGL state machine works and all its relevant stages. Vertex shaders, fragment shaders, and geometry shaders will be covered, as well some use cases and an introduction to the math needed for lighting algorithms or transforms. Generic GPU programming (GPGPU) will also be covered. After reading GLSL Essentials you will be ready to generate any rendering effect you need.
Table of Contents (13 chapters)

The Language


When you start coding a shader, you have to keep in mind one important thing: which GLSL version you are going to code for. This is usually a minimum requirements decision for your application. GLSL version is always bound to a specific OpenGL version, so in order to choose a GLSL version that supports the features we need, we are also tied to the minimum OpenGL version that supports that GLSL version.

At the moment of writing this book, I had to decide which version of GLSL to use. As we will talk about the compute shaders, we need to go to the minimum version that support them in a native way (not through extensions), and that's GLSL Version 4.30.6.

The official GLSL specification could be a good reference resource, once you have finished reading this book. You will be able to find the full list of functions in the tables located in the specification. The 4.30.6 GLSL specification can be downloaded directly from the OpenGL official site: https://www.opengl.org/registry/doc/GLSLangSpec...