Book Image

OpenGL 4 Shading Language Cookbook - Third Edition

By : David Wolff
Book Image

OpenGL 4 Shading Language Cookbook - Third Edition

By: David Wolff

Overview of this book

OpenGL 4 Shading Language Cookbook, Third Edition provides easy-to-follow recipes that first walk you through the theory and background behind each technique, and then proceed to showcase and explain the GLSL and OpenGL code needed to implement them. The book begins by familiarizing you with beginner-level topics such as compiling and linking shader programs, saving and loading shader binaries (including SPIR-V), and using an OpenGL function loader library. We then proceed to cover basic lighting and shading effects. After that, you'll learn to use textures, produce shadows, and use geometry and tessellation shaders. Topics such as particle systems, screen-space ambient occlusion, deferred rendering, depth-based tessellation, and physically based rendering will help you tackle advanced topics. OpenGL 4 Shading Language Cookbook, Third Edition also covers advanced topics such as shadow techniques (including the two of the most common techniques: shadow maps and shadow volumes). You will learn how to use noise in shaders and how to use compute shaders. The book provides examples of modern shading techniques that can be used as a starting point for programmers to expand upon to produce modern, interactive, 3D computer-graphics applications.
Table of Contents (17 chapters)
Title Page
Packt Upsell

Using program pipelines

Program pipeline objects were introduced as part of the separable shader objects extension, and moved into core OpenGL with version 4.1. They allow programmers to mix and match shader stages from multiple separable shader programs. To understand how this works and why it may be useful, let's go through a hypothetical example. 

Suppose we have one vertex shader and two fragment shaders. Suppose that the code in the vertex shader will function correctly with both fragment shaders. I could simply create two different shader programs, reusing the OpenGL shader object containing the vertex shader. However, if the vertex shader has a lot of uniform variables, then every time that I switch between the two shader programs, I would (potentially) need to reset some or all of those uniform variables. This is because the uniform variables are part of the shader program's state, so changes to the uniforms in one program would not carry over to the other program, even when the two...