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
Contributors
Preface
Index

Getting a list of active uniform variables


While it is a simple process to query for the location of an individual uniform variable, there may be instances where it can be useful to generate a list of all active uniform variables. For example, one might choose to create a set of variables to store the location of each uniform and assign their values after the program is linked. This would avoid the need to query for uniform locations when setting the value of the uniform variables, creating slightly more efficient code.

The process for listing uniform variables is very similar to the process for listing attributes (see the Getting a list of active vertex input attributes and locations recipe), so this recipe will refer the reader back to the previous recipe for a detailed explanation.

Getting ready

Start with a basic OpenGL program that compiles and links a shader program. In the following recipes, we'll assume that the handle to the program is in a variable named programHandle.

How to do it...