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

Applying a 2D texture

In GLSL, applying a texture to a surface involves accessing texture memory to retrieve a color associated with a texture coordinate, and then applying that color to the output fragment. The application of the color to the output fragment could involve mixing the color with the color produced by a shading model, simply applying the color directly, using the color in the reflection model, or some other mixing process. In GLSL, textures are accessed via sampler variables. A sampler variable is a handle to a texture unit. It is typically declared as a uniform variable within the shader and initialized within the main OpenGL application to point to the appropriate texture unit. 



In this recipe, we'll look at a simple example involving the application of a 2D texture to a surface, as shown in the following image. We'll use the texture color as the diffuse (and ambient) reflectivity term in the Blinn-Phong reflection model. The following image shows the results of a brick...