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

Building a C++ shader program class


If you are using C++, it can be very convenient to create classes to encapsulate some of the OpenGL objects. A prime example is the shader program object. In this recipe, we'll look at a design for a C++ class that can be used to manage a shader program.

Getting ready

There's not much to prepare for with this one; you just need a build environment that supports C++. Also, I'll assume that you are using GLM for matrix and vector support; if not, just leave out the functions involving the GLM classes.

How to do it...

First, we'll use a custom exception class for errors that might occur during compilation or linking:

class GLSLProgramException : public std::runtime_error { 
public: 
  GLSLProgramException( const string & msg ) : 
       std::runtime_error(msg) { } 
};

We'll use enum for the various shader types:

namespace GLSLShader { 
  enum GLSLShaderType { 
        VERTEX = GL_VERTEX_SHADER,  
        FRAGMENT = GL_FRAGMENT_SHADER,  
        GEOMETRY = GL_GEOMETRY_SHADER...