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

Creating a fractal texture using the compute shader


The Mandelbrot set is based on iterations of the following complex polynomial:

z and c are complex numbers. Starting with the value z = 0 + 0i, we apply the iteration repeatedly until a maximum number of iterations is reached or the value of z exceeds a specified maximum. For a given value of c, if the iteration remains stable (z doesn't increase above the maximum) the point is inside the Mandelbrot set and we color the position corresponding to c black. Otherwise, we color the point based on the number of iterations it took for the value to exceed the maximum.

In the following image, the image of the Mandelbrot set is applied as a texture to a cube:

We'll use the compute shader to evaluate the Mandelbrot set. Since this is another image-based technique, we'll use a two-dimensional compute space with one compute shader invocation per pixel. Each invocation can work independently, and doesn't need to share any data with other invocations.

Getting...