Book Image

OpenGL 4.0 Shading Language Cookbook

Book Image

OpenGL 4.0 Shading Language Cookbook

Overview of this book

The OpenGL Shading Language (GLSL) is a programming language used for customizing parts of the OpenGL graphics pipeline that were formerly fixed-function, and are executed directly on the GPU. It provides programmers with unprecedented flexibility for implementing effects and optimizations utilizing the power of modern GPUs. With version 4.0, the language has been further refined to provide programmers with greater flexibility, and additional features have been added such as an entirely new stage called the tessellation shader. The OpenGL Shading Language 4.0 Cookbook provides easy-to-follow examples that first walk you through the theory and background behind each technique then go on to provide and explain the GLSL and OpenGL code needed to implement it. Beginning level through to advanced techniques are presented including topics such as texturing, screen-space techniques, lighting, shading, tessellation shaders, geometry shaders, and shadows. The OpenGL Shading Language 4.0 Cookbook is a practical guide that takes you from the basics of programming with GLSL 4.0 and OpenGL 4.0, through basic lighting and shading techniques, to more advanced techniques and effects. It presents techniques for producing basic lighting and shading effects; examples that demonstrate how to make use of textures for a wide variety of effects and as part of other techniques; examples of screen-space techniques, shadowing, tessellation and geometry shaders, noise, and animation. The OpenGL Shading Language 4.0 Cookbook 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 (16 chapters)
OpenGL 4.0 Shading Language Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Creating a noise texture using libnoise


To create a texture for use as a source of noise, we need some way to generate noise values. Implementing a proper noise generator from scratch can be a fairly daunting task. However, we can avoid that by making use of the very nice, open source library libnoise, available from http://libnoise.sourceforge.net. Libnoise is a C++ based library that is released under the Gnu LGPL. It provides a very simple and modular interface to coherent noise generation routines via noise modules. The modules can be chained and linked together in various ways to generate a wide variety of interesting generators. The website has a set of simple tutorials that can help get you started.

Downloading and compiling libnoise is fairly straightforward, and there is good documentation on the website just listed. However, if you are compiling for Windows using MinGW, you will need to make some adjustments to the Makefile in order to properly link the DLL.

In this recipe, we'll...