Table Of ContentOpenGL 4 Shading
Language Cookbook
Second Edition
Over 70 recipes demonstrating simple and advanced
techniques for producing high-quality, real-time 3D
graphics using OpenGL and GLSL 4.x
David Wolff
BIRMINGHAM - MUMBAI
OpenGL 4 Shading Language Cookbook
Second Edition
Copyright © 2013 Packt Publishing
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First published: July 2011
Second edition: December 2013
Production Reference: 1171213
Published by Packt Publishing Ltd.
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ISBN 978-1-78216-702-0
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Cover Image by Aniket Sawant ([email protected])
Credits
Author Project Coordinator
David Wolff Shiksha Chaturvedi
Reviewers Proofreaders
Bartłomiej Filipek Elinor Perry-Smith
Thomas Le Guerroué-Drévillon Chris Smith
Muhammad Mobeen Movania
Indexer
Dario Scarpa
Mariammal Chettiyar
Javed Rabbani Shah
Graphics
Acquisition Editors
Sheetal Aute
Gregory Wild
Ronak Dhruv
Edward Gordon
Usha Iyer
Production Coordinator
Nilesh R. Mohite
Lead Technical Editor
Neeshma Ramakrishnan
Cover Work
Nilesh R. Mohite
Technical Editors
Kunal Anil Gaikwad
Jinesh Kampani
Aman Preet Singh
About the Author
David Wolff is an associate professor in the Computer Science and Computer Engineering
Department at Pacific Lutheran University (PLU). He received a PhD in Physics and an MS in
Computer Science from Oregon State University. He has been teaching computer graphics to
undergraduates at PLU for over 10 years, using OpenGL.
About the Reviewers
Bartłomiej Filipek is an experienced software developer with a passion for teaching.
He has been leading OpenGL and graphics programming courses at Jagiellonian University in
Cracow for around five years now. Additionally he gives lectures and workshops about modern
C++ techniques at local universities.
His professional experience focuses mostly on native application development including
rendering systems, large-scale software development, game engines, multimedia
applications, user interfaces, GPU computing, and even biofeedback.
He shares his programming stories at his blog: http://www.bfilipek.com/.
Thomas Le Guerroué-Drévillon is a freshly graduated software engineer. Having a
profound interest in mathematics and drawing, it came easily to him to mix together these
two passions in one field: computer graphics.
Originally French, he used up all the opportunities given by his university to study and work
all around the world. It allowed him to enjoy his first international experience in Estonia, the
second in the prestigious KAIST in South Korea, and finally ending up now in Canada.
Even though his university provided the mathematical background, he got his experience with
OpenGL and GLSL on his own. He believes that the link between the well documented API and
the shader samples is missing. Thus he naturally accepted to review this cookbook, which for
him is the material he would have loved to get a hand on when he started developing interests
in OpenGL/GLSL.
Dr. Muhammad Mobeen Movania received his PhD degree in Advance Computer
Graphics and Visualization from Nanyang Technological University, Singapore. After finishing
his PhD, he joined Institute for Infocomm Research, A-Star, Singapore to work on Augmented
Reality based Virtual Tryon and Cloth Simulation systems using GPU and OpenGL. Before
joining NTU, he was a junior graphics programmer at Data Communication and Control (DCC)
Pvt. Ltd., Karachi, Pakistan. He worked on DirectX and OpenGL API for producing real-time
interactive tactical simulators and dynamic integrated training simulators. His research
interests include GPU-based volumetric rendering techniques, GPU technologies, real-time
soft body physics, real-time dynamic shadows, real-time collision detection and response,
and hierarchical geometric data structures. He is also the author of the OpenCloth project
(http://code.google.com/p/opencloth), which implements various cloth simulation
algorithms in OpenGL. His blog (http://mmmovania.blogspot.com) lists a lot of useful
graphics tips and tricks. When not involved with computer graphics, he composes music and
is an avid squash player.
Dr. Mobeen has published several conference and journal papers on real-time computer
graphics and visualization. Recently, he authored a book on OpenGL (OpenGL Development
Cookbook by Packt Publishing, published in 2013) which details several applied recipes using
modern OpenGL. He has also authored a book chapter in another book (OpenGL Insights by
AK Peters/CRC Press, published in 2012).
Dr. Mobeen is currently an Assistant Professor at DHA Suffa University, Karachi, Pakistan
where he is busy nurturing young minds to become outstanding programmers and
researchers of tomorrow.
I would like to thank almighty ALLAH for bestowing his countless blessings
on me and my family. After that, I would like to extend my gratitude towards
my family, my parents (Mr. and Mrs. Abdul Aziz Movania), my wife (Tanveer
Taji), my sisters (Mrs. Azra Saleem and Mrs. Sajida Shakir), my brothers (Mr.
Khalid Movania and Mr. Abdul Majid Movania), all my nephews/nieces and
my daughter (Muntaha Movania).
Dario Scarpa has been coding for fun and profit for the last 15 years, and has no intention
to stop. Jumping around among IT jobs as developer/sysadmin, amateur video game
programming, and CS exams at the University of Salerno (Italy), he also managed to work with
Adventure Productions in building Zodiac, a digital delivery platform focused on adventure
games. At the time of reviewing this book, he's about to get his Master's degree, with a thesis
on computer graphics that got him working intensively with—guess what—OpenGL.
Javed Rabbani Shah received his degree in Electrical Engineering from the University of
Engineering and Technology, Lahore, Pakistan in 2004. He started his professional career
by joining Delta Indus Systems (now Vision Master Inc.), where he worked with solder paste
inspection systems for statistical process control involving technologies such as Image
Processing, 3D Machine Vision, and FPGAs. He then joined the Embedded Systems Division of
Mentor Graphics in 2007 and got the opportunity to work with the Nucleus+ real-time operating
system, USB 2.0 middleware, WebKit, and OpenGL ES 2.0. He spearheaded the effort to
integrate OpenGL ES 2.0 features in Mentor's cross-platform Inflexion 3D user interface engine.
He is currently working at Saffron Digital in central London, where he is involved in work
related to cross-platform secure video playback, DRM, and UltraViolet technologies.
In his spare time, he likes to learn emerging technologies like OpenGL ES 3.0 and OpenCL.
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Table of Contents
Preface 1
Chapter 1: Getting Started with GLSL 7
Introduction 7
Using a function loader to access the latest OpenGL functionality 10
Using GLM for mathematics 13
Determining the GLSL and OpenGL version 15
Compiling a shader 17
Linking a shader program 21
Sending data to a shader using vertex attributes and vertex buffer objects 25
Getting a list of active vertex input attributes and locations 34
Sending data to a shader using uniform variables 37
Getting a list of active uniform variables 41
Using uniform blocks and uniform buffer objects 43
Getting debug messages 49
Building a C++ shader program class 52
Chapter 2: The Basics of GLSL Shaders 57
Introduction 57
Implementing diffuse, per-vertex shading with a single point light source 60
Implementing per-vertex ambient, diffuse, and specular (ADS) shading 65
Using functions in shaders 71
Implementing two-sided shading 75
Implementing flat shading 79
Using subroutines to select shader functionality 81
Discarding fragments to create a perforated look 86
Chapter 3: Lighting, Shading, and Optimization 91
Introduction 91
Shading with multiple positional lights 92
