OpenGL is a powerful software interface used to produce high-quality, computer-generated images and interactive applications using 2D and 3D objects, bitmaps, and color images.
The OpenGL® Programming Guide, Fifth Edition, provides definitive and comprehensive information on OpenGL and the OpenGL Utility Library. The previous edition covered OpenGL through Version 1.4. This fifth edition of the best-selling "red book" describes the latest features of OpenGL Versions 1.5 and 2.0, including the introduction of the OpenGL Shading Language.
You will find clear explanations of OpenGL functionality and many basic computer graphics techniques, such as building and rendering 3D models; interactively viewing objects from different perspective points; and using shading, lighting, and texturing effects for greater realism. In addition, this book provides in-depth coverage of advanced techniques, including texture mapping, antialiasing, fog and atmospheric effects, NURBS, image processing, and more. The text also explores other key topics such as enhancing performance, OpenGL extensions, and cross-platform techniques.
This fifth edition has been extensively updated to include the newest features of OpenGL Versions 1.5 and 2.0, including:
- Storage of vertex arrays in buffer objects for faster rendering
- Occlusion queries for course-grain visibility testing
- Non-power-of-two dimensioned texture maps
- Point sprites
- Separate stencil operations for RGB and alpha
- Rendering to multiple color buffers using GLSL
Most importantly, this edition discusses the OpenGL Shading Language (GLSL) and explains the mechanics of using this new language to create complex graphics effects and boost the computational power of OpenGL.
About the Author
Dave Shreiner, a leading OpenGL consultant, was a longtime member of the core OpenGL team at SGI. He authored the first commercial OpenGL training course, and has been developing computer graphics applications for more than two decades.
Excerpt. © Reprinted by permission. All rights reserved.
The OpenGL graphics system is a software interface to graphics hardware. (The GL stands for Graphics Library.) It allows you to create interactive programs that produce color images of moving three-dimensional objects. With OpenGL, you can control computer-graphics technology to produce realistic pictures or ones that depart from reality in imaginative ways. This guide explains how to program with the OpenGL graphics system to deliver the visual effect you want.
What This Guide Contains
This guide has 15 chapters. The first five chapters present basic information that you need to understand to be able to draw a properly colored and lit three-dimensional object on the screen.
- Chapter 1, “Introduction to OpenGL,” provides a glimpse into the kinds of things OpenGL can do. It also presents a simple OpenGL program and explains essential programming details you need to know for subsequent chapters.
- Chapter 2, “State Management and Drawing Geometric Objects,” explains how to create a three-dimensional geometric description of an object that is eventually drawn on the screen.
- Chapter 3, “Viewing,” describes how such three-dimensional models are transformed before being drawn on a two-dimensional screen. You can control these transformations to show a particular view of a model.
- Chapter 4, “Color,” describes how to specify the color and shading method used to draw an object.
- Chapter 5, “Lighting,” explains how to control the lighting conditions surrounding an object and how that object responds to light (that is, how it reflects or absorbs light). Lighting is an important topic, since objects usually don’t look three-dimensional until they’re lit.
The remaining chapters explain how to optimize or add sophisticated features to your three-dimensional scene. You might choose not to take advantage of many of these features until you’re more comfortable with OpenGL. Particularly advanced topics are noted in the text where they occur.
- Chapter 6, “Blending, Antialiasing, Fog, and Polygon Offset,” describes techniques essential to creating a realistic scene—alpha blending (to create transparent objects), antialiasing (to eliminate jagged edges), atmospheric effects (to simulate fog or smog), and polygon offset (to remove visual artifacts when highlighting the edges of filled polygons).
- Chapter 7, “Display Lists,” discusses how to store a series of OpenGL commands for execution at a later time. You’ll want to use this feature to increase the performance of your OpenGL program.
- Chapter 8, “Drawing Pixels, Bitmaps, Fonts, and Images," discusses how to work with sets of two-dimensional data as bitmaps or images. One typical use for bitmaps is describing characters in fonts.
- Chapter 9, “Texture Mapping,” explains how to map one-, two-, and three-dimensional images called textures onto three-dimensional objects. Many marvelous effects can be achieved through texture mapping.
- Chapter 10, “The Framebuffer,” describes all the possible buffers that can exist in an OpenGL implementation and how you can control them. You can use the buffers for such effects as hidden-surface elimination, stenciling, masking, motion blur, and depth-of-field focusing.
- Chapter 11, “Tessellators and Quadrics,” shows how to use the tessellation and quadrics routines in the GLU (OpenGL Utility Library).
- Chapter 12, “Evaluators and NURBS,” gives an introduction to advanced techniques for efficient generation of curves or surfaces.
- Chapter 13, “Selection and Feedback,” explains how you can use OpenGL’s selection mechanism to select an object on the screen. Additionally, the chapter explains the feedback mechanism, which allows you to collect the drawing information OpenGL produces, rather than having it be used to draw on the screen.
- Chapter 14, “Now That You Know,” describes how to use OpenGL in several clever and unexpected ways to produce interesting results. These techniques are drawn from years of experience with both OpenGL and the technological precursor to OpenGL, the Silicon Graphics IRIS Graphics Library.
- Chapter 15, “OpenGL 2.0 and the OpenGL Shading Language,” discusses the changes that OpenGL 2.0 introduces. This includes an introduction to the OpenGL Shading Language, also commonly called the "GLSL," which allows you to take control of portions of OpenGL’s processing for vertices and fragments. This functionality can greatly enhance the image quality and computational power of OpenGL.
In addition, there are several appendices that you will likely find useful:
- Appendix A, “Order of Operations,” gives a technical overview of the operations OpenGL performs, briefly describing them in the order in which they occur as an application executes.
- Appendix B, “State Variables,” lists the state variables that OpenGL maintains and describes how to obtain their values.
- Appendix C, “OpenGL and Window Systems,” briefly describes the routines available in window-system-specific libraries, which are extended to support OpenGL rendering. Window system interfaces to the X Window System, Apple MacIntosh, IBM OS/2, and Microsoft Windows are discussed here.
- Appendix D, “Basics of GLUT: The OpenGL Utility Toolkit,” discusses the library that handles window system operations. GLUT is portable and it makes code examples shorter and more comprehensible.
- Appendix E, “Calculating Normal Vectors,” tells you how to calculate normal vectors for different types of geometric objects.
- Appendix F, “Homogeneous Coordinates and Transformation Matrices,” explains some of the mathematics behind matrix transformations.
- Appendix G, “Programming Tips,” lists some programming tips based on the intentions of the designers of OpenGL that you might find useful.
- Appendix H, “OpenGL Invariance,” describes when and where an OpenGL implementation must generate the exact pixel values described in the OpenGL specification.
- Appendix I, “Built-In OpenGL Shading Language Variables and Functions,” lists all of the built-in variables and functions available in the OpenGL Shading Language.
Finally, an extensive Glossary defines the key terms used in this guide.
What’s New in This Edition
The fifth edition of the OpenGL Programming Guide includes new and updated material, covering both OpenGL Versions 1.5 and 2.0:
- Coverage of the following new core capabilities of OpenGL Version 1.5 has been added:
- Storage of vertex arrays in buffer objects
- Occlusion queries
- Addition of GL_LEQUAL and GL_GEQUAL texture comparison functions for use with shadow-mapping
- Minor token updates
- Coverage of the following OpenGL 2.0 core features:
- Addition of the OpenGL Shading Language for programming vertex and fragment shaders
- Output of different color values to multiple color buffers from programmable shaders
- Relaxation of the power-of-two size requirement for texture maps
- Rendering of texture-mapped point sprites
- Separate stencil operations for front- and back- facing polygons
- Bug fixes
What You Should Know Before Reading This Guide
This guide assumes only that you know how to program in the C language and that you have some background in mathematics (geometry, trigonometry, linear algebra, calculus, and differential geometry). Even if you have little or no experience with computer graphics technology, you should be able to follow most of the discussions in this book. Of course, computer graphics is a huge subject, so you may want to enrich your learning experience with supplemental reading:
- Computer Graphics: Principles and Practice by James D. Foley, Andries van Dam, Steven K. Feiner, and John F. Hughes (Addison-Wesley, 1990)— This book is an encyclopedic treatment of the subject of computer graphics. It includes a wealth of information but is probably best read after you have some experience with the subject.
- 3D Computer Graphics by Andrew S. Glassner (The Lyons Press, 1994)— This book is a nontechnical, gentle introduction to computer graphics. It focuses on the visual effects that can be achieved, rather than on the techniques needed to achieve them.
Another great place for all sorts of general information is the Official OpenGL Web Site. This Web site contains software, documentation, FAQs, and news. It is always a good place to start any search for answers to your OpenGL questions:
Once you begin programming with OpenGL, you might want to obtain the OpenGL Reference Manual by the OpenGL Architecture Review Board (also published by Addison-Wesley), which is designed as a companion volume to this guide. The Reference Manual provides a technical view of how OpenGL operates on data that describes a geometric object or an image to produce an image on the screen. It also contains full descriptions of each set of related OpenGL commands—the parameters used by the commands, the default values for those parameters, and what the commands accomplish. Many OpenGL implementations have this same material online, in the form of manual pages or other help documents, which are probably more up-to-date. Ther...