"NVIDIA's core strategy is to deliver a breakthrough product every six months, doubling performance with each generation at a rate of essentially Moore's Law cubed." --Jen-Hsun Huang
"Children crawl before they walk, walk before they run--each generally a precondition for the other." --Lillian Breslow Rubin
Computer graphics technology, like all computer technology, advances at a staggering rate. In the late 1990s, the first hardware-accelerated 3D graphics cards for consumers signaled the dawn of a new age in 3D graphics software development. Already, these cards are gathering in landfills, superseded by more powerful and advanced hardware.
If you're new to OpenGL, you probably wish you could dive in and start writing advanced OpenGL applications. Although many advanced graphics programming books exist, most assume familiarity with OpenGL or some other 3D graphics Application Programmer Interface (API). Before you tackle more advanced programming tasks, you need a way to get up to speed on OpenGL quickly.
About the Book
OpenGL® Distilled is a concise book about the essential, commonly used features of modern OpenGL, the industry-standard cross-platform API for high-performance 3D computer graphics. By focusing on essential OpenGL features, eliminating discussion of algorithms, and pointing the reader to sources of additional information, OpenGL® Distilled provides useful information quickly and concisely.
OpenGL version 1.0 was introduced by SGI in 1992 and quickly dominated the 3D software development industry. It is available for several versions of Microsoft Windows, Linux, and Unix, and for Apple Mac OS. Graphics hardware manufacturers supporting OpenGL include 3Dlabs, ATI, Intel, Matrox, NVIDIA, and SGI.
The fact that OpenGL is an open standard is certainly one reason for its popularity. The OpenGL feature set is determined by the OpenGL Architecture Review Board (ARB), a governing body composed of representatives from several major hardware and software companies. This group meets regularly to discuss and approve additions and modifications to the OpenGL specification. The ARB's multivendor nature ensures that OpenGL runs equally well on a wide variety of graphics architectures.
This book documents OpenGL version 2.0, released in September 2004. Although OpenGL has evolved significantly since its initial release, each version has remained compatible with previous versions. The benefits of backward compatibility are obvious, and several companies have taken advantage of OpenGL's stability to amortize the expense of software development.
Over time, some older OpenGL features fell into disfavor as the ARB added new rendering methods and paradigms to the OpenGL standard. Still other features never quite caught on with the developer community for a variety of reasons, such as corner-case or platform-specific applicability, overlapping or limited functionality, or nearly universal inefficient implementation.
The addition of new functionality, while continuing to keep older (and increasingly obsolete) features for backward compatibility, has resulted in a bulky and more complex OpenGL specification. Consider:
- In 1992, the original OpenGL version 1.0 specification contained 163 pages. Today, the OpenGL version 2.0 specification contains 368 pages, and the OpenGL Shading Language supplement increases this page count to a total of 474.
- Addison-Wesley's definitive OpenGL® Programming Guide and OpenGL® Reference Manual (the red and blue books), first published in 1993 to document the OpenGL version 1.0 standard, totaled 960 pages. In their most recent editions, documenting OpenGL versions 1.4 and 2.0, they total more than 1,600 pages. With the addition of the recently published OpenGL® Shading Language, Second Edition (the orange book), the page count tops 2,400.
Although such comprehensive documentation is indispensable for experienced programmers, the documentation's growth in size and complexity over the years has increased the learning curve for new OpenGL developers. Furthermore, finding advice on accepted modern usage is difficult for new OpenGL programmers due to the sheer magnitude of information or time wasted learning outdated methodologies and paradigms.
OpenGL® Distilled addresses these issues by presenting only the essential elements of modern OpenGL used in current 3D software development. To meet this goal, several features of OpenGL have been left out of this book. OpenGL Distilled presents the commonly used features and accepted practices in modern OpenGL programming. Features that have fallen into disfavor are omitted except where they help illustrate accepted practices or important concepts. Each chapter begins with a summary of what is and what is not covered.
To reduce the learning curve further, OpenGL® Distilled presents information in a direct, how-to style so that readers can find information quickly without wading through extraneous information. For this reason, there is little explanation or discussion of graphics algorithms. Shadow algorithms (discussed in Chapter 6) are the exception because of their almost-universal applicability and lack of direct OpenGL support. For other algorithms, OpenGL® Distilled assumes that the reader is familiar with computer graphics or is reading OpenGL® Distilled as part of a university-level computer graphics course.
This book presents the subset of OpenGL that most programmers can use to do the majority of their OpenGL programming. Because this material is a subset, the reader will likely desire access to more information. For this reason, OpenGL® Distilled serves as a gateway or road map to additional OpenGL and 3D graphics programming information. This book will frequently refer to the following resources:
- The official OpenGL Web site, http://www.opengl.org, is home to several developer forums, example programs, utility libraries, white papers, documentation, hyperlinks, and other valuable OpenGL resources.
- The OpenGL Graphics System: A Specification, by Mark Segal and Kurt Akeley, edited by Jon Leech, is OpenGL's complete and formal specification. Though intended for OpenGL implementers, its information is indispensable for application programmers. It's freely available as a PDF file from the OpenGL Web site.
- OpenGL® Programming Guide, Fifth Edition, by OpenGL ARB, Dave Shreiner, Mason Woo, Jackie Neider, and Tom Davis (Addison-Wesley), better known as the red book, is the definitive OpenGL programming guide. Furthermore, it contains extensive discussions of graphics algorithms and their implementation in OpenGL.
- OpenGL® Reference Manual, Fourth Edition, by OpenGL ARB and Dave Shreiner (Addison-Wesley), better known as the blue book, is the definitive OpenGL programmer's reference.
- OpenGL® Shading Language, Second Edition, by Randi Rost (Addison-Wesley), better known as the orange book, documents OpenGL's interface to programmable graphics hardware. This functionality is part of the OpenGL version 2.0 specification.
- Computer Graphics: Principles and Practice, Second Edition, by James D. Foley, Andries van Dam, Steven K. Feiner, and John F. Hughes (Addison-Wesley), and 3D Computer Graphics, by Alan Watt (Addison-Wesley), are both excellent general 2D and 3D computer graphics texts.
OpenGL® Distilled is intended for C++ programmers who are new to OpenGL.This book assumes moderate familiarity with computer graphics. The reader should be familiar with graphics resources, texts, and algorithms. Graphics expertise is not required to make use of this book. The reader doesn't need to know how to code Bresenham's algorithm, for example, but should be familiar with the concept of scan conversion. Experience with another graphics API is helpful but isn't a prerequisite.
The reader should be familiar with the C++ programming language. The example source code on the book's Web site is in C++, and will build and run in Microsoft Windows, Apple Mac OS, and most flavors of Linux and Unix. Many of the code snippets in the book should be comprehensible to any programmer who is familiar with C and who has access to a C++ reference manual.
The reader should be familiar with vector and matrix mathematics as covered in a typical linear-algebra course. The reader should understand matrix concatenation and vector-matrix multiplication. Readers already familiar with transformation and coordinate systems from another 3D graphics API will find OpenGL® Distilled an easy read. For readers unfamiliar with this subject, many general 3D graphics texts cover the subject adequately, such as Chapter 5, "Geometrical Transformations," in Computer Graphics: Principles and Practice.The reader should, of course, be familiar with basic mathematics such as algebra, geometry, and trigonometry.
Format of the Book
OpenGL® Distilled consists of eight chapters followed by four appendices and an index.
Chapter 1, "An Introduction to OpenGL," presents OpenGL architecture and concepts in broad terms. It also introduces the GLUT and GLU support libraries, discusses setting up an OpenGL development environment, and presents a simple OpenGL example. This chapter concludes with an extensive history of the OpenGL API.
Chapter 2, "Drawing Primitives," covers how to use OpenGL to render geometric data. It describes the OpenGL drawing primitive types and how to render them by using the vertex array and buffer object features. This chapter also presents other drawing details, such as clearing the framebuffer, order dependence, and the depth test.
Chapter 3, "Transformation and Viewing," describes the OpenGL transformation pipeline. This chapter covers how to position and...