The OpenGL Extensions Guide

Rating:
Summary: Excellent reference!
Review: Finally! this book is a long overdue alternative to reading the raw extension specs on opengl.org. It covers all of the extensions I've ever needed, and a few more that I didn't even know existed. The only thing I can complain about is that is doesn't have anything on pbuffers, but don't get me wrong, this book is nice and meaty and is a great resource for opengl programmers. Definitely recommended!

Rating:
Summary: Good reference, but slightly disappointing
Review: I've often been frustrated by the fact that it's often hard to find good documentation for OpenGL extensions. The information in the extension registry, as well as in the latest OpenGL spec (for extensions that have been promoted to the core) is generally intended for OpenGL implementers, not OpenGL developers, so there usually isn't much about how or why you would use the extension. Sometimes, you can find papers and demos from one of the hardware vendors, such as Nvidia or ATI, but more often than not, you're left figuring it out on your own.

So when I heard about this book, I was really looking forward to it. Given the high quality of the author's other works, I expected it to immediately take a place on my desk.

This book is essentially an expansion of the information contained in the extension registry. It's considerably more user-friendly, the explanations are more detailed, and it conveniently groups the extensions by their functional area. However, it really doesn't discuss how or why you would use each extension in a game or graphics application. Nor does it include any demos, or even sample code. These factors keep the book from being as useful as it could have been.

Overall, this is a good book, and it provides a great reference for the extensions it covers, but it could have gone farther with showing you how to use them.

Rating:
Summary: Useful reference, but incomplete and becoming outdated
Review: The OpenGL Extensions Guide provides a comprehensive reference for the main OpenGL extensions in use circa 2003. The extensions covered enable OpenGL support for features like new blending modes, texture environments, a variety of texture formats, fragment shading, pixel formats, point parameters, and assembly language vertex and fragment programs. The book devotes a chapter to each extension covered, and discusses the new functions, enums, constants, and general functionality provided by each extension. For several extensions, usage scenarios and example code are provides. By far the most useful chapters are the ones covering vertex and fragment programs, as the book provides a complete reference for the assembly languages and the OpenGL mechanisms for loading programs, setting attributes and parameters, etc. The program dialects covered are ARB vertex and fragment programs, as well as some proprietary NVIDIA versions.

For all its strengths, this book does have some flaws. First, the book is useful only if you already know, in general terms, what a particular extension does and you have a specific need for that functionality in your program. The book does not really give a general overview of the extensions, nor does it provide typical usage scenarios and sample code in all cases. In other words, the book is strictly a reference, since it provides very little introductory or tutorial material.

Second, the book is already getting out-of-date. There are a number of extensions that, in early 2005, are becoming widely used. These include:

Multiple Render Targets: The GL_ARB_draw_buffers and GL_ATI_draw_buffers extensions provide the ability to write color output to multiple buffers in a single rendering pass from a fragment program.

Non-power-of-two textures: The GL_ARB_non_power_of_two extension relaxes the requirement that OpenGL textures have power-of-two dimensions. It also provides more reasonable behavior in terms of texture coordinates and coordinate wrap modes than the GL_NV_texture_rectangle extension, which is discussed. Also, GL_NV_texture_rectangle has been supplanted by GL_EXT_texture_rectangle, which is not discussed.

OpenGL shading language: This is the wave of the future. OpenGL 2.0 provides a high-level programming language for writing vertex and fragment programs, and its functionality is exposed through several extensions. Of course, this wasn't available in 2003.

Vertex and pixel buffer objects: The GL_ARB_vertex_buffer_object and GL_ARB_pixel_buffer_object extensions allow the programmer to create vertex and pixel buffers in high-performance video memory (managed by the driver) and do things like copy a pixel buffer into a vertex buffer. This allows you to do things like render new vertex positions into a pixel buffer, and then use the pixel values as the vertex input in a subsequent rendering pass.

The verdict: The OpenGL Extensions Guide provides comprehensive material about a wide range of extensions in use in 2003. It has virtually no tutorial material and several of the extension covered in this book are becoming obsolete. Also, several important new extensions are not covered. Hopefully a new edition will cover more relevant material, although this is obviously a moving target.

Rating:
Summary: Good as reference, but hard to learn from
Review: The reason why I only give this book 3 stars is that the book can only be used as a reference to OpenGL extensions. There is no demos or even source-code provided with the book, which makes the book extremely hard to learn from because you won't find any working code, just each extension described. Being an experienced OpenGL programmer this is not a huge problem for me, but since I believe many beginner OpenGL programmers find this books topic interesting, I thought I would warn you. Eric Lengyel is a great writer and his Mathematics for Game Programmers is a must-have. So before buying this book, please make sure that you are skilled enough to learn from a reference-book with no demos!

Rating:
Summary: Good reference
Review: This was a good reference book, but unfortunatelly it got outdated very fast... I wish it had more indepth explanations in some cases but it does the job.