Open GL Super Bible

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The same was true of the original 2D graphics accelerators for Windows. Accelerated boards quickly became affordable; it was virtually free to get the extra speed boost. Finally, there’s the example of fax/modems. Go ahead, try to find a modem (a new one, now) that won’t also work as a fax board. The chip manufacturers put all the logic on one chip and mass-produced standard modems right out of existence.

Clearly, 3D on the PC is here to stay, and it is only going to get better and faster as time moves on. In early 1995, Microsoft purchased RenderMorphics, Ltd., creators of the Reality Lab 3D API. This is a high-performance 3D library for creating real-time 3D graphics on PC hardware. The Reality Labs API is faster than OpenGL, but its performance comes at the cost of some visual fidelity. In addition, not all of OpenGL’s special effects and capabilities are present in the Reality Labs API. But it’s still perfectly well-suited for PC-based games in which speed is more important than absolute visual realism (for now!).

With the next release of the DirectX libraries, the Reality Labs API will be folded into Direct 3D. There will be two modes of operation for Direct3D: a retained mode, which is the original Reality Labs functionality; and an immediate mode, which is a lower-level API that operates closer to the hardware. The relationship between retained mode and immediate mode is similar to that between Open Inventor and OpenGL. The retained mode is a higher-level interface that simplifies scene creation and object manipulation, and is actually built using the immediate mode API.

The good news for OpenGL developers is that OpenGL will be able to take advantage of Direct 3D drivers that accelerate D3D immediate mode. Thus, the accelerated gaming graphics cards are also going to accelerate OpenGL performance. As PCs get even faster, as the competition among 3D graphics board vendors produces faster accelerators with even more features, the time will come when real-time OpenGL performance will be available on ordinary PCs. This time is approaching, and developers (maybe even you) will need to find other ways to distinguish their 3D products besides brute speed.

OpenGL will be an excellent choice for producing visually stunning effects and more realistic scenes and imagery. As fast 3D becomes a reality, your investment in OpenGL will not go to waste. For the very near term, it’s likely that the DirectX API will continue to dominate for fast games and blood-splattering action on Windows. However, OpenGL is simply unchallenged when it comes to realistic cross-platform effects. Currently the hottest markets for OpenGL-based software are the entertainment industry (movie and commercial special effects), scientific and educational modeling, and simulation. In addition, many game developers are discovering that they can use OpenGL to create their title screens, background bitmaps, and textures, and even computer-generated animations (.avi or .mpg files).


When 2D graphics acceleration first became available, it was only for the few “power users” who really needed the extra boost in speed. Today, a Windows accelerated graphics card is standard fare. Games may still be the driving force behind 3D acceleration, but the development community is ready to take advantage of 3D acceleration “as long as it’s there.”

You can be sure that the size, complexity, and functionality of software will always grow to match or overcome capabilities of hardware. It’s hard to imagine that color computers were once difficult to justify. Who remembers when the 386 was hailed as a “high-end” processor intended only for servers and scientific or engineering workstations? They said the same thing about the 486, the Pentium, and now the Pentium Pro. Anyone with a pulse and an IQ over 2 should be able to see a pattern here.

Soon everyday PC graphics cards will support both 3D and 2D acceleration under Windows. Just as color computers evolved from their “games” stereotyping, 3D gaming technology will also evolve into a real and valuable feature that we will learn to take for granted. The difference between hardware-accelerated 3D and software-only 3D is as dramatic as the difference between making music with your PC speaker and having a Sound Blaster. In the same way that sound cards are now becoming as commonplace as color monitors, 3D acceleration will become just another feature bullet on the sides of all those computer boxes in the electronics section of your local discount department store.

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