Technical Notes

Reflection X and OpenGL/GLX
Technical Note 1122
Last Reviewed 31-May-2006
Applies To
Reflection X version 12.0 through 14.x
Silicon Graphics IRIS
Silicon Graphics OpenGL
Summary

This technical note answers common questions about Reflection X and OpenGL. Topics covered in this note include displaying OpenGL-based applications, OpenGL extensions, DGL errors, IRIS GL, color support in OpenGL, and OpenGL support for Microsoft Windows.

OpenGL

OpenGL is a vendor-neutral, industry-standard API originally developed by Silicon Graphics, Inc. (SGI) for 2D and 3D visual applications. OpenGL allows programmers to produce high-quality color images of 2D and 3D objects. It is a rendering-only API providing 2D and 3D graphics functions, including modeling, transformations, color, lighting, and smooth shading, as well as advanced features like texture mapping. OpenGL is independent of the operating system (it doesn't create or destroy windows, resize or stack them, and so on). It has been integrated with Microsoft Windows, the X Window System on UNIX, and OS/2. GLX is an X extension that serves as the "glue-logic" between the OpenGL 3D renderer and Reflection X.

Reflection X and OpenGL

The GLX extension allows X windows applications to use the OpenGL support in Microsoft Windows through Reflection X. Reflection X supports Windows software rendering, 3D accelerated, and OpenGL accelerated video modes. CAD/CAM, modeling, animation, and simulation applications use the GLX support to take advantage of OpenGL 2D and 3D advanced imaging support. OpenGL support is available on all video cards; however, OpenGL specific video cards run faster and often offer additional functionality.

OpenGL Extensions

Reflection X supports all standard and some proprietary OpenGL extensions. The version of GLX used by Reflection X is based on the version of GLX the client side is using. Reflection supports GLX versions 1.1 through 1.3.

To determine which extensions your host supports, check its man pages.

Reflection X and IRIS GL

Reflection X does not support SGI (Silicon Graphics, Inc.) IRIS GL applications. IRIS GL clients are different from OpenGL/GLX based clients in that they can be run only on hardware that supports IRIS GL, which uses Distributed Graphics Library (DGL) utilities for doing remote client/server processing.

OpenGL/GLX is now the official strategic interface for 3D computer graphics at SGI. SGI has promoted the use of OpenGL for several years now, and most newer 3D applications will be written to the OpenGL API. Many UNIX workstation vendors have licensed OpenGL for use in their X software products (IBM, Digital, and Sun all have add-on OpenGL software products available). All SGI IRIX machines now come with OpenGL.

For further information about SGI, IRIS GL and OpenGL/GLX, see the SGI web site at http://www.sgi.com/products/software/opengl/.

If an IRIS GL client attempts to make a DGL socket connection to the DGL daemon on the remote X server (the PC running Reflection X), an error message will occur, such as the following:

• dgl error (TCP connect): Connection refused
• dgl error (default init): default dglopen(enterprise:0) returned -127
• The remote machine is not DGL capable
• DGL error

An example of an IRIS GL client that comes with most IRIS systems is jot (a text editor).Color Display Problems

Display problems can often be solved by changing the video resolution within your Windows operating system. Running in higher depths like 16-bit, 24-bit, or 32-bit can yield better results when displaying 3D graphics. Follow the steps below to change this setting.

1. Access the Windows Control Panel.
2. Double-click the Display option.
3. Modify the Color setting (depending on your operating system, this options is referred to as Color palette, Color settings, or Color quality).

4. Click OK.

Reflection X, OpenGL, and Sun Solaris

If you are accessing a Sun Solaris host and are experiencing difficulties launching an OpenGL application, such as the 3D wheel demo application, you may want to apply Sun patch 113887, which focuses on OpenGL libraries.

Warning: This is a Sun patch. Read and review the patch information to decide if applying this patch in your host environment is appropriate.

To locate the patch, go to the SunSolve Patch Support Portal at http://sunsolve.sun.com/pub-cgi/show.pl?target=patchpage, enter the patch ID, 113887, in the PatchFinder field, and click Find Patch.