Amiga Plus 1995 #2

home *** CD-ROM | disk | FTP | other *** search

/ Amiga Plus 1995 #2 / Amiga Plus CD - 1995 - No. 2.iso / internet / faq / englisch / comp.graphics.opengl < prev next >

Wrap

Text File | 1995-04-11 | 38.9 KB | 965 lines

* marks recently modified answers or new questions Q1: What is OpenGL? Q2: What is the relationship between IRIS GL and OpenGL? Q3: What does the .gl or .GL file format have to do with OpenGL? Q4: Where are World Wide Web sites for OpenGL? * Q5: What documentation is available for OpenGL? (A bibliography of OpenGL documents is listed here.) Where can I get the OpenGL specification? Q6: Where can I find OpenGL source code examples? For instance, where can I find the GLUT toolkit or examples which mix OpenGL with Motif and use the Motif widget? Q7: Which vendors are supporting OpenGL? Q8: What OpenGL implementations are available? Q9: How do I contribute OpenGL code examples to a publicly accessible archive? Q10: Will OpenGL code be source code or binary code compatible with IRIS GL code? Q11: Why should I port my IRIS GL application to OpenGL? Q12: How much work is it to convert an IRIS GL program to OpenGL? What are the major differences between them? Q13: Who needs to license OpenGL? Who doesn't? How is a commercial license acquired? Q14: How does a university or research institution acquire access to OpenGL source code? Q15: Why doesn't SGI provide a free implementation of OpenGL? * Q15: Where is Mesa 3D? Q16: What are the conformance tests? Q17: How is the OpenGL governed? Who decides what changes can be made? Q18: Who are the current ARB members? Q19: What is the philosophy behind the structure of the ARB? Q20: How does the OpenGL ARB operate logistically? When does the ARB have meetings? Q21: How do additional members join the OpenGL ARB? Q22: So if I'm not a member of the ARB, am I shut out of the decision making process? Q23: Are ARB meetings open to observers? Q24: What is the OpenGL Advisory Forum? Q25: When using Xlib, how do I create a borderless window? Q26: How do I switch between single buffer and double buffer mode? Q27: On my machine, it appears that glXChooseVisual is only able to match double-buffered visuals. I want to have more bits of color resolution, so how do I render in single buffer mode? ------ Subject: Q1: What is OpenGL? A: OpenGL is the software interface for graphics hardware that allows graphics programmers to produce high-quality color images of 3D objects. OpenGL is a rendering only, vendor neutral API providing 2D and 3D graphics functions, including modelling, transformations, color, lighting, smooth shading, as well as advanced features like texture mapping, NURBS, fog, alpha blending and motion blur. OpenGL works in both immediate and retained (display list) graphics modes. OpenGL is window system and operating system independent. OpenGL has been integrated with Windows NT and with the X Window System under UNIX. Also, OpenGL is network transparent. A defined common extension to the X Window System allows an OpenGL client on one vendor's platform to run across a network to another vendor's OpenGL server. ------ Subject: Q2: What is the relationship between IRIS GL and OpenGL? A: IRIS GL is the predecessor to OpenGL. After other implementors had experience trying to port the IRIS GL to their own machines, it was learned that the IRIS GL was too tied to a specific window system or hardware. Based upon consultations with several implementors, OpenGL is much more platform independent. IRIS GL is being maintained and bugs will be fixed, but SGI will no longer add enhancements. OpenGL is now the strategic interface for 3-D computer graphics. ------ Subject: Q3: What does the .gl or .GL file format have to do with OpenGL? A: .gl files have nothing to do with OpenGL. It's a file format for images, which has no relationship to IRIS GL or OpenGL. ------ Subject: Q4: Where are World Wide Web sites for OpenGL? A: OpenGL--The Integration of Windowing and 3D Graphics. WWW URL http://hertz.eng.ohio-state.edu/~hts/opengl/article.html Maintained by Harry Shamansky. OpenGL WWW Center. WWW URL http://www.sgi.com/tech/openGL/opengl.html Maintained by Mason Woo. ------ Subject: Q5: What documentation is available for OpenGL? (A bibliography of OpenGL documents is listed here.) Where can I get the OpenGL specification? A: A 2 volume set, The OpenGL Technical Library (The OpenGL Programming Guide and The OpenGL Reference Manual) is published by Addison-Wesley. The ISBN numbers for both English and Japanese versions are listed below. You can purchase the books in extremely large volume by calling Robert Shepard of Addison-Wesley +1-617-944-3700 ext 2435. The man pages for the OpenGL API, its Utility Library (GLU), and the X server extension API (GLX) and a PostScript version of the OpenGL specification are available via anonymous, public ftp, on the machine sgigate.sgi.com in ~ftp/pub/opengl/doc. The OpenGL, OpenGL Utility Library, X extensions and GLX protocol specifications are all in the file, specs.tar.Z, which has been tar'd and compressed. Please read the accompanying README file, which explains the copyright and trademark rules for usage of the specification. Possession of the OpenGL Specification does not grant the right to reproduce, create derivative works based on or distribute or manufacture, use or sell anything that embodies the specification without an OpenGL license from SGI. What follows is a bibliography of articles, books, and papers written about OpenGL. Books (in English) ------------------ Neider, Jackie, Tom Davis, and Mason Woo, OpenGL Programming Guide: The Official Guide to Learning OpenGL, Release 1, Addison-Wesley, Reading, Massachusetts, 1993 (ISBN 0-201-63274-8). OpenGL Architecture Review Board, OpenGL Reference Manual: The Official Reference Document for OpenGL, Release 1, Addison-Wesley, Reading, Massachusetts, 1992 (ISBN 0-201-63276-4). Magazine articles ----------------- Bruno, Lee. "Sun Continues to Resist OpenGL Tide," Open Systems Today, November 28, 1994, p. SF1, SF5-6. Davis, Tom. "Moving to OpenGL," IRIS Universe, Number 25, Summer, 1993. Deffeyes, Suzy and John Spitzer. "OpenGL on OS/2," OS/2 Developer Magazine, Nov/Dec 94, pages 34-45. Glazier, Bill. "The 'Best Principle': Why OpenGL is emerging as the 3D graphics standard," Computer Graphics World, April, 1992. "Industry group pushing 3-D graphics standard," Computer Design, July, 1994, p. 50, 52. Karlton, Phil. "Integrating the GL into the X environment: a high performance rendering extension working with and not against X," The X Resource: Proceeding of the 6th Annual X Technical Conference, O'Reilly Associates, Issue 1, Winter, 1992. Kilgard, Mark, Simon Hui, Allen Leinwand, and Dave Spalding. ``X Server Multi-rendering for OpenGL and PEX,'' The X Resource Proceedings of the 8th Annual X Technical Conference, O'Reily and Associates, Sebastopol, California, January 1994. Kilgard, Mark J. "OpenGL & X: An Introduction," The X Journal. November-December, 1993, page 36-51. Kilgard, Mark J. "Using OpenGL with Xlib," The X Journal. January-February, 1994, page 46-65. Kilgard, Mark J. "Using OpenGL with Motif," The X Journal. July-August, 1994. "OpenGL Programs a New Horizon for Sun," SunWorld, January, 1994, page 15-17. Prosise, Jeff. "Advanced 3-D Graphics for Windows NT 3.5: Introducing the OpenGL Interface, Part I," Microsoft Systems Journal, October, 1994, Vol. 9, Number 10, pages 15-29. Prosise, Jeff. "Advanced 3-D Graphics for Windows NT 3.5: Introducing the OpenGL Interface, Part II," Microsoft Systems Journal, November, 1994, Vol. 9, Number 11. Prosise, Jeff. "Understanding Modelview Transformations in OpenGL for Windows NT," Microsoft Systems Journal, February, 1995, Vol. 10, Number 2. Japanese language magazine articles and books --------------------------------------------- Nikkei Electronics, No. 616, Sept. 5, 1994, p. 99-105. PIXEL, No. 143, 8/94, p. 65 ("From the Editor's Desk"), p. 117-121 ("3D API, OpenGL"). Neider, Jackie, Tom Davis, and Mason Woo, OpenGL Programming Guide: The Official Guide to Learning OpenGL, Release 1, Addison-Wesley Publishers Japan, Tokyo, 1993 (ISBN 4-7952-9645-6). OpenGL Architecture Review Board, OpenGL Reference Manual: The Official Reference Document for OpenGL, Release 1, Addison-Wesley Publishers Japan, Tokyo, 1992 (ISBN 4-7952-9644-8). Sasaki, Akiko and Masayuki Matsumoto, Software Design, "Chapter 3: OpenGL", November 11, 1994, ISSN 0916-6297, p. 26-48. Woo, Mason, "OpenGL," Nikkei Computer Graphics, November, 1994, p. 142. Technical reports ----------------- Segal, Mark and Kurt Akeley. The OpenGL Graphics System: A Specification. Technical report, Silicon Graphics Computer Systems, Mountain View, California, 1992, revised 1993. Segal, Mark and Kurt Akeley. The OpenGL Graphics Interface. Technical paper, Silicon Graphics Computer Systems, Mountain View, California, 1993. ------ Subject: Q6: Where can I find OpenGL source code examples? For instance, where can I find the GLUT toolkit or examples which mix OpenGL with Motif and use the Motif widget? You can get the source code examples which are found in the OpenGL Programming Guide via anonymous, public ftp on sgigate.sgi.com in the file ~ftp/pub/opengl/opengl.tar.Z Mark Kilgard has created an ftp site for source code, which is part of his articles in the X Journal magazine. This includes the GLUT toolkit and OpenGL with Motif examples. The directory is: sgigate.sgi.com:~ftp/pub/opengl/xjournal The specification, source code (including FORTRAN bindings), and articles for GLUT (Graphics Library Utility Toolkit) is in: sgigate.sgi.com:~ftp/pub/opengl/xjournal/GLUT ( URL ftp://sgigate.sgi.com/pub/opengl/xjournal/GLUT/ ) This distribution of GLUT should compile on: o DEC Alpha workstation running OSF/1 with Open3D layered product o IBM RS/6000 workstations running AIX with OpenGL support o SGI workstation running IRIX 5.2 or higher supporting OpenGL o Template Graphics Software's OpenGL for Sun workstations GLUT version 2 is under development. Here's what GLUT version 2 will have: o Spaceball(TM) support: glutSpaceballMotionFunc, glutSpaceballRotateFunc, glutSpaceballButtonFunc o Dial and button box support: glutDialsFunc, glutButtonBoxFunc o Tablet support: glutTabletMotionFunc, glutTabletButtonFunc o Multisampling OpenGL extension support (for Reality Engine class graphics systems supporting multisampling, requires IRIX 5.3). o OpenGL extension query support: glutExtensionSupported o Function key support: glutSpecialFunc (before, using glutKeyboardFunc only registered a callback for keys which generate ASCII characters). o New glutGet parameters for info about input device characteristics. The version 2 functionality is fully backward compatible with the version 1 functionality. ------ Subject: Q7: Which vendors are supporting OpenGL? A: OpenGL is supported by many hardware and software vendors. As of January, 1995, OpenGL has been licensed to: AT&T, Cirrus Logic (which supports the A1060 technology, formerly from Austek Microsystems), Cray Research, Daikin, Digital Equipment, 3Dlabs (formerly Du Pont Pixel; supporting the GLINT OpenGL chip), Evans & Sutherland, Harris Computer, Hitachi, IBM, the Institute for Information Industry, Intel, Intergraph, Japan Radio Co., Kendall Square Research, Kubota Pacific, Media Vision, Microsoft, miro, NEC, Portable Graphics, RasterOps, SPEA, Samsung, Sony, Template Graphics Software, and Univel. The machines supported by OpenGL licensees constitute over 95% of the graphics workstation marketplace, as well as the majority of the PC market. ------ Subject: Q8: What OpenGL implementations are available? A: Digital (DEC) ------- ----- Digital Equipment Corporation offers OpenGL to its customers as part of the the DEC Open3D layered product. DEC Open3D is available for DEC OSF/1 AXP and DEC OpenVMS AXP workstations. Supported graphics devices include: PXG (all devices in the PXG family with z-buffers) ZLX-M1 ZLX-M2 ZLX-E1 ZLX-E2 At this time, Digital Equipment Corporation has no plans to offer Open3D on either VAXstations or DECstations. Digital Equipment Corporation (DEC) is shipping accelerated OpenGL for Windows NT on our AlphaStation models 200 and 400 using the ZLXp-E1, ZLXp-E2, and ZLXp-E3 graphics options. Now you can unleash the industry-leading speed and power of Digital's Alpha AXP technology with low-cost high-performance graphics accelerators that will change the way you view your work. The ZLXp-E1 provides leading 2D performance inexpensively. And breakthrough dithering technology lets the ZLXp-E1 display 3D smooth shaded images in 8 planes with outstanding quality. Coupled with the ZLXp-E1's excellent performance, Digital's patented dithering capability provides an ideal solution for professionals in CASE, ECAD, and mechanical product design. The ZLXp-E2 delivers the high-performance and 24 plane, true color capability needed for image processing, medical imaging, desktop publishing, graphics arts, and multimedia. The ZLXp-E2 can be configured to run 8 bits double buffered with a 16 bit Z buffer, providing full dedicated hardware support for 3D applications. The ZLXp-E3, featuring true color capability and a full 24 bit Z buffer for even more complex solid model rendering, is ideal for mechanical CAD and computer-aided molecular design. For further information contact your Digital Equipment sales representative. IBM --- IBM offers OpenGL 1.0 at several different price and performance points, on most configurations of it's RS/6000 workstation line. Hardware accelerated OpenGL is available through two recently announced products: the mid-range POWERgraphics GXT1000 and the high-end Freedom Series /6000. Both platforms provide h/w support for texture mapping, accumulation, stencil and alpha buffers, as well as a h/w accelerated lighting and geometry transformation pipeline. The Freedom Series is based on an architecture developed by Evans and Sutherland. OpenGL is supported on most other RS/6000 configurations, including the GXT100 and GXT150 graphics adapters for the PowerPC-based /6000's as well as on the CGDA, the Gt1 family, the Gt3 family, and the Gt4 family of graphics adapters. This support is provided through SoftGraphics, a highly-tuned, highly-optimized pure software implementation of OpenGL. (Because of the lack of support for an RGB X11 TrueColor visual on the 3D-HP-CGP and GTO adapters, OpenGL is not offered on these machines. This is the only exception to OpenGL support on the RS/6000 line. Sorry). OpenGL requires AIX 3.2.5 or later. At the Fall '93 Comdex, IBM exhibited a software technology that allowed OpenGL to run under OS/2. The interface that integrates OpenGL with OS/2 was presented to the OpenGL ARB for review. Beta versions of that interface will be available in the first half of 1994, through the OS/2 Developer CD-ROM distribution. To purchase these products, contact your local IBM sales office. Intergraph ---------- Intergraph Computer Systems is currently shipping high-performance, PCI-based, OpenGL accelerators on its TD series of Personal Workstations. Using state of the art dedicated hardware, the GLZ and GLI graphics products dramatically accelerate OpenGL and offer the high performance and features traditionally found only on much more expensive workstations. These accelerators are available on Intergraph's TD-4 and TD-5 dual-Pentium Personal Workstations running Windows NT. GLZ and GLI offer advanced features such as: - 24-bit, double buffered image planes at all display resolutions up to 2 Mpixels - 24-bit (GLZ) or 32-bit (GLI) Z-Buffer - Full hardware support for Gouraud shading - Full hardware support for texture processing (GLI only) with 8 MTexels of texture storage - Industry-standard PCI bus interface with DMA engine - Support for multi-sync monitors up to 2 Mpixels at 76Hz vertical refresh - Stereo ready - Multiple color palette support - 10-bit gamma correction For additional information call 1 (800) 763-0242 or browse Intergraph's WWW pages at http://www.intergraph.com. Microsoft --------- OpenGL is offered as a standard feature of Microsoft Windows NT Workstation version 3.5. The Microsoft implementation of OpenGL runs with any computer and video hardware that is compatible with Windows NT 3.5. Microsoft also provides documentation, sample source code, and development tools to help build OpenGL applications in the Win32 Software Development Kit. The Win32 SDK is available via Microsoft's Developer Network. For more information on the Win32 SDK, please call: US at 1-800-759-5474 International at +1-402-691-0173 Portable Graphics, Inc. ---------------------------------------------------------- 3D Graphics Development and Porting Tools Portable Graphics, a subsidiary of Evans & Sutherland Computer Corporation, provides GL-based development and porting tools for a variety of workstation platforms. Products for PCs (Windows NT, OS/2, Windows 95) will be available in 1995. OpenGL for Sun: Portable Graphics' implementation of OpenGL for Sun is optimized for the SPARC/Solaris environment and passes the ARB conformance tests, including GLX server requirements for interoperability. Interoperability ensures consistent client-server communications between any OpenGL implementation across an X11 network. Native OpenGL on Freedom Series will be available from Evans & Sutherland in 1st Quarter 1995. OpenGL can coexist with PHIGS, PEX, or NPGL (IRIS GL 4.0-compatible) applications on the same device. Portable Graphics supplies the GLU library, and widget sets for both Motif and OPEN LOOK. Portable Graphics is an SMCC Catalyst Strategic Developer. OpenGL for HP: Hewlett-Packard has choosen Evans & Sutherland (E&S) as its OpenGL supplier. OpenGL For Hewlett-Packard from E&S is now shipping for the HP Freedom Series accelerators. For your convenience, development licenses can be purchased directly from Hewlett-Packard or from Portable Graphics. Portable Graphics offers volume and educational discounts. OpenGL for the entire HP graphics accelerator product line is in development at E&S for release in Summer 1995. Developers who wish to develop OpenGL and Open Inventor applications for HP workstations with CRX or HCRX accelerators or the Model 712, can get started now using NPGL and IRIS Inventor. These applications can then be converted to OpenGL and Open Inventor when these products support the entire Series 700 product line. Custom OpenGL Ports: Portable Graphics offers custom OpenGL ports for PC and workstation graphics accelerator manufacturers, and consulting services to hardware manufacturers and software developers. Open Inventor - 3D Developer's Toolkit: Portable Graphics also licenses Open Inventor from Silicon Graphics. Open Inventor is currently available on the IBM RISC System/6000, Sun SPARCstation systems and HP Series 700 workstations with Freedom Series graphics accelerators. Portable Graphics will also provide Open Inventor for HP Series 700 workstations, Windows NT, Windows 95 and OS/2. Portable Graphics offers IRIS Inventor for HP and Sun workstations. EDISON - Extensions to Open Inventor: Portable Graphics is currently developing extensions to Open Inventor. The product, which is called EDISON, will provide the framework to seamlessly link other software modules to Open Inventor. The first extension released under EDISON will be the SHAPES Geometric Modeling System from XOX Corporation (Minneapolis, MN). By combining SHAPES and Open Inventor via EDISON, developers will obtain a powerful geometric computing system based on mathematical standards that also features an easy-to-use, interactive user interface and graphics rendering capabilities. The EDISON extensions to Open Inventor will be available in mid-1995 for Silicon Graphics workstations, followed by support for Sun, IBM, and HP workstations, and Windows NT, Windows 95 and OS/2. Portable Graphics products are sold direct from the U.S. headquarters and the U.K. office. Authorized distributors are located in Australia, France, Germany, Japan and Taiwan. For more information about OpenGL, Open Inventor, EDISON extensions to Open Inventor, IRIS Inventor, or NPGL, contact: Portable Graphics, Inc. One Technology Center 2201 Donley Drive, Suite 365 Austin, TX 78758 E-mail: glware@portable.com Voice: (512) 719-8000 Fax: (512) 832-0752 Portable Graphics, Inc. "An Evans & Sutherland Company" One Technology Center 2201 Donley Drive, Suite 365 Austin, TX 78758 Silicon Graphics --- Starting with IRIX 5.2, OpenGL is supported for the following graphics workstations: Indy - Indy 8/24 bits Indigo - Entry Level, XS, XS24, XZ, Elan Indigo2 - XL, XZ, Extreme Crimson - Entry Level, XS, XS24, Elan, Extreme, RealityEngine Onyx - VTX, RealityEngine, RealityEngine2 4D30/35 - Elan With IRIX 5.3, OpenGL is supported for these workstations: Personal IRIS Graphics: 8-bit, G, TG (except GR1.1) VGX, VGXT, Skywriter This leaves the following graphics families with no OpenGL implementation: IRIS 1000, 2000, and 3000 series IRIS 4D/G, GT, GTX Personal IRIS GR1.1 (suggest purchasing graphics board upgrade to GR1.2) Sony ---- Sony offers OpenGL on the complete range of its RISC based NEWS workstations. Sony OpenGL requires NEWS OS 6.0.1 and later. This is a pure software implementation. Starting in September 1994, Sony have hardware support for OpenGL on its 3D graphics workstations: on the NWS-5000G and the 3D graphics acceleration card NWB-1501 for NWS-5000 series workstations. Template Graphics Software, Inc. (TGS) -------------------------------------- The Standard in Graphics Tools * OpenGL - Accelerated to Hardware (Sun, Apple, Microsoft Windows 3.1) TGS is providing OpenGL direct to Sun SPARC Solaris 2.x acceleration hardware. This differs from other software-only products in that it avoids the additional XGL software layer. The result is a fast performing and fully functional OpenGL for Sun workstations and clone systems. (OpenGL for Solaris from TGS was recently selected by Aries Research as the OpenGL to be sold with their SPARC systems.) * In final beta now, available via ftp * 100% functional today * Direct acceleration for Sun ZX, Turbo ZX * Direct support for GX, TGX, SX board sets * X11 network rendering to X terminals, PC-X servers, etc. * PostScript hardcopy (on final release) * GLX server extension for Solaris (on final) * Does not require XGL for rendering TGS will also be providing OpenGL for Apple Power Macintosh in early 1995, with a software-rendering and graphics acceleration version. TGS is working with 3D chip/board vendors to deliver accelerated OpenGL for the Power Mac platform. TGS will also be providing OpenGL for Windows 3.1, direct to GDI, to ISV and and OEM customers. OpenGL for Windows 3.1 is fully portable with the OpenGL for Windows NT 3.5 provided by Microsoft, including the WGL component. * Open Inventor - C++ 3D Graphics Toolkit TGS will be a single-stop solution for Open Inventor 2.0 on UNIX and PC systems, outside of SGI of course! * Open Inventor for Solaris - shipping (beta) * Open Inventor for IBM AIX - shipping (beta) * Open Inventor for Windows NT 3.5 - in alpha * Open Inventor for Windows 3.1 - 2Q95 * Open Inventor for Windows 95 - TBA * Open Inventor for DEC OSF/1 - 2Q95 * Open Inventor for HP - 2Q95 * Open Inventor for Apple - 3Q95 * Open Inventor for OS/2 - TBA Note: All of our Open Inventor products are tightly integrated into the OpenGL on each system, including support for 3rd party acceleration boards from Evans & Sutherland, GLINT, and others. TGS is unique in our support for a direct to hardware OpenGL for Solaris, Apple and is the only vendor to support OpenGL for Win32s (Windows 3.1). * TGS Power Tools (tm) for Open Inventor TGS is also developing TGS Power Tools(tm) for Open Inventor which will include: * Power Filters (tm) - Import/Export of 3D metafiles * Power Viewers (tm) - 3D Desktop Utilties * Web3D (tm) - 3D Internet tools Additional information on TGS Power Tools will be provided on request. * Sales and Support TGS has supported ISV's and professional graphics software developers since 1982 from our San Diego headquarters. TGS has regional sales offices in San Jose, Houston, Atlanta and Boston. We also have distribution partners in Europe and Asia. For additional information on TGS graphics software: Template Graphics Software 9920 Pacific Heights Blvd. #200 San Diego, CA 92121 WWW = http://www.sd.tgs.com/~template info@tgs.com Robert J. Weideman, V.P. Marketing (619)457-5359 x229 (619)452-2547 (fax) robert@tgs.com 3Dlabs ------ 3Dlabs Inc. (formerly Du Pont Pixel) announced that they will be providing a direct implementation of OpenGL to run on their GLINT graphic processor. Available Q4 94. For further information contact 3Dlabs at +1-408 436 3455. SGI does not speak for any other company. However, this space is available for any company who wishes to state status reports or release dates for their OpenGL implementation. Please send e-mail to opengl-secretary@sgi.com to add to this section. ------ Subject: Q9: How do I contribute OpenGL code examples to a publicly accessible archive? A: To contribute to the public OpenGL archive, send mail to opengl-contrib@sgi.com. Your mail should contain: The material to be archived, or instructions for obtaining it. An announcement suitable for posting to comp.graphics.opengl. SGI will place the material in the OpenGL/contrib directory on sgigate.sgi.com and post the announcement to this newsgroup. To retrieve something from the archive, use anonymous ftp to sgigate.sgi.com. Once connected, cd to the directory OpenGL. (Case is significant.) Currently there are two subdirectories: doc Manual pages for OpenGL and related libraries. contrib Contributions from the public. Note that all contributions are distributed as-is; neither SGI nor the other companies on the OpenGL Architecture Review Board make any legally valid claims about the robustness or usefulness of this software. If you do not have access to anonymous ftp, consider using an "ftp-by-mail" server. For information on one such server, send mail to ftpmail@decwrl.dec.com with a message body containing only the word "help". ------ Subject: Q10: Will OpenGL code be source code or binary code compatible with IRIS GL code? A: OpenGL code is neither binary nor source code compatible with IRIS GL code. It was decided to bite the bullet at this time to make OpenGL incompatible with IRIS GL and fix EVERYTHING that made IRIS GL difficult to port or use. For example, the gl prefix has been added to every command: glVertex(), glColor(), etc. ------ Subject: Q11: Why should I port my IRIS GL application to OpenGL? SGI will be maintaining the old IRIS GL, but not enhancing it. OpenGL is the API of choice on all new SGI machines. OpenGL has no subsets. You can use the same functionality on all machines from SGI or from other vendors. OpenGL is better integrated with the X Window System than the old IRIS GL. For example, you can mix OpenGL and X or Display PostScript drawing operations in the same window. The OpenGL naming scheme, argument list conventions, and rendering semantics are cleaner than those of IRIS GL. This should make OpenGL code easier to understand and maintain. ------ Subject: Q12: How much work is it to convert an IRIS GL program to OpenGL? What are the major differences between them? There is a fair amount of work, most of which is in substituting for window management or input handling routines, for which the equivalents are not OpenGL, but the local window system, such as the X Windows System or Windows NT. And all routine names have changed, at least, minimally; for example: ortho() is now glOrtho(). To help ease the way, port to "mixed model" right away, mixing the X Window System calls to open and manage windows, cursors, and color maps and read events of the window system, mouse and keyboard. You can do that now with IRIS GL, if you are running IRIX 4.0. In the X Window System, display mode choices (such as single or double buffering, color index or RGBA mode) must be declared before the window is initially opened. You may also substitute for other IRIS GL routines, such as using a OSF/Motif menu system, in place of the IRIS GL pop-up menus. You should use glXUseXFont(), whenever you were using the font manager with IRIS GL. Tables for states such as lighting or line and polygon stipples will be gone. Instead of using a def/set or def/bind sequence to load a table, you turn on the state with glEnable() and also declare the current values for that state. Colors are best stored as floating point values, scaled from 0.0 to 1.0 (0% to 100%). Alpha is fully integrated in the RGBA mode and at least source alpha will be available on all OpenGL implementations. OpenGL will not arbitrarily limit the number of bits per color to 8. Clearing the contents of buffers no longer uses the current color, but a special "clearing" color for each buffer (color, depth, stencil, and accumulation). The transformation matrix has changed. In OpenGL, there is no single matrix mode. Matrices are now column-major and are post-multiplied, although that does NOT change the calling order of these routines from IRIS GL to OpenGL. OpenGL's glRotate*() now allows for a rotation around an arbitrary axis, not just the x, y, and z axes. lookat() of IRIS GL is now gluLookAt(), which takes an up vector value, not merely a twist. There is no polarview() in OpenGL, but a series of glRotate*()s and glTranslate*()s can do the same thing. There are no separate depth cueing routines in OpenGL. Use linear fog. Feedback and selection (picking) return values, which are different from those found on any IRIS GL implementation. For selection and picking, depth values will be returned for each hit. In OpenGL, feedback and selection will now be standardized on all hardware platforms. ------ Subject: Q13: Who needs to license OpenGL? Who doesn't? How is a commercial license acquired? A: Companies which will be creating or selling binaries of the OpenGL library will need to license OpenGL. Typical examples of licensees include hardware vendors, such as Digital Equipment, IBM, and Silicon Graphics who would distribute OpenGL with the system software on their workstations or PCs. Also, some software vendors, such as Du Pont Pixel, MediaVision, and Portable Graphics, have a business in creating and distributing versions of OpenGL, and they need to license OpenGL. Applications developers do NOT need to license OpenGL. If a developer wants to use OpenGL, that developer needs to obtain copies of a linkable OpenGL library for a particular machine. Those OpenGL libraries may be bundled in with the development and/or run-time options or may be purchased from a third-party software vendor, without licensing the source code or use of the OpenGL(TM) trademark. Since many implementations will be a shared library on a hardware platform, the royalty sometimes will be charged for each hardware platform. In those cases, it would not be charged for each application which used OpenGL. In general, licensing a source code implementation of OpenGL would not be useful for an application developer, because the binary created from that implementation would not be accelerated and optimized to run on the graphics hardware of a machine. If you need a license or would like more information, call Mason Woo at (415) 390-4205 or e-mail him at woo@sgi.com. There are licenses available restricted to site (local) usage, or permitting redistribution of binary code. The limited source license provides a sample implementation of OpenGL for $50,000. The license for commerical redistribution of OpenGL binaries has two most commonly chosen levels. Level 1 costs $25,000. Level 2 costs $100,000, and includes the sample implementation of OpenGL. Both levels require a $5 royalty for every copy of the OpenGL binary, which is redistributed. ------ Subject: Q14: How does a university or research institution acquire access to OpenGL source code? A: There is a university/research institution licensing program. A university license entitles the institution to generate binaries and copy them anywhere, so long as nothing leaves the institution. The OpenGL source and derived binaries can only be used for non-commercial purposes on-campus. A university license costs $500 and can be obtained by contacting woo@sgi.com. ------ Subject: Q15: Where is Mesa 3D? A: From brianp@ssec.wisc.edu (Brian Paul) Mesa is a free implementation of the OpenGL API. About all you need is X and an ANSI C compiler. There is a WWW page at http://www.ssec.wisc.edu/~brianp/Mesa.html You can get mesa from iris.ssec.wisc.edu in the pub/misc/ directory. ------ Subject: Q16: What are the conformance tests? A: The conformance tests are a suite of programs which judge the success of an OpenGL implementation. Each implementor is required to run these tests and pass them in order to call their implementation with the trademark OpenGL. Passing the conformance tests ensures source code compatibility of applications across all OpenGL implementations. ------ Subject: Q17: How is the OpenGL governed? Who decides what changes can be made? A: OpenGL is controlled by an independent board, the Architecture Review Board (ARB). Each member of the ARB has one vote. The permanent members of the ARB are DEC, IBM, Intel, Microsoft, and SGI. Additional members will be added over time. The ARB governs the future of OpenGL, proposing and approving changes to the specification, new releases, and conformance testing. ------ Subject: Q18: Who are the current ARB members? A: In alphabetical order: Digital Equipment, Evans & Sutherland, IBM, Intel, Intergraph, Microsoft, and Silicon Graphics. ------ Subject: Q19: What is the philosophy behind the structure of the ARB? A: The ARB is intended to be able to respond quickly and flexibly to evolutionary changes in computer graphics technology. The ARB is currently "lean and mean" to encourage speedy communication and decision-making. Its members are highly motivated in ensuring the success of OpenGL. ------ Subject: Q20: How does the OpenGL ARB operate logistically? When does the ARB have meetings? A: ARB meetings are held about once a quarter. The meetings rotate among sites hosted by the ARB members. To learn the date and place of the next OpenGL ARB meeting, watch the news group comp.graphics.opengl for posting announcing the next "OpenGL Advisory Forum/OpenGL ARB meetings" or e-mail opengl-secretary@sgi.com and ask for the information. Meetings are run by a set of by-laws, which are currently being approved. When they are approved, the by-laws will be publicly available for inspection. Minutes to the ARB meeting are posted to comp.graphics.opengl. ------ Subject: Q21: How do additional members join the OpenGL ARB? A: The intention is that additional members may be added on a permanent basis or for a one-year term. The one-year term members would be voting members, added on a rotating basis, so that different viewpoints (such as ISV's) could be incorporated into new releases. Under the by-laws, SGI formally nominates new members. ------ Subject: Q22: So if I'm not a member of the ARB, am I shut out of the decision making process? A: There are many methods by which you can influence the evolution of OpenGL. 1) Contribute to the comp.graphics.opengl news group. Most members of the ARB read the news group religiously. 2) Contact any member of the ARB and convince that member that your proposal is worth their advocacy. Any ARB member may present a proposal, and all ARB members have equal say. 3) Come to OpenGL ARB and speak directly to ARB. ------ Subject: Q23: Are ARB meetings open to observers? A: The ARB meeting will be open to observers, but we want to keep the meeting small. Currently, up to five non-voting representatives who inform the ARB secretary in advance, can observe and participate in the ARB meeting. At any time, the ARB reserves the right to change the number of observers. ------ Subject: Q24: What is the OpenGL Advisory Forum? A: The Advisory Forum is intended to start as an informal, self-governing group of people, highly interested in OpenGL. Corporations, universities, or individuals can be members of the Advisory Forum. OpenGL Advisory Forum meetings will be scheduled sporadically, usually to coincide with trade shows or other popular gatherings where people would be interested in programming with OpenGL. ------ Subject: Q25: When using Xlib, how do I create a borderless window? A: <from blythe@sgi.com (David Blythe)> Essentially you can create the window with override-redirect (see man xcreatewindow) which is the sledgehammer approach or you can change the _MOTIF_WM_HINTS property to tell the window manager to leave your windows undecorated. <from alex@eagle.hd.hac.com (Alex Madarasz)> Also of note is that the window manager decorations of any client can be turned off by putting something like the following in the .Xdefaults file in your home directory - assuming you aren't overriding them in your app: 4Dwm*ClientAppOrClassName*clientDecoration: none ( see the 4Dwm / mwm man pages for a full description of this resource ) ( you must restart the window manager or logout/login for 4Dwm resources to take effect ) "none" will remove all of the window manager decorations - border, title bar etc. ------ Subject: Q26: How do I switch between single buffer and double buffer mode? A: <from mjk@sgi.com (Mark Kilgard) and blythe@sgi.com (David Blythe)> When using OpenGL with X, switching between a double buffered and single buffered window can be accomplished by creating a "container" X window and creating two subwindows, one with a double buffer visual, the other with a single buffer visual. Make sure the subwindows are each the full size of their parent window. You can then use XRaiseWindow or XLowerWindow to change the stacking order of the two subwindows to switch between double buffering and single buffering. You will need to create a separate context for each of the two windows since they have different visual types. You will need to make the appropriate window/context pair current when you switch modes. IRIS GL made it easy to switch between double buffering and single buffering. But essentially, IRIS GL implemented the above process internally. ------ Subject: Q27: On my machine, it appears that glXChooseVisual is only able to match double-buffered visuals. I want to have more bits of color resolution, so how do I render in single buffer mode? A: <from mjk@sgi.com (Mark Kilgard)> On mid- to low-end machines with double buffer hardware, you'll probably find you get twice as much color resolution using a single buffer visual. But if there is no hardware double buffering support, the double buffered and single buffered visuals are generally the same depth (the back buffer is "carved" out of software). Search again for a double buffered visual. If you find one, use it instead. Call glDrawBuffer(GL_FRONT) though to make sure you are drawing to the front buffer (the default for a double buffered visual is to draw into the back buffer).