The Puzzle of 3-D Graphics on Linux
Over the past year, there has been a drastic change in how Linux is viewed by gamers. No longer relegated to the role of just a dedicated server, gamers are using Linux in increasing numbers as their primary OS and as their gaming platform. And as if using Linux wasn't a challenge enough in itself, anyone trying to set up a Linux box to play a 3-D game will find the path fraught with a plethora of confusing acronyms and names. From OpenGL to DRI to DGA, each term refers to a particular part of the full scene of Linux graphics. Here we put those pieces together for our readers to give them a broader view of what Linux has to offer now and what it will offer, in the near future.
We start by looking at OpenGL, a name that's gotten a lot of use lately, especially in reference to games and professional design applications. Originally called IRIS GL, OpenGL (Open Graphics Library) is a programming library that provides a rich array of graphics functions, both 2-D and 3-D, allowing the programmer to represent any object they design on the screen. It was developed by Silicon Graphics (SGI) and has become a standard graphics application programming interface (API) on many platforms including UNIX, Linux, Microsoft Windows and Apple Macintosh. While OpenGL is the standard for high-end graphics applications where programmers have found it powerful and easy to use, most people have heard of OpenGL in reference to the Quake series of games from id Software. It has been used as part of the graphics renderer since Quake 1, where it has shown itself to be a powerful game graphics API as well. The standard for OpenGL is an open one, independent of hardware platforms, windowing systems and operating systems. Thus the word “Open” as part of the name.
In order for OpenGL to be used in an OS, someone must create a library to implement the function calls OpenGL programs make. However, to call your implementation by the name “OpenGL”, you must actually obtain a license from SGI (or Microsoft). In fact, getting a license will earn you a package of code, called a Sample Implementation and written in C, from which you can build your OpenGL library on your platform. But since the standard for OpenGL is an open one, working from the SI isn't required. In fact, that's what Mesa is all about: it is an implementation created from scratch without a license from SGI and without any code from SGI. To use the OpenGL trademark, however, you must get a license from SGI and your implementation must be robust enough to pass a set of conformance tests developed by the OpenGL Architecture Review Board (ARB). The ARB historically consisted primarily of high-end hardware manufacturers and SGI itself, but now includes some game hardware manufacturers. It is worth noting that, while SGI created OpenGL, the future of the API is controlled by the ARB where SGI sits as one of many members.
Recently, SGI released a Sample Implementation (SI) that can be used to implement the API on any hardware platform with an appropriate compiler. This source code is very similar to the one sold to hardware vendors that implement OpenGL drivers for their video cards. While it has been said that the SI is now open-source software, this isn't entirely true. As of this writing, there are still some issues with the license attached to the SI that prevent it from being truly open.
Many people associate OpenGL with hardware acceleration. While it is true that OpenGL runs very quickly when it has hardware assistance, that acceleration is not required to run an OpenGL application. With a software OpenGL library, OpenGL applications can run and render the same image as they would with hardware acceleration, albeit significantly slower unless the program is very simple. When hardware acceleration is available (in the form of a 3-D graphics card and a driver written for that card), OpenGL applications can run very quickly and smoothly, since most of the intense operations have been offloaded from the CPU to the dedicated graphics board. However, not every accelerator has the ability to perform all the features of OpenGL. When a feature is not supported in hardware, the library may fall back to a software implementation which uses your CPU. For example, very few consumer-class video cards will do transform and lighting (T&L), so normal triangle setup is often done partially in hardware and the rest in software.
Since its initial creation, OpenGL has undergone several revisions and now stands at version 1.2.
In Linux, the implementation of OpenGL used most often is Mesa, created by Brian Paul.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide