Ying Tong Iddle I Po

The world and its Free Software loving dog have exploded all over the Internet at the news of SGI changing one of the licenses it uses to open source software to make it FSF-tolerated. Why is this exciting one asks? Well it is because it is widely being reported as SGI Open Sourcing OpenGL. This is a proper hand.slap(head) statement as I shall explain. Already it has lead to a number of misconceptions:

• Anyone using OpenGL under Linux has been using non-Free software. This is false. The OpenGL implementation on Linux is not, necessarily, related to the SGI offering at all. For example, the popular Mesa 3D library forms the base of most FLOSS OpenGL stacks. Certainly if you are using an Intel card, your OpenGL implementation is delocalised over Mesa and the X11 licensed driver in X.org. The SGI code has no effect on you.
• The OpenGL I’m using is written by SGI. Unlikely, see below for what OpenGL actually is. SGI released a reference implementation of OpenGL for people to test against but it only implements OpenGL 1.2. In computer graphics terms, that is roughly equivalent to the age of the Roman Empire.
• There is one ‘true’ OpenGL implementation. OpenGL is not a piece of software at all. Rather it is an API specification. It is, if it can be said to exist tangibly at all, a pile of paper. It is also a trademark which prevents Mesa 3D claiming anything other than it is a ’similar’ API to OpenGL.

What people should be celebrating is that now a large amount of SGI’s other FLOSS projects now can earn their ‘F’.

For anyone that might care, here is a quick ‘n’ dirty piece of Python code that allows me to control the circus cannon my sister bought me for my birthday. YMMV and you’ll probably need to change the device name in send_cmd().

from __future__ import with_statement
import curses

def send_cmd(cmd):
  try:
    with open('/dev/hidraw1', 'wb') as outfile:
      outfile.write("\x00")
      outfile.write("%c" % int(cmd))
  except:
    pass

def mainbody(stdscr):
  quit = False
  while(not quit):
    a = '%c' % stdscr.getch()
    if(a == 'a'):
      stdscr.addstr(1,0,"left ")
      send_cmd(4)
    elif(a == 'd'):
      stdscr.addstr(0,0,"right")
      send_cmd(8)
    elif(a == 's'):
      stdscr.addstr(0,0,"up   ")
      send_cmd(2)
    elif(a == 'w'):
      stdscr.addstr(0,0,"down ")
      send_cmd(1)
    elif(a == 'f'):
      stdscr.addstr(0,0,"fire ")
      send_cmd(16)
    elif(a == 'x'):
      stdscr.addstr(0,0,"stop ")
      send_cmd(0)
    elif(a == 'q'):
      stdscr.addstr(0,0,"quit ")
      send_cmd(0)
      quit = True

if(__name__ == '__main__'):
  curses.wrapper(mainbody)

Thursday’s Metro wins this week’s Wareham award for most bizarre headline:

Giant ice penis - is climate change to blame?

Personally I’m not a fan of swearing as part of written media. Swearing is, to my mind, an entirely verbal thing—a rapid expression of frustration if you will. I’m about to break my own swearing rules for a video which, I am presuming, is the result of Microsoft paying Jerry Seinfeld $10⁷.

OMG, WHAT THE FUCKITY FUCK FUCK?!?!///elevenslash

I recommend people taking a look at these two interesting LHC webcams.

In the tradition of ‘release early, release often’, I ‘released’ version 0.0.4 of Firtree today. Release is a strong word since, for the 0.0 series, ‘release’ basically means ‘bump minor version and build packages’. Feel free to add the Firtree APT sources if you’re an Ubuntu person and have a play.

I’m also starting to write a Python-based tutorial series which will end with the page curl example I blogged about earlier. Along with all this joy, I added a screenshots page so that you can drool at mindless eye candy :).

New in this release are image accumulators, so that you can easily perform effects which ‘feed back’ the result of one iteration into the next. Also new is the option to use the Mesa 3d software renderer instead of your hardware GL implementation so that you can tell if bugs are your vendor’s or mine :).

Switching GL backends within one process is a surprisingly hard thing to do. GL doesn’t really have the concept of different devices, or renderers, built into it and the nVidia and Mesa 3d libraries tried very hard to tread on each other’s toes.

So, Intarwebs, I’ve often toyed with attending a local Alpha course. Pros and cons?

The WebAIM site has a most amusing article up at the moment about the history of user agent strings—the name your web browser uses to identify itself to a website you are visiting. From the article:

And Netscape said, let us make fun of Microsoft and refer to Windows as “poorly debugged device drivers,” and Microsoft was angry. And so Microsoft made their own web browser, which they called Internet Explorer, hoping for it to be a “Netscape Killer”. And Internet Explorer supported frames, and yet was not Mozilla, and so was not given frames. And Microsoft grew impatient, and did not wish to wait for webmasters to learn of IE and begin to send it frames, and so Internet Explorer declared that it was “Mozilla compatible” and began to impersonate Netscape, and called itself Mozilla/1.22 (compatible; MSIE 2.0; Windows 95), and Internet Explorer received frames, and all of Microsoft was happy, but webmasters were confused.