Saturday, October 13, 2007

Quaternions, Embedding Python and just passing time

Quaternions are an old and elegant mathematical concept. Superseded in higher dimensions by tensors and other associated constructs but still holding sway in graphics and gaming and mechanics. I have had exposure these fun representations of rotation through both graphics in WorldWind and lately, satellite mechanics, through implementation of optical models in Ossim. There is talk of implementing matching and stereo analysis solution for terrain generation using the optical models within the ossim framework, let's see where it leads.

The other thing taking up my time is getting a Qgis release out. The one with Python bindings is proving to be a real nuisance, making installers in Windows is such a pain mainly due to lack of coherent location of all the dependencies and mess in the registry for locating them even while they are there. Hence the windows package inherently gets larger and larger as I struggle to throw all but the kitchen sink in to ensure all the stuff needed is there and the user does not fall into dll-hell. So far I have packaged Qt,Gdal,Grass,Msys-Mingw,Gpsbabel,PyQt4 and who knows what else into it. I might also have to include an optional embedded python, just in case Python is not cleanly detected on the system. So far Gary Sherman has managed to coax it to work on Windows Vista and Aaron Racicot on Windows XP.

Here are revised steps:
  1. Install Python 2.5
  2. Install PyQt4
  3. Install Qgis with Python bindings - will replace some PyQt4 binaries with compatible ones.
The whole beast is now some 62MB-20MB is PyQt4 I had to include. I am looking at adding SIP as well, to get rid of step 2. If need be a simple python distro to rid of 1 as well. Since this will bloat things up there will be a Python-less installer too, as a compromise. I simply wish windows had a better system for binary reuse ( well outside of .NET and the evils of the registry).

When the installer is not building in NSIS I have been raking up gold and monster corpses in Dungeon Runners, lucky it is a fast hack and slash. Cheap ($5 p.m), totally unaddictive (unlike WoW) and free from gold farmers since you can't drop the gold.
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