xearth (was: Re: Linux OS)

From: Jules Richardson <julesrichardsonuk_at_yahoo.co.uk>
Date: Mon Oct 18 16:52:24 2004

On Mon, 2004-10-18 at 21:21 +0000, Ethan Dicks wrote:
> On Mon, Oct 18, 2004 at 06:32:17PM +0000, Jules Richardson wrote:
> > On Mon, 2004-10-18 at 17:41 +0000, Ethan Dicks wrote:
> > > I've been hacking xearth recently to render the Polar regions white.
> > > Unfortunately, the shape tables are not commented, so I have to go
> > > through manually to determine what shapes correspond to what land
> > > features.
> >
> > Now that's pretty cool. Will you be releasing it into the wider
> > world? :)
> Naturally. I'm really big on Open/Shared Source.

Well let me know when it's done! We've got a few Unix systems at the
museum onto which I was going to put xearth anyway :)

> > I wonder if a modern version is overdue that does do some pretty good
> > shading approximation of all the landmasses? And even better, some form
> > of chaotic cloud approximation to give it that real 'earth from space'
> > feel!
> Hmm... I just did a trivial code tweak... the hardest thing I'm doing
> is reviewing (and commenting!) hundreds of shape structures.

Sure. It's a non-trivial exercise, for sure. Looking at images like
(warning, big file):


I wonder if that many colours are needed - given the scale of the globe,
colour changes are very rapid. Maybe a base palette of 16 blues, greens
and browns would work, with a handful of duplicates fading to various
shades of grey (from black to white) to allow clouds and shadows. Do-
able within a 256 colour palette for a screensaver I would think anyway
- not sure if it'd require too many colours to have it as a background
to a desktop on an 8 bit display though.

Cloud algorithms are somewhat beyond me, however :-)

Aside: We just installed a 6 CPU HP T500 the other day which is crying
out for something visual on it to chew up serious CPU cycles :) I hung
an 8 bit xterm off it the other day; just need to get gcc on there and
then I can build some useful stuff (xfractint and POV seem like good
places to start)


Received on Mon Oct 18 2004 - 16:52:24 BST

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