XEarth
Version 0.11b 32-bit (30 Nov 2006)
Version 0.11b 32-bit (30 Nov 2006)
XEarth displays an image of the Earth on the RISC OS pinboard. The image is accurately shaded according to the position of the sun, and is updated regularly. The display is highly configurable, and the program can also be used to generate useful images – both still and animated – of the globe for other purposes (such as the picture above).
XEarth was originally written for the X-Window system by Kirk Johnson, and version 1.00 was ported to RISC OS by Matthew Bloch. This version has been recompiled to be 32-bit compatible, and uses ConfiX to provide a simple configuration front end.
For license details, please read the Copyright section at the end of the ManPage document.
XEarth 0.11 should run on RISC OS 3.10 or higher, including RISC OS 5; this application works on both 26- and 32-bit machines.
In order to use the graphical configuration facility, you need to have the free ConfiX universal configuration utility. This is available from the X-Ample Technology web site at http://www.xat.nl/en/riscos/sw/confix/.
If you wish to create animations, you will need Peter Hartley's InterGIF, available from http://utter.chaos.org.uk/~pdh/software/intergif.htm. The included IGViewer application is useful for viewing animations, although most web browsers will also display them. Note that the version of IGViewer on Peter Hartley's page is not 32-bit compatible (though InterGIF itself is); there is an unofficial 32-bit version at http://eis.bris.ac.uk/~ccjpb/ftp/.
Double-click on the !XEarth application in a Filer directory display. An icon will appear on the right-hand side of the iconbar, and after a while the pinboard image should change to an image of the Earth.
XEarth has to do a large number of calculations to generate the image, so it does take some time (perhaps 30 seconds on an Iyonix, depending on the settings and screen size). But the program takes considerable care to do its work in the background, so it shouldn't impinge on your normal usage of the machine.
The iconbar icon has two states:
idling
XEarth is currently calculating a new image
You can force XEarth to generate a new image by clicking Adjust on the icon.
Clicking Select on the iconbar icon opens the configuration window:
The main configuration dialogue
Change any settings you like, then click on Save. XEarth will restart with your new settings - but remember that the program takes a while to generate a new image.
There are various preset configurations available. To choose one, click on Profiles and select from the menu, then Save. Try these out – by examining the settings, they'll give you a feel for what the various options do. Use the "Save as" option from the configuration menu to create a new profile. Note that the profiles beginning with "XM" are animations; please read the animation section below before trying these.
The first three tabs at the top select between the overall look, detailed positioning and rendering options. The first dialogue lets you set the projection type and the size and position of the Earth within the desktop screen. You can also choose the time between updates.
The viewing position can be specified in four ways:
Use the Rendering tab to select day/night shading and whether stars are drawn in 'space'. The stars are not accurate representations of the sky! They're just random dots.
Please note that there are a number of extra options that can't be set using the ConfiX dialogue. You can however set these on the command line, as before – edit the file !XEarth.doit, which contains a single line which is executed when the application is run. Note that this will be overwritten by any subsequent configuration change.
The fourth tab lets you create a sprite from the current settings. As well as providing useful images, you can use this feature to get a quick preview of your settings.
The sprites are saved in the images directory inside the !XEarth application (though you can change this in the !Boot file if you wish). This operates independently of the pinboard display – don't forget to turn off the Create a sprite option if you want to modify the pinboard.
Set the size of the output sprite using the arrows (or type in the values), and change the filename if you wish. Selecting Display will open the image automatically in your preferred sprite editor (probably Paint). The Open button opens the directory where the sprites are stored.
Click on Save to create the sprite. Large sprites can take a while to generate, so wait until they've finished before looking at them.
If you've specified any shifts for the Earth image (in the first tab), remember to modify these appropriately for the size of the sprite. All other values will scale according to the output size.
The final pair of tabs are used for creating animations. This is inevitably somewhat more complicated to set up, but the presets provided should get you started. Note that like sprite creation, making an animation is completely separate from the pinboard display – you can experiment merrily and the backdrop will continue as normal.
Animation works like this: the normal settings (in the first three tabs) control the start of the animation, and you define another configuration for the last frame, using the two animation tabs. Clicking on Save generates a series of images between these two points, which InterGIF then processes and combines into an animation.
All operations are done in a task window, so although creating an animation can take some time, you can still use the computer normally.
The first animation dialogue
The first tab contains controls for the main features of the animation, which cannot be varied from frame to frame. Set up the size of your animation, the number of frames and the delay between frames here. You can also specify a filename; clicking on Open will open the directory where the animations are stored.
Selecting Masked will make all black pixels – space – in the image transparent. If you select Display the animation will be Filer_Run on completion, which should open it in IGViewer (click on the arrow to start it).
The Report progress button opens a taskwindow where the various stages are reported on. As creating an animation can take some time this is useful as confirmation that something is happening.
Directing the animation
The second tab contains many of the same controls as the main set-up tabs, and lets you set up the view for the final frame. Most features can be animated, and they can be combined arbitrarily.
Animations never include the random starfield, for obvious reasons.
The presets provided in Profiles demonstrate a few of the variations. All the animations start with "XM".
The script used to generate the animations is in the file called "script" in the animations directory. All the sprites used for each animation are left in the !XEarth.temp directory, so you can tweak the files and run them through InterGIF again if you wish (to adjust the individual frame timings, for example – see the InterGIF manual for details).
For details of command-line usage, see !XEarth.Docs.ManPage.
Also see the original Acorn conversion notes, !XEarth.Docs.AcornHelp.
All credit goes to the original authors of the software:
Document: !XEarth.Docs.XHelp/htm
Description: Help file for XEarth application version 0.11 (32-bit build)
Version: 1.02 (Thu, Nov 30, 2006)
Author: © Chris Terran/Lee Montgomerie/Vermilion Sands 2006
Format: HTML
Email: chris@roast.iconbar.com
Web: http://www.roast.iconbar.com