BackTrack - Backdrop image rotator

by Matt Harris


This program changes the Pinboard backdrop display at regular intervals, cycling through a pre-defined set of sprites. In order to use it therefore, you must have Pinboard running. This will be the case if you have RISC OS 3 and you haven't explicitly quit Pinboard using the Task Manager.

An easy check to see if Pinboard is running is to look in the Task Manager window, which can be opened by clicking on the Acorn icon at the extreme right-hand side of the icon bar. The name Pinboard will appear in either the list of Module tasks or Application tasks if it is running.

If it is not running, you may be able to restart it by saving all your work, then pressing F12 and typing
  RmReinit Pinboard
and then pressing Return. You may then have to reset your computer.

The program is provided with a set of default sprites which can be reached by holding down Shift and clicking on the !BackTrack icon in a directory display. In the new directory display that opens, there will be an Images directory containing the various backdrop sprites. Once BackTrack is installed on your hard disc, you can add or remove sprites as you wish.

BackTrack works by loading each backdrop sprite in turn after a user-specified interval. It reads the sprites from a specified directory, reading the catalogue and loading sprites in alphabetical order. It is possible to configure the program to use an alternative directory from which to source its sprites.

To configure the program hold down the Alt key whilst double-
clicking on the icon in the directory display. If this month's Measure program is loaded, you will have to close its window first as it also uses the Alt key and will make it difficult to open BackTrack's configuration window.

The configuration window is fairly self-explanatory. It sets up a default display mode for the backdrop sprite, which can be overriden as described later. The available modes are exactly the same as those used by Pinboard:
Scaled:  the picture is scaled to fill the screen.
Centred:  the picture is displayed at normal size in the middle of the screen, with a grey border if it does not fill the screen.
Tiled:  multiple copies of the picture at its original size are displayed across the whole screen.

You can also specify the delay between loading one backdrop and the next. The value can range from 15 seconds to 1 hour. You can set up an alternative directory to use for backdrop sprites by dragging the directory from the Filer display into the bottom section of the configuration window.

You can override the default display mode for any sprite by suffixing the filename with any of these character sequences:
-S for Scaled
-C for Centred
-T for Tiled
So to display a sprite file 'Back1' always using centred mode, regardless of the default, you should rename the file 'Back1-C'.


 Copyright RISC User 1994
