Because it's pretty, that's why. It also helps to prolong the life of your monitor by preventing stationary images from 'burning in' on the screen.
{subhead}What does Blackout do?
Blackout is a sub-program of Black Hole II. If you have the Screen Saver enabled, Black Hole will watch you, very closely. If you leave your computer unattended for a certain length of time Black Hole will run Blackout. Blackout will then entertain the empty room by displaying one of several pretty patterns or silly effects until you come back. By moving the mouse or pressing a key you will stop Blackout and the world will return to normal.
{subhead}Configuring Blackout
You also have a choice of pretty pattern and a variable delay before it cuts in. You can set these by clicking on the 'Configure..." button in the Blackout section of the Black Hole configuration window. This opens the BlackOut Configuration window.
{sprite}configwin
At the top is a box telling you what the currently selected screen saver is. You can choose a new one by clicking on the arrow icon next to this box and selecting a screen saver name from the menu that appears. Note that these are not very helpfully named. This is intentional, to make you think.
Next to the 'Saver' box is a white box labelled 'Delay (mins)'. This is the time (in minutes) of inactivity on your behalf before Blackout will be started. You can type any number in here, including decimals.
The screen saver will not operate unless the 'Enabled' option is selected.
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The rest of it is far too complicated for you. Just be thankful you've read this far without your brain exploding.
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{subsub}Parameters
Below this lot is a scrollable bit labelled 'Parameters'. In here you enter any user-configurable parameters required by the screen saver. All savers will provide some defaults but you can play with them. Each parameter will have a description and a writable icon into which you can type your new value.
Some of the screen savers have a parameter called 'Faster'. If this is set to
1, then the screen saver will run a little bit faster. Why? Well. Usually Blackout will monitor the screen to see if any windows have opened while it has been running. If any have, then they will have opened in front of Blackout and will therefore be ruining the display. When Faster is not 1, Blackout will make sure any windows which open in front of it get hidden. But all this checking slows things down a bit. By using the Faster option you can stop this checking taking place. Simple, innit?
{subsub}Saving Your Options and Parameters
When you click the 'Save' button, the selected screen saver, password, and timeout are saved to disc. The Parameters for the selected screen saver are also saved. Once you've saved a set of Parameters they become the defaults for that saver so you can change it and thengo back to it without losing your favourite options.
{subsub}Random Choice of Screen Saver
You can select a 'Random' option. This makes Blackout choose one screen saver at random and run it. The Random saver has some parameters, the first of which is 'Change Time'. Once it has started, Blackout will run for this length of time (in minutes), then it will choose a new saver. The other parameters are a list of screen savers which will NOT be run. You should set these up carefully, especially remembering that some of the savers will not work on RISC OS versions earlier than 3.50.
Before choosing the Random Option you can go through each saver individually and set up your favourite set of parameters, then click 'Save'. This will save the parameters for that saver so that they get used when that saver is chosen by the Random Option. When you've done this, Select Random and click Save again.
{subsub}The other bits.
If you want to see what the screen saver will look like, click on the 'Demo' button. This will run Blackout so you can see what it looks like and what difference changing the parameters has made. The demo will continue until you move the mouse or press a key.
To forget all your changes and revert to what the options were before you started Configuring, click Cancel.
To quit Configuration and update the settings without making the change permanent, click OK.
{subsub}Sleep Corner.
When the screen saver is enabled, you can force it to cut it by putting the mouse in the bottom left corner of the screen for a few seconds.
{subsub}No Sleep Corner.
You can prevent the screen saver from cutting in by leaving the mouse in the top right corner of the screen.
{subhead}Passwords.
A subtle security feature. Blackout allows you to protect your computer from prying eyes by not allowing you to return to the desktop without entering a password. What will happen if you have a password set is that when someone attempts to stop Blackout (by moving the mouse, etc.) a window will pop open asking for the password. If the wrong password is entered, Blackout will not stop and so your desktop will remain invisible.
To set a password, click the Change Password... button. This opens a window which will ask you to type your new password. The password will display as a string of *s to prevent anyone watching from seeing it. Press Return or click OK. You will then be asked to retype the password for confirmation.
If you already have a password set and you want to change it you must first enter the old password.
To clear the password so that the password feature does not operate, simply press Return without entering any text when asked for the New Password.
{subhead}User-Defined Screensavers
If you have a knowledge of BASIC you can write your own screen saver to be included in BlackOut. This has its own separate help topic.
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{subhead}Credit
People with a RISC PC will notice that if they use a screensaver with a black background (such as Stars), the screen will fade nicely to black before the saver starts. This is acheived entirely thanks to the module 'Compo Support' which was written by Rob Davison. His copyright message is included in help for 'Legal and Copyright'.
{subhead}Notes on some of the Screen Savers included
Some of these (notably the psychedelic ones) will not be visible to people who do not have RiscOS 3.50 or later.
{subsub}Blocks
turns the desktop into one of those sliding block puzzles. Because of the way this is written (sloppily) you can only make the speed 1, 2 or 4.
{subsub}Demolition
Bounces a ball around the screen. The ball destroys all object in its path.
{subsub}DimScreen
This is pure minimalism. Turns down the brightness of the screen by a user-defined amount.
{subsub}Fractal1
One of those little fractal things with dots.
{subsub}Hypno
Not really very good.
{subsub}Hypno2
is a bit similar to Hypno only less so.
{subsub}Lines
bounces a line around the screen creating some occasionally interesting interference patterns.
{subsub}Melt
Melts your screen. Unlike other screen savers of this type, Melt actually looks realistic. Sometimes.
{subsub}Message
Scrolls a message across the screen in your choice of outline font. The message it uses is taen at random from a text file. By default this is the file !BlackOut.TagLines, but you can change this.
{subsub}Orbits
Simulates a three-body planetary system. I shall explain some of the parameters in more detail:
{tab}
Timestep: Is the amount of time that is assumed to elapse between each calculation. Making this smaller makes the apparent movement slower and increases the accuracy.
Scale Factor: Should be obvious.
Speed: Controls the speed of the thing. This is separate from Timestep; altering Speed simply changes the number of calculations per second.
Most orbit simulations end up with all three bodies disappearing into nowhere. If this happens the screen saver will restart using the same parameters but with a smaller scale so more of the stuff will fit on. This process will repeat until the scale factor can't go any lower, at which point the thing will restart with random parameters.
The planets will leave a coloured trail behind them. The width of the trail is proportional to the mass of the planet. And the size of the planet is also roughly proportional to its mass.
{notab}
{subsub}Pendulums
is a simulation of a 2 pendulum harmonograph.
{subsub}Psych1-3
These use Rob Davison's palette munging module to mind-warping effect. Try Psych1 in a dark room, if you dare. People subject to epileptic fits may wish to view these through dark glasses. And I'm only half-joking. These will only work on Risc OS 3.50 or later. Before it starts it will attempt to change into a screen mode with 16 million colours at 800x600 resolution. If your machine cannot support this you will get an effect which is not nearly as frightening and actually looks quite crap.
Note to clever buggers: Those of you who like to think you're clever and have deleted that file 'Bandlimit' from your boot directory will notice that the palette swirling and fadeouts don't work any more. So put it back.
Are psychedelic versions of the basic screensavers.
{subsub}SlideShow
This will only work on a Risc PC with Risc OS 3.60 (or later). It will display a series of JPEG images (which you must supply) in sequence. Pictures larger than the screen will be scaled to fit. You must specify the directory where the JPEG files are stored. The saver will display any JPEGs in that directory and also in any sub-directories, but not any sub-sub-directories. If you see what I mean.
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Ignore the 3rd parameter, it is for specifying which screen mode to use and is far too complicated for you.
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You can select which screen mode to use by altering the Mode String supplied. The default is 800x600 pixels and 16 million colours. The screen saver will change back to your current mode when you quit the screen saver.
I wrote this to make use of the large number of very nice JPEG images supplied with Risc OS 3.6.
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{subsub}Sprites
Makes a lot of sprites fly towards you. You can use any sprite from the WIMP sprite pool. Note that this may not work correctly in 16 colour modes.
{subsub}Stars
Fly through space - the stars fly towards you.
{subsub}Swarm
Simulates a swarm of bees trapped inside your monitor
{subsub}Swirl
is a variation on Squares and Squares2
{subsub}Toasters
Was mostly written by Robin Moffatt. He also drew the nice sprites.
Note that some of the above may run quite slowly if you use modes with more than 256 colours. This is because they are badly written.
{subhead}Public Domain Notice:
The Public Domain rules concerning Blackout are slightly different from the rest of Black Hole.
Blackout is phase 5¼b of Fat German Production's now defunct plan for world domination. It is released by courtesy of the Fat German in association with the Great Green Gollywog, his minions, and his sister Ethel. It may be freely copied and used, as long as the following conditions are met:
a) That this notice is distributed unchanged with every copy.
b) That the application is supplied unmodified. Extra screen savers may be inculded by anyone who wishes to, but all other parts of the program are to be regarded as sacred.
c) No charge is made for the distribution. Public domain libraries may make a small charge to cover distribution costs. It is highly unethical, not to mention dishonest to make a charge for software which programmers have intended to be freely distributed, especially if none of that profit finds its way to the programmer.
d) Neither !BlackOut or !BlkOutCfg may be distributed separately from !BlakHole2.
e) Anyone who drives a Honda CRX must destroy it before I will allow them to use this program.
All copyright is reserved. You may not use any part of this application in any project which is to be sold for profit without my express permission in writing.
All code in the file 'BlackOut' is copyleft. You may use it in whatever way you feel fit. Code in the directory 'Savers' is fit for butchering in all manner of ways. You may steal any bits of code to use in your own savers unless the author of the saver has specifically asked you not to by including a REM statement to that effect at the start of his saver.
The program 'Blackout' may not be distributed in modified form without my permisson.
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If you can think if any ways to improve the code then please do so, and let me know.
