GuShH's DevBlog » quake http://gushh.net/blog This blog is about software, electronics engineering and game development. Tue, 24 Jan 2012 00:31:00 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 Random Floats using built-in PRNG http://gushh.net/blog/random-floats-using-built-in-prng/ http://gushh.net/blog/random-floats-using-built-in-prng/#comments Sat, 13 Jun 2009 16:59:58 +0000 GuShH http://gushh.net/blog/?p=78 Random floats are kind of a mystical thing in PB, however it can be achieved to a certain degree without having to stack calls on a per decimal fashion.

Here is a simple implementation that will get you going, this is meant specifically for games but it could find other uses…

Macro RandomF() ; returns a random float from 0.0 to 1.0
	( Random(64325) * 0.00001555 )
EndMacro
Macro RandomFC() ; returns a random float from -1.0 to 1.0
	( 2.0 * ( RandomF() - 0.5 ) )
EndMacro

Try it out yourself, if you need a wider range of numbers just multiply the result by a certain factor. I use this and other similar macros for most of my float random needs in PB. Should you need to stack the calls, just make procedures out of the macros.

Similar routines are found inside the Quake3 sources if you care to read them (hint: if you look carefuly there is a comment line inside the game source that reads “// What the fuck?” — Just priceless, seriously).

Cheers.

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