www.delorie.com/gnu/docs/xaos/xaos_2.html   search  
Buy GNU books!

An fast realtime interactive fractal zoomer

[ < ] [ > ]   [ << ] [ Up ] [ >> ]         [Top] [Contents] [Index] [ ? ]

1.1 Why yet another fractal generator?

We decided to make XaoS, because all fractal browsers we know needs long time to calculate every image. You may browse nice images generated by them but real impression from fractal--they self similarity and possible infinite zooming into nice part of fractals can be seen only in animation. There are many programs available that makes nice animations but they takes long time to calculate and lots of space on disc. Most of animations are quite ugly because their authors can't see it without many hours of calculations.

Natural question is: it is possible to generate such animation in realtime? Ansver was negative for many years, since Mandelbrot set is very computational expensive. Thinks are changing. Today's computer are fast enought to calculate aprox. 1000 pixels per frame. It is enought for very low resolution animation (30x30). Several programs doing that are available. But 30x30 animation still looks quite ugly. To make animation nice you need at least 320x200 pixels. And thats 65 times more! One possibility is wait until computers will be fast enought, but it should take many years and then 320x200 animations will be obsolette and everyone will want 1024x768 resolution instead.

We found special algorithm that saves up to 99.98% of calculations during zooming by reusing pixels already caluclated in previous frames. There were some programs doing similiar trick before but we don't know about any able to do zooming interactivly in same or higher speed than XaoS does. Many other tricks was later implemented into XaoS to archieve higher framerate. Now XaoS does up to 120 frames per second at 120Mhz pentium in fullscreen 320x200 animation and calculates at the avearge 160 (0.24%) pixels per frame. This makes XaoS fast enought to archeieve primary goal--realtime animation, but there is still many places for improvement, since more complex fractals, higher resolutions, or slower computers still brings many problems.

[ < ] [ > ]   [ << ] [ Up ] [ >> ]         [Top] [Contents] [Index] [ ? ]

  webmaster     delorie software   privacy  
  Copyright 2003   by The Free Software Foundation     Updated Jun 2003