November 2003 - Fractdev - mailman.xmission.com

Zoom box movement in autokey files
by Gerald K. Dobiasovsky 15 Jan '04

15 Jan '04

Hi... Not that it matters much, since fractint's autokey feature doesn't seem to be used by many: When playing an autokey file that was created for version 19.x and earlier, panning the zoom box now moves it too far, resulting in a much different image than was intended. This can be checked using demo.bat, demo.par and basic.key from the autokey files created for version 19.x and still part of the fractint distribution, choosing "Basic commands demo". (Not to forget: One has to change line 25 in basic.key from "DOWN * 2" to "DOWN * 4" to adapt it to the additional two prompts on the <x> screen introduced in, I think, fractint 20.1.) Regards, Gerald

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Re: WinFract, parallel development, etc
by Edwin 22 Nov '03

22 Nov '03

Hi, Florian's wish list sounds very appealing, and also fairly familiar - I've seen similar discussions before (eg http://protofractals.sourceforge.net/ has very similar suggestions). Where things become difficult is translating the grand plan into practice both because it's a huge amount of work and because with such a plethora of platforms (Windows, DOS, Linux X11, command-line, Java, Mac...) it becomes hard to serve them all well. It's also hard to get enough developers to agree on a common approach to implement the grand plan - witness just how many small fractal programs are listed on SourceForge. While this discussion on approaches is going on, I thought I'd mention that I'm currently tinkering with my own fractal program (http://gnofract4d.sourceforge.net/) Currently it's limited to Linux and to a small set of built-in fractals, though internally it's divided into a fairly platform-neutral C++ library and a front-end which does the GUI stuff. One interesting quirk which I've found is great for performance (but not so great for portability) is that to draw a fractal it splices together fragments of C++ code at runtime, runs the compiler, and calls the resulting code. This means that everything runs at full speed- the iteration and bailout functions can be inlined completely. My latest scheme is a full-blown compiler for Fractint (and some UltraFractal) formulas, which will compile the formula to C. This way I hope to be able to run user-specified formulas as fast as built-in functions. I have this about half-implemented - the lexer, parser and translation to intermediate code are all working - next I need to sort out the back end. Anyway, it's good to see some ideas being thrown about. I'd be interested in collaborating if anyone has any concrete plans... Regards, -- Edwin

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WinFract, parallel development, etc
by White, Jim (ITD) 11 Nov '03

11 Nov '03

Re: Notes from Paul de Leeuw et al regarding WinFract I've been running FractInt formulas and Par's in a program I built in Visual (and Power) Basic. Before anybody laughs, I should point at that this is no Mickey-Mouse program at all! I divided the project into 4 distinct components: 1. Fractal Engine - raw calculations 2. Formula interpreter 2. Display/graphics 3. Front-end, UI VB's IDE made the engine development easy to modify and test. Once I had a good initial version I then switched it into PowerBasic (which runs VB-syntax code much faster and makes DLL's). All other functions are done by VB (using API for graphics, of course). I don't need anything fancy, as my preferred mode of operation is to use online display as a guide only - I save images (like Fractint does with the "saveiter"), and have a separate render program for experimenting with colouring. It's all floating-point, I use 80-bit FP in the Engine (PowerBasic has an "Ext" datatype for this), and am currently looking at GMP/MPFR as an arbitrary-precision option. The advantage of all this is that front-end changes and extensions are very easy to do in VB, and I don't have to deal with MFC at all, VB does it for me. Jim White MathImagics, Uki NSW, Australia Jim.White(a)defra.gsi.gov.uk Department for Environment, Food and Rural Affairs (Defra) This email and any attachments is intended for the named recipient only. Its unauthorised use, disclosure, storage or copying is not permitted. If you have received it in error, please destroy all copies and inform the sender. Whilst this email and associated attachments will have been checked for known viruses whilst within Defra systems we can accept no responsibility once it has left our systems. Communications on Defra's computer systems may be monitored and/or recorded to secure the effective operation of the system and for other lawful purposes.

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tim's request: relaxed zoombox scrolling
by Charlie Chernohorsky 07 Nov '03

07 Nov '03

hi tim, this spring, you talked about not scrolling unless the zoombox touches the edge of the screen (ie. visible part of image) since that would be too ambiguous, i simply made it to scroll when the zoombox center touches the edge of the screen.. i've sent a diff to jonathan.. try it and tell me, please, whether it fulfils your request charlie ____________________________________________________________ Vychází Best of Chinaski-PREMIUM. 21 největších hitů včetně tří novinek- nahlédněte do historie i budoucnosti jedné z nejoblíbenějších kapel současnosti!http://ad2.seznam.cz/redir.cgi?instance=63636%26url=http://www.chinaski.cz

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