can't reproduce FOTD 17-04-97
Here's another one that doesn't render right on xfractint. Compare to <http://www.nahee.com/FOTD/FotD_97-04-17.html> ; Date: Thu, 17 Apr 1997 22:20:52 -0400 (EDT) ; ; To: fractal-art@aros.net ; ; From: Jim Muth <jamth@mindspring.com> ; Reply-To: fractal-art@aros.net ; ; Subject: [fractal-art] FOTD 17-04-97 ; ; Id: <1.5.4.16.19970417222218.2f071480@pop.mindspring.com> ; --------- ; ; Fractal visionaries: ; ; Here's a soft and pleasant three-armed fractal fern generated ; from the power 1000 Mandelbrot figure. Normally, such a large ; exponent will give nothing more than a circle, but the extra ; term in the formula not only turns the figure inside out, it ; reduces the number of arms to 3, while retaining the delicate ; fern-like characteristics of the ultra-high order mandeloids. ; Like yesterday's fractal, this one also seems nearly impossible ; to color poorly. ; ; ; Jim Muth ; jamth@mindspring.com ; ; ; START PARAMETER FILE================================================ fracfern { reset=1950 type=formula formulafile=fracfern.frm formulaname=fracfern passes=1 center-mag=0.636995/8.88178e-015/0.07861635 float=y maxiter=10000 bailout=100 inside=bof60 logmap=yes symmetry=xaxis periodicity=10 colors=0007A86A85B84C73C7<37>_K__K_ZJZ<32>B7LHCLCHKCKKNNKSNK<13>XQGXQGWR\ F<39>t6lu5mw3m<21>USn<63>w7Lw7Lx5M<19>eTDCHA<4>8F9 } frm:fracfern {; Jim Muth z=c=pixel: z=z^1000*(c^(-1002))+c, |z| <= 10000 } ; END PARAMETER FILE================================================== ; ; ; ------------------------------------------------------------- ; Thanks for using Fractal-Art, The Fractal Art Discussion List ; Post Message: fractal-art@aros.net ; Get Commands: majordomo@aros.net "help" ; Administrator: noring@netcom.com ; Unsubscribe: majordomo@aros.net "unsubscribe fractal-art" -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
Rich, Part of the problem is the difference between the formula parsers. The Xfractint code is using the C parser and Fractint uses the assembly parser. There is something else going on, also, because the image generated using Fractint with debug=90 (to force the use of the C code) doesn't match what we are seeing. I'll have to look into it. Jonathan
Here's another one that doesn't render right on xfractint.
Compare to <http://www.nahee.com/FOTD/FotD_97-04-17.html>
; START PARAMETER FILE================================================
fracfern { reset=1950 type=formula formulafile=fracfern.frm formulaname=fracfern passes=1 center-mag=0.636995/8.88178e-015/0.07861635 float=y maxiter=10000 bailout=100 inside=bof60 logmap=yes symmetry=xaxis periodicity=10 colors=0007A86A85B84C73C7<37>_K__K_ZJZ<32>B7LHCLCHKCKKNNKSNK<13>XQGXQGWR\ F<39>t6lu5mw3m<21>USn<63>w7Lw7Lx5M<19>eTDCHA<4>8F9 }
frm:fracfern {; Jim Muth z=c=pixel: z=z^1000*(c^(-1002))+c, |z| <= 10000 }
; END PARAMETER FILE==================================================
In article <1277777015.1860.5.camel@jonathan-desktop>, Jonathan Osuch <osuchj@avalon.net> writes:
Part of the problem is the difference between the formula parsers. The Xfractint code is using the C parser and Fractint uses the assembly parser. There is something else going on, also, because the image generated using Fractint with debug=90 (to force the use of the C code) doesn't match what we are seeing. I'll have to look into it.
Yes, my Win32 port also uses the C parser and there are some FOTDs that don't render right there as well. I have gone over the C parser code at one time attempting to find something offensive that would lead to the difference, but I didn't spot any obvious errors in all my reviews. I'm not an x86 assembly guru, so I haven't really studied the x86 assembly parser code and attempted to correlate it to the C code. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
Rich,
Yes, my Win32 port also uses the C parser and there are some FOTDs that don't render right there as well. I have gone over the C parser code at one time attempting to find something offensive that would lead to the difference, but I didn't spot any obvious errors in all my reviews. I'm not an x86 assembly guru, so I haven't really studied the x86 assembly parser code and attempted to correlate it to the C code.
The major difference is that the parser assembly code uses 80-bit real numbers in the FPU and maintains the results during all calculations at 80-bits. The parser C code uses 64-bit real numbers. There are also a bunch of additional optimizations that the assembly code does that we would like to implement in the C code. Jonathan
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Richard