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The Fred Fish Collection 1.5
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MandelMountains
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Release.doc
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1990-10-23
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MandelMountains V2.1 by Mathias Ortmann
Unfortunately, the 'real' turbo version of MandelMountains V2.0 (which
was intended to support 68020/30 and 68881/82 machines) was bugged and
didn't work properly (never try to develop software for processors you
don't actually have!). - Is the working turbo version of MandelMountains
really doomed to non-existence, only because the author has no chance (no
money) to get his hands on an accelerator board?
Well, now there IS a turbo version, and it WORKS: MandelMountains V2.1
is TWO TO THREE TIMES FASTER than MandelMountains V2.0 - without ANY
additional hardware!
Hard to believe, but true.
How was this quantum leap in performance possible?
Most of the speedup is based on using fixed point instead of floating point
arithmetic. The genius behind the new, tremendously fast routines is Doug
Houck, author of the programs FracGen (shareware), Doug's Math Aquarium
(commercial) and MathVISION (commercial), who offered me a technology
trade: His fixed point arithmetic Mandelbrot set calculation routines in
exchange for my tips on shaded rendering.
Everybody will profit from this: The MathVISION users get even smoother
pictures, and the MandelMountains users much faster calculation speed.
No sooner had I experienced the speed of integer/fixed point arithmetic,
than I rewrote most of the rendering algorithm in assembler, using double
precision floating point format only where necessary, otherwise FFP and, if
possible, integer arithmetic. Note the increased drawing speed!
A problem in MandelMountains V1.1/V2.0 was the incompatibility of the image
files with some (not all) of the commercial graphics software (e.g.
Butcher, ShowPrint II and older versions of DPaint), which crashed when
trying to load compressed MandelMountains images.
I checked my IFF/ILBM compression algorithm and found that it was not
fully standard - some strange bug caused trashed BODY chunks.
After having replaced it with the original algorithm published by EA/C-A,
the problem was solved.
Another advantage: The files produced by the new algorithm are some
kilobytes shorter than the old ones, so it's a good idea to load and
re-save all previously generated images!
To be absolutely sure, I implemented the option to save an image without
the MMD1 chunk, so the image files can be loaded into software having
problems with alien IFF chunks.
Be careful when saving without MMD1 chunk: The resulting file cannot be
loaded into MandelMountains any more!
The third change in MandelMountains V2.1: the workbench window will not be
cleared during rendering, so the parameters remain visible. The menu will
stay active, too, although only a few menu options will be available.
Probably the most useful feature is that the task priority is now
changeable during computation.
Doug Houck also gave me a valuable comment on the lacking response from the
USA on MandelMountains V1.1:
"America is a big enough country that we seldom have to deal with airmail and
other currencies, which we see as an inconvenience. Especially if we have
to go the post office to get a customs sticker, or to the bank to get an
international money order, it's too much of a threshhold to get over.
On the other hand, in the European Community, you are much more used to
dealing with other languages/currencies/airmail, and it's no big bother to
send a couple measly dollars/francs/Deutschmarks via airmail to a starving
Shareware author."
So here are some hints how to send disks/cash:
To send a single disk, a legal size envelope will be enough, for more disks
preferably use a padded envelope. In the latter case, you'll need a customs
sticker which you get at your post office. Mark the contents as Public
Domain disk, value $1 - and it will work just fine.
To send cash, you can simply put on two first-class stamps (2 * 25 = 50
cents), an airmail envelope is desirable but not necessary.
At this point, I have to thank everybody who supported me with shareware
contributions, suggestions and criticism. I have finally achieved an
international echo - from Germany, Switzerland, Denmark, Great Britain, the
USA, and even from Australia!
If the support continues in this way, MandelMountains V3.0 will be reality
in a not too far future - with animation, support for 3D glasses (in case I
get the technical specifications) and many other new features.
SUPPORT SHAREWARE!
IMAGE SERVICE:
If you have produced some really good looking images, feel free to send
them to me for inclusion in the MandelMountains Image Bank. If you are
a registered MandelMountains user, you'll get your disk returned with a
selection of the best images I received up to that time, and (if available)
a new version of MandelMountains (please state which version you're using).
About the parameter files:
In the 'Parameters' subdirectory you'll find some files containing the
parameters of sample images (some of them were already published with older
releases of MandelMountains, so this is also a special service for the new
users).
To re-render one of the images, simply load it (a black screen will be
displayed), choose your preferred screen size (default is small/interlaced,
but I recommend overscan/interlaced) and start the rendering.
Mandel1.PARM - Example1.pic/Fish #295
Mandel2.PARM - ExamplePAL.pic/Fish #295
Mandel3.PARM - Example3.pic/Fish #295, but MUCH better!
Mandel4.PARM - new
Mandel5.PARM - Mandel1.NTSC/Fish #354
Mandel6.PARM - new
Mandel7.PARM - new
Julia1.PARM - new
Julia2.PARM - Julia2.PAL/Fish #354
Julia3.PARM - new
MandelMountains Program History:
** Version 2.0 -> 2.1 ********************************************************
- Increased rendering speed by implementing Doug Houck's fixed point
arithmetic Mandelbrot/Julia set iteration routines and optimizing the
whole rendering algorithm (2-3 times faster).
- Implemented a new IFF/ILBM compression algorithm, resulting in better
compatibility with commercial graphics software and shorter image
files.
- Added the option to save without MMD1 chunk.
- Parameters remain visible during rendering, as well as the menu is
not disabled any more.
- Added a 'library check' mechanism. Probably due to a bug in the
exec.library, libraries loaded from disk can be flushed if there
is not enough memory, even if they are being used! To avoid crashes
caused by this, I re-open all disk-resident libraries after each
memory allocating operation to make sure they are still present.
- Fixed several minor bugs.
** Version 1.1 -> 2.0 ********************************************************
- Added the JULIA SET option
- Added the DOUBLE PRECISION mode for higher magnification factors and
for making use of an optional 68881/82 coprocessor (with 1.3 libraries)
- Replaced my own file requester by Justin V. McCormick's great PathMaster
- Extended the layout of the parameter display window (including display
of the magnification factor)
- Color Range now changeable with the F1/F2 keys
- Fixed a bug that caused a black 1-pixel border at the right edge of an image
- Implemented the Depth and HZoom precalculation
- Optimized rendering routines - now about 5-15% faster!
- Fixed the problem with the vertical sprite bar sometimes appearing in the
lower part of the screen on PAL Amigas (probably caused by a bug in
the graphics.library). Since FreeSprite() didn't work, I had to use
a more rude method: I now directly disable Sprite DMA by resetting
the appropriate bit in DMACON. Sorry, but I couldn't find a better solution!
- When saving an image for the second time, the icon will NOT be written
again, thus preserving the position of the old one.
- Fixed several minor bugs.
******************************************************************************