I think I give up for today...
Seems something I changed fixed/broke the glitches in a different way. this is near the location in the first post in this thread, but the glitches are now fuzzy instead of bold. I had to translate the minibrot because with the reference inside the whole image was solid black...
offsetting the location (and thus primary reference) by 1/4 pixel increments changes the texture of the glitched area
still not correct. this one has subtler textures in the glitch region instead of pixelated rectangles...
made another little techno thing, using some ideas from https://mathr.co.uk/blog/2015-06-26_calendar_2015_gradient.html
I spent most of this evening making backup floppies of my vital tools, because I was getting some read errors on various disks... one of them even had a bad sector and couldn't be reformatted.
I now have 3x Workbench2.0 copies, 2x BlitzBasic2, and 2x of my code+tools disk (with my MIDI transfer stuff, useful tools like LhA, DMS, XCopy, and also Workbench2.0 in 8 DMS parts).
I found some issues with my Amiga implementation of recv7 - somehow it uses much more RAM than it's supposed to, and with memory fragmentation it's only reliable for small transfers (e.g. 64KiB), hence the 8 parts.
So I guess I need to write a much more elaborate program, probably with more than one task (thread). One for allocating memory blocks and filling them from the serial port, one to decode them from 7bit-MIDI-safe to normal 8bit data, and one to write them out to disk and free/recycle the memory. And all of this with a way to interrupt with Ctrl-C.
I also got some software failure messages, 0100 000C if I remember correctly - that might be my code writing out of boudnds RAM it shouldn't be? Or some of the other programs I'm running. Strangely soft reboot wouldn't fix it, I had to power off/on at the brick.
I set up my A500+ again, using ATI TV Wonder video capture card in a Pentium 4 desktop, connected to a VGA monitor.
I found the floppy disk with my utils (written in Blitz Basic 2) for sending/receiving files via MIDI SysEx. recompiled the receiver with a larger buffer size so I could send LhA.run downloaded from aminet (buffer needs to be at least 2N+3 bytes for an N byte file). made a backup as the disk had some read/write errors.
I needed to write 2 small utils in C on the Linux side to do the what the attachched did on the Amiga side, but I made them work as stdio filters - the actual transfer is done with the amidi tool.
Then connecting MIDI: the Amiga external ProMIDI interface out/in to my Linux external UA-25 interface in/out (got them plugged correctly on first try).
Transferred lha.run to Amiga, ran it to decompress it, archived my source code to a new lha archive, transferred them to Linux.
Set up FS-UAE on my laptop, installed Workbench2.0_GB.adf onto a virtual hard drive, rebooted, installed Blitz Basic 2 from CD ISO (downloaded from archive.org), installed lha.run amigae33a.lha and ec33a.lha from aminet, so that I can do some develoment emulated, with a keyboard that works properly (A500+'s E key is broken, and 2 and S are a bit dodgy).
Cantor target fractal loop
2 refractive spheres inside a checkered sphere. Colour fringes from varying index of refraction vs wavelength. Performance is much faster with explicit ray-sphere intersections than SDF ray marching, for this simple scene on my tablet.
Eventually I did the algebra by hand for the visualisation part. The analytic part (root-finding, etc) is still broken at the moment.
Formula is z^2 |z|^a + c, with a fractional and/or negative. I also implemented power 3 and 4 versions. In the animation, a varies between about +/-0.4.
I added motion blur as suggested by lycium in the fractal chats discord, not sure if I like it (I think 8 subframes is not enough to avoid steppy appearance, and rendering 8x as many frames takes 8x as long, it took 3 hours to render 1024 images for this 128 frame output, not counting the time taken to trace the rays to the locations etc).
quite pleased with parts of this, though when the number of branches jumps a few times in quick succession it's a bit annoying. maybe i can ping-pong some of the longer sections (corresponding to the 1/3, 1/2, 2/3 child bulbs)
The first 3 prefixes were 1 1/2 2 1/2 3 followed by:
- 1/10 28
- 1/8 24 1/2 28
- 1/7 21 1/2 28
where the first is what I designed, and the other 2 are extrapolated. I think the change of /10 to /8 and /7 messed up the structural assumptions of the suffix, which was
1/2 56 1/2 57 1/2 58 1/3 144 1/2 145 1/2 146 1/3 320 ... 1378
In particular the influencing island had period 3 and the influencing angle was n/10, so 3*10=30 aligned nicely with the repeated structure of p->2p+30 in the angled internal addresses; while the non-n/10 addresses are forced/unrelated so don't look as good...
mildly stroboscopic animation
Playing with colour cycling again, this time with OpenGL GLSL colouring algorithms (for colouring based on distance estimate (black filaments) and iteration count (white and red bands).
Software: KF, plus a bash script to update the ColorOffset field in the palette, plus ImageMagick and gifsicle.
In the process was reminded of old idea to make ColorOffset fractional instead of integer for more flexibility. Also old feature requests to have colour cycling in-program.
Magic number for this fractal is 30, the red bands are spaced that many iterations apart making the colours synchronize with the shapes.
Also worked on the transformation dialog, moved the "Auto Skew (Escape)" feature there from the old Newton zoom dialog.
I made it display the difference between the old transformation and new transformation, as trying to display the total transformation in an editable way was getting too confusing for me. (The difference is needed to warp the image without recalculating the pixels, the total is needed for recalculating the pixels at which point the warping transformation should be reset to identity.)
I also made it so the number entry boxes have spin buttons so that editing is easier (in fact you can get live results from the edit boxes, rather than having to edit without being able to see the results before clicking OK).
making art with maths and algorithms
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