kf 2.15 released

I actually released kf-2.15 a couple of weeks ago, but I didn't get around to posting here about it. The highlights include OpenCL support (if you have a good GPU, this can make rendering faster, especially for hybrid formulas), hybrid formula designer (lots of options to make custom fractals), and exponential map transformation for optimizing zoom animations.

kf-2.15.1 (2020-10-28)

OpenCL support for perturbation iterations (requires double precision support on device: CPUs should work, some GPUs might not)

hybrid formula editor (design your own fractal formula)

exponential map coordinate transformation (useful for export to zoomasm for efficient video assembly)

rotation and skew transformations are rewritten to be more flexible (but old skewed/rotated KFR locations will not load correctly)

kf-tile.exe tool supports the new rotation and skew transformations

the bitrotten skew animation feature is removed

a few speed changes in built in formulas (one example, RedShiftRider 4 with derivatives is almost 2x faster due to using complex analytic derivatives instead of 2x2 Jacobian matrix derivatives)

flip imaginary part of Buffalo power 2 (to match other powers; derivative was flipped already)

slope implementation rewritten (appearance is different but it is now independent of zoom level and iteration count)

smooth (log) iteration count is offset so dwell bands match up with the phase channel

swiftly followed by

kf-2.15.1.1 (2020-10-28)

fix OpenCL support for NVIDIA GPUs (reported by bezo97)

fix crash in aligned memory (de)allocation (reported by gerrit)

documentation improvements (thanks to FractalAlex)

and today by

kf-2.15.1.2 (2020-11-08)

refactor OpenCL error handling to display errors in the GUI without exiting

OpenCL hybrids: fix breaking typo in neg x (reported by Microfractal)

I recorded a screencast video to show how to make fractal zoom videos with kf-2.15 and zoomasm-1.0, and there are a couple of zoom videos I made with them too:

Making fractal zoom videos with kf-2.15 and zoomasm-1.0: https://archive.org/details/making-fractal-zoom-videos-with-kf-2.15-and-zoomasm-1.0; https://www.youtube.com/watch?v=72IIn7C3UeI
Charred Bard: https://archive.org/details/charred-bard; https://www.youtube.com/watch?v=NMKBBk-yf_4
Special Branch: https://archive.org/details/special-branch; https://www.youtube.com/watch?v=uQDV87vVIxk