https://github.com/nqpz/futswirl

Fun with IFS fractals :boom:
https://github.com/nqpz/futswirl

fractals futhark

Last synced: 26 days ago
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Fun with IFS fractals :boom:

• Host: GitHub
• URL: https://github.com/nqpz/futswirl
• Owner: nqpz
• License: gpl-3.0
• Created: 2019-07-06T22:41:11.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2024-02-04T15:53:54.000Z (9 months ago)
• Last Synced: 2024-03-18T17:25:41.106Z (8 months ago)
• Topics: fractals, futhark
• Language: Futhark
• Homepage:
• Size: 184 KB
• Stars: 4
• Watchers: 3
• Forks: 1
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: COPYING

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README

        
# futswirl

![Screenshot](swirl.png)

futswirl is a small framework for working with

[IFS](https://en.wikipedia.org/wiki/Iterated_function_system) fractals.

Requires [Futhark](http://futhark-lang.org) and SDL2 and SDL2-ttf

libraries with associated header files.

## Building and running

Run `make run` to build and run in a window.  Adjust settings in

`settings.fut`.

## Rendering approaches

futswirl supports two ways of rendering fractals:

  - **scalarloop**: Every point is calculated efficiently without any

    intermediate memory accesses.  This approach also allows rendering

    more points that can be manifested in memory, as the mapping over

    all points is fused with the later pixel rendering phase.

  - **cullbranches** (default): When zoomed in, this approach will

    choose to not calculate branches whose points are not shown.  This

    allows for much further zooming, but needs to loop over arrays, not

    scalars, and as such has more memory accesses than the

    **scalarloop** approach.  Note: You might run out of memory if you

    don't watch out.  Also, fractals have varying levels of locality, so

    this approach will not always be able to cull a lot (the printed

    "rotated square radius" value needs to be low).

## Controls

  - `ESC`: Exit the program.

  - `F1`: Toggle the text in the upper-left corner.

  - `1`: Generate a new random fractal (shown when the default fractal

    `random` is picked).

  - `2`, `3`, `4`: Do the same as `r`, but limit the kind of random

    fractals to 2, 3, or 4 transforms per iteration.

  - `0`: Toggle auto mode.  When enabled, futswirl will automatically

    generate new random fractals (when the default `random` is picked)

    once in a while.

  - `r`: Toggle between the two rendering approaches.

  - `d`: Toggle between 2D fractals and 3D fractals.

  - `f`: Toggle between 32-bit floats and 64-bit floats.

  - Left/right: Change which fractal to show.

  - Down/up: Adjust the number of iterations for the current kind of

    fractal (only affects the scalarloop rendering approach).

  - PageUp/PageDown: Zoom in/out.

  - Home: Reset viewport.

  - Left click and drag: Adjust the viewport.

  - Mouse wheel scroll: Zoom in/out.

  - Right click: Automatic zoom.

  - Right click and mouse wheel scroll: Adjust automatic zoom speed.

  - Shift+Left/Right/Down/Up: Adjust the viewport.

  - Space: Pause/unpause.

Time moves slower when zoomed in.  This keeps the fractal movement at a

manageable pace even when the viewport is small.

## Adding new fractals

Define your fractals in `swirl/fractals_2d.fut` and `swirl/fractals_3d.fut`.

## License

futswirl is free software under the terms of the GNU General Public

License version 3 (or any later version).  Copyright (C) 2019, 2020

Niels G. W. Serup.