Flitter is a functional programming language and declarative system for describing 2D and 3D visuals. The language is designed to encourage an iterative, explorative, play-based approach to constructing visuals.
The engine is able to live reload all code and assets (including shaders, images, videos, models, etc.) while retaining the current system state - thus supporting live-coding. It also has support for interacting with running programs via MIDI surfaces.
Flitter is implemented in a mix of Python and Cython and requires at least
OpenGL 3.3 (Core Profile) or OpenGL ES 3.0. At least Python 3.10 is also
required as the code uses match/case syntax.
Flitter is designed for expressivity and ease of engine development over raw performance, but is fast enough to be able to do interesting things.
The engine that runs the language is capable of:
- 2D drawing (loosely based on an HTML canvas/SVG model)
- 3D rendering,
including:
- primitive box, sphere, cylinder and cone shapes
- external triangular mesh models in a variety of formats including OBJ and STL
- planar slicing, union, difference and intersection of solid models
- ambient, directional, point/sphere, line/capsule and spotlight sources (currently shadowless)
- multiple (simultaneous) cameras with individual control over location, field-of-view, clip planes, render buffer size, color depth, MSAA samples, perspective/orthographic projection, fog, conversion to monochrome and colour tinting
- PBR forward-rendering pipeline with emissive objects, transparency and translucency, plus the ability to plug in custom GLSL shaders for arbitrary groups of objects
- texture mapping, including with the output of other visual units (e.g., a drawing canvas or a video)
- simulating physical particle systems, including spring/rod/rubber-band constraints, gravity, electrostatic charge, adhesion, buoyancy, inertia, drag, barriers and particle collisions
- playing videos at arbitrary speeds (including in reverse)
- running GLSL shaders as stacked image filters and generators, with per-frame control of arbitrary uniforms
- compositing all of the above and rendering to one or more windows
- saving rendered output to image and video files (including lockstep frame-by-frame video output suitable for producing perfect loops and direct generation of animated GIFs)
- taking live inputs from Ableton Push 2 or Behringer X-Touch mini MIDI surfaces (other controllers relatively easy to add)
- driving arbitrary DMX fixtures via an Entec-compatible USB DMX interface
- driving a LaserCube plugged in over USB (other lasers probably easy-ish to support)
Flitter can be installed from the flitter-lang PyPI
package with:
pip3 install flitter-langand then run as:
flitter path/to/some/flitter/script.flMore details can be found in the installation documentation.
The documentation is available on Read the Docs.
There are a few quick examples in the main repository. However, there is also a separate repo containing many more interesting examples that are worth checking out.