Crate turbine_reactive

Design, Animate and Program Geometry

With other words: It is a type safe, dynamic, functional reactive library with homotopy maps.

This library uses ideas researched by Sven Nilsen of using homotopy maps to construct geometry. Control points flags and ragdoll engine is based on Cutout Pro's Elemento.

Motivation

This libray is intended for design, animating and programming geometry.

Function reactive programming is more fun when dynamic. This means the user can modify the behavior at runtime.

The use of homotopy maps is a promising technique for constructing geometry. A homotopy map is a continuous function that maps from N-dimension normalized coordinates to some M-dimensional space. See https://github.com/pistondevelopers/construct for more information.

The problem with dynamic frameworks for functional reactive programming is that there often is a tradeoff with making it nice to use at compile time. For example, when getting a reference to a spline, it is easy to accidentally use it with another type, e.g. a surface.

By separating memory by function types, it is possible to make the API type safe in Rust.

Features (work in progress)

• Functional graph evaluation
• Environment with time and delta time (allows formal reasoning about animation and motion)
• Homotopy maps up to 4D
• Colors (converts sRGB to linear color space for internal use)
• Ragdoll physics
• Fine tuned control over caching
• Control point selection and locking

Goals

• Create a modernized version of Cutout Pro's Elemento core for use in Turbine
• Reusable in other game engines
• Design for editing in VR
• AI behavior trees (not decided yet)

Design

All data is stored in memory by their function type. This means one function can reference another function using an index, while keeping type safety at compile time.

Objects are created by combining functions.

Modules

color	Helper methods for colors
fns	Higher order structures for functions (including data).
ptr	Pointers to higher order structures.

Structs

Cache	Used to store temporary values of shared functions to speed up computation. By default, all function outputs that are referenced more than once are cached. To signal that some function output should be cached, None is stored in a hash map. When performing the first computation of that output, Some(value) is stored in the cache.
Environment	Used to set runtime behavior of external evaluation.
Physics	Stores intermediate data for physics simulation.
Reactor	Stores data for an reactive document.
Selection	Stores selection state.

Type Definitions

Bone1	Bone for 1D.
Bone2	Bone for 2D.
Bone3	Bone for 3D.
Bone4	Bone for 4D.
BoneRef1	Bone reference for 1D.
BoneRef2	Bone reference for 2D.
BoneRef3	Bone reference for 3D.
BoneRef4	Bone reference for 4D.
Color	Color stored as normalized [r, g, b, a].
ColorComponent	Color component type.
Spline1	Spline for scalars.
Spline2	Spline for 2D.
Spline3	Spline for 3D.
Spline4	Spline for 4D.
SplineRef1	Spline reference for scalar.
SplineRef2	Spline reference for 2D.
SplineRef3	Spline reference for 3D.
SplineRef4	Spline reference for 4D.
Surface1	Surface for 1D.
Surface2	Surface for 2D.
Surface3	Surface for 3D.
Surface4	Surface for 4D.
SurfaceRef1	Surface reference for scalar.
SurfaceRef2	Surface reference for 2D.
SurfaceRef3	Surface reference for 3D.
SurfaceRef4	Surface reference for 4D.