[−][src]Crate gravitas
Gravitas is a collection of equations for making UI elements move in response to touch gestures.
There are also implementations for Java and JavaScript (which has some interactive examples).
Each simulation models a single value and generally has a setup function that takes the initial position and velocity. Normally you would compute these in response to a touch gesture ending. All of the simulations are parametric over time and have been algebraically integrated (rather than using a numerical integration method at runtime). The advantage of algebraic integration is lower CPU overhead, and no odd behavior if frames are dropped.
Structs
| Friction | a position with velocity that slows down due to drag. |
| Gravity | a position under the influence of gravity (or any other constant acceleration), as defined by Newton's 2nd Law: |
| Scroll | a combination of friction and springs to create a touch-driven scrolling simulation. |
| Spring | a position controlled by a spring as defined by Hooke's law, |
Traits
| Simulation | common methods implemented by every simulation allowing easy integration into an animation system. |