A Flutter project that uses explicit animations in a simple simulation of particles. The particles' movement is roughly based on the classic "N-Body" problem, in which each one exerts an attractive force on each other one inversely proportional to their distance apart.
Roughly speaking, the force calculation is Newton's law of universal gravitation. From there, some liberties are taken with how it affects velocity (let's be honest: so that I don't have to remember calculus). As an additional simplification, this simulation is only 2-dimensional!
The main body of the simulation is a Stack, and each particle widget is wrapped in Positioned to represent an x,y coordinate system.
The movement is controlled by an explicit animation. Each particle is has its own Animatable (the super-class of Tween), and all operate with the same controller.
On every frame/tick, the Animatable performs the calculation of what every particle widget's new velocity should be, and updates their locations appropriately.
This implementation makes no attempt at using correct math nor any of the known n-body optimizations. As such, it is an O(n2) calculation on every frame.
This project was also used as a platform for myself to learn more Flutter things. Nothing here should be taken as recommendations or best practices.