Particle Simulator

In this particle simulator you can watch (and create) small particles, which, through attraction and repulsion, form interesting structures and even moving objects. 

This game is not finished and in active development. Please report any bug or tell me if you have a suggestion.

Controls:
SPACE: (un)pause game
1-6: quickspawn particles (1: red, 2: yellow, 3: green, 4: teal, 5: blue, 6: magenta)
LMB: spawn particle of selected colour
RMB: delete particles in circle
Mouse wheel: in-/decrease deletion radius

Menu
Open the control menu by clicking on the small (+) button in the top right.
There you can change:

• which particle is active for spawning
• delete all particles on the screen
• reset the sim, by deleting and creating new particles and randomizing the attraction values
• randomize the attraction values (explanation further down)
• change the attraction model (explanation further down)
• Change Temp (random movements)
• Change Size (purely visual)
• Change Friction (how quickly particles slow down if no attraction happens)
• Change Speed (general speed of movement)
• Toggle screen wrapping (if true, particles can teleport from one edge to the other)
• Toggle Connections (show which particles are in range for attraction (in red) or repulsion (in blue))
• Toggle Vectors (show movement direction & speed of particles)

Attraction Matrix & Attraction Model
Each particle colour is either attracted or repeled by each particle colour (even itself). In the code this is a value between -1.0 and 1.0 (negative values are repel, positive attract). 

At the start of the game a matrix (i.e. grid) is generated that determines these values. This can be regenerated.

The actual strength of attraction is further determined by the attraction model, currently 2 models are in the sim. In both all particles repel each other if they get too close. 

• In the first, the attraction gets stronger, has a maximum at the halfway distance,  then weaker and lands on zero. This creates large segmented structures.
• In the second model, the attraction simply linearly rises to its maximum at the minimal distance. This creates small, dense, energetic clusters.
• The third setting simply disables all attraction or repulsion.