I want to avoid overlapping particles like this:

Right now when adding particles (left mouse) i add 2 particles instead of 1. One is fixed at it's position (which i call anchor) and the other is not (which i call node). Then i make spring between the anchor and the node.

I make a repulsion for all the nodes.

This work's quite well (better then the image above).

However, i tried to get it working with zoom. So they only get pushed away by zooming (so most likely by zooming out).

It works a litle but not as good as i want to.

Also sometimes when you zoom very far and then zoom back the particles stay on top of each other no matter what.

Could someone help me?

1. 
   
2. import traer.physics.*;
3. 
   
4. ParticleSystem physics;
5. 
   
6. float particleMass = 1.0;
7. 
   
8. float zoom = 1;
9. 
   
10. float d_strength = 0;
11. 
    
12. void setup() {
13.   size(600, 600);
14.   smooth();
15.   frameRate(30);
16.   
17.   physics = new ParticleSystem();  
18.   physics.setGravity(0.0);
19.   physics.setDrag(1.0);
20. }
21. 
    
22. void draw() {
23.   background(255);
24.   
25.   physics.tick();
26.   
27.   for(int i = 0; i < physics.numberOfSprings(); i++) {
28.     Spring s = physics.getSpring(i);
29.     Particle anchor = s.getOneEnd();
30.     Particle node = s.getTheOtherEnd();
31.       
32.     noStroke();
33.     fill(255, 0, 0, 100);
34.     ellipse(zoomX(node.position().x()), zoomY(node.position().y()), 15, 15);  
35.     
36.     stroke(0);
37.     line(zoomX(node.position().x()), zoomY(node.position().y()), zoomX(anchor.position().x()), zoomY(anchor.position().y()));
38.   }
39.   
40.   fill(0);
41.   text("zoom: "+zoom, 20, 20);
42.   text("d_strength: "+d_strength, 20, 50);
43.   
44.   
45. }
46. 
    
47. float zoomX(float x) {
48.   return (x-width/2)*zoom+width/2;
49. }
50. 
    
51. float zoomY(float y) {
52.   return (y-height/2)*zoom+height/2;
53. }
54. 
    
55. float unzoomX(float x) {
56.   return (x - width/2) / zoom + width/2;  
57. }
58. 
    
59. float unzoomY(float y) {
60.   return (y - height/2) / zoom + height/2;  
61. }
62. 
    
63. void keyPressed() {
64.   if(key == '-') {
65.      zoom -= 0.1; 
66.      setAttractionStrengthBasedOnZoom();
67.   }  
68.   if (key == '=') {
69.     zoom += 0.1; 
70.     setAttractionStrengthBasedOnZoom();
71.   }
72.   
73. 
    
74. }
75. 
    
76. void setAttractionStrengthBasedOnZoom() {
77.     for(int i = 0; i < physics.numberOfAttractions(); i++) {
78.       Attraction a = physics.getAttraction(i);
79.       float stength = map(zoom, 0, 1, -2000, -1000); 
80.       stength = min(0, stength);
81.       a.setStrength(stength);
82.       d_strength = stength;
83.     }
84. }
85. 
    
86. 
    
87. void mousePressed() {
88.   
89.     Particle anchor = physics.makeParticle(particleMass, unzoomX(mouseX), unzoomY(mouseY), 0);
90.     anchor.makeFixed();
91.     
92.     Particle  node = physics.makeParticle(particleMass, unzoomX(mouseX), unzoomY(mouseY), 0);
93.     
94.     // If they are strong they act like a stick. If they are weak they take a long time to return to their rest length
95.     float strength = 1;
96.     // If springs have high damping they don't overshoot and they settle down quickly, with low damping springs oscillate.
97.     float damping = 1;
98.     // the spring wants to be at this length and acts on the particles to push or pull them exactly this far apart at all times.
99.     float restLength = 0;
100.     
101.     physics.makeSpring(anchor, node, strength, damping, restLength);
102.     
103.     // make repulsion for new one with every node
104.     for(int i = 0; i < physics.numberOfSprings(); i++) {
105.       Spring s = physics.getSpring(i);
106.       Particle a = s.getTheOtherEnd();
107.       strength = -1000;
108.       // wtf does this do?
109.       // 0 and i dont see shit
110.       // 500 and they will overlap when i click on them
111.       float minimumDistance = 10;
112.       physics.makeAttraction(a, node, strength, minimumDistance);
113.     } 
114.     
115.     // sloppy fast way to make sure new added one has same strength as others
116.     setAttractionStrengthBasedOnZoom();
117.  
118.     
119. }