Implement velocity changing

static/js/background_anim.js

@@ -14,6 +14,9 @@ const DOT_FILL_COLOUR = "#666";
 const DOT_OUTLINE_COLOUR = "#444";
 const LINE_COLOUR = "#777";
 
+const VELOCITY_SLOWDOWN_MULTIPLIER = 0.998;
+const VELOCITY_PUSH_MULTIPLIER = 1.8;
+
 // ----
 
 // Sort-of constants (change with window size)
@@ -211,6 +214,10 @@ const physics = () => {
         dot.vx = clamp(dot.vx, -VELOCITY_MAX, VELOCITY_MAX);
         dot.vy = clamp(dot.vy, -VELOCITY_MAX, VELOCITY_MAX);
 
+        // Slow down velocity
+        dot.vx *= VELOCITY_SLOWDOWN_MULTIPLIER;
+        dot.xy *= VELOCITY_SLOWDOWN_MULTIPLIER;
+
         // Stop velocity from going below initial velocity
         if(dot.vx < dot.initial_vx) {
             dot.vx = dot.initial_vx;
@@ -222,9 +229,11 @@ const physics = () => {
         // Invert velocities if off-screen and not already inverted
         if ((dot.x < 0 && dot.vx < 0) || (dot.x > canvas.width && dot.vx > 0)) {
             dot.vx = -dot.vx;
+            dot.vx *= VELOCITY_PUSH_MULTIPLIER;
         }
         if ((dot.y < 0 && dot.vy < 0) || (dot.y > canvas.height && dot.vy > 0)) {
             dot.vy = -dot.vy;
+            dot.vy *= VELOCITY_PUSH_MULTIPLIER;
         }
 
         // Make dots velocities react to mouse movement (deflected by mouse)
@@ -241,6 +250,9 @@ const physics = () => {
             dot.vx = -dot.vx;
             dot.vy = -dot.vy;
 
+            dot.vx *= VELOCITY_PUSH_MULTIPLIER;
+            dot.vy *= VELOCITY_PUSH_MULTIPLIER;
+
             dot.x = cx;
             dot.y = cy;
         }