Particle Link

A Java Swing project that simulates a dynamic particle field where particles move, bounce off walls, and connect with nearby particles using color-blended lines. Inspired by Diogo Correia's website's background;

This project was built as a practice exercise to explore:

• OOP in Java
• Swing graphics and rendering
• Animation using javax.swing.Timer
• Color manipulation using HSB (Hue, Saturation, Brightness)

Overview

• 100 animated particles
• Directional movement using trigonometry
• Border collision detection with color changes
• Dynamic line connections betweens nearby particles

Preview

How It Works

Each Particle object contains:

• x, y - Position
• r - Radius
• dir - Direction (degrees)
• hue - Color value (HSB)

Movement is calculated using basic trigonometry.

double rad = Math.toRadians(dir);
x += Math.sin(rad) * step;
y -= Math.cos(rad) * step;

How the blending works:

1. Calculate the difference between two hues.

$\Delta h_{\text{raw}} = h_2 - h_1$

float dif = hue2 - hue;

2. Finding the shortest path around the colour wheel to ensure proper colour blending.

$\Delta h_{\text{circle}} = \left( (\Delta h_{\text{raw}} + 180^\circ) \bmod 360^\circ \right) - 180^\circ$

dif = ((dif + 180f) % 360f);
if (dif < 0) dif += 360f;
dif -= 180f;

3. Mixing the hues by moving halfway toward the second particle's hue.

$h_{\text{mix}} = (h_1 + \frac{\Delta h_{\text{circle}}}{2}) \bmod 360^\circ$

float mixedHue = (hue + dif / 2f + 360f) % 360f;