Lava-lamp color

Intro

This is a cool simulation of a lava lamp implemented using “metaballs”. This time the lava lamp is colorful.

What do you need?

To run the code in this article you don’t need to install anything on your local computer.

Just open the online JavaScript playground from codeguppy.com/code.html and copy and paste the following code in the integrated editor.

When ready, press the “Play” button to run the code.

Source code

// Color lava lamp with metaballs
const w = 80;
const h = 60;
const displayStyle = 2;

var mult = 900;
var scaleX = width / w;
var scaleY = height / h;

colorMode(HSB);
noStroke();

var balls = [];

function enter()
{
    for(var i = 0; i < 5; i++)
    {
        balls.push({ x : random(w), y : random(h), dx : random(1, 2), dy : random(1,2)});
    }
}

function loop()
{
    update();
    display();
}

function update()
{
    for(var b of balls)
    {
        b.x += b.dx;
        b.y += b.dy;

        if (b.x > w || b.x < 0)
            b.dx *= -1;

        if (b.y > h || b.y < 0)
            b.dy *= -1;
    }
}

function display()
{
    for(var x = 0; x < w; x++)
    {
        for(var y = 0; y < h; y++)
        {
            var sum = 0;

            for(var b of balls)
            {
                sum += 1 / dist(x, y, b.x, b.y);
            }

            var col = mult * sum;
            displayDot(x, y, col);
        }
    }
}

function displayDot(x, y, col)
{
    fill(col, 255, 255);

    switch(displayStyle)
    {
        case 0:
            rect(x, y, 1, 1);
            break;
        case 1:
            rect(x * scaleX, y * scaleY, scaleX, scaleY);
            break;
        case 2:
            ellipse(x * scaleX + scaleX / 2, y * scaleY + scaleY / 2, scaleX, scaleY);
            break;
    }
}

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