let video;

let trackingColor = [0, 255, 0]; // Red color to track

let threshold = 40; // Threshold for color matching

let lastPosition;

let currentPosition;

​

function setup() {

  createCanvas(800, 600);

  frameRate(30);

  video = createCapture(VIDEO);

  video.size(800, 600);

  video.hide();

​

  particle = new Projectile(createVector(random(0, width / 2), random(height / 2, height)), createVector(3, -12));

  background(210);

}

​

function draw() {

  background(210, 210, 210, 5);

​

  // Update and draw the particle

  particle.update();

  particle.draw();

​

  // Create new particle on DOWN_ARROW key press

  if (keyIsDown(DOWN_ARROW)) {

    background(210);

    particle = new Projectile(createVector(random(0, width / 2), random(height / 2, height)), createVector(random(1, 8), random(-1, -15)));

  }

​

  // Display the video feed

  image(video, 0, 0);

​

  // Track the color and draw the marker

  trackColor();

  if (currentPosition) {

    fill(255, 0, 0);

    noStroke();

    ellipse(currentPosition.x, currentPosition.y, 10, 10);

  }

​

  // Predict the next position based on velocity

  if (lastPosition && currentPosition) {

    let velocity = p5.Vector.sub(currentPosition, lastPosition);

    let predictedPosition = p5.Vector.add(currentPosition, velocity);

​

    fill(0, 255, 0);

    ellipse(predictedPosition.x, predictedPosition.y, 10, 10);

  }

​

  lastPosition = currentPosition ? currentPosition.copy() : null;

}

​

function trackColor() {

  video.loadPixels();

  let closestDistance = Infinity;

  currentPosition = null;

​

  for (let y = 0; y < video.height; y++) {

    for (let x = 0; x < video.width; x++) {

      let index = (x + y * video.width) * 4;

      let r = video.pixels[index];

      let g = video.pixels[index + 1];

      let b = video.pixels[index + 2];

​

      let d = dist(r, g, b, trackingColor[0], trackingColor[1], trackingColor[2]);

      if (d < threshold && d < closestDistance) {

        closestDistance = d;

        currentPosition = createVector(x, y);

      }

    }

  }

}

​