90 lines
1.9 KiB
Plaintext
90 lines
1.9 KiB
Plaintext
// The Nature of Code
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// Daniel Shiffman
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// http://natureofcode.com
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// Vehicle class
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class Vehicle {
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// All the usual stuff
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PVector position;
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PVector velocity;
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PVector acceleration;
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float r;
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float maxforce; // Maximum steering force
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float maxspeed; // Maximum speed
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// Constructor initialize all values
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Vehicle(float x, float y) {
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position = new PVector(x, y);
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r = 12;
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maxspeed = 3;
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maxforce = 0.2;
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acceleration = new PVector(0, 0);
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velocity = PVector.random2D();
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velocity.mult(random(1,4));
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}
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void applyForce(PVector force) {
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// We could add mass here if we want A = F / M
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acceleration.add(force);
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}
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// Alignment
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// For every nearby boid in the system, calculate the average velocity
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void align (ArrayList<Vehicle> boids) {
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float neighbordist = 30;
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PVector sum = new PVector(0, 0);
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int count = 0;
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for (Vehicle other : vehicles) {
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float d = PVector.dist(position, other.position);
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if ((d > 0) && (d < neighbordist)) {
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sum.add(other.velocity);
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count++;
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}
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}
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if (count > 0) {
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sum.div((float)count);
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sum.normalize();
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sum.mult(maxspeed);
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PVector steer = PVector.sub(sum, velocity);
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steer.limit(maxforce);
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applyForce(steer);
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}
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}
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// Method to update position
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void update() {
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// Update velocity
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velocity.add(acceleration);
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// Limit speed
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velocity.limit(maxspeed);
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position.add(velocity);
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// Reset accelertion to 0 each cycle
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acceleration.mult(0);
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}
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void display() {
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fill(175);
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stroke(0);
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pushMatrix();
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translate(position.x, position.y);
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ellipse(0, 0, r, r);
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popMatrix();
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}
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// Wraparound
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void borders() {
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if (position.x < -r) position.x = width+r;
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if (position.y < -r) position.y = height+r;
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if (position.x > width+r) position.x = -r;
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if (position.y > height+r) position.y = -r;
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}
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}
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