94 lines
2.0 KiB
Plaintext
94 lines
2.0 KiB
Plaintext
// The Nature of Code
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// Daniel Shiffman
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// http://natureofcode.com
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class Vehicle {
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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 maxspeed;
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float maxforce;
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Vehicle(float x, float y) {
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acceleration = new PVector(0, 0);
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velocity = new PVector(1,0);
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velocity.mult(5);
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position = new PVector(x, y);
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r = 3;
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maxspeed = 3;
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maxforce = 0.15;
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}
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void run() {
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update();
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display();
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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 boundaries() {
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PVector desired = null;
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// Predict position 25 (arbitrary choice) frames ahead
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PVector predict = velocity.get();
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predict.mult(25);
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PVector futureposition = PVector.add(position, predict);
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float distance = PVector.dist(futureposition,circleposition);
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if (distance > circleRadius) {
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PVector toCenter = PVector.sub(circleposition,position);
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toCenter.normalize();
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toCenter.mult(velocity.mag());
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desired = PVector.add(velocity,toCenter);
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desired.normalize();
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desired.mult(maxspeed);
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}
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if (desired != null) {
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PVector steer = PVector.sub(desired, velocity);
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steer.limit(maxforce);
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applyForce(steer);
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}
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fill(255,0,0);
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ellipse(futureposition.x,futureposition.y,4,4);
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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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void display() {
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// Draw a triangle rotated in the direction of velocity
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float theta = velocity.heading2D() + radians(90);
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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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rotate(theta);
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beginShape(TRIANGLES);
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vertex(0, -r*2);
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vertex(-r, r*2);
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vertex(r, r*2);
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endShape();
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popMatrix();
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}
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}
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