player.js

class Player {
    constructor() {
        this.position = createVector(
            gTerrain.width * 0.2,
            gTerrain.height / 2
        );

        this.acceleration = createVector();
        this.velocity = createVector();
        this.isDead = false;

        // amount of frames the player was alive
        this.framesAlive = 0;

        this.referenceMaxVelocity = 3;

        // make radius depend on terrain height (-> dynamic)
        this.radius = gTerrain.height * 0.03;

        // amount of sensors of each player
        this.sensorAmount = 12;
        // sensors that measure distance between player and terrain / obstacles
        this.sensors = [];

        // current calculated fitness of the player
        this.fitness = 0;

        /*
        input: 	amount of sensors and x/y velocity
        output:	x/y acceleration
        */
        this.inputNeurons = this.sensorAmount + 2;
        this.hiddenNeurons = [10, 7];
        this.outputNeurons = 2;

        // neural network that serves as the "brain"
        this.neuralNet = new biolib.Perceptron(this.inputNeurons, ...this.hiddenNeurons, this.outputNeurons);
        this.neuralNet.setActivationFunction(biolib.Activation.TANH);

        this.initSensors();
    }

    initSensors() {
        let directions = Utilities.getCircumferencePoints(0, 0, 1, this.sensorAmount);

        for (let i = 0; i < directions.length; i++) {
            // increase direction length to reduce processing power
            directions[i].mult(3);

            this.sensors.push(new Sensor(directions[i].x, directions[i].y));
        }
    }

    show() {
        fill(225, 99, 72);
        stroke(182, 78, 56);
        strokeWeight(4);

        ellipse(this.position.x, this.position.y, this.radius * 2, this.radius * 2);
        ellipse(this.position.x, this.position.y + this.radius);

        this.showSensors();
    }

    showSensors() {
        if (!this.isDead) {
            for (let i = 0; i < this.sensors.length; i++) {
                //this.sensors[i].show();
            }
        }
    }

    update() {
        // don't do anything if player is dead
        if (this.isDead) {
            this.position.x -= gTerrain.velocity;
            return;
        }

        this.updateSensors();
        this.updateAcceleration();

        this.velocity.add(this.acceleration);
        this.position.add(this.velocity);

        this.framesAlive++;

        // check for terrain / obstacle collisions
        if (gTerrain.collidesCircle(this.position.x, this.position.y, this.radius)) {
            this.isDead = true;
        }
    }

    updateSensors() {
        for (let i = 0; i < this.sensors.length; i++) {
            this.sensors[i].update(this.position.x, this.position.y);
        }
    }

    updateAcceleration() {
        let input = [];

        for (let i = 0; i < this.sensors.length; i++) {
            input[i] = map(pow(this.sensors[i].distance, 2), 0, pow(gTerrain.height, 2), -1, 1);
        }

        input.push(map(pow(this.velocity.x, 3), -pow(this.referenceMaxVelocity, 3), pow(this.referenceMaxVelocity, 3), -1, 1));
        input.push(map(pow(this.velocity.y, 3), -pow(this.referenceMaxVelocity, 3), pow(this.referenceMaxVelocity, 3), -1, 1));

        let output = this.neuralNet.feedForward(input);

        this.acceleration.x = output[0];
        this.acceleration.y = output[1];
    }

    calculateFitness() {
        this.fitness = pow(this.framesAlive, 3);
    }
}