boids-sim/Flock.js at main · RichuSuresh/boids-sim · GitHub

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class Flock{
    constructor(boids) {
        this.boids = boids;
        this.avoidFactor = 0.005;
        this.protectedRange = 25;
        this.visibleRange = 150;
        this.matchingFactor = 0.05;
        this.centeringFactor = 0.001;
        this.turnFactor = 0.08;
    }

    algorithm(){

        this.boids.forEach(boid => {
            let closeDx = 0;
            let closeDy = 0;
            let xposAvg = 0;
            let yposAvg = 0;
            let xvelAvg = 0;
            let yvelAvg = 0;
            let neighbouringBoids = 0;
            const otherBoids = this.boids.filter(otherBoid => otherBoid != boid)
            otherBoids.forEach(otherBoid => {
                let dx = boid.x - otherBoid.x;
                let dy = boid.y - otherBoid.y;
                if (Math.abs(dx) < this.protectedRange && Math.abs(dy) < this.protectedRange){
                    const distance = dx * dx + dy * dy;
                    if (distance < this.protectedRange * this.protectedRange){
                        closeDx += boid.x - otherBoid.x;
                        closeDy += boid.y - otherBoid.y;
                    }
                    else if (distance < this.visibleRange * this.visibleRange){
                        xposAvg += otherBoid.x;
                        yposAvg += otherBoid.y;
                        xvelAvg += otherBoid.vx;
                        yvelAvg += otherBoid.vy;
                        neighbouringBoids++;
                    }
                }
            })
            if (neighbouringBoids > 0){
                xposAvg = xposAvg / neighbouringBoids;
                yposAvg = yposAvg / neighbouringBoids;
                xvelAvg = xvelAvg / neighbouringBoids;
                yvelAvg = yvelAvg / neighbouringBoids;

                boid.vx = (boid.vx +
                        (xposAvg - boid.x)*this.centeringFactor +
                        (xvelAvg - boid.vx)*this.matchingFactor)

                boid.vy = (boid.vy +
                        (yposAvg - boid.y)*this.centeringFactor +
                        (yvelAvg - boid.vy)*this.matchingFactor)
            }

            boid.vx += (closeDx * this.avoidFactor);
            boid.vy += (closeDy * this.avoidFactor);

            const marginY = 300
            const marginX = 400
            if (boid.y < marginY){
                boid.vy += this.turnFactor;
            }
            if (boid.x > window.innerWidth - marginX){
                boid.vx -= this.turnFactor;
            }
            if (boid.x < marginX){
                boid.vx += this.turnFactor;
            }
            if (boid.y > window.innerHeight - marginY){
                boid.vy -= this.turnFactor;
            }
        })
    }
    move(){
        this.algorithm()
        this.boids.forEach(boid => {
            boid.move()
        });
    }
}

export default Flock