class Bird{
	
	constructor(x){
		this.x = x;
		this.y = random(height * 0.05, height * 0.3);
		this.v = random([true, false]) ? random(3, 5) : random(-3, -5);
		this.length = random(50, 100);
	}
	
	move(){
		this.x += this.v;
		if (this.x - this.length / 2 > worldWidth) this.x = -this.length / 2;
		if (this.x + this.length / 2 < 0) this.x = worldWidth + this.length / 2;
	}
	
	show(){
		let wing = sin(0.02 * PI * this.x);
		if (this.x + this.length / 2 > viewPort.x && this.x - this.length / 2 < viewPort.x + width){
			fill(0);
			beginShape();
			vertex(this.x - this.length / 2, this.y);
			vertex(this.x - this.length * 0.4, this.y - this.length * 0.1);
			vertex(this.x + this.length * 0.15, this.y - this.length * 0.1);
			vertex(this.x + this.length * 0.15, this.y - this.length * 0.1 - this.length * 0.4 * wing);
			vertex(this.x + this.length * 0.1, this.y - this.length * 0.1 - this.length * 0.5 * wing);
			vertex(this.x + this.length * 0.05, this.y - this.length * 0.1 - this.length * 0.4 * wing);
			vertex(this.x, this.y - this.length * 0.1 - this.length * 0.5 * wing);
			vertex(this.x - this.length * 0.05, this.y - this.length * 0.1 - this.length * 0.4 * wing);
			vertex(this.x - this.length * 0.1, this.y - this.length * 0.1 - this.length * 0.5 * wing);
			vertex(this.x - this.length * 0.15, this.y - this.length * 0.1 - this.length * 0.4 * wing);
			vertex(this.x - this.length * 0.15, this.y - this.length * 0.1);
			vertex(this.x + this.length * 0.4, this.y - this.length * 0.1);
			vertex(this.x + this.length / 2, this.y);
			vertex(this.x + this.length * 0.4, this.y + this.length * 0.1);
			vertex(this.x - this.length * 0.4, this.y + this.length * 0.1);
			endShape();
			fill(255);
			ellipse(this.x + ((this.v > 0) ? 1 : -1) * this.length * 0.4, this.y - this.length * 0.025, this.length * 0.05);
		}
	}
}