Emanuele Feronato

Talking about BoxHead game, Flash and Game development.

One of the most popular Flash games is BoxHead by Sean Cooper, that released the 5th game of the series called The Zombie Wars.

At the moment I am just giving a small prototype of the “hero” controlled with arrow keys and the “zombie” chasing the hero.

One of the interesting things about BoxHead is that all movements are based upon old 8-ways system… this means hero and zombies can walk only on 0, 45, 90, 135, 180, 225, 270 and 315 degrees.

So there is not so much trigonometry involved in it.

_root.attachMovie("hero","hero",_root.getNextHighestDepth(),{_x:250, _y:200});
_root.attachMovie("zombie","zombie",_root.getNextHighestDepth(),{_x:25, _y:20});
hero_speed = 1.5;
zombie_speed = 1;
zombie.same_rotation = 0;
hero.onEnterFrame = function() {
	xspeed = 0;
	yspeed = 0;
	if (Key.isDown(Key.LEFT)) {
		xspeed -= hero_speed;
	}
	if (Key.isDown(Key.RIGHT)) {
		xspeed += hero_speed;
	}
	if (Key.isDown(Key.UP)) {
		yspeed -= hero_speed;
	}
	if (Key.isDown(Key.DOWN)) {
		yspeed += hero_speed;
	}
	if ((xspeed != 0) and (yspeed != 0)) {
		xspeed *= 0.707;
		yspeed *= 0.707;
	}
	this._x += xspeed;
	this._y += yspeed;
	switch (xspeed) {
		case hero_speed :
			this._rotation = 90;
			break;
		case -hero_speed :
			this._rotation = -90;
			break;
		default :
			switch (yspeed) {
				case hero_speed :
					this._rotation = 180;
					break;
				case -hero_speed :
					this._rotation = 0;
					break;
				case hero_speed*0.707 :
					if (xspeed == hero_speed*0.707) {
						this._rotation = 135;
					}
					if (xspeed -= hero_speed*0.707) {
						this._rotation = -135;
					}
					break;
				case -hero_speed*0.707 :
					if (xspeed == hero_speed*0.707) {
						this._rotation = 45;
					}
					if (xspeed -= hero_speed*0.707) {
						this._rotation = -45;
					}
					break;
			}
	}
};
zombie.onEnterFrame = function() {
	this.same_rotation++;
	dist_x = this._x-hero._x;
	dist_y = this._y-hero._y;
	angle = Math.atan2(dist_y, dist_x);
	real_rotation = angle*57.2957795-90;
	this._save_rotation = this._rotation;
	if (this.same_rotation>15) {
		this._rotation = Math.round(real_rotation/45)*45;
	}
	if (this._rotation != this._save_rotation) {
		this.same_rotation = 0;
	}
	switch (this._rotation) {
		case 0 :
			this._y -= zombie_speed;
			break;
		case 45 :
			this._y -= zombie_speed*0.707;
			this._x += zombie_speed*0.707;
			break;
		case 90 :
			this._x += zombie_speed;
			break;
		case 135 :
			this._y += zombie_speed*0.707;
			this._x += zombie_speed*0.707;
			break;
		case -180 :
			this._y += zombie_speed;
			break;
		case -135 :
			this._y += zombie_speed*0.707;
			this._x -= zombie_speed*0.707;
			break;
		case -90 :
			this._x -= zombie_speed;
			break;
		case -45 :
			this._y -= zombie_speed*0.707;
			this._x -= zombie_speed*0.707;
			break;
	}
};

I will comment the code later, meanwhile if you have questions post them in the comments.

Download the source code and give me feedback