three.proton/src/zone/ScreenZone.js

three.Proton is an easily customizable html5 particle engine for three.js

(function(Proton, undefined) {
    /**
     * ScreenZone is a 3d line zone
     * @param {Number|Vector3D} x1 - the line's start point of x value or a Vector3D Object
     * @param {Number|Vector3D} y1 - the line's start point of y value or a Vector3D Object
     * @param {Number} z1 - the line's start point of z value 
     * @param {Number} x2 - the line's end point of x value 
     * @param {Number} y2 - the line's end point of y value 
     * @param {Number} z2 - the line's end point of z value 
     * @example 
     * var lineZone = new Proton.ScreenZone(0,0,0,100,100,0);
     * or
     * var lineZone = new Proton.ScreenZone(new Proton.Vector3D(0,0,0),new Proton.Vector3D(100,100,0));
     * @extends {Zone}
     * @constructor
     */
    function ScreenZone(camera, renderer, dis, dir) {
        ScreenZone._super_.call(this);

        this.camera = camera;
        this.renderer = renderer;
        this.dis = dis || 20;
        dir = dir || "1234";
        for (var i = 1; i < 5; i++)
            this["d" + i] = dir.indexOf(i + "") >= 0;

        this.name = "ScreenZone";
    }


    Proton.Util.inherits(ScreenZone, Proton.Zone);
    ScreenZone.prototype.getPosition = function() {
        var vec2 = new Proton.Vector3D,
            canvas;

        return function() {
            canvas = this.renderer.domElement;
            vec2.x = Math.random() * canvas.width;
            vec2.y = Math.random() * canvas.height;
            this.vector.copy(Proton.THREEUtil.toSpacePos(vec2, this.camera, canvas));
            return this.vector;
        }
    }();

    ScreenZone.prototype._dead = function(particle) {
        var pos = Proton.THREEUtil.toScreenPos(particle.p, this.camera, this.renderer.domElement);
        var canvas = this.renderer.domElement;

        if ((pos.y + particle.radius < -this.dis) && this.d1) {
            particle.dead = true;
        } else if ((pos.y - particle.radius > canvas.height + this.dis) && this.d3) {
            particle.dead = true;
        }

        if ((pos.x + particle.radius < -this.dis) && this.d4) {
            particle.dead = true;
        } else if ((pos.x - particle.radius > canvas.width + this.dis) && this.d2) {
            particle.dead = true;
        }
    }

    ScreenZone.prototype._cross = function() {
        var vec2 = new Proton.Vector3D;
        return function(particle) {
            var pos = Proton.THREEUtil.toScreenPos(particle.p, this.camera, this.renderer.domElement);
            var canvas = this.renderer.domElement;

            if (pos.y + particle.radius < -this.dis) {
                vec2.x = pos.x;
                vec2.y = canvas.height + this.dis + particle.radius;
                particle.p.y = Proton.THREEUtil.toSpacePos(vec2, this.camera, canvas).y;
            } else if (pos.y - particle.radius > canvas.height + this.dis) {
                vec2.x = pos.x;
                vec2.y = -this.dis - particle.radius;
                particle.p.y = Proton.THREEUtil.toSpacePos(vec2, this.camera, canvas).y;
            }

            if (pos.x + particle.radius < -this.dis) {
                vec2.y = pos.y;
                vec2.x = canvas.width + this.dis + particle.radius;
                particle.p.x = Proton.THREEUtil.toSpacePos(vec2, this.camera, canvas).x;
            } else if (pos.x - particle.radius > canvas.width + this.dis) {
                vec2.y = pos.y;
                vec2.x = -this.dis - particle.radius;
                particle.p.x = Proton.THREEUtil.toSpacePos(vec2, this.camera, canvas).x;
            }
        }
    }();

    ScreenZone.prototype._bound = function(particle) {
        var pos = Proton.THREEUtil.toScreenPos(particle.p, this.camera, this.renderer.domElement);
        var canvas = this.renderer.domElement;

        if (pos.y + particle.radius < -this.dis) {
            particle.v.y *= -1;
        } else if (pos.y - particle.radius > canvas.height + this.dis) {
            particle.v.y *= -1;
        }

        if (pos.x + particle.radius < -this.dis) {
            particle.v.y *= -1;
        } else if (pos.x - particle.radius > canvas.width + this.dis) {
            particle.v.y *= -1;
        }
    }

    Proton.ScreenZone = ScreenZone;
})(Proton);