blobimage.js

blobimage.js

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function Vector(x, y) {
    this.x = x;
    this.y = y;

    this.equal = function(v) {
        return this.x == v.getX() && this.y == v.getY();
    }
    this.getX = function() {
        return this.x;
    }
    this.getY = function() {
        return this.y;
    }
    this.setX = function(x) {
        this.x = x;
    }
    this.setY = function(y) {
        this.y = y;
    }
    this.addX = function(x) {
        this.x += x;
    }
    this.addY = function(y) {
        this.y += y;
    }
    this.set = function(v) {
        this.x = v.getX();
        this.y = v.getY();
    }
    this.add = function(v) {
        this.x += v.getX();
        this.y += v.getY();
    }
    this.sub = function(v) {
        this.x -= v.getX();
        this.y -= v.getY();
    }
    this.dotProd = function(v) {
        return this.x * v.getX() + this.y * v.getY();
    }
    this.length = function() {
        return Math.sqrt(this.x * this.x + this.y * this.y);
    }
    this.scale = function(scaleFactor) {
        this.x *= scaleFactor;
        this.y *= scaleFactor;
    }
    this.toString = function() {
        return " X: " + this.x + " Y: " + this.y;
    }
}

function Environment(x, y, w, h) {
    this.left = x;
    this.right = x + w;
    this.top = y;
    this.buttom = y + h;
    this.r = new Vector(0.0, 0.0);

    this.collision = function(curPos, prevPos) {
        var collide = false;
        var i;

        if (curPos.getX() < this.left) {
            curPos.setX(this.left);
            collide = true;
        } else if (curPos.getX() > this.right) {
            curPos.setX(this.right);
            collide = true;
        }
        if (curPos.getY() < this.top) {
            curPos.setY(this.top);
            collide = true;
        } else if (curPos.getY() > this.buttom) {
            curPos.setY(this.buttom);
            collide = true;
        }
        return collide;
    }
    this.draw = function(ctx, scaleFactor) {}
}

function PointMass(cx, cy, mass) {
    this.cur = new Vector(cx, cy);
    this.prev = new Vector(cx, cy);
    this.mass = mass;
    this.force = new Vector(0.0, 0.0);
    this.result = new Vector(0.0, 0.0);
    this.friction = 0.01;

    this.getXPos = function() {
        return this.cur.getX();
    }
    this.getYPos = function() {
        return this.cur.getY();
    }
    this.getPos = function() {
        return this.cur;
    }
    this.getXPrevPos = function() {
        return this.prev.getX();
    }
    this.getYPrevPos = function() {
        return this.prev.getY();
    }
    this.getPrevPos = function() {
        return this.prev;
    }
    this.addXPos = function(dx) {
        this.cur.addX(dx);
    }
    this.addYPos = function(dy) {
        this.cur.addY(dy);
    }
    this.setForce = function(force) {
        this.force.set(force);
    }
    this.addForce = function(force) {
        this.force.add(force);
    }
    this.getMass = function() {
        return this.mass;
    }
    this.setMass = function(mass) {
        this.mass = mass;
    }
    this.move = function(dt) {
        var t, a, c, dtdt;

        dtdt = dt * dt;

        a = this.force.getX() / this.mass;
        c = this.cur.getX();
        t = (2.0 - this.friction) * c - (1.0 - this.friction) * this.prev.getX() + a * dtdt;
        this.prev.setX(c);
        this.cur.setX(t);

        a = this.force.getY() / this.mass;
        c = this.cur.getY();
        t = (2.0 - this.friction) * c - (1.0 - this.friction) * this.prev.getY() + a * dtdt;
        this.prev.setY(c);
        this.cur.setY(t);
    }
    this.setFriction = function(friction) {
        this.friction = friction;
    }
    this.getVelocity = function() {
        var cXpX, cYpY;

        cXpX = this.cur.getX() - this.prev.getX();
        cYpY = this.cur.getY() - this.prev.getY();

        return cXpX * cXpX + cYpY * cYpY;
    }
    this.draw = function(ctx, scaleFactor) {
        ctx.lineWidth = 2;
        ctx.fillStyle = '#000000';
        ctx.strokeStyle = '#000000';
        ctx.beginPath();
        ctx.arc(this.cur.getX() * scaleFactor,
            this.cur.getY() * scaleFactor,
            4.0, 0.0, Math.PI * 2.0, true);
        ctx.fill();
    }
}

function ConstraintY(pointMass, y, shortConst, longConst) {
    this.pointMass = pointMass;
    this.y = y;
    this.delta = new Vector(0.0, 0.0);
    this.shortConst = shortConst;
    this.longConst = longConst;

    this.sc = function() {
        var dist;

        dist = Math.abs(this.pointMass.getYPos() - this.y);
        this.delta.setY(-dist);

        if (this.shortConst != 0.0 && dist < this.shortConst) {
            var scaleFactor;

            scaleFactor = this.shortConst / dist;
            this.delta.scale(scaleFactor);
            pointMass.getPos().sub(this.delta);
        } else if (this.longConst != 0.0 && dist > this.longConst) {
            var scaleFactor;

            scaleFactor = this.longConst / dist;
            this.delta.scale(scaleFactor);
            pointMass.getPos().sub(this.delta);
        }
    }
}

function Joint(pointMassA, pointMassB, shortConst, longConst) {
    this.pointMassA = pointMassA;
    this.pointMassB = pointMassB;
    this.delta = new Vector(0.0, 0.0);
    this.pointMassAPos = pointMassA.getPos();
    this.pointMassBPos = pointMassB.getPos();

    this.delta.set(this.pointMassBPos);
    this.delta.sub(this.pointMassAPos);

    this.shortConst = this.delta.length() * shortConst;
    this.longConst = this.delta.length() * longConst;
    this.scSquared = this.shortConst * this.shortConst;
    this.lcSquared = this.longConst * this.longConst;

    this.setDist = function(shortConst, longConst) {
        this.shortConst = shortConst;
        this.longConst = longConst;
        this.scSquared = this.shortConst * this.shortConst;
        this.lcSquared = this.longConst * this.longConst;
    }
    this.scale = function(scaleFactor) {
        this.shortConst = this.shortConst * scaleFactor;
        this.longConst = this.longConst * scaleFactor;
        this.scSquared = this.shortConst * this.shortConst;
        this.lcSquared = this.longConst * this.longConst;
    }
    this.sc = function() {
        this.delta.set(this.pointMassBPos);
        this.delta.sub(this.pointMassAPos);

        var dp = this.delta.dotProd(this.delta);

        if (this.shortConst != 0.0 && dp < this.scSquared) {
            var scaleFactor;

            scaleFactor = this.scSquared / (dp + this.scSquared) - 0.5;

            this.delta.scale(scaleFactor);

            this.pointMassAPos.sub(this.delta);
            this.pointMassBPos.add(this.delta);
        } else if (this.longConst != 0.0 && dp > this.lcSquared) {
            var scaleFactor;

            scaleFactor = this.lcSquared / (dp + this.lcSquared) - 0.5;

            this.delta.scale(scaleFactor);

            this.pointMassAPos.sub(this.delta);
            this.pointMassBPos.add(this.delta);
        }
    }
}

function Stick(pointMassA, pointMassB) {
    function pointMassDist(pointMassA, pointMassB) {
        var aXbX, aYbY;

        aXbX = pointMassA.getXPos() - pointMassB.getXPos();
        aYbY = pointMassA.getYPos() - pointMassB.getYPos();

        return Math.sqrt(aXbX * aXbX + aYbY * aYbY);
    }

    this.length = pointMassDist(pointMassA, pointMassB);
    this.lengthSquared = this.length * this.length;
    this.pointMassA = pointMassA;
    this.pointMassB = pointMassB;
    this.delta = new Vector(0.0, 0.0);

    this.getPointMassA = function() {
        return this.pointMassA;
    }
    this.getPointMassB = function() {
        return this.pointMassB;
    }
    this.scale = function(scaleFactor) {
        this.length *= scaleFactor;
        this.lengthSquared = this.length * this.length;
    }
    this.sc = function(env) {
        var dotProd, scaleFactor;
        var pointMassAPos, pointMassBPos;

        pointMassAPos = this.pointMassA.getPos();
        pointMassBPos = this.pointMassB.getPos();

        this.delta.set(pointMassBPos);
        this.delta.sub(pointMassAPos);

        dotProd = this.delta.dotProd(this.delta);

        scaleFactor = this.lengthSquared / (dotProd + this.lengthSquared) - 0.5;
        this.delta.scale(scaleFactor);

        pointMassAPos.sub(this.delta);
        pointMassBPos.add(this.delta);
    }
    this.setForce = function(force) {
        this.pointMassA.setForce(force);
        this.pointMassB.setForce(force);
    }
    this.addForce = function(force) {
        this.pointMassA.addForce(force);
        this.pointMassB.addForce(force);
    }
    this.move = function(dt) {
        this.pointMassA.move(dt);
        this.pointMassB.move(dt);
    }
    this.draw = function(ctx, scaleFactor) {
        this.pointMassA.draw(ctx, scaleFactor);
        this.pointMassB.draw(ctx, scaleFactor);

        ctx.lineWidth = 3;
        ctx.fillStyle = '#000000';
        ctx.strokeStyle = '#000000';
        ctx.beginPath();
        ctx.moveTo(this.pointMassA.getXPos() * scaleFactor,
            this.pointMassA.getYPos() * scaleFactor);
        ctx.lineTo(this.pointMassB.getXPos() * scaleFactor,
            this.pointMassB.getYPos() * scaleFactor);
        ctx.stroke();
    }
}

function Spring(restLength, stiffness, damper, pointMassA, pointMassB) {
    this.restLength = restLength;
    this.stiffness = stiffness;
    this.damper = damper;
    this.pointMassA = pointMassA;
    this.pointMassB = pointMassB;
    this.tmp = Vector(0.0, 0.0);

    this.sc = function(env) {
        env.collistion(this.pointMassA.getPos(), this.pointMassA.getPrevPos());
        env.collistion(this.pointMassB.getPos(), this.pointMassB.getPrevPos());
    }

    this.move = function(dt) {
        var aXbX;
        var aYbY;
        var springForce;
        var length;

        aXbX = this.pointMassA.getXPos() - this.pointMassB.getXPos();
        aYbY = this.pointMassA.getYPos() - this.pointMassB.getYPos();

        length = Math.sqrt(aXbX * aXbX + aYbY * aYbY);
        springForce = this.stiffness * (length / this.restLength - 1.0);

        var avXbvX;
        var avYbvY;
        var damperForce;

        avXbvX = this.pointMassA.getXVel() - this.pointMassB.getXVel();
        avYbvY = this.pointMassA.getYVel() - this.pointMassB.getYVel();

        damperForce = avXbvX * aXbX + avYbvY * aYbY;
        damperForce *= this.damper;

        var fx;
        var fy;

        fx = (springForce + damperForce) * aXbX;
        fy = (springForce + damperForce) * aYbY;

        this.tmp.setX(-fx);
        this.tmp.setY(-ft);
        this.pointMassA.addForce(this.tmp);

        this.tmp.setX(fx);
        this.tmp.setY(ft);
        this.pointMassB.addForce(this.tmp);

        this.pointMassA.move(dt);
        this.pointMassB.move(dt);
    }
    this.addForce = function(force) {
        this.pointMassA.addForce(force);
        this.pointMassB.addForce(force);
    }
    this.draw = function(ctx, scaleFactor) {
        this.pointMassA.draw(ctx, scaleFactor);
        this.pointMassB.draw(ctx, scaleFactor);

        ctx.fillStyle = '#000000';
        ctx.strokeStyle = '#000000';
        ctx.beginPath();
        ctx.moveTo(this.pointMassA.getXPos() * scaleFactor,
            this.pointMassA.getYPos() * scaleFactor);
        ctx.lineTo(this.pointMassB.getXPos() * scaleFactor,
            this.pointMassB.getXPos() * scaleFactor);
        ctx.stroke();
    }
}

function Blob(x, y, radius, numPointMasses) {
    this.x = x;
    this.y = y;
    this.sticks = new Array();
    this.pointMasses = new Array();
    this.joints = new Array();
    this.middlePointMass;
    this.radius = radius;
    this.drawFaceStyle = 1;
    this.drawEyeStyle = 1;
    this.selected = false;

    numPointMasses = 8;

    var f = 0.1;
    var low = 0.95,
        high = 1.05;
    var t, i, p;

    function clampIndex(index, maxIndex) {
        index += maxIndex;
        return index % maxIndex;
    }

    for (i = 0, t = 0.0; i < numPointMasses; i++) {
        this.pointMasses[i] = new PointMass(Math.cos(t) * radius + x, Math.sin(t) * radius + y, 1.0);
        t += 2.0 * Math.PI / numPointMasses;
    }

    this.middlePointMass = new PointMass(x, y, 1.0);

    this.pointMasses[0].setMass(4.0);
    this.pointMasses[1].setMass(4.0);

    for (i = 0; i < numPointMasses; i++) {
        this.sticks[i] = new Stick(this.pointMasses[i], this.pointMasses[clampIndex(i + 1, numPointMasses)]);
    }

    for (i = 0, p = 0; i < numPointMasses; i++) {
        this.joints[p++] = new Joint(this.pointMasses[i], this.pointMasses[clampIndex(i + numPointMasses / 2 + 1, numPointMasses)], low, high);
        this.joints[p++] = new Joint(this.pointMasses[i], this.middlePointMass, high * 0.9, low * 1.1); // 0.8, 1.2 works  
    }

    this.addBlob = function(blob) {
        var index = this.joints.length;
        var dist;

        this.joints[index] = new Joint(this.middlePointMass, blob.getMiddlePointMass(), 0.0, 0.0);
        dist = this.radius + blob.getRadius();
        this.joints[index].setDist(dist * 0.95, 0.0);
    }
    this.getMiddlePointMass = function() {
        return this.middlePointMass;
    }
    this.getRadius = function() {
        return this.radius;
    }
    this.getXPos = function() {
        return this.middlePointMass.getXPos();
    }
    this.getYPos = function() {
        return this.middlePointMass.getYPos();
    }
    this.scale = function(scaleFactor) {
        var i;

        for (i = 0; i < this.joints.length; i++) {
            this.joints[i].scale(scaleFactor);
        }
        for (i = 0; i < this.sticks.length; i++) {
            this.sticks[i].scale(scaleFactor);
        }
        this.radius *= scaleFactor;
    }

    this.move = function(dt) {
        var i;

        for (i = 0; i < this.pointMasses.length; i++) {
            this.pointMasses[i].move(dt);
        }
        this.middlePointMass.move(dt);
    }
    this.sc = function(env) {
        var i, j;

        for (j = 0; j < 4; j++) {
            for (i = 0; i < this.pointMasses.length; i++) {
                if (env.collision(this.pointMasses[i].getPos(), this.pointMasses[i].getPrevPos()) == true) {
                    this.pointMasses[i].setFriction(0.75);
                } else {
                    this.pointMasses[i].setFriction(0.01);
                }
            }
            for (i = 0; i < this.sticks.length; i++) {
                this.sticks[i].sc(env);
            }
            for (i = 0; i < this.joints.length; i++) {
                this.joints[i].sc();
            }
        }
    }
    this.setForce = function(force) {
        var i;

        for (i = 0; i < this.pointMasses.length; i++) {
            this.pointMasses[i].setForce(force);
        }
        this.middlePointMass.setForce(force);
    }
    this.addForce = function(force) {
        var i;

        for (i = 0; i < this.pointMasses.length; i++) {
            this.pointMasses[i].addForce(force);
        }
        this.middlePointMass.addForce(force);
        this.pointMasses[0].addForce(force);
        this.pointMasses[0].addForce(force);
        this.pointMasses[0].addForce(force);
        this.pointMasses[0].addForce(force);
    }
    this.moveTo = function(x, y) {
        var i, blobPos;

        blobPos = this.middlePointMass.getPos();
        x -= blobPos.getX(x);
        y -= blobPos.getY(y);

        for (i = 0; i < this.pointMasses.length; i++) {
            blobPos = this.pointMasses[i].getPos();
            blobPos.addX(x);
            blobPos.addY(y);
        }
        blobPos = this.middlePointMass.getPos();
        blobPos.addX(x);
        blobPos.addY(y);
    }
    this.setSelected = function(selected) {
        this.selected = selected;
    }

    this.drawEars = function(ctx, scaleFactor) {
        ctx.strokeStyle = "#000000";
        ctx.fillStyle = "#FFFFFF";
        ctx.lineWidth = 2;

        ctx.beginPath();
        ctx.moveTo((-0.55 * this.radius) * scaleFactor, (-0.35 * this.radius) * scaleFactor);
        ctx.lineTo((-0.52 * this.radius) * scaleFactor, (-0.55 * this.radius) * scaleFactor);
        ctx.lineTo((-0.45 * this.radius) * scaleFactor, (-0.40 * this.radius) * scaleFactor);
        ctx.fill();
        ctx.stroke();

        ctx.beginPath();
        ctx.moveTo((0.55 * this.radius) * scaleFactor, (-0.35 * this.radius) * scaleFactor);
        ctx.lineTo((0.52 * this.radius) * scaleFactor, (-0.55 * this.radius) * scaleFactor);
        ctx.lineTo((0.45 * this.radius) * scaleFactor, (-0.40 * this.radius) * scaleFactor);
        ctx.fill();
        ctx.stroke();
    }

    this.drawHappyEyes1 = function(ctx, scaleFactor) {
        ctx.lineWidth = 1;
        ctx.fillStyle = "#FFFFFF";
        ctx.beginPath();
        ctx.arc((-0.15 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor,
            this.radius * 0.12 * scaleFactor, 0, 2.0 * Math.PI, false);
        ctx.fill();
        ctx.stroke();

        ctx.beginPath();
        ctx.arc((0.15 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor,
            this.radius * 0.12 * scaleFactor, 0, 2.0 * Math.PI, false);
        ctx.fill();
        ctx.stroke();

        ctx.fillStyle = "#000000";
        ctx.beginPath();
        ctx.arc((-0.15 * this.radius) * scaleFactor,
            (-0.17 * this.radius) * scaleFactor,
            this.radius * 0.06 * scaleFactor, 0, 2.0 * Math.PI, false);
        ctx.fill();

        ctx.beginPath();
        ctx.arc((0.15 * this.radius) * scaleFactor,
            (-0.17 * this.radius) * scaleFactor,
            this.radius * 0.06 * scaleFactor, 0, 2.0 * Math.PI, false);
        ctx.fill();
    }
    this.drawHappyEyes2 = function(ctx, scaleFactor) {
        ctx.lineWidth = 1;
        ctx.fillStyle = "#FFFFFF";
        ctx.beginPath();
        ctx.arc((-0.15 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor,
            this.radius * 0.12 * scaleFactor, 0, 2.0 * Math.PI, false);
        ctx.stroke();

        ctx.beginPath();
        ctx.arc((0.15 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor,
            this.radius * 0.12 * scaleFactor, 0, 2.0 * Math.PI, false);
        ctx.stroke();

        ctx.lineWidth = 1;
        ctx.beginPath();
        ctx.moveTo((-0.25 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor);
        ctx.lineTo((-0.05 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor);
        ctx.stroke();

        ctx.beginPath();
        ctx.moveTo((0.25 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor);
        ctx.lineTo((0.05 * this.radius) * scaleFactor,
            (-0.20 * this.radius) * scaleFactor);
        ctx.stroke();
    }
    this.drawHappyFace1 = function(ctx, scaleFactor) {
        ctx.lineWidth = 2;
        ctx.strokeStyle = "#000000";
        ctx.fillStyle = "#000000";
        ctx.beginPath();
        ctx.arc(0.0, 0.0,
            this.radius * 0.25 * scaleFactor, 0, Math.PI, false);
        ctx.stroke();
    }
    this.drawHappyFace2 = function(ctx, scaleFactor) {
        ctx.lineWidth = 2;
        ctx.strokeStyle = "#000000";
        ctx.fillStyle = "#000000";
        ctx.beginPath();
        ctx.arc(0.0, 0.0,
            this.radius * 0.25 * scaleFactor, 0, Math.PI, false);
        ctx.fill();
    }
    this.drawOohFace = function(ctx, scaleFactor) {
        ctx.lineWidth = 2;
        ctx.strokeStyle = "#000000";
        ctx.fillStyle = "#000000";
        ctx.beginPath();
        ctx.arc(0.0, (0.1 * this.radius) * scaleFactor,
            this.radius * 0.25 * scaleFactor, 0, Math.PI, false);
        ctx.fill();

        ctx.beginPath();

        ctx.moveTo((-0.25 * this.radius) * scaleFactor, (-0.3 * this.radius) * scaleFactor);
        ctx.lineTo((-0.05 * this.radius) * scaleFactor, (-0.2 * this.radius) * scaleFactor);
        ctx.lineTo((-0.25 * this.radius) * scaleFactor, (-0.1 * this.radius) * scaleFactor);

        ctx.moveTo((0.25 * this.radius) * scaleFactor, (-0.3 * this.radius) * scaleFactor);
        ctx.lineTo((0.05 * this.radius) * scaleFactor, (-0.2 * this.radius) * scaleFactor);
        ctx.lineTo((0.25 * this.radius) * scaleFactor, (-0.1 * this.radius) * scaleFactor);

        ctx.stroke();
    }
    this.drawFace = function(ctx, scaleFactor) {


        if (this.drawFaceStyle == 1 && Math.random() < 0.05) {
            this.drawFaceStyle = 2;
        } else if (this.drawFaceStyle == 2 && Math.random() < 0.1) {
            this.drawFaceStyle = 1;
        }

        if (this.drawEyeStyle == 1 && Math.random() < 0.025) {
            this.drawEyeStyle = 2;
        } else if (this.drawEyeStyle == 2 && Math.random() < 0.3) {
            this.drawEyeStyle = 1;
        }

        if (this.middlePointMass.getVelocity() > 0.004) {
            this.drawOohFace(ctx, scaleFactor);
        } else {
            if (this.drawFaceStyle == 1) {
                this.drawHappyFace1(ctx, scaleFactor, 0.0, -0.3);
            } else {
                this.drawHappyFace2(ctx, scaleFactor, 0.0, -0.3);
            }

            if (this.drawEyeStyle == 1) {
                this.drawHappyEyes1(ctx, scaleFactor, 0.0, -0.3);
            } else {
                this.drawHappyEyes2(ctx, scaleFactor, 0.0, -0.3);
            }
        }
    }
    this.getPointMass = function(index) {
        index += this.pointMasses.length;
        index = index % this.pointMasses.length;
        return this.pointMasses[index];
    }
    this.drawBody = function(ctx, scaleFactor) {
        var i;
    
        ctx.strokeStyle = "#000000";
        if (this.selected == true) {
            ctx.fillStyle = "#FFCCCC";
        } else {
            ctx.fillStyle = "#FFFFFF";
        }
        ctx.lineWidth = 5;
        ctx.beginPath();
        ctx.moveTo(this.pointMasses[0].getXPos() * scaleFactor,
            this.pointMasses[0].getYPos() * scaleFactor);




        for (i = 0; i < this.pointMasses.length; i++) {
            var px, py, nx, ny, tx, ty, cx, cy;
            var prevPointMass, currentPointMass, nextPointMass, nextNextPointMass;

            prevPointMass = this.getPointMass(i - 1);
            currentPointMass = this.pointMasses[i];
            nextPointMass = this.getPointMass(i + 1);
            nextNextPointMass = this.getPointMass(i + 2);

            tx = nextPointMass.getXPos();
            ty = nextPointMass.getYPos();

            cx = currentPointMass.getXPos();
            cy = currentPointMass.getYPos();

            px = cx * 0.5 + tx * 0.5;
            py = cy * 0.5 + ty * 0.5;

            nx = cx - prevPointMass.getXPos() + tx - nextNextPointMass.getXPos();
            ny = cy - prevPointMass.getYPos() + ty - nextNextPointMass.getYPos();

            px += nx * 0.16;
            py += ny * 0.16;

            px = px * scaleFactor;
            py = py * scaleFactor;

            tx = tx * scaleFactor;
            ty = ty * scaleFactor;

            //ctx.bezierCurveTo(px, py, tx, ty, tx, ty);
        }


	    var imageObj = new Image();
    	imageObj.src = 'http://2.bp.blogspot.com/-XNMmYECsALk/T37gk7mlWaI/AAAAAAAAATg/mM-XXtf5rZ0/s1600/bubble.png';
        ctx.drawImage(imageObj,px, py,100,100);

        ctx.closePath();
        ctx.stroke();
        ctx.fill();
    }
    this.drawSimpleBody = function(ctx, scaleFactor) {
        for (i = 0; i < this.sticks.length; i++) {
            this.sticks[i].draw(ctx, scaleFactor);
        }
    }

    this.draw = function(ctx, scaleFactor) {
        var i;
        var up, ori, ang;

        this.drawBody(ctx, scaleFactor);

        ctx.strokeStyle = "#000000";
        ctx.fillStyle = "#000000"

        ctx.save();
        ctx.translate(this.middlePointMass.getXPos() * scaleFactor,
            (this.middlePointMass.getYPos() - 0.35 * this.radius) * scaleFactor);

        up = new Vector(0.0, -1.0);
        ori = new Vector(0.0, 0.0);
        ori.set(this.pointMasses[0].getPos());
        ori.sub(this.middlePointMass.getPos());
        ang = Math.acos(ori.dotProd(up) / ori.length());
        if (ori.getX() < 0.0) {
            ctx.rotate(-ang);
        } else {
            ctx.rotate(ang);
        }

        // this.drawEars(ctx, scaleFactor); 
        // this.drawFace(ctx, scaleFactor);

        ctx.restore();
    }
}

function BlobCollective(x, y, startNum, maxNum) {
    this.maxNum = maxNum;
    this.numActive = 1;
    this.blobs = new Array();
    this.tmpForce = new Vector(0.0, 0.0);
    this.selectedBlob = null;

    this.blobs[0] = new Blob(x, y, 0.4, 8);

    this.split = function() {
        var i, maxIndex = 0,
            maxRadius = 0.0;
        var emptySlot;
        var motherBlob, newBlob;

        if (this.numActive == this.maxNum) {
            return;
        }

        emptySlot = this.blobs.length;
        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] != null && this.blobs[i].getRadius() > maxRadius) {
                maxRadius = this.blobs[i].getRadius();
                motherBlob = this.blobs[i];
            } else if (this.blobs[i] == null) {
                emptySlot = i;
            }
        }

        motherBlob.scale(0.75);
        newBlob = new Blob(motherBlob.getXPos(),
            motherBlob.getYPos(), motherBlob.getRadius(), 8);

        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] == null) {
                continue;
            }
            this.blobs[i].addBlob(newBlob);
            newBlob.addBlob(this.blobs[i]);
        }
        this.blobs[emptySlot] = newBlob;

        this.numActive++;
    }

    this.findSmallest = function(exclude) {
        var minRadius = 1000.0,
            minIndex;
        var i;

        for (i = 0; i < this.blobs.length; i++) {
            if (i == exclude || this.blobs[i] == null) {
                continue;
            }
            if (this.blobs[i].getRadius() < minRadius) {
                minIndex = i;
                minRadius = this.blobs[i].getRadius();
            }
        }
        return minIndex;
    }
    this.findClosest = function(exclude) {
        var minDist = 1000.0,
            foundIndex, dist, aXbX, aYbY;
        var i;
        var myPointMass, otherPointMass;

        myPointMass = this.blobs[exclude].getMiddlePointMass();
        for (i = 0; i < this.blobs.length; i++) {
            if (i == exclude || this.blobs[i] == null) {
                continue;
            }

            otherPointMass = this.blobs[i].getMiddlePointMass();
            aXbX = myPointMass.getXPos() - otherPointMass.getXPos();
            aYbY = myPointMass.getYPos() - otherPointMass.getYPos();
            dist = aXbX * aXbX + aYbY * aYbY;
            if (dist < minDist) {
                minDist = dist;
                foundIndex = i;
            }
        }
        return foundIndex;
    }
    this.join = function() {
        var blob1Index, blob2Index, blob1, blob2;
        var r1, r2, r3;

        if (this.numActive == 1) {
            return;
        }

        blob1Index = this.findSmallest(-1);
        blob2Index = this.findClosest(blob1Index);

        r1 = this.blobs[blob1Index].getRadius();
        r2 = this.blobs[blob2Index].getRadius();
        r3 = Math.sqrt(r1 * r1 + r2 * r2);

        this.blobs[blob1Index] = null;
        this.blobs[blob2Index].scale(0.945 * r3 / r2);

        this.numActive--;
    }

    this.selectBlob = function(x, y) {
        var i, minDist = 10000.0;
        var otherPointMass;
        var selectedBlob;
        var selectOffset = null;

        if (this.selectedBlob != null) {
            return;
        }

        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] == null) {
                continue;
            }

            otherPointMass = this.blobs[i].getMiddlePointMass();
            aXbX = x - otherPointMass.getXPos();
            aYbY = y - otherPointMass.getYPos();
            dist = aXbX * aXbX + aYbY * aYbY;
            if (dist < minDist) {
                minDist = dist;
                if (dist < this.blobs[i].getRadius() * 0.5) {
                    this.selectedBlob = this.blobs[i];
                    selectOffset = {
                        x: aXbX,
                        y: aYbY
                    };
                }
            }
        }

        if (this.selectedBlob != null) {
            this.selectedBlob.setSelected(true);
        }
        return selectOffset;
    }
    this.unselectBlob = function() {
        if (this.selectedBlob == null) {
            return;
        }
        this.selectedBlob.setSelected(false);
        this.selectedBlob = null;
    }
    this.selectedBlobMoveTo = function(x, y) {
        if (this.selectedBlob == null) {
            return;
        }
        this.selectedBlob.moveTo(x, y);
    }

    this.move = function(dt) {
        var i;

        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] == null) {
                continue;
            }
            this.blobs[i].move(dt);
        }
    }
    this.sc = function(env) {
        var i;

        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] == null) {
                continue;
            }
            this.blobs[i].sc(env);
        }
        if (this.blobAnchor != null) {
            this.blobAnchor.sc();
        }
    }
    this.setForce = function(force) {
        var i;

        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] == null) {
                continue;
            }
            if (this.blobs[i] == this.selectedBlob) {
                this.blobs[i].setForce(new Vector(0.0, 0.0));
                continue;
            }
            this.blobs[i].setForce(force);
        }
    }
    this.addForce = function(force) {
        var i;

        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] == null) {
                continue;
            }
            if (this.blobs[i] == this.selectedBlob) {
                continue;
            }
            this.tmpForce.setX(force.getX() * (Math.random() * 0.75 + 0.25));
            this.tmpForce.setY(force.getY() * (Math.random() * 0.75 + 0.25));
            this.blobs[i].addForce(this.tmpForce);
        }
    }
    this.draw = function(ctx, scaleFactor) {
        var i;

        for (i = 0; i < this.blobs.length; i++) {
            if (this.blobs[i] == null) {
                continue;
            }
            this.blobs[i].draw(ctx, scaleFactor);
        }
    }
}

function debug(msg, okFunc, cancelFunc) {
    if (confirm(msg) == true && okFunc != null) {
        okFunc();
    } else if (cancelFunc != null) {
        cancelFunc();
    }
}

var env;
var width = 1000.0;
var height = 800.0;
var scaleFactor = 200.0;
var blobColl;
var gravity;
var stopped;
var savedMouseCoords = null;
var selectOffset = null;

function update() {
    var dt = 0.05;

    if (savedMouseCoords != null && selectOffset != null) {
        blobColl.selectedBlobMoveTo(savedMouseCoords.x - selectOffset.x,
            savedMouseCoords.y - selectOffset.y);
    }

    blobColl.move(dt);
    blobColl.sc(env);
    blobColl.setForce(gravity);
}

function draw() {
    var canvas = document.getElementById('blob');
    if (canvas.getContext == null) {
        return;
    }

    var ctx = canvas.getContext('2d');

    ctx.clearRect(0, 0, width, height);

    env.draw(ctx, scaleFactor);
    blobColl.draw(ctx, scaleFactor);
}

function timeout() {
    draw();
    update();

    if (stopped == false) {
        setTimeout('timeout()', 30);
    }
}

function init() {
    var canvas = document.getElementById('blob');
    if (canvas.getContext == null) {
        alert("You need Firefox version 1.5 or higher for this to work, sorry.");
        return;
    }

    document.onkeydown = function(event) {
        var keyCode;

        if (event == null) {
            keyCode = window.event.keyCode;
        } else {
            keyCode = event.keyCode;
        }

        switch (keyCode) {
            // left 
            case 37:
                blobColl.addForce(new Vector(-50.0, 0.0));
                break;

                // up 
            case 38:
                blobColl.addForce(new Vector(0.0, -50.0));
                break;

                // right 
            case 39:
                blobColl.addForce(new Vector(50.0, 0.0));
                break;

                // down
            case 40:
                blobColl.addForce(new Vector(0.0, 50.0));
                break;

                // join 'j' 
            case 74:
                blobColl.join();
                break;

                // split 'h'
            case 72:
                blobColl.split();
                break;

                // toggle gravity 'g'
            case 71:
                toggleGravity();
                break;

            default:
                break;
        }
    }


    function getMouseCoords(event) {
        if (event == null) {
            event = window.event;
        }
        if (event == null) {
            return null;
        }
        if (event.pageX || event.pageY) {
            return {
                x: event.pageX / scaleFactor,
                y: event.pageY / scaleFactor
            };
        }
        return null;
    }
    document.onmousedown = function(event) {
        var mouseCoords;

        if (stopped == true) {
            return;
        }
        mouseCoords = getMouseCoords(event);
        if (mouseCoords == null) {
            return;
        }
        selectOffset = blobColl.selectBlob(mouseCoords.x, mouseCoords.y);
    }
    document.onmouseup = function(event) {
        blobColl.unselectBlob();
        savedMouseCoords = null;
        selectOffset = null;
    }
    document.onmousemove = function(event) {
        var mouseCoords;

        if (stopped == true) {
            return;
        }
        if (selectOffset == null) {
            return;
        }
        mouseCoords = getMouseCoords(event);
        if (mouseCoords == null) {
            return;
        }
        blobColl.selectedBlobMoveTo(mouseCoords.x - selectOffset.x, mouseCoords.y - selectOffset.y);

        savedMouseCoords = mouseCoords;
    }

    env = new Environment(0.2, 0.2, 2.6, 1.6);
    blobColl = new BlobCollective(1.0, 1.0, 1, 200);
    gravity = new Vector(0.0, 10.0);
    stopped = false;

    timeout();
}

function stop() {
    stopped = true;
}

function start() {
    stopped = false;
    timeout();
}

function toggleGravity() {
    if (gravity.getY() > 0.0) {
        gravity.setY(0.0);
    } else {
        gravity.setY(10.0);
    }
}




function go() {
    jQuery("body").prepend('<canvas id="blob" width="600" height="400" style="position:fixed;padding:0;margin:0;top:0;left:0;width: 100%;height: 100%;z-index:10000;"></canvas>');
    init();
}

function yep() {
    blobColl.split();
}
setTimeout(function() {
    jQuery.noConflict();
    go();
    var id = setInterval(yep, 3000);
    toggleGravity();
}, 2000);