function Camera(speed, pos, up, right, target)

{

    this.speed = speed;

    this.pos = vec3.create(pos || [0, 0, 7]);

    this.up = vec3.create([0, 1, 0]);

    this.right = vec3.create([1, 0, 0]);

    this.target = vec3.create([0, 0, -1]);

    normalize([this.up, this.right, this.target]);

    this.matrix = mat4.create();

    this.pitchUp = vec3.create([0, 1, 0]);

    this.yawUp = vec3.create([0, 1, 0]);

    this.pitchRight = vec3.create([1, 0, 0]);

    this.yawRight = vec3.create([1, 0, 0]);

    this.pitchTarget = vec3.create([0, 0, -1]);

    this.yawTarget = vec3.create([0, 0, -1]);

    this.pitchMatrix = mat4.create();

    this.yawMatrix = mat4.create();

    mat4.identity(this.pitchMatrix);

    mat4.identity(this.yawMatrix);

}

Camera.prototype.moveLeft = function()

{

    var dir = vec3.create(this.right);

    vec3.scale(dir, -this.speed.h);

    vec3.add(this.pos, dir);

}

Camera.prototype.moveRight = function()

{

    var dir = vec3.create(this.right);

    vec3.scale(dir, this.speed.h);

    vec3.add(this.pos, dir);

}

Camera.prototype.moveUp = function()

{  

    var dir = vec3.create(this.up);

    vec3.scale(dir, this.speed.v);

    vec3.add(this.pos, dir);

}

Camera.prototype.moveDown = function()

{ 

    var dir = vec3.create(this.up);

    vec3.scale(dir, -this.speed.v);

    vec3.add(this.pos, dir);

}

Camera.prototype.zoom = function(delta) 

{

    var dir = vec3.create(this.target);

    vec3.scale(dir, delta * this.speed.zoom);

    vec3.add(this.pos, dir); 

}

Camera.prototype.pitch = function(delta)

{

    delta *= -this.speed.pitch;

    vec3.scale(this.pitchTarget, Math.cos(delta));

    vec3.scale(this.pitchUp, Math.sin(delta));

    vec3.add(this.pitchTarget, this.pitchUp);

    vec3.normalize(this.pitchTarget);

    vec3.cross(this.pitchTarget, this.pitchRight, this.pitchUp);

    vec3.scale(this.pitchUp, -1);

}

Camera.prototype.yaw = function(delta)

{

    delta *= -this.speed.yaw;

    vec3.scale(this.yawRight, Math.cos(delta));

    vec3.scale(this.yawTarget, Math.sin(delta));

    vec3.add(this.yawRight, this.yawTarget);

    vec3.normalize(this.yawRight);

    vec3.cross(this.yawRight, this.yawUp, this.yawTarget);

    vec3.scale(this.yawTarget, -1);

}

Camera.prototype.rotate = function(angles)

{

    angles = [angles[0] * -this.speed.pitch, 

	      angles[1] * -this.speed.yaw, 

	      angles[2] * -this.speed.roll];

    vec3.scale(this.target, Math.cos(angles[1]) * Math.sin(angles[0]));

    vec3.scale(this.up, Math.sin(angles[1]));

    vec3.scale(this.right, Math.cos(angles[0]));

    vec3.add(this.right, this.target);

    vec3.add(this.target, this.up);

    vec3.normalize(this.target);

    vec3.normalize(this.right);

    vec3.cross(this.target, this.right, this.up);

    vec3.scale(this.up, -1);

    vec3.cross(this.right, this.up, this.target);

    vec3.scale(this.target, -1);

}

Camera.prototype.roll = function(delta)

{

}

Camera.prototype.update = function()

{

    // vec3.add(this.right, this.pitchRight);

    // vec3.add(this.up, this.pitchUp);

    // vec3.add(this.target, this.pitchTarget);

    // vec3.add(this.right, this.yawRight);

    // vec3.add(this.up, this.yawUp);

    // vec3.add(this.target, this.yawTarget);

    // vec3.normalize(this.right);

    // vec3.normalize(this.up);

    // vec3.normalize(this.target);

    var x = vec3.dot(this.right, this.pos);

    var y = vec3.dot(this.up, this.pos);

    var z = vec3.dot(this.target, this.pos);

    this.matrix = mat4.create([this.right[0], this.up[0], -this.target[0], 0,

     			       this.right[1], this.up[1], -this.target[1], 0,

     			       this.right[2], this.up[2], -this.target[2], 0,

     			       -x, -y, z, 1]);    

    //vec3.cross(this.yawRight, this.pitchRight);

    //vec3.cross(this.yawUp, this.pitchUp);

    //vec3.cross(this.yawTarget, this.pitchTarget);

    this.pitchMatrix = mat4.create([this.pitchRight[0], this.pitchUp[0], -this.pitchTarget[0], 0,

     			       this.pitchRight[1], this.pitchUp[1], -this.pitchTarget[1], 0,

     			       this.pitchRight[2], this.pitchUp[2], -this.pitchTarget[2], 0,

			       0, 0, 0, 1]);

    this.yawMatrix = mat4.create([this.yawRight[0], this.yawUp[0], -this.yawTarget[0], 0,

     			       this.yawRight[1], this.yawUp[1], -this.yawTarget[1], 0,

     			       this.yawRight[2], this.yawUp[2], -this.yawTarget[2], 0,

			       0, 0, 0, 1]);

    mat4.multiply(this.matrix, this.pitchMatrix);

    mat4.multiply(this.matrix, this.yawMatrix);

}