File: src/shapes/Shape.js
module.exports = Shape;
/**
* Base class for shapes.
* @class Shape
* @constructor
*/
function Shape(type){
this.type = type;
/**
* Bounding circle radius of this shape
* @property boundingRadius
* @type {Number}
*/
this.boundingRadius = 0;
/**
* Collision group that this shape belongs to (bit mask). See <a href="http://www.aurelienribon.com/blog/2011/07/box2d-tutorial-collision-filtering/">this tutorial</a>.
* @property collisionGroup
* @type {Number}
* @example
* // Setup bits for each available group
* var PLAYER = Math.pow(2,0),
* ENEMY = Math.pow(2,1),
* GROUND = Math.pow(2,2)
*
* // Put shapes into their groups
* player1Shape.collisionGroup = PLAYER;
* player2Shape.collisionGroup = PLAYER;
* enemyShape .collisionGroup = ENEMY;
* groundShape .collisionGroup = GROUND;
*
* // Assign groups that each shape collide with.
* // Note that the players can collide with ground and enemies, but not with other players.
* player1Shape.collisionMask = ENEMY | GROUND;
* player2Shape.collisionMask = ENEMY | GROUND;
* enemyShape .collisionMask = PLAYER | GROUND;
* groundShape .collisionMask = PLAYER | ENEMY;
*
* @example
* // How collision check is done
* if(shapeA.collisionGroup & shapeB.collisionMask)!=0 && (shapeB.collisionGroup & shapeA.collisionMask)!=0){
* // The shapes will collide
* }
*/
this.collisionGroup = 1;
/**
* Collision mask of this shape. See .collisionGroup.
* @property collisionMask
* @type {Number}
*/
this.collisionMask = 1;
if(type) this.updateBoundingRadius();
/**
* Material to use in collisions for this Shape. If this is set to null, the world will use default material properties instead.
* @property material
* @type {Material}
*/
this.material = null;
/**
* Area of this shape.
* @property area
* @type {Number}
*/
this.area = 0;
this.updateArea();
};
Shape.CIRCLE = 1;
Shape.PARTICLE = 2;
Shape.PLANE = 4;
Shape.CONVEX = 8;
Shape.LINE = 16;
Shape.RECTANGLE = 32;
Shape.CAPSULE = 64;
/**
* Should return the moment of inertia around the Z axis of the body given the total mass. See <a href="http://en.wikipedia.org/wiki/List_of_moments_of_inertia">Wikipedia's list of moments of inertia</a>.
* @method computeMomentOfInertia
* @param {Number} mass
* @return {Number} If the inertia is infinity or if the object simply isn't possible to rotate, return 0.
*/
Shape.prototype.computeMomentOfInertia = function(mass){
throw new Error("Shape.computeMomentOfInertia is not implemented in this Shape...");
};
/**
* Returns the bounding circle radius of this shape.
* @method updateBoundingRadius
* @return {Number}
*/
Shape.prototype.updateBoundingRadius = function(){
throw new Error("Shape.updateBoundingRadius is not implemented in this Shape...");
};
/**
* Update the .area property of the shape.
* @method updateArea
*/
Shape.prototype.updateArea = function(){
// To be implemented in all subclasses
};