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File: src/geometry/Bounds.js

                                /**
                                * The `Matter.Bounds` module contains methods for creating and manipulating axis-aligned bounding boxes (AABB).
                                *
                                * @class Bounds
                                */
                                
                                var Bounds = {};
                                
                                module.exports = Bounds;
                                
                                (function() {
                                
                                    /**
                                     * Creates a new axis-aligned bounding box (AABB) for the given vertices.
                                     * @method create
                                     * @param {vertices} vertices
                                     * @return {bounds} A new bounds object
                                     */
                                    Bounds.create = function(vertices) {
                                        var bounds = { 
                                            min: { x: 0, y: 0 }, 
                                            max: { x: 0, y: 0 }
                                        };
                                
                                        if (vertices)
                                            Bounds.update(bounds, vertices);
                                        
                                        return bounds;
                                    };
                                
                                    /**
                                     * Updates bounds using the given vertices and extends the bounds given a velocity.
                                     * @method update
                                     * @param {bounds} bounds
                                     * @param {vertices} vertices
                                     * @param {vector} velocity
                                     */
                                    Bounds.update = function(bounds, vertices, velocity) {
                                        bounds.min.x = Infinity;
                                        bounds.max.x = -Infinity;
                                        bounds.min.y = Infinity;
                                        bounds.max.y = -Infinity;
                                
                                        for (var i = 0; i < vertices.length; i++) {
                                            var vertex = vertices[i];
                                            if (vertex.x > bounds.max.x) bounds.max.x = vertex.x;
                                            if (vertex.x < bounds.min.x) bounds.min.x = vertex.x;
                                            if (vertex.y > bounds.max.y) bounds.max.y = vertex.y;
                                            if (vertex.y < bounds.min.y) bounds.min.y = vertex.y;
                                        }
                                        
                                        if (velocity) {
                                            if (velocity.x > 0) {
                                                bounds.max.x += velocity.x;
                                            } else {
                                                bounds.min.x += velocity.x;
                                            }
                                            
                                            if (velocity.y > 0) {
                                                bounds.max.y += velocity.y;
                                            } else {
                                                bounds.min.y += velocity.y;
                                            }
                                        }
                                    };
                                
                                    /**
                                     * Returns true if the bounds contains the given point.
                                     * @method contains
                                     * @param {bounds} bounds
                                     * @param {vector} point
                                     * @return {boolean} True if the bounds contain the point, otherwise false
                                     */
                                    Bounds.contains = function(bounds, point) {
                                        return point.x >= bounds.min.x && point.x <= bounds.max.x 
                                               && point.y >= bounds.min.y && point.y <= bounds.max.y;
                                    };
                                
                                    /**
                                     * Returns true if the two bounds intersect.
                                     * @method overlaps
                                     * @param {bounds} boundsA
                                     * @param {bounds} boundsB
                                     * @return {boolean} True if the bounds overlap, otherwise false
                                     */
                                    Bounds.overlaps = function(boundsA, boundsB) {
                                        return (boundsA.min.x <= boundsB.max.x && boundsA.max.x >= boundsB.min.x
                                                && boundsA.max.y >= boundsB.min.y && boundsA.min.y <= boundsB.max.y);
                                    };
                                
                                    /**
                                     * Translates the bounds by the given vector.
                                     * @method translate
                                     * @param {bounds} bounds
                                     * @param {vector} vector
                                     */
                                    Bounds.translate = function(bounds, vector) {
                                        bounds.min.x += vector.x;
                                        bounds.max.x += vector.x;
                                        bounds.min.y += vector.y;
                                        bounds.max.y += vector.y;
                                    };
                                
                                    /**
                                     * Shifts the bounds to the given position.
                                     * @method shift
                                     * @param {bounds} bounds
                                     * @param {vector} position
                                     */
                                    Bounds.shift = function(bounds, position) {
                                        var deltaX = bounds.max.x - bounds.min.x,
                                            deltaY = bounds.max.y - bounds.min.y;
                                            
                                        bounds.min.x = position.x;
                                        bounds.max.x = position.x + deltaX;
                                        bounds.min.y = position.y;
                                        bounds.max.y = position.y + deltaY;
                                    };
                                    
                                })();
                                
                                    
0.18.0