flatland.js

/**
 * Project: DarlingJS
 *
 * Flatland Extensions (2D).
 * Inspired by http://en.wikipedia.org/wiki/Flatland
 *
 * Copyright (c) 2013, Eugene-Krevenets
 */

(function(darlingjs, darlingutil) {
    'use strict';

    var m = darlingjs.module('ngFlatland');

    /**
     * Component describe position in 2D environment
     */
    m.$c('ng2D', {
        x: 0.0,
        y: 0.0
    });

    m.$c('ng2DSize', {
        width: 10.0,
        height: 10.0
    });

    m.$c('ng2DRotation', {
        rotation: 0.0
    });

    m.$c('ng2DCircle', {
        radius: 10.0
    });

    m.$c('ng2DPolygon', {
        line: null
    });

    //Markers or State in FiniteStateMachine
    m.$c('ngGoingLeft', {});
    m.$c('ngGoingRight', {});

    //Service
    m.$s('ng2DViewPort', {
        lookAt: {x:0.0, y:0.0},
        width: 640,
        height: 480
    });

    m.$c('ngSelected');

    m.$s('ngFollowSelected', {
        _avgPosition: {x:0.0, y:0.0},

        shift: {
            x: 0.0,
            y: 0.0
        },

        $require: ['ng2D', 'ngSelected'],

        $beforeUpdate: function() {
            this._avgPosition.x = 0.0;
            this._avgPosition.y = 0.0;
            this._avgPosition.count = 0;
        },

        $update: ['$entity', function($entity) {
            this._avgPosition.x += $entity.ng2D.x;
            this._avgPosition.y += $entity.ng2D.y;
            this._avgPosition.count++;
        }],

        $afterUpdate: ['ng2DViewPort', function(ng2DViewPort) {
            if (this._avgPosition.count > 1) {
                var coef = 1 / this._avgPosition.count;
                this._avgPosition.x *= coef;
                this._avgPosition.y *= coef;
            }

            ng2DViewPort.lookAt.x = this._avgPosition.x + this.shift.x;
            ng2DViewPort.lookAt.y = this._avgPosition.y + this.shift.y;
        }]
    });

    /**
     * Marker for elements that doesn't influenced by the viewPort
     */
    m.$c('ngLockViewPort', {
        lockX: true,
        lockY: true
    });

    /**
     * Component of moving entity. Can be used in any dimension.
     */
    m.$c('ngShiftMove', {
    });

    m.$s('ng2DShiftMovingSystem', {
        $require: ['ng2D', 'ngShiftMove'],

        $addEntity : function($entity) {
            $entity.ngShiftMove.dx = $entity.ngShiftMove.dx || 0.0;
            $entity.ngShiftMove.dy = $entity.ngShiftMove.dy || 0.0;
        },

        $update: ['$entity', '$time', function($entity, $time) {
            $entity.ng2D.x += 0.001 * $entity.ngShiftMove.dx * $time;
            $entity.ng2D.y += 0.001 * $entity.ngShiftMove.dy * $time;
        }]
    });
})(darlingjs, darlingutil);