1 /*
  2     Copyright 2008-2014
  3         Matthias Ehmann,
  4         Michael Gerhaeuser,
  5         Carsten Miller,
  6         Bianca Valentin,
  7         Alfred Wassermann,
  8         Peter Wilfahrt
  9 
 10     This file is part of JSXGraph.
 11 
 12     JSXGraph is free software dual licensed under the GNU LGPL or MIT License.
 13 
 14     You can redistribute it and/or modify it under the terms of the
 15 
 16       * GNU Lesser General Public License as published by
 17         the Free Software Foundation, either version 3 of the License, or
 18         (at your option) any later version
 19       OR
 20       * MIT License: https://github.com/jsxgraph/jsxgraph/blob/master/LICENSE.MIT
 21 
 22     JSXGraph is distributed in the hope that it will be useful,
 23     but WITHOUT ANY WARRANTY; without even the implied warranty of
 24     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 25     GNU Lesser General Public License for more details.
 26 
 27     You should have received a copy of the GNU Lesser General Public License and
 28     the MIT License along with JSXGraph. If not, see <http://www.gnu.org/licenses/>
 29     and <http://opensource.org/licenses/MIT/>.
 30  */
 31 
 32 
 33 /*global JXG: true, define: true*/
 34 /*jslint nomen: true, plusplus: true*/
 35 
 36 /* depends:
 37  see define call
 38  */
 39 
 40 /**
 41  * @fileoverview Example file for a triangle implemented as a extension to JSXGraph.
 42  */
 43 
 44 define([
 45     'jxg', 'options', 'utils/type', 'base/constants', 'base/line', 'base/polygon', 'base/point', 'base/element'
 46 ], function (JXG, Options, Type, Const, Line, Polygon, Point, GeometryElement) {
 47 
 48     "use strict";
 49 
 50     var priv = {
 51             removeSlopeTriangle: function () {
 52                 Polygon.Polygon.prototype.remove.call(this);
 53 
 54                 this.board.removeObject(this.toppoint);
 55                 this.board.removeObject(this.glider);
 56 
 57                 this.board.removeObject(this.baseline);
 58                 this.board.removeObject(this.basepoint);
 59 
 60                 this.board.removeObject(this.label);
 61             },
 62             Value: function () {
 63                 return this.tangent.getSlope();
 64             }
 65         };
 66 
 67     /**
 68      * @class Slope triangle for a point on a line.
 69      * @pseudo
 70      * @name Slopetriangle
 71      * @augments JXG.Line
 72      * @constructor
 73      * @type JXG.Polygon
 74      * @throws {Error} If the element cannot be constructed with the given parent objects an exception is thrown.
 75      * Parameter options:
 76      * @param {JXG.Line} t A tangent based on a glider on some object, e.g. curve, circle, line or turtle.
 77      * @param {JXG.Line_JXG.Point} li, p A line and a point on that line. 
 78      *  The user has to take care that the point is a member of the line.
 79      * @example
 80      * // Create a slopetriangle on a tangent
 81      * var f = board.create('plot', ['sin(x)']),
 82      *     g = board.create('glider', [1, 2, f]),
 83      *     t = board.create('tangent', [g]),
 84      *     
 85      *     st = board.create('slopetriangle', [t]);
 86      *     
 87      * </pre><div id="951ccb6a-52bc-4dc2-80e9-43db064f0f1b" style="width: 300px; height: 300px;"></div>
 88      * <script type="text/javascript">
 89      * (function () {
 90      *   var board = JXG.JSXGraph.initBoard('951ccb6a-52bc-4dc2-80e9-43db064f0f1b', {boundingbox: [-5, 5, 5, -5], axis: true, showcopyright: false, shownavigation: false}),
 91      *     f = board.create('plot', ['sin(x)']),
 92      *     g = board.create('glider', [1, 2, f]),
 93      *     t = board.create('tangent', [g]),
 94      *     
 95      *     st = board.create('slopetriangle', [t]);
 96      * })();
 97      * </script><pre>
 98      * 
 99      * @example
100      * // Create a on a line and a point on that line
101      * var p1 = board.create('point', [-2, 3]),
102      *     p2 = board.create('point', [2, -3]),
103      *     li = board.create('line', [p1, p2]),
104      *     p = board.create('glider', [0, 0, li]),
105      * 
106      *     st = board.create('slopetriangle', [li, p]);
107      *
108      * </pre><div id="b52f451c-22cf-4677-852a-0bb9d764ee95" style="width: 300px; height: 300px;"></div>
109      * <script type="text/javascript">
110      * (function () {
111      *   var board = JXG.JSXGraph.initBoard('b52f451c-22cf-4677-852a-0bb9d764ee95', {boundingbox: [-5, 5, 5, -5], axis: true, showcopyright: false, shownavigation: false}),
112      *     p1 = board.create('point', [-2, 3]),
113      *     p2 = board.create('point', [2, -3]),
114      *     li = board.create('line', [p1, p2]),
115      *     p = board.create('glider', [0, 0, li]),
116      * 
117      *     st = board.create('slopetriangle', [li, p]);
118      * })();
119      * </script><pre>
120      */
121     JXG.createSlopeTriangle = function (board, parents, attributes) {
122         var el, tangent, tglide, glider, toppoint, baseline, basepoint, label, attr;
123 
124         if (parents.length === 1 && parents[0].type === Const.OBJECT_TYPE_TANGENT) {
125             tangent = parents[0];
126             tglide = tangent.glider;
127         } else if (parents.length === 2 &&
128                 parents[0].elementClass === Const.OBJECT_CLASS_LINE && Type.isPoint(parents[1])) {
129             tangent = parents[0];
130             tglide = parents[1];
131         } else {
132             throw new Error("JSXGraph: Can't create slope triangle with parent types '" + (typeof parents[0]) + "'.");
133         }
134 
135         attr = Type.copyAttributes(attributes, board.options, 'slopetriangle', 'basepoint');
136         basepoint = board.create('point', [function () {
137             return [tglide.X() + 1,  tglide.Y()];
138         }], attr);
139 
140         attr = Type.copyAttributes(attributes, board.options, 'slopetriangle', 'baseline');
141         baseline = board.create('line', [tglide, basepoint], attr);
142 
143         attr = Type.copyAttributes(attributes, board.options, 'slopetriangle', 'glider');
144         glider = board.create('glider', [tglide.X() + 1, tglide.Y(), baseline], attr);
145 
146         attr = Type.copyAttributes(attributes, board.options, 'slopetriangle', 'toppoint');
147         toppoint = board.create('point', [function () {
148             return [glider.X(), glider.Y() + (glider.X() - tglide.X()) * tangent.getSlope()];
149         }], attr);
150 
151         attr = Type.copyAttributes(attributes, board.options, 'slopetriangle');
152         el = board.create('polygon', [tglide, glider, toppoint], attr);
153 
154         el.Value = priv.Value;
155         el.tangent = tangent;
156 
157         attr = Type.copyAttributes(attributes, board.options, 'slopetriangle', 'label');
158         label = board.create('text', [
159             function () { return glider.X() + 0.1; },
160             function () { return (glider.Y() + toppoint.Y()) * 0.5; },
161             function () { return ''; }
162         ], attr);
163 
164         label._setText(function () { return el.Value().toFixed(label.visProp.digits); });
165         label.prepareUpdate().update().updateRenderer();
166 
167         el.glider = glider;
168         el.basepoint = basepoint;
169         el.baseline = baseline;
170         el.toppoint = toppoint;
171         el.label = label;
172 
173         el.methodMap = JXG.deepCopy(el.methodMap, {
174             tangent: 'tangent',
175             glider: 'glider',
176             basepoint: 'basepoint',
177             baseline: 'baseline',
178             toppoint: 'toppoint',
179             label: 'label',
180             Value: 'Value',
181             V: 'Value'
182         });
183 
184         el.remove = priv.removeSlopeTriangle;
185 
186         return el;
187     };
188 
189     JXG.registerElement('slopetriangle', JXG.createSlopeTriangle);
190 
191     return {
192         createSlopeTriangle: JXG.createSlopeTriangle
193     };
194 });
195