Редактирование: JavaScript-mechanics-box2D

[[ТМ|Кафедра ТМ]] > [[Программирование]] > [[Программирование и моделирование в Интернет|Интернет]] > [[JavaScript-программирование|JavaScript]] > '''Механика Box2D''' <HR>

<htmlet nocache="yes">tcvetkov/another_authors/box2D/box2D_example_TM</htmlet>

<div class="mw-collapsible mw-collapsed" style="width:100%" >
'''Текст программы на языке JavaScript, использованы библиотека [http://box2d-js.sourceforge.net/ Box2DJS], а также исходный код с сайта библиотеки. Для простоты js-скрипт интегрирован прямо в html файл:''' <div class="mw-collapsible-content">
Файл '''"box2D_example.html"'''
<syntaxhighlight lang="javascript" line start="1" enclose="div">
<html>
   <head>
      <title>Box2dWeb example</title>
   </head>
   <body onload="init();">
      <canvas id="canvas" width="600" height="400"></canvas>
   </body>
   <script type="text/javascript" src="Box2dWeb-2.1.a.3.min.js"></script>
   <script type="text/javascript">
      var world;

      function init() {
         var   b2Vec2 = Box2D.Common.Math.b2Vec2
         	,	b2BodyDef = Box2D.Dynamics.b2BodyDef
         	,	b2Body = Box2D.Dynamics.b2Body
         	,	b2FixtureDef = Box2D.Dynamics.b2FixtureDef
         	,	b2Fixture = Box2D.Dynamics.b2Fixture
         	,	b2World = Box2D.Dynamics.b2World
         	,	b2MassData = Box2D.Collision.Shapes.b2MassData
         	,	b2PolygonShape = Box2D.Collision.Shapes.b2PolygonShape
         	,	b2CircleShape = Box2D.Collision.Shapes.b2CircleShape
         	,	b2DebugDraw = Box2D.Dynamics.b2DebugDraw
            ;

         world = new b2World(
               new b2Vec2(0, 10)    //gravity
            ,  true                 //allow sleep
         );

         var fixDef = new b2FixtureDef;
         fixDef.density = 1.0;
         fixDef.friction = 0.5;
         fixDef.restitution = 0.2;

         var bodyDef = new b2BodyDef;

         //create ground
         bodyDef.type = b2Body.b2_staticBody;
         bodyDef.position.x = 10;
         bodyDef.position.y = 13;
         fixDef.shape = new b2PolygonShape;
         fixDef.shape.SetAsBox(10, 0.01);
         world.CreateBody(bodyDef).CreateFixture(fixDef);


         //create some objects
          bodyDef.type = b2Body.b2_dynamicBody;

          fixDef.shape = new b2PolygonShape;    // добавим прямоугольник
          fixDef.shape.SetAsBox(0.5, 2);        // размеры прямоугольника
          bodyDef.position.x = 10;
          bodyDef.position.y = 10;
          world.CreateBody(bodyDef).CreateFixture(fixDef);

          fixDef.shape = new b2PolygonShape;
          fixDef.shape.SetAsBox(2, 0.5);
          bodyDef.position.x = 10;
          bodyDef.position.y = 8;
          world.CreateBody(bodyDef).CreateFixture(fixDef);

          fixDef.shape = new b2CircleShape(2);  // добавим круг
          bodyDef.position.x = 13;
          bodyDef.position.y = 3;
          world.CreateBody(bodyDef).CreateFixture(fixDef);


         //setup debug draw
         var debugDraw = new b2DebugDraw();
			debugDraw.SetSprite(document.getElementById("canvas").getContext("2d"));
			debugDraw.SetDrawScale(30.0);
			debugDraw.SetFillAlpha(0.3);
			debugDraw.SetLineThickness(1.0);
			debugDraw.SetFlags(b2DebugDraw.e_shapeBit | b2DebugDraw.e_jointBit);
			world.SetDebugDraw(debugDraw);

         window.setInterval(update, 1000 / 60);
      };

      function update() {
         world.Step(
               1 / 60   //frame-rate
            ,  10       //velocity iterations
            ,  10       //position iterations
         );
         world.DrawDebugData();
         world.ClearForces();
      };

   </script>
</html>
</syntaxhighlight>
</div>
</div>

== См. также ==
[http://box2d-javascript-fun.appspot.com/ Примеры]

[[Category: Виртуальная лаборатория]]
[[Category: Программирование]]
[[Category: JavaScript]]