using System; using System.Collections.Generic; using System.Text; using FarseerPhysics.Collision.Shapes; using FarseerPhysics.Common; using FarseerPhysics.Dynamics; using FarseerPhysics.Dynamics.Joints; using FarseerPhysics.Factories; using Microsoft.Xna.Framework; using Microsoft.Xna.Framework.Graphics; using Microsoft.Xna.Framework.Input; namespace FarseerPhysics.SamplesFramework { internal class GameDemo1 : PhysicsGameScreen, IDemoScreen { private float _acceleration; private Body _board; private Sprite _box; private List _boxes; private Sprite _bridge; private List _bridgeSegments; private Body _car; private Sprite _carBody; private Body _ground; private float _hzBack; private float _hzFront; private float _maxSpeed; private float _scale; private LineJoint _springBack; private LineJoint _springFront; private Sprite _teeter; private Sprite _wheel; private Body _wheelBack; private Body _wheelFront; private float _zeta; #region IDemoScreen Members public string GetTitle() { return "Racing Car"; } public string GetDetails() { StringBuilder sb = new StringBuilder(); sb.AppendLine("TODO: Add sample description!"); sb.AppendLine(string.Empty); sb.AppendLine("GamePad:"); sb.AppendLine(" - Exit to menu: Back button"); sb.AppendLine(string.Empty); sb.AppendLine("Keyboard:"); sb.AppendLine(" - Exit to menu: Escape"); return sb.ToString(); } #endregion public override void LoadContent() { base.LoadContent(); World.Gravity = new Vector2(0f, 10f); HasCursor = false; EnableCameraControl = true; HasVirtualStick = true; _hzFront = 8.5f; _hzBack = 5.0f; _zeta = 0.85f; _maxSpeed = 50.0f; #if WINDOWS_PHONE _scale = 2f / 3f; #else _scale = 1f; #endif // terrain _ground = new Body(World); { Vertices terrain = new Vertices(); terrain.Add(new Vector2(-20f, -5f)); terrain.Add(new Vector2(-20f, 0f)); terrain.Add(new Vector2(20f, 0f)); terrain.Add(new Vector2(25f, -0.25f)); terrain.Add(new Vector2(30f, -1f)); terrain.Add(new Vector2(35f, -4f)); terrain.Add(new Vector2(40f, 0f)); terrain.Add(new Vector2(45f, 0f)); terrain.Add(new Vector2(50f, 1f)); terrain.Add(new Vector2(55f, 2f)); terrain.Add(new Vector2(60f, 2f)); terrain.Add(new Vector2(65f, 1.25f)); terrain.Add(new Vector2(70f, 0f)); terrain.Add(new Vector2(75f, -0.3f)); terrain.Add(new Vector2(80f, -1.5f)); terrain.Add(new Vector2(85f, -3.5f)); terrain.Add(new Vector2(90f, 0f)); terrain.Add(new Vector2(95f, 0.5f)); terrain.Add(new Vector2(100f, 1f)); terrain.Add(new Vector2(105f, 2f)); terrain.Add(new Vector2(110f, 2.5f)); terrain.Add(new Vector2(115f, 1.3f)); terrain.Add(new Vector2(120f, 0f)); terrain.Add(new Vector2(160f, 0f)); terrain.Add(new Vector2(159f, 10f)); terrain.Add(new Vector2(201f, 10f)); terrain.Add(new Vector2(200f, 0f)); terrain.Add(new Vector2(240f, 0f)); terrain.Add(new Vector2(250f, -5f)); terrain.Add(new Vector2(250f, 10f)); terrain.Add(new Vector2(270f, 10f)); terrain.Add(new Vector2(270f, 0)); terrain.Add(new Vector2(310f, 0)); terrain.Add(new Vector2(310f, -5)); for (int i = 0; i < terrain.Count - 1; ++i) { FixtureFactory.AttachEdge(terrain[i], terrain[i + 1], _ground); } _ground.Friction = 0.6f; } // teeter board { _board = new Body(World); _board.BodyType = BodyType.Dynamic; _board.Position = new Vector2(140.0f, -1.0f); PolygonShape box = new PolygonShape(1f); box.SetAsBox(10.0f, 0.25f); _teeter = new Sprite(ScreenManager.Assets.TextureFromShape(box, MaterialType.Pavement, Color.LightGray, 1.2f)); _board.CreateFixture(box); RevoluteJoint teeterAxis = JointFactory.CreateRevoluteJoint(_ground, _board, Vector2.Zero); teeterAxis.LowerLimit = -8.0f * Settings.Pi / 180.0f; teeterAxis.UpperLimit = 8.0f * Settings.Pi / 180.0f; teeterAxis.LimitEnabled = true; World.AddJoint(teeterAxis); _board.ApplyAngularImpulse(-100.0f); } // bridge { _bridgeSegments = new List(); const int segmentCount = 20; PolygonShape shape = new PolygonShape(1f); shape.SetAsBox(1.0f, 0.125f); _bridge = new Sprite(ScreenManager.Assets.TextureFromShape(shape, MaterialType.Dots, Color.SandyBrown, 1f)); Body prevBody = _ground; for (int i = 0; i < segmentCount; ++i) { Body body = new Body(World); body.BodyType = BodyType.Dynamic; body.Position = new Vector2(161f + 2f * i, 0.125f); Fixture fix = body.CreateFixture(shape); fix.Friction = 0.6f; JointFactory.CreateRevoluteJoint(World, prevBody, body, -Vector2.UnitX); prevBody = body; _bridgeSegments.Add(body); } JointFactory.CreateRevoluteJoint(World, _ground, prevBody, Vector2.UnitX); } // boxes { _boxes = new List(); PolygonShape box = new PolygonShape(1f); box.SetAsBox(0.5f, 0.5f); _box = new Sprite(ScreenManager.Assets.TextureFromShape(box, MaterialType.Squares, Color.SaddleBrown, 2f)); Body body = new Body(World); body.BodyType = BodyType.Dynamic; body.Position = new Vector2(220f, -0.5f); body.CreateFixture(box); _boxes.Add(body); body = new Body(World); body.BodyType = BodyType.Dynamic; body.Position = new Vector2(220f, -1.5f); body.CreateFixture(box); _boxes.Add(body); body = new Body(World); body.BodyType = BodyType.Dynamic; body.Position = new Vector2(220f, -2.5f); body.CreateFixture(box); _boxes.Add(body); } // car { Vertices vertices = new Vertices(8); vertices.Add(new Vector2(-2.5f, 0.08f)); vertices.Add(new Vector2(-2.375f, -0.46f)); vertices.Add(new Vector2(-0.58f, -0.92f)); vertices.Add(new Vector2(0.46f, -0.92f)); vertices.Add(new Vector2(2.5f, -0.17f)); vertices.Add(new Vector2(2.5f, 0.205f)); vertices.Add(new Vector2(2.3f, 0.33f)); vertices.Add(new Vector2(-2.25f, 0.35f)); PolygonShape chassis = new PolygonShape(vertices, 2f); _car = new Body(World); _car.BodyType = BodyType.Dynamic; _car.Position = new Vector2(0.0f, -1.0f); _car.CreateFixture(chassis); _wheelBack = new Body(World); _wheelBack.BodyType = BodyType.Dynamic; _wheelBack.Position = new Vector2(-1.709f, -0.78f); Fixture fix = _wheelBack.CreateFixture(new CircleShape(0.5f, 0.8f)); fix.Friction = 0.9f; _wheelFront = new Body(World); _wheelFront.BodyType = BodyType.Dynamic; _wheelFront.Position = new Vector2(1.54f, -0.8f); _wheelFront.CreateFixture(new CircleShape(0.5f, 1f)); Vector2 axis = new Vector2(0.0f, -1.2f); _springBack = new LineJoint(_car, _wheelBack, _wheelBack.Position, axis); _springBack.MotorSpeed = 0.0f; _springBack.MaxMotorTorque = 20.0f; _springBack.MotorEnabled = true; _springBack.Frequency = _hzBack; _springBack.DampingRatio = _zeta; World.AddJoint(_springBack); _springFront = new LineJoint(_car, _wheelFront, _wheelFront.Position, axis); _springFront.MotorSpeed = 0.0f; _springFront.MaxMotorTorque = 10.0f; _springFront.MotorEnabled = false; _springFront.Frequency = _hzFront; _springFront.DampingRatio = _zeta; World.AddJoint(_springFront); _carBody = new Sprite(ScreenManager.Content.Load("Samples/car"), AssetCreator.CalculateOrigin(_car) / _scale); _wheel = new Sprite(ScreenManager.Content.Load("Samples/wheel")); } Camera.MinRotation = -0.05f; Camera.MaxRotation = 0.05f; Camera.TrackingBody = _car; Camera.EnableTracking = true; } public override void Update(GameTime gameTime, bool otherScreenHasFocus, bool coveredByOtherScreen) { _springBack.MotorSpeed = Math.Sign(_acceleration) * MathHelper.SmoothStep(0f, _maxSpeed, Math.Abs(_acceleration)); if (Math.Abs(_springBack.MotorSpeed) < _maxSpeed * 0.06f) { _springBack.MotorEnabled = false; } else { _springBack.MotorEnabled = true; } base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen); } public override void HandleInput(InputHelper input, GameTime gameTime) { if (input.VirtualState.ThumbSticks.Left.X > 0.5f) { _acceleration = Math.Min(_acceleration + (float)(2.0 * gameTime.ElapsedGameTime.TotalSeconds), 1f); } else if (input.VirtualState.ThumbSticks.Left.X < -0.5f) { _acceleration = Math.Max(_acceleration - (float)(2.0 * gameTime.ElapsedGameTime.TotalSeconds), -1f); } else if (input.VirtualState.Buttons.A == ButtonState.Pressed) { _acceleration = 0f; } else { _acceleration -= Math.Sign(_acceleration) * (float)(2.0 * gameTime.ElapsedGameTime.TotalSeconds); } base.HandleInput(input, gameTime); } public override void Draw(GameTime gameTime) { ScreenManager.SpriteBatch.Begin(0, null, null, null, null, null, Camera.View); // draw car ScreenManager.SpriteBatch.Draw(_wheel.Texture, ConvertUnits.ToDisplayUnits(_wheelBack.Position), null, Color.White, _wheelBack.Rotation, _wheel.Origin, _scale, SpriteEffects.None, 0f); ScreenManager.SpriteBatch.Draw(_wheel.Texture, ConvertUnits.ToDisplayUnits(_wheelFront.Position), null, Color.White, _wheelFront.Rotation, _wheel.Origin, _scale, SpriteEffects.None, 0f); ScreenManager.SpriteBatch.Draw(_carBody.Texture, ConvertUnits.ToDisplayUnits(_car.Position), null, Color.White, _car.Rotation, _carBody.Origin, _scale, SpriteEffects.None, 0f); // draw teeter ScreenManager.SpriteBatch.Draw(_teeter.Texture, ConvertUnits.ToDisplayUnits(_board.Position), null, Color.White, _board.Rotation, _teeter.Origin, 1f, SpriteEffects.None, 0f); // draw bridge for (int i = 0; i < _bridgeSegments.Count; ++i) { ScreenManager.SpriteBatch.Draw(_bridge.Texture, ConvertUnits.ToDisplayUnits(_bridgeSegments[i].Position), null, Color.White, _bridgeSegments[i].Rotation, _bridge.Origin, 1f, SpriteEffects.None, 0f); } // draw boxes for (int i = 0; i < _boxes.Count; ++i) { ScreenManager.SpriteBatch.Draw(_box.Texture, ConvertUnits.ToDisplayUnits(_boxes[i].Position), null, Color.White, _boxes[i].Rotation, _box.Origin, 1f, SpriteEffects.None, 0f); } ScreenManager.SpriteBatch.End(); ScreenManager.LineBatch.Begin(Camera.SimProjection, Camera.SimView); // draw ground for (int i = 0; i < _ground.FixtureList.Count; ++i) { ScreenManager.LineBatch.DrawLineShape(_ground.FixtureList[i].Shape, Color.Black); } ScreenManager.LineBatch.End(); base.Draw(gameTime); } } }