MonoGame.Samples/FarseerSamples/Samples/SimpleDemo5.cs

using System.Text;
using FarseerPhysics.Dynamics;
using Microsoft.Xna.Framework;

namespace FarseerPhysics.SamplesFramework
{
    internal class SimpleDemo5 : PhysicsGameScreen, IDemoScreen
    {
        private Agent _agent;
        private Border _border;
        private Objects _circles;
        private Objects _gears;
        private Objects _rectangles;
        private Objects _stars;

        #region IDemoScreen Members

        public string GetTitle()
        {
            return "Collision Categories";
        }

        public string GetDetails()
        {
            StringBuilder sb = new StringBuilder();
            sb.AppendLine("This demo shows how to setup complex collision scenerios.");
            sb.AppendLine("In this demo:");
            sb.AppendLine("  - Circles and rectangles are set to only collide with themselves.");
            sb.AppendLine("  - Stars are set to collide with gears.");
            sb.AppendLine("  - Gears are set to collide with stars.");
            sb.AppendLine("  - The agent is set to collide with everything but stars");
            sb.AppendLine(string.Empty);
            sb.AppendLine("GamePad:");
            sb.AppendLine("  - Rotate agent: left and right triggers");
            sb.AppendLine("  - Move agent: right thumbstick");
            sb.AppendLine("  - Move cursor: left thumbstick");
            sb.AppendLine("  - Grab object (beneath cursor): A button");
            sb.AppendLine("  - Drag grabbed object: left thumbstick");
            sb.AppendLine("  - Exit to menu: Back button");
            sb.AppendLine(string.Empty);
            sb.AppendLine("Keyboard:");
            sb.AppendLine("  - Rotate agent: left and right arrows");
            sb.AppendLine("  - Move agent: A,S,D,W");
            sb.AppendLine("  - Exit to menu: Escape");
            sb.AppendLine(string.Empty);
            sb.AppendLine("Mouse / Touchscreen");
            sb.AppendLine("  - Grab object (beneath cursor): Left click");
            sb.AppendLine("  - Drag grabbed object: move mouse / finger");
            return sb.ToString();
        }

        #endregion

        public override void LoadContent()
        {
            base.LoadContent();

            World.Gravity = Vector2.Zero;

            _border = new Border(World, this, ScreenManager.GraphicsDevice.Viewport);

            //Cat1=Circles, Cat2=Rectangles, Cat3=Gears, Cat4=Stars
            _agent = new Agent(World, this, Vector2.Zero);

            //Collide with all but stars
            _agent.CollisionCategories = Category.All & ~Category.Cat4;
            _agent.CollidesWith = Category.All & ~Category.Cat4;

            Vector2 startPosition = new Vector2(-20f, -11f);
            Vector2 endPosition = new Vector2(20, -11f);
            _circles = new Objects(World, this, startPosition, endPosition, 15, 0.6f, ObjectType.Circle);

            //Collide with itself only
            _circles.CollisionCategories = Category.Cat1;
            _circles.CollidesWith = Category.Cat1;

            startPosition = new Vector2(-20, 11f);
            endPosition = new Vector2(20, 11f);
            _rectangles = new Objects(World, this, startPosition, endPosition, 15, 1.2f, ObjectType.Rectangle);

            //Collides with itself only
            _rectangles.CollisionCategories = Category.Cat2;
            _rectangles.CollidesWith = Category.Cat2;

            startPosition = new Vector2(-20, 7);
            endPosition = new Vector2(-20, -7);
            _gears = new Objects(World, this, startPosition, endPosition, 5, 0.6f, ObjectType.Gear);

            //Collides with stars
            _gears.CollisionCategories = Category.Cat3;
            _gears.CollidesWith = Category.Cat3 | Category.Cat4;

            startPosition = new Vector2(20, 7);
            endPosition = new Vector2(20, -7);
            _stars = new Objects(World, this, startPosition, endPosition, 5, 0.6f, ObjectType.Star);

            //Collides with gears
            _stars.CollisionCategories = Category.Cat4;
            _stars.CollidesWith = Category.Cat3 | Category.Cat4;

            SetUserAgent(_agent.Body, 1000f, 400f);
        }

        public override void Draw(GameTime gameTime)
        {
            ScreenManager.SpriteBatch.Begin(0, null, null, null, null, null, Camera.View);
            _agent.Draw();
            _circles.Draw();
            _rectangles.Draw();
            _stars.Draw();
            _gears.Draw();
            ScreenManager.SpriteBatch.End();
            _border.Draw();
            base.Draw(gameTime);
        }
    }
}