using System;
using System.Collections.Generic;
using FarseerPhysics.Collision.Shapes;
using FarseerPhysics.Common;
using FarseerPhysics.Common.Decomposition;
using FarseerPhysics.Dynamics;
using FarseerPhysics.Dynamics.Joints;
using Microsoft.Xna.Framework;
namespace FarseerPhysics.Factories
{
/// <summary>
/// An easy to use manager for creating paths.
/// </summary>
public static class PathManager
{
#region LinkType enum
public enum LinkType
{
Revolute,
Slider
}
#endregion
//Contributed by Matthew Bettcher
/// <summary>
/// Convert a path into a set of edges and attaches them to the specified body.
/// Note: use only for static edges.
/// </summary>
/// <param name="path">The path.</param>
/// <param name="body">The body.</param>
/// <param name="subdivisions">The subdivisions.</param>
public static void ConvertPathToEdges(Path path, Body body, int subdivisions)
{
Vertices verts = path.GetVertices(subdivisions);
if (path.Closed)
{
LoopShape loop = new LoopShape(verts);
body.CreateFixture(loop);
}
else
{
for (int i = 1; i < verts.Count; i++)
{
body.CreateFixture(new EdgeShape(verts[i], verts[i - 1]));
}
}
}
/// <summary>
/// Convert a closed path into a polygon.
/// Convex decomposition is automatically performed.
/// </summary>
/// <param name="path">The path.</param>
/// <param name="body">The body.</param>
/// <param name="density">The density.</param>
/// <param name="subdivisions">The subdivisions.</param>
public static void ConvertPathToPolygon(Path path, Body body, float density, int subdivisions)
{
if (!path.Closed)
throw new Exception("The path must be closed to convert to a polygon.");
List<Vector2> verts = path.GetVertices(subdivisions);
List<Vertices> decomposedVerts = EarclipDecomposer.ConvexPartition(new Vertices(verts));
//List<Vertices> decomposedVerts = BayazitDecomposer.ConvexPartition(new Vertices(verts));
foreach (Vertices item in decomposedVerts)
{
body.CreateFixture(new PolygonShape(item, density));
}
}
/// <summary>
/// Duplicates the given Body along the given path for approximatly the given copies.
/// </summary>
/// <param name="world">The world.</param>
/// <param name="path">The path.</param>
/// <param name="shapes">The shapes.</param>
/// <param name="type">The type.</param>
/// <param name="copies">The copies.</param>
/// <param name="userData"></param>
/// <returns></returns>
public static List<Body> EvenlyDistributeShapesAlongPath(World world, Path path, IEnumerable<Shape> shapes,
BodyType type, int copies, object userData)
{
List<Vector3> centers = path.SubdivideEvenly(copies);
List<Body> bodyList = new List<Body>();
for (int i = 0; i < centers.Count; i++)
{
Body b = new Body(world);
// copy the type from original body
b.BodyType = type;
b.Position = new Vector2(centers[i].X, centers[i].Y);
b.Rotation = centers[i].Z;
foreach (Shape shape in shapes)
{
b.CreateFixture(shape, userData);
}
bodyList.Add(b);
}
return bodyList;
}
public static List<Body> EvenlyDistributeShapesAlongPath(World world, Path path, IEnumerable<Shape> shapes,
BodyType type, int copies)
{
return EvenlyDistributeShapesAlongPath(world, path, shapes, type, copies, null);
}
/// <summary>
/// Duplicates the given Body along the given path for approximatly the given copies.
/// </summary>
/// <param name="world">The world.</param>
/// <param name="path">The path.</param>
/// <param name="shape">The shape.</param>
/// <param name="type">The type.</param>
/// <param name="copies">The copies.</param>
/// <param name="userData">The user data.</param>
/// <returns></returns>
public static List<Body> EvenlyDistributeShapesAlongPath(World world, Path path, Shape shape, BodyType type,
int copies, object userData)
{
List<Shape> shapes = new List<Shape>(1);
shapes.Add(shape);
return EvenlyDistributeShapesAlongPath(world, path, shapes, type, copies, userData);
}
public static List<Body> EvenlyDistributeShapesAlongPath(World world, Path path, Shape shape, BodyType type,
int copies)
{
return EvenlyDistributeShapesAlongPath(world, path, shape, type, copies, null);
}
//TODO: Comment better
/// <summary>
/// Moves the body on the path.
/// </summary>
/// <param name="path">The path.</param>
/// <param name="body">The body.</param>
/// <param name="time">The time.</param>
/// <param name="strength">The strength.</param>
/// <param name="timeStep">The time step.</param>
public static void MoveBodyOnPath(Path path, Body body, float time, float strength, float timeStep)
{
Vector2 destination = path.GetPosition(time);
Vector2 positionDelta = body.Position - destination;
Vector2 velocity = (positionDelta / timeStep) * strength;
body.LinearVelocity = -velocity;
}
/// <summary>
/// Attaches the bodies with revolute joints.
/// </summary>
/// <param name="world">The world.</param>
/// <param name="bodies">The bodies.</param>
/// <param name="localAnchorA">The local anchor A.</param>
/// <param name="localAnchorB">The local anchor B.</param>
/// <param name="connectFirstAndLast">if set to <c>true</c> [connect first and last].</param>
/// <param name="collideConnected">if set to <c>true</c> [collide connected].</param>
public static List<RevoluteJoint> AttachBodiesWithRevoluteJoint(World world, List<Body> bodies,
Vector2 localAnchorA,
Vector2 localAnchorB, bool connectFirstAndLast,
bool collideConnected)
{
List<RevoluteJoint> joints = new List<RevoluteJoint>(bodies.Count + 1);
for (int i = 1; i < bodies.Count; i++)
{
RevoluteJoint joint = new RevoluteJoint(bodies[i], bodies[i - 1], localAnchorA, localAnchorB);
joint.CollideConnected = collideConnected;
world.AddJoint(joint);
joints.Add(joint);
}
if (connectFirstAndLast)
{
RevoluteJoint lastjoint = new RevoluteJoint(bodies[0], bodies[bodies.Count - 1], localAnchorA,
localAnchorB);
lastjoint.CollideConnected = collideConnected;
world.AddJoint(lastjoint);
joints.Add(lastjoint);
}
return joints;
}
/// <summary>
/// Attaches the bodies with revolute joints.
/// </summary>
/// <param name="world">The world.</param>
/// <param name="bodies">The bodies.</param>
/// <param name="localAnchorA">The local anchor A.</param>
/// <param name="localAnchorB">The local anchor B.</param>
/// <param name="connectFirstAndLast">if set to <c>true</c> [connect first and last].</param>
/// <param name="collideConnected">if set to <c>true</c> [collide connected].</param>
/// <param name="minLength">Minimum length of the slider joint.</param>
/// <param name="maxLength">Maximum length of the slider joint.</param>
/// <returns></returns>
public static List<SliderJoint> AttachBodiesWithSliderJoint(World world, List<Body> bodies, Vector2 localAnchorA,
Vector2 localAnchorB, bool connectFirstAndLast,
bool collideConnected, float minLength,
float maxLength)
{
List<SliderJoint> joints = new List<SliderJoint>(bodies.Count + 1);
for (int i = 1; i < bodies.Count; i++)
{
SliderJoint joint = new SliderJoint(bodies[i], bodies[i - 1], localAnchorA, localAnchorB, minLength,
maxLength);
joint.CollideConnected = collideConnected;
world.AddJoint(joint);
joints.Add(joint);
}
if (connectFirstAndLast)
{
SliderJoint lastjoint = new SliderJoint(bodies[0], bodies[bodies.Count - 1], localAnchorA, localAnchorB,
minLength, maxLength);
lastjoint.CollideConnected = collideConnected;
world.AddJoint(lastjoint);
joints.Add(lastjoint);
}
return joints;
}
}
}
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