opensim/OpenSim/Region/PhysicsModules/BulletS/BSConstraintCollection.cs

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using System;
using System.Collections.Generic;
using System.Text;
using log4net;
using OpenMetaverse;

namespace OpenSim.Region.PhysicsModule.BulletS
{
    public sealed class BSConstraintCollection : IDisposable
    {
        // private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
        // private static readonly string LogHeader = "[CONSTRAINT COLLECTION]";

        delegate bool ConstraintAction(BSConstraint constrain);

        private List<BSConstraint> m_constraints;
        private BulletWorld m_world;

        public BSConstraintCollection(BulletWorld world)
        {
            m_world = world;
            m_constraints = new List<BSConstraint>();
        }

        public void Dispose()
        {
            this.Clear();
        }

        public void Clear()
        {
            lock (m_constraints)
            {
                foreach (BSConstraint cons in m_constraints)
                {
                    cons.Dispose();
                }
                m_constraints.Clear();
            }
        }

        public bool AddConstraint(BSConstraint cons)
        {
            lock (m_constraints)
            {
                // There is only one constraint between any bodies. Remove any old just to make sure.
                RemoveAndDestroyConstraint(cons.Body1, cons.Body2);

                m_constraints.Add(cons);
            }

            return true;
        }

        // Get the constraint between two bodies. There can be only one.
        // Return 'true' if a constraint was found.
        public bool TryGetConstraint(BulletBody body1, BulletBody body2, out BSConstraint returnConstraint)
        {
            bool found = false;
            BSConstraint foundConstraint = null;

            uint lookingID1 = body1.ID;
            uint lookingID2 = body2.ID;
            lock (m_constraints)
            {
                foreach (BSConstraint constrain in m_constraints)
                {
                    if ((constrain.Body1.ID == lookingID1 && constrain.Body2.ID == lookingID2)
                        || (constrain.Body1.ID == lookingID2 && constrain.Body2.ID == lookingID1))
                    {
                        foundConstraint = constrain;
                        found = true;
                        break;
                    }
                }
            }
            returnConstraint = foundConstraint;
            return found;
        }

        // Remove any constraint between the passed bodies.
        // Presumed there is only one such constraint possible.
        // Return 'true' if a constraint was found and destroyed.
        public bool RemoveAndDestroyConstraint(BulletBody body1, BulletBody body2)
        {
            bool ret = false;
            lock (m_constraints)
            {
                BSConstraint constrain;
                if (this.TryGetConstraint(body1, body2, out constrain))
                {
                    // remove the constraint from our collection
                    ret = RemoveAndDestroyConstraint(constrain);
                }
            }

            return ret;
        }

        // The constraint MUST exist in the collection
        // Could be called if the constraint was previously removed.
        // Return 'true' if the constraint was actually removed and disposed.
        public bool RemoveAndDestroyConstraint(BSConstraint constrain)
        {
            bool removed = false;
            lock (m_constraints)
            {
                // remove the constraint from our collection
                removed = m_constraints.Remove(constrain);
            }
            // Dispose() is safe to call multiple times
            constrain.Dispose();
            return removed;
        }

        // Remove all constraints that reference the passed body.
        // Return 'true' if any constraints were destroyed.
        public bool RemoveAndDestroyConstraint(BulletBody body1)
        {
            List<BSConstraint> toRemove = new List<BSConstraint>();
            uint lookingID = body1.ID;
            lock (m_constraints)
            {
                foreach (BSConstraint constrain in m_constraints)
                {
                    if (constrain.Body1.ID == lookingID || constrain.Body2.ID == lookingID)
                    {
                        toRemove.Add(constrain);
                    }
                }
                foreach (BSConstraint constrain in toRemove)
                {
                    m_constraints.Remove(constrain);
                    constrain.Dispose();
                }
            }
            return (toRemove.Count > 0);
        }

        public bool RecalculateAllConstraints()
        {
            bool ret = false;
            lock (m_constraints)
            {
                foreach (BSConstraint constrain in m_constraints)
                {
                    constrain.CalculateTransforms();
                    ret = true;
                }
            }
            return ret;
        }
    }
}