OpenSimMirror/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs

309 lines
11 KiB
C#
Executable File

/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
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* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the OpenSimulator Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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*/
using System;
using System.Collections.Generic;
using System.Text;
using OMV = OpenMetaverse;
namespace OpenSim.Region.Physics.BulletSPlugin
{
public class BSLinkset
{
private static string LogHeader = "[BULLETSIM LINKSET]";
private BSPrim m_linksetRoot;
public BSPrim Root { get { return m_linksetRoot; } }
private BSScene m_scene;
private List<BSPrim> m_children;
// We lock the diddling of linkset classes to prevent any badness.
// This locks the modification of the instances of this class. Changes
// to the physical representation is done via the tainting mechenism.
private object m_linksetActivityLock = new Object();
// We keep the prim's mass in the linkset structure since it could be dependent on other prims
private float m_mass;
public float LinksetMass
{
get
{
m_mass = ComputeLinksetMass();
return m_mass;
}
}
public OMV.Vector3 CenterOfMass
{
get { return ComputeLinksetCenterOfMass(); }
}
public OMV.Vector3 GeometricCenter
{
get { return ComputeLinksetGeometricCenter(); }
}
public BSLinkset(BSScene scene, BSPrim parent)
{
// A simple linkset of one (no children)
m_scene = scene;
m_linksetRoot = parent;
m_children = new List<BSPrim>();
m_mass = parent.MassRaw;
}
// Link to a linkset where the child knows the parent.
// Parent changing should not happen so do some sanity checking.
// We return the parent's linkset so the child can track it's membership.
public BSLinkset AddMeToLinkset(BSPrim child, BSPrim parent)
{
lock (m_linksetActivityLock)
{
parent.Linkset.AddChildToLinkset(child);
}
return parent.Linkset;
}
public BSLinkset RemoveMeFromLinkset(BSPrim child)
{
lock (m_linksetActivityLock)
{
if (IsRoot(child))
{
// if root of linkset, take the linkset apart
while (m_children.Count > 0)
{
// Note that we don't do a foreach because the remove routine
// takes it out of the list.
RemoveChildFromLinkset(m_children[0]);
}
m_children.Clear(); // just to make sure
}
else
{
// Just removing a child from an existing linkset
RemoveChildFromLinkset(child);
}
}
// The child is down to a linkset of just itself
return new BSLinkset(m_scene, child);
}
// An existing linkset had one of its members rebuilt or something.
// Undo all the physical linking and rebuild the physical linkset.
public bool RefreshLinkset(BSPrim requestor)
{
return true;
}
// Return 'true' if the passed object is the root object of this linkset
public bool IsRoot(BSPrim requestor)
{
return (requestor.LocalID == m_linksetRoot.LocalID);
}
// Return 'true' if this linkset has any children (more than the root member)
public bool HasAnyChildren { get { return (m_children.Count > 0); } }
// Return 'true' if this child is in this linkset
public bool HasChild(BSPrim child)
{
bool ret = false;
foreach (BSPrim bp in m_children)
{
if (child.LocalID == bp.LocalID)
{
ret = true;
break;
}
}
return ret;
}
private float ComputeLinksetMass()
{
float mass = m_linksetRoot.MassRaw;
foreach (BSPrim bp in m_children)
{
mass += bp.MassRaw;
}
return mass;
}
private OMV.Vector3 ComputeLinksetCenterOfMass()
{
OMV.Vector3 com = m_linksetRoot.Position * m_linksetRoot.MassRaw;
float totalMass = m_linksetRoot.MassRaw;
foreach (BSPrim bp in m_children)
{
com += bp.Position * bp.MassRaw;
totalMass += bp.MassRaw;
}
com /= totalMass;
return com;
}
private OMV.Vector3 ComputeLinksetGeometricCenter()
{
OMV.Vector3 com = m_linksetRoot.Position;
foreach (BSPrim bp in m_children)
{
com += bp.Position * bp.MassRaw;
}
com /= m_children.Count + 1;
return com;
}
// I am the root of a linkset and a new child is being added
public void AddChildToLinkset(BSPrim pchild)
{
BSPrim child = pchild;
if (!HasChild(child))
{
m_children.Add(child);
m_scene.TaintedObject(delegate()
{
DebugLog("{0}: AddChildToLinkset: adding child {1} to {2}", LogHeader, child.LocalID, m_linksetRoot.LocalID);
DetailLog("{0},AddChildToLinkset,child={1}", m_linksetRoot.LocalID, pchild.LocalID);
PhysicallyLinkAChildToRoot(pchild); // build the physical binding between me and the child
});
}
return;
}
// I am the root of a linkset and one of my children is being removed.
// Safe to call even if the child is not really in my linkset.
public void RemoveChildFromLinkset(BSPrim pchild)
{
BSPrim child = pchild;
if (m_children.Remove(child))
{
m_scene.TaintedObject(delegate()
{
DebugLog("{0}: RemoveChildFromLinkset: Removing constraint to {1}", LogHeader, child.LocalID);
DetailLog("{0},RemoveChildFromLinkset,child={1}", m_linksetRoot.LocalID, pchild.LocalID);
if (m_children.Count == 0)
{
// if the linkset is empty, make sure all linkages have been removed
PhysicallyUnlinkAllChildrenFromRoot();
}
else
{
PhysicallyUnlinkAChildFromRoot(pchild);
}
});
}
else
{
// This will happen if we remove the root of the linkset first. Non-fatal occurance.
// m_scene.Logger.ErrorFormat("{0}: Asked to remove child from linkset that was not in linkset", LogHeader);
}
return;
}
// Create a constraint between me (root of linkset) and the passed prim (the child).
// Called at taint time!
private void PhysicallyLinkAChildToRoot(BSPrim childPrim)
{
// Zero motion for children so they don't interpolate
childPrim.ZeroMotion();
// relative position normalized to the root prim
OMV.Quaternion invThisOrientation = OMV.Quaternion.Inverse(m_linksetRoot.Orientation);
OMV.Vector3 childRelativePosition = (childPrim.Position - m_linksetRoot.Position) * invThisOrientation;
// relative rotation of the child to the parent
OMV.Quaternion childRelativeRotation = invThisOrientation * childPrim.Orientation;
// create a constraint that allows no freedom of movement between the two objects
// http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
// DebugLog("{0}: CreateLinkset: Adding a constraint between root prim {1} and child prim {2}", LogHeader, LocalID, childPrim.LocalID);
DetailLog("{0},LinkAChildToMe,taint,root={1},child={2}", m_linksetRoot.LocalID, m_linksetRoot.LocalID, childPrim.LocalID);
BSConstraint constrain = m_scene.Constraints.CreateConstraint(
m_scene.World, m_linksetRoot.Body, childPrim.Body,
childRelativePosition,
childRelativeRotation,
OMV.Vector3.Zero,
OMV.Quaternion.Identity);
constrain.SetLinearLimits(OMV.Vector3.Zero, OMV.Vector3.Zero);
constrain.SetAngularLimits(OMV.Vector3.Zero, OMV.Vector3.Zero);
// tweek the constraint to increase stability
constrain.UseFrameOffset(m_scene.BoolNumeric(m_scene.Params.linkConstraintUseFrameOffset));
constrain.TranslationalLimitMotor(m_scene.BoolNumeric(m_scene.Params.linkConstraintEnableTransMotor),
m_scene.Params.linkConstraintTransMotorMaxVel,
m_scene.Params.linkConstraintTransMotorMaxForce);
}
// Remove linkage between myself and a particular child
// Called at taint time!
private void PhysicallyUnlinkAChildFromRoot(BSPrim childPrim)
{
DebugLog("{0}: PhysicallyUnlinkAChildFromRoot: RemoveConstraint between root prim {1} and child prim {2}",
LogHeader, m_linksetRoot.LocalID, childPrim.LocalID);
DetailLog("{0},PhysicallyUnlinkAChildFromRoot,taint,root={1},child={2}", m_linksetRoot.LocalID, m_linksetRoot.LocalID, childPrim.LocalID);
// BulletSimAPI.RemoveConstraint(_scene.WorldID, LocalID, childPrim.LocalID);
m_scene.Constraints.RemoveAndDestroyConstraint(m_linksetRoot.Body, childPrim.Body);
}
// Remove linkage between myself and any possible children I might have
// Called at taint time!
private void PhysicallyUnlinkAllChildrenFromRoot()
{
// DebugLog("{0}: PhysicallyUnlinkAllChildren:", LogHeader);
DetailLog("{0},PhysicallyUnlinkAllChildren,taint", m_linksetRoot.LocalID);
m_scene.Constraints.RemoveAndDestroyConstraint(m_linksetRoot.Body);
// BulletSimAPI.RemoveConstraintByID(_scene.WorldID, LocalID);
}
// Invoke the detailed logger and output something if it's enabled.
private void DebugLog(string msg, params Object[] args)
{
m_scene.Logger.DebugFormat(msg, args);
}
// Invoke the detailed logger and output something if it's enabled.
private void DetailLog(string msg, params Object[] args)
{
m_scene.PhysicsLogging.Write(msg, args);
}
}
}