public void Build(IList <ISpaceObject> objs)
{
if (null == m_Objects || m_Objects.Length < objs.Count)
{
m_ObjectNum = 0;
m_Objects = new KdTreeObject[objs.Count * 2];
foreach (ISpaceObject obj in objs)
{
m_Objects[m_ObjectNum++] = new KdTreeObject(obj);
}
}
else
{
m_ObjectNum = 0;
foreach (ISpaceObject obj in objs)
{
if (null == m_Objects[m_ObjectNum])
{
m_Objects[m_ObjectNum] = new KdTreeObject(obj);
}
else
{
m_Objects[m_ObjectNum].CopyFrom(obj);
}
++m_ObjectNum;
}
}
if (m_ObjectNum > 0)
{
if (null == m_KdTree || m_KdTree.Length < 3 * m_ObjectNum)
{
m_KdTree = new KdTreeNode[3 * m_ObjectNum];
for (int i = 0; i < m_KdTree.Length; ++i)
{
m_KdTree[i] = new KdTreeNode();
}
}
m_MaxNodeNum = 2 * m_ObjectNum;
BuildImpl();
}
}
/* Search for the best new velocity. */
public Vector3 ComputeNewVelocity(ISpaceObject obj, Vector3 prefDir, float timeStep, KdTree kdTree, KdObstacleTree kdObstacleTree, float maxSpeed, float neighborDist, bool isUsingAvoidanceVelocity)
{
ComputeNeighbors(obj, kdTree, kdObstacleTree, maxSpeed, neighborDist);
ClearOrcaLine();
Vector3 position = obj.GetPosition();
float radius = (float)obj.GetRadius();
Vector3 velocity = obj.GetVelocity();
Vector3 newVelocity = new Vector3();
float invTimeHorizonObst = 1.0f / m_TimeHorizonObst;
/* Create obstacle ORCA lines. */
for (int i = 0; i < m_ObstacleNeighbors.Count; ++i)
{
Obstacle obstacle1 = m_ObstacleNeighbors[i].Value;
Obstacle obstacle2 = obstacle1.m_NextObstacle;
Vector3 relativePosition1 = obstacle1.m_Point - position;
Vector3 relativePosition2 = obstacle2.m_Point - position;
/*
* Check if velocity obstacle of obstacle is already taken care of by
* previously constructed obstacle ORCA lines.
*/
bool alreadyCovered = false;
for (int j = 0; j < m_OrcaLines.Count; ++j)
{
if (VectorMath.det(invTimeHorizonObst * relativePosition1 - m_OrcaLines[j].point, m_OrcaLines[j].direction) - invTimeHorizonObst * radius >= -VectorMath.EPSILON && VectorMath.det(invTimeHorizonObst * relativePosition2 - m_OrcaLines[j].point, m_OrcaLines[j].direction) - invTimeHorizonObst * radius >= -VectorMath.EPSILON)
{
alreadyCovered = true;
break;
}
}
if (alreadyCovered)
{
continue;
}
/* Not yet covered. Check for collisions. */
float distSq1 = VectorMath.absSq(relativePosition1);
float distSq2 = VectorMath.absSq(relativePosition2);
float radiusSq = VectorMath.sqr(radius);
Vector3 obstacleVector = obstacle2.m_Point - obstacle1.m_Point;
float s = -VectorMath.dot(relativePosition1, obstacleVector) / VectorMath.absSq(obstacleVector);
float distSqLine = VectorMath.absSq(-relativePosition1 - s * obstacleVector);
OrcaLine line;
if (s < 0 && distSq1 <= radiusSq)
{
/* Collision with left vertex. Ignore if non-convex. */
if (obstacle1.m_IsConvex)
{
line.point = new Vector3();
line.direction = VectorMath.normalize(new Vector3(-relativePosition1.Z, 0, relativePosition1.X));
AddOrcaLine(line);
}
continue;
}
else if (s > 1 && distSq2 <= radiusSq)
{
/* Collision with right vertex. Ignore if non-convex
* or if it will be taken care of by neighoring obstace */
if (obstacle2.m_IsConvex && VectorMath.det(relativePosition2, obstacle2.m_UnitDir) >= 0)
{
line.point = new Vector3();
line.direction = VectorMath.normalize(new Vector3(-relativePosition2.Z, 0, relativePosition2.X));
AddOrcaLine(line);
}
continue;
}
else if (s >= 0 && s < 1 && distSqLine <= radiusSq)
{
/* Collision with obstacle segment. */
line.point = new Vector3();
line.direction = -obstacle1.m_UnitDir;
AddOrcaLine(line);
continue;
}
/*
* No collision.
* Compute legs. When obliquely viewed, both legs can come from a single
* vertex. Legs extend cut-off line when nonconvex vertex.
*/
Vector3 leftLegDirection, rightLegDirection;
if (s < 0 && distSqLine <= radiusSq)
{
/*
* Obstacle viewed obliquely so that left vertex
* defines velocity obstacle.
*/
if (!obstacle1.m_IsConvex)
{
/* Ignore obstacle. */
continue;
}
obstacle2 = obstacle1;
float leg1 = VectorMath.sqrt(distSq1 - radiusSq);
leftLegDirection = new Vector3(relativePosition1.X * leg1 - relativePosition1.Z * radius, 0, relativePosition1.X * radius + relativePosition1.Z * leg1) / distSq1;
rightLegDirection = new Vector3(relativePosition1.X * leg1 + relativePosition1.Z * radius, 0, -relativePosition1.X * radius + relativePosition1.Z * leg1) / distSq1;
}
else if (s > 1 && distSqLine <= radiusSq)
{
/*
* Obstacle viewed obliquely so that
* right vertex defines velocity obstacle.
*/
if (!obstacle2.m_IsConvex)
{
/* Ignore obstacle. */
continue;
}
obstacle1 = obstacle2;
float leg2 = VectorMath.sqrt(distSq2 - radiusSq);
leftLegDirection = new Vector3(relativePosition2.X * leg2 - relativePosition2.Z * radius, 0, relativePosition2.X * radius + relativePosition2.Z * leg2) / distSq2;
rightLegDirection = new Vector3(relativePosition2.X * leg2 + relativePosition2.Z * radius, 0, -relativePosition2.X * radius + relativePosition2.Z * leg2) / distSq2;
}
else
{
/* Usual situation. */
if (obstacle1.m_IsConvex)
{
float leg1 = VectorMath.sqrt(distSq1 - radiusSq);
leftLegDirection = new Vector3(relativePosition1.X * leg1 - relativePosition1.Z * radius, 0, relativePosition1.X * radius + relativePosition1.Z * leg1) / distSq1;
}
else
{
/* Left vertex non-convex; left leg extends cut-off line. */
leftLegDirection = -obstacle1.m_UnitDir;
}
if (obstacle2.m_IsConvex)
{
float leg2 = VectorMath.sqrt(distSq2 - radiusSq);
rightLegDirection = new Vector3(relativePosition2.X * leg2 + relativePosition2.Z * radius, 0, -relativePosition2.X * radius + relativePosition2.Z * leg2) / distSq2;
}
else
{
/* Right vertex non-convex; right leg extends cut-off line. */
rightLegDirection = obstacle1.m_UnitDir;
}
}
/*
* Legs can never point into neighboring edge when convex vertex,
* take cutoff-line of neighboring edge instead. If velocity projected on
* "foreign" leg, no constraint is added.
*/
Obstacle leftNeighbor = obstacle1.m_PrevObstacle;
bool isLeftLegForeign = false;
bool isRightLegForeign = false;
if (obstacle1.m_IsConvex && VectorMath.det(leftLegDirection, -leftNeighbor.m_UnitDir) >= 0.0f)
{
/* Left leg points into obstacle. */
leftLegDirection = -leftNeighbor.m_UnitDir;
isLeftLegForeign = true;
}
if (obstacle2.m_IsConvex && VectorMath.det(rightLegDirection, obstacle2.m_UnitDir) <= 0.0f)
{
/* Right leg points into obstacle. */
rightLegDirection = obstacle2.m_UnitDir;
isRightLegForeign = true;
}
/* Compute cut-off centers. */
Vector3 leftCutoff = invTimeHorizonObst * (obstacle1.m_Point - position);
Vector3 rightCutoff = invTimeHorizonObst * (obstacle2.m_Point - position);
Vector3 cutoffVec = rightCutoff - leftCutoff;
/* Project current velocity on velocity obstacle. */
/* Check if current velocity is projected on cutoff circles. */
float t = (obstacle1 == obstacle2 ? 0.5f : VectorMath.dot((velocity - leftCutoff), cutoffVec) / VectorMath.absSq(cutoffVec));
float tLeft = VectorMath.dot((velocity - leftCutoff), leftLegDirection);
float tRight = VectorMath.dot((velocity - rightCutoff), rightLegDirection);
if ((t < 0.0f && tLeft < 0.0f) || (obstacle1 == obstacle2 && tLeft < 0.0f && tRight < 0.0f))
{
/* Project on left cut-off circle. */
Vector3 unitW = VectorMath.normalize(velocity - leftCutoff);
line.direction = new Vector3(unitW.Z, 0, -unitW.X);
line.point = leftCutoff + radius * invTimeHorizonObst * unitW;
AddOrcaLine(line);
continue;
}
else if (t > 1.0f && tRight < 0.0f)
{
/* Project on right cut-off circle. */
Vector3 unitW = VectorMath.normalize(velocity - rightCutoff);
line.direction = new Vector3(unitW.Z, 0, -unitW.X);
line.point = rightCutoff + radius * invTimeHorizonObst * unitW;
AddOrcaLine(line);
continue;
}
/*
* Project on left leg, right leg, or cut-off line, whichever is closest
* to velocity.
*/
float distSqCutoff = ((t <0.0f || t> 1.0f || obstacle1 == obstacle2) ? float.PositiveInfinity : VectorMath.absSq(velocity - (leftCutoff + t * cutoffVec)));
float distSqLeft = ((tLeft < 0.0f) ? float.PositiveInfinity : VectorMath.absSq(velocity - (leftCutoff + tLeft * leftLegDirection)));
float distSqRight = ((tRight < 0.0f) ? float.PositiveInfinity : VectorMath.absSq(velocity - (rightCutoff + tRight * rightLegDirection)));
if (distSqCutoff <= distSqLeft && distSqCutoff <= distSqRight)
{
/* Project on cut-off line. */
line.direction = -obstacle1.m_UnitDir;
line.point = leftCutoff + radius * invTimeHorizonObst * new Vector3(-line.direction.Z, 0, line.direction.X);
AddOrcaLine(line);
continue;
}
else if (distSqLeft <= distSqRight)
{
/* Project on left leg. */
if (isLeftLegForeign)
{
continue;
}
line.direction = leftLegDirection;
line.point = leftCutoff + radius * invTimeHorizonObst * new Vector3(-line.direction.Z, 0, line.direction.X);
AddOrcaLine(line);
continue;
}
else
{
/* Project on right leg. */
if (isRightLegForeign)
{
continue;
}
line.direction = -rightLegDirection;
line.point = rightCutoff + radius * invTimeHorizonObst * new Vector3(-line.direction.Z, 0, line.direction.X);
AddOrcaLine(line);
continue;
}
}
int numObstLines = m_OrcaLines.Count;
float invTimeHorizon = 1.0f / m_TimeHorizon;
/* Create obj ORCA lines. */
for (int i = 0; i < m_ObjNeighbors.Count; ++i)
{
KdTreeObject other = m_ObjNeighbors[i].Value;
if (obj == other.SpaceObject)
{
continue;
}
Vector3 relativePosition = other.Position - position;
Vector3 relativeVelocity = velocity - other.Velocity;
float distSq = VectorMath.absSq(relativePosition);
float combinedRadius = radius + other.Radius;
float combinedRadiusSq = VectorMath.sqr(combinedRadius);
OrcaLine line;
Vector3 u;
if (distSq > combinedRadiusSq)
{
/* No collision. */
Vector3 w = relativeVelocity - invTimeHorizon * relativePosition;
/* Vector from cutoff center to relative velocity. */
float wLengthSq = VectorMath.absSq(w);
float dotProduct1 = VectorMath.dot(w, relativePosition);
if (dotProduct1 < 0.0f && VectorMath.sqr(dotProduct1) > combinedRadiusSq * wLengthSq)
{
/* Project on cut-off circle. */
float wLength = VectorMath.sqrt(wLengthSq);
Vector3 unitW = w / wLength;
line.direction = new Vector3(unitW.Z, 0, -unitW.X);
u = (combinedRadius * invTimeHorizon - wLength) * unitW;
}
else
{
/* Project on legs. */
float leg = VectorMath.sqrt(distSq - combinedRadiusSq);
if (VectorMath.det(relativePosition, w) > 0.0f)
{
/* Project on left leg. */
line.direction = new Vector3(relativePosition.X * leg - relativePosition.Z * combinedRadius, 0, relativePosition.X * combinedRadius + relativePosition.Z * leg) / distSq;
}
else
{
/* Project on right leg. */
line.direction = -new Vector3(relativePosition.X * leg + relativePosition.Z * combinedRadius, 0, -relativePosition.X * combinedRadius + relativePosition.Z * leg) / distSq;
}
float dotProduct2 = VectorMath.dot(relativeVelocity, line.direction);
u = dotProduct2 * line.direction - relativeVelocity;
}
}
else
{
/* Collision. Project on cut-off circle of time timeStep. */
float invTimeStep = 1.0f / timeStep;
/* Vector from cutoff center to relative velocity. */
Vector3 w = relativeVelocity - invTimeStep * relativePosition;
float wLength = VectorMath.abs(w);
if (wLength < VectorMath.EPSILON)
{
//LogSystem.Error("RvoAlgorithm error: Objects already overlap ! {0}({1}):{2}-{3}({4}):{5}", obj.GetID(), obj.GetObjType(), obj.GetPosition().ToString(), other.SpaceObject.GetID(), other.SpaceObject.GetObjType(), other.Position.ToString());
continue;
}
Vector3 unitW = w / wLength;
line.direction = new Vector3(unitW.Z, 0, -unitW.X);
u = (combinedRadius * invTimeStep - wLength) * unitW;
}
line.point = velocity + 0.5f * u;
AddOrcaLine(line);
}
Vector3 avoidanceVelocity;
if (isUsingAvoidanceVelocity)
{
avoidanceVelocity = obj.GetVelocity();
}
else
{
avoidanceVelocity = new Vector3();
}
int lineFail = LinearProgram2(m_OrcaLines, maxSpeed, prefDir, avoidanceVelocity, false, ref newVelocity);
if (lineFail < m_OrcaLines.Count)
{
LinearProgram3(m_OrcaLines, numObstLines, lineFail, maxSpeed, avoidanceVelocity, ref newVelocity);
}
return(newVelocity);
}
private void BuildImpl()
{
m_BuildStack.Push(0);
m_BuildStack.Push(m_ObjectNum);
m_BuildStack.Push(0);
while (m_BuildStack.Count >= 3)
{
int begin = m_BuildStack.Pop();
int end = m_BuildStack.Pop();
int node = m_BuildStack.Pop();
m_KdTree[node].m_Begin = begin;
m_KdTree[node].m_End = end;
float minX = m_Objects[begin].MinX;
float maxX = m_Objects[begin].MaxX;
float minZ = m_Objects[begin].MinZ;
float maxZ = m_Objects[begin].MaxZ;
for (int i = begin + 1; i < end; ++i)
{
float newMaxX = m_Objects[i].MaxX;
float newMinX = m_Objects[i].MinX;
float newMaxZ = m_Objects[i].MaxZ;
float newMinZ = m_Objects[i].MinZ;
if (minX > newMinX)
{
minX = newMinX;
}
if (maxX < newMaxX)
{
maxX = newMaxX;
}
if (minZ > newMinZ)
{
minZ = newMinZ;
}
if (maxZ < newMaxZ)
{
maxZ = newMaxZ;
}
}
m_KdTree[node].m_MinX = minX;
m_KdTree[node].m_MaxX = maxX;
m_KdTree[node].m_MinZ = minZ;
m_KdTree[node].m_MaxZ = maxZ;
if (end - begin > c_MaxLeafSize)
{
bool isVertical = (maxX - minX > maxZ - minZ);
float splitValue = (isVertical ? 0.5f * (maxX + minX) : 0.5f * (maxZ + minZ));
int left = begin;
int right = end;
while (left < right)
{
while (left < right && (isVertical ? m_Objects[left].Position.X : m_Objects[left].Position.Z) < splitValue)
{
++left;
}
while (right > left && (isVertical ? m_Objects[right - 1].Position.X : m_Objects[right - 1].Position.Z) >= splitValue)
{
--right;
}
if (left < right)
{
KdTreeObject tmp = m_Objects[left];
m_Objects[left] = m_Objects[right - 1];
m_Objects[right - 1] = tmp;
++left;
--right;
}
}
if (left == end)
{
--left;
}
int leftSize = left - begin;
if (leftSize == 0)
{
++leftSize;
++left;
}
m_KdTree[node].m_Left = node + 1;
m_KdTree[node].m_Right = node + 1 + (2 * leftSize - 1);
if (m_KdTree[node].m_Left >= m_MaxNodeNum || m_KdTree[node].m_Right >= m_MaxNodeNum)
{
LogSystem.Error("KdTree Error, node:{0} left:{1} right:{2} leftSize:{3} begin:{4} end:{5} maxNodeNum:{6}", node, left, right, leftSize, begin, end, m_MaxNodeNum);
}
m_BuildStack.Push(m_KdTree[node].m_Left);
m_BuildStack.Push(left);
m_BuildStack.Push(begin);
m_BuildStack.Push(m_KdTree[node].m_Right);
m_BuildStack.Push(end);
m_BuildStack.Push(left);
}
}
}
