private bool CheckVisibilityRecursive(Vector3 q1, Vector3 q2, float radius, ObstacleTreeNode node) { if (node == null) { return(true); } else { Obstacle obstacle1 = node.m_Obstacle; Obstacle obstacle2 = obstacle1.m_NextObstacle; float q1LeftOfI = VectorMath.leftOf(obstacle1.m_Point, obstacle2.m_Point, q1); float q2LeftOfI = VectorMath.leftOf(obstacle1.m_Point, obstacle2.m_Point, q2); float invLengthI = 1.0f / VectorMath.absSq(obstacle2.m_Point - obstacle1.m_Point); if (q1LeftOfI >= 0.0f && q2LeftOfI >= 0.0f) { return(CheckVisibilityRecursive(q1, q2, radius, node.m_Left) && ((VectorMath.sqr(q1LeftOfI) * invLengthI >= VectorMath.sqr(radius) && VectorMath.sqr(q2LeftOfI) * invLengthI >= VectorMath.sqr(radius)) || CheckVisibilityRecursive(q1, q2, radius, node.m_Right))); } else if (q1LeftOfI <= 0.0f && q2LeftOfI <= 0.0f) { return(CheckVisibilityRecursive(q1, q2, radius, node.m_Right) && ((VectorMath.sqr(q1LeftOfI) * invLengthI >= VectorMath.sqr(radius) && VectorMath.sqr(q2LeftOfI) * invLengthI >= VectorMath.sqr(radius)) || CheckVisibilityRecursive(q1, q2, radius, node.m_Left))); } else if (q1LeftOfI >= 0.0f && q2LeftOfI <= 0.0f) { /* One can see through obstacle from left to right. */ return(CheckVisibilityRecursive(q1, q2, radius, node.m_Left) && CheckVisibilityRecursive(q1, q2, radius, node.m_Right)); } else { float point1LeftOfQ = VectorMath.leftOf(q1, q2, obstacle1.m_Point); float point2LeftOfQ = VectorMath.leftOf(q1, q2, obstacle2.m_Point); float invLengthQ = 1.0f / VectorMath.absSq(q2 - q1); return(point1LeftOfQ * point2LeftOfQ >= 0.0f && VectorMath.sqr(point1LeftOfQ) * invLengthQ > VectorMath.sqr(radius) && VectorMath.sqr(point2LeftOfQ) * invLengthQ > VectorMath.sqr(radius) && CheckVisibilityRecursive(q1, q2, radius, node.m_Left) && CheckVisibilityRecursive(q1, q2, radius, node.m_Right)); } } }
private ObstacleTreeNode BuildRecursive(IList <Obstacle> obstacles) { if (obstacles.Count == 0) { return(null); } else { ObstacleTreeNode node = new ObstacleTreeNode(); int optimalSplit = 0; int minLeft = obstacles.Count; int minRight = obstacles.Count; for (int i = 0; i < obstacles.Count; ++i) { int leftSize = 0; int rightSize = 0; Obstacle obstacleI1 = obstacles[i]; Obstacle obstacleI2 = obstacleI1.m_NextObstacle; /* Compute optimal split node. */ for (int j = 0; j < obstacles.Count; ++j) { if (i == j) { continue; } Obstacle obstacleJ1 = obstacles[j]; Obstacle obstacleJ2 = obstacleJ1.m_NextObstacle; float j1LeftOfI = VectorMath.leftOf(obstacleI1.m_Point, obstacleI2.m_Point, obstacleJ1.m_Point); float j2LeftOfI = VectorMath.leftOf(obstacleI1.m_Point, obstacleI2.m_Point, obstacleJ2.m_Point); if (j1LeftOfI >= -VectorMath.EPSILON && j2LeftOfI >= -VectorMath.EPSILON) { ++leftSize; } else if (j1LeftOfI <= VectorMath.EPSILON && j2LeftOfI <= VectorMath.EPSILON) { ++rightSize; } else { ++leftSize; ++rightSize; } if (new FloatPair(Math.Max(leftSize, rightSize), Math.Min(leftSize, rightSize)) >= new FloatPair(Math.Max(minLeft, minRight), Math.Min(minLeft, minRight))) { break; } } if (new FloatPair(Math.Max(leftSize, rightSize), Math.Min(leftSize, rightSize)) < new FloatPair(Math.Max(minLeft, minRight), Math.Min(minLeft, minRight))) { minLeft = leftSize; minRight = rightSize; optimalSplit = i; } } { /* Build split node. */ IList <Obstacle> leftObstacles = new List <Obstacle>(minLeft); for (int n = 0; n < minLeft; ++n) { leftObstacles.Add(null); } IList <Obstacle> rightObstacles = new List <Obstacle>(minRight); for (int n = 0; n < minRight; ++n) { rightObstacles.Add(null); } int leftCounter = 0; int rightCounter = 0; int i = optimalSplit; Obstacle obstacleI1 = obstacles[i]; Obstacle obstacleI2 = obstacleI1.m_NextObstacle; for (int j = 0; j < obstacles.Count; ++j) { if (i == j) { continue; } Obstacle obstacleJ1 = obstacles[j]; Obstacle obstacleJ2 = obstacleJ1.m_NextObstacle; float j1LeftOfI = VectorMath.leftOf(obstacleI1.m_Point, obstacleI2.m_Point, obstacleJ1.m_Point); float j2LeftOfI = VectorMath.leftOf(obstacleI1.m_Point, obstacleI2.m_Point, obstacleJ2.m_Point); if (j1LeftOfI >= -VectorMath.EPSILON && j2LeftOfI >= -VectorMath.EPSILON) { leftObstacles[leftCounter++] = obstacles[j]; } else if (j1LeftOfI <= VectorMath.EPSILON && j2LeftOfI <= VectorMath.EPSILON) { rightObstacles[rightCounter++] = obstacles[j]; } else { /* Split obstacle j. */ float t = VectorMath.det(obstacleI2.m_Point - obstacleI1.m_Point, obstacleJ1.m_Point - obstacleI1.m_Point) / VectorMath.det(obstacleI2.m_Point - obstacleI1.m_Point, obstacleJ1.m_Point - obstacleJ2.m_Point); Vector3 splitpoint = obstacleJ1.m_Point + t * (obstacleJ2.m_Point - obstacleJ1.m_Point); Obstacle newObstacle = new Obstacle(); newObstacle.m_Point = splitpoint; newObstacle.m_PrevObstacle = obstacleJ1; newObstacle.m_NextObstacle = obstacleJ2; newObstacle.m_IsConvex = true; newObstacle.m_UnitDir = obstacleJ1.m_UnitDir; m_Obstacles.Add(newObstacle); obstacleJ1.m_NextObstacle = newObstacle; obstacleJ2.m_PrevObstacle = newObstacle; if (j1LeftOfI > 0.0f) { leftObstacles[leftCounter++] = obstacleJ1; rightObstacles[rightCounter++] = newObstacle; } else { rightObstacles[rightCounter++] = obstacleJ1; leftObstacles[leftCounter++] = newObstacle; } } } node.m_Obstacle = obstacleI1; node.m_Left = BuildRecursive(leftObstacles); node.m_Right = BuildRecursive(rightObstacles); return(node); } } }