void RayIntersectorKDTreeNode::TestSplit(const Vector<UINT> &TriangleIndices, const RayIntersectorKDTree &Root, UINT Axis, const Rectangle3f &BBox, UINT &LeftCount, UINT &RightCount) const
{
float SplitPoint = BBox.Center()[Axis];
LeftCount = 0;
RightCount = 0;
for(UINT TriangleIndex = 0; TriangleIndex < TriangleIndices.Length(); TriangleIndex++)
{
UINT LeftVertices = 0, RightVertices = 0;
const UINT BaseIndexIndex = TriangleIndices[TriangleIndex] * 3;
for(UINT VertexIndex = 0; VertexIndex < 3; VertexIndex++)
{
const Vec3f &CurVertex = Root._Vertices[Root._Indices[BaseIndexIndex + VertexIndex]];
if(CurVertex[Axis] < SplitPoint)
{
LeftVertices++;
}
if(CurVertex[Axis] >= SplitPoint)
{
RightVertices++;
}
}
bool OnLeftSide = (LeftVertices > RightVertices);
bool OnRightSide = !OnLeftSide;
if(OnLeftSide)
{
LeftCount++;
}
if(OnRightSide)
{
RightCount++;
}
}
}
bool RayIntersectorKDTreeNode::FindBestSplit(const Vector<UINT> &TriangleIndices, const RayIntersectorKDTree &Root, UINT &Axis, float &SplitValue) const
{
Rectangle3f BBox = ComputeBBox(TriangleIndices, Root);
int BestAxis = -1;
UINT BestChildImprovement = 8;
for(UINT CurAxis = 0; CurAxis < 3; CurAxis++)
{
UINT LeftCount, RightCount;
TestSplit(TriangleIndices, Root, CurAxis, BBox, LeftCount, RightCount);
/*const UINT BestChildCost = TriangleIndices.Length();
const UINT WorstChildCost = TriangleIndices.Length() * 2;
const UINT ActualChildCost = LeftCount + RightCount;
const float CurAxisValue = float(ActualChildCost) / float(WorstChildCost);*/
const UINT CurChildImprovement = Math::Min(TriangleIndices.Length() - LeftCount, TriangleIndices.Length() - RightCount);
if(CurChildImprovement > BestChildImprovement && LeftCount > 0 && RightCount > 0)
{
BestAxis = CurAxis;
BestChildImprovement = CurChildImprovement;
}
}
if(BestAxis == -1)
{
return false;
}
else
{
Axis = BestAxis;
SplitValue = BBox.Center()[Axis];
return true;
}
}
void MeshDistanceBruteForce::InitMeshList(const Vector< pair<const BaseMesh*, Matrix4> > &meshes)
{
UINT triangleSum = 0;
const UINT meshCount = meshes.Length();
for(UINT meshIndex = 0; meshIndex < meshCount; meshIndex++)
{
triangleSum += meshes[meshIndex].first->FaceCount();
}
_triangles.Allocate(triangleSum);
UINT triangleListIndex = 0;
for(UINT meshIndex = 0; meshIndex < meshCount; meshIndex++)
{
const BaseMesh &curMesh = *meshes[meshIndex].first;
const Matrix4 &curTransform = meshes[meshIndex].second;
const UINT triangleCount = curMesh.FaceCount();
const MeshVertex *vertices = curMesh.Vertices();
const DWORD *indices = curMesh.Indices();
for(UINT triangleIndex = 0; triangleIndex < triangleCount; triangleIndex++)
{
TriangleEntry &curEntry = _triangles[triangleListIndex];
curEntry.V[0] = curTransform.TransformPoint(vertices[ indices[ triangleIndex * 3 + 0 ] ].Pos);
curEntry.V[1] = curTransform.TransformPoint(vertices[ indices[ triangleIndex * 3 + 1 ] ].Pos);
curEntry.V[2] = curTransform.TransformPoint(vertices[ indices[ triangleIndex * 3 + 2 ] ].Pos);
Rectangle3f curBBox = Rectangle3f::ConstructFromTwoPoints(curEntry.V[0], curEntry.V[1]);
curBBox.ExpandBoundingBox(curEntry.V[2]);
curEntry.center = curBBox.Center();
curEntry.variance = curBBox.Variance();
triangleListIndex++;
}
}
}
bool MeshDistanceBruteForce::IntersectMeshList(const Vector< pair<const BaseMesh*, Matrix4> > &meshes) const
{
const UINT meshCount = meshes.Length();
const UINT mTriangleCount = _triangles.Length();
for(UINT meshIndex = 0; meshIndex < meshCount; meshIndex++)
{
const BaseMesh &curMesh = *meshes[meshIndex].first;
const Matrix4 &curTransform = meshes[meshIndex].second;
const UINT triangleCount = curMesh.FaceCount();
const MeshVertex *vertices = curMesh.Vertices();
const DWORD *indices = curMesh.Indices();
for(UINT outerTriangleIndex = 0; outerTriangleIndex < triangleCount; outerTriangleIndex++)
{
const Vec3f t0 = curTransform.TransformPoint(vertices[ indices[ outerTriangleIndex * 3 + 0 ] ].Pos);
const Vec3f t1 = curTransform.TransformPoint(vertices[ indices[ outerTriangleIndex * 3 + 1 ] ].Pos);
const Vec3f t2 = curTransform.TransformPoint(vertices[ indices[ outerTriangleIndex * 3 + 2 ] ].Pos);
Rectangle3f curBBox = Rectangle3f::ConstructFromTwoPoints(t0, t1);
curBBox.ExpandBoundingBox(t2);
const Vec3f center = curBBox.Center();
const Vec3f variance = curBBox.Variance();
for(UINT innerTriangleIndex = 0; innerTriangleIndex < mTriangleCount; innerTriangleIndex++)
{
const TriangleEntry &curEntry = _triangles[innerTriangleIndex];
if(Math::Abs(center.x - curEntry.center.x) <= variance.x + curEntry.variance.x &&
Math::Abs(center.y - curEntry.center.y) <= variance.y + curEntry.variance.y &&
Math::Abs(center.z - curEntry.center.z) <= variance.z + curEntry.variance.z)
{
if(Math::DistanceTriangleTriangleSq(t0, t1, t2, curEntry.V[0], curEntry.V[1], curEntry.V[2]) == 0.0f)
{
float value = Math::DistanceTriangleTriangleSq(t0, t1, t2, curEntry.V[0], curEntry.V[1], curEntry.V[2]);
return true;
}
}
}
}
}
return false;
}
void BaseMesh::CreateBox(const Rectangle3f &Rect)
{
Vec3f Dimensions = Rect.Dimensions();
CreateBox(Dimensions.x, Dimensions.y, Dimensions.z, 0);
Translate(Rect.Center());
}