static void kdSerialize(u::vector<unsigned char> &buffer, const T *data, size_t size) {
const unsigned char *const beg = (const unsigned char *const)data;
const unsigned char *const end = ((const unsigned char *const)data) + size;
buffer.insert(buffer.end(), beg, end);
}
kdNode::kdNode(kdTree *tree, const u::vector<int> &tris, size_t recursionDepth)
: m_front(nullptr)
, m_back(nullptr)
, m_sphereRadius(0.0f)
{
const size_t triangleCount = tris.size();
if (recursionDepth > tree->m_depth)
tree->m_depth = recursionDepth;
if (recursionDepth > kdTree::kMaxRecursionDepth)
return;
tree->m_nodeCount++;
if (!calculateSphere(tree, tris)) {
u::Log::err("[world] => level geometry is too large: collision detection and rendering may not work");
return;
}
u::vector<int> fx, fy, fz; // front
u::vector<int> bx, by, bz; // back
u::vector<int> sx, sy, sz; // split
u::vector<int> *const frontList[3] = { &fx, &fy, &fz };
u::vector<int> *const backList[3] = { &bx, &by, &bz };
u::vector<int> *const splitList[3] = { &sx, &sy, &sz };
m::plane plane[3];
float ratio[3];
size_t best = recursionDepth % 3;
// find a plane which gives a good balanced node
for (size_t i = 0; i < 3; i++) {
split(tree, tris, m::axis(i), *frontList[i], *backList[i], *splitList[i], plane[i]);
const size_t fsize = (*frontList[i]).size();
const size_t bsize = (*backList[i]).size();
if (fsize > bsize)
ratio[i] = (float)bsize / (float)fsize;
else
ratio[i] = (float)fsize / (float)bsize;
}
float bestRatio = 0.0f;
for (size_t i = 0; i < 3; i++) {
if (ratio[i] > bestRatio) {
best = i;
bestRatio = ratio[i];
}
}
m_splitPlane = plane[best];
// when there isn't many triangles left, create a leaf. In doing so we can
// continue to create further subdivisions.
if (frontList[best]->size() == 0 || backList[best]->size() == 0 || triangleCount <= kdTree::kMaxTrianglesPerLeaf) {
// create subspace with `triangleCount` polygons
m_triangles.insert(m_triangles.begin(), tris.begin(), tris.end());
tree->m_leafCount++;
return;
}
// insert the split triangles on both sides of the plane.
frontList[best]->insert(frontList[best]->end(), splitList[best]->begin(), splitList[best]->end());
backList[best]->insert(backList[best]->end(), splitList[best]->begin(), splitList[best]->end());
// recurse
m_front = new kdNode(tree, *frontList[best], recursionDepth + 1);
m_back = new kdNode(tree, *backList[best], recursionDepth + 1);
}