godot/thirdparty/thekla_atlas/nvmesh/weld/Snap.cpp

101 lines
2.5 KiB
C++

// This code is in the public domain -- castanyo@yahoo.es
#include <nvcore/RadixSort.h>
#include <nvmesh/weld/Snap.h>
#include <nvmesh/TriMesh.h>
#include <nvmesh/geometry/Bounds.h>
using namespace nv;
namespace {
// Snap the given vertices.
void Snap(TriMesh::Vertex & a, TriMesh::Vertex & b, float texThreshold, float norThreshold)
{
a.pos = b.pos = (a.pos + b.pos) * 0.5f;
if (equal(a.tex.x, b.tex.x, texThreshold) && equal(a.tex.y, b.tex.y, texThreshold)) {
b.tex = a.tex = (a.tex + b.tex) * 0.5f;
}
if (equal(a.nor.x, b.nor.x, norThreshold) && equal(a.nor.y, b.nor.y, norThreshold) && equal(a.nor.z, b.nor.z, norThreshold)) {
b.nor = a.nor = (a.nor + b.nor) * 0.5f;
}
};
} // nv namespace
uint nv::SnapVertices(TriMesh * mesh, float posThreshold, float texThreshold, float norThreshold)
{
nvDebug("--- Snapping vertices.\n");
// Determine largest axis.
Box box = MeshBounds::box(mesh);
Vector3 extents = box.extents();
int axis = 2;
if( extents.x > extents.y ) {
if( extents.x > extents.z ) {
axis = 0;
}
}
else if(extents.y > extents.z) {
axis = 1;
}
// @@ Use diagonal instead!
// Sort vertices according to the largest axis.
const uint vertexCount = mesh->vertexCount();
nvCheck(vertexCount > 2); // Must have at least two vertices.
// Get pos channel.
//PiMesh::Channel * pos_channel = mesh->GetChannel(mesh->FindChannel(VS_POS));
//nvCheck( pos_channel != NULL );
//const PiArray<Vec4> & pos_array = pos_channel->data;
Array<float> distArray;
distArray.resize(vertexCount);
for(uint v = 0; v < vertexCount; v++) {
if (axis == 0) distArray[v] = mesh->vertexAt(v).pos.x;
else if (axis == 1) distArray[v] = mesh->vertexAt(v).pos.y;
else distArray[v] = mesh->vertexAt(v).pos.z;
}
RadixSort radix;
const uint * xrefs = radix.sort(distArray.buffer(), distArray.count()).ranks();
nvCheck(xrefs != NULL);
uint snapCount = 0;
for(uint v = 0; v < vertexCount-1; v++) {
for(uint n = v+1; n < vertexCount; n++) {
nvDebugCheck( distArray[xrefs[v]] <= distArray[xrefs[n]] );
if (fabs(distArray[xrefs[n]] - distArray[xrefs[v]]) > posThreshold) {
break;
}
TriMesh::Vertex & v0 = mesh->vertexAt(xrefs[v]);
TriMesh::Vertex & v1 = mesh->vertexAt(xrefs[n]);
const float dist = length(v0.pos - v1.pos);
if (dist <= posThreshold) {
Snap(v0, v1, texThreshold, norThreshold);
snapCount++;
}
}
}
// @@ todo: debug, make sure that the distance between vertices is now >= threshold
nvDebug("--- %u vertices snapped\n", snapCount);
return snapCount;
};