1 files changed, 100 insertions, 0 deletions
diff --git a/thirdparty/thekla_atlas/nvmesh/weld/Snap.cpp b/thirdparty/thekla_atlas/nvmesh/weld/Snap.cpp
new file mode 100644
index 0000000000..b6bff4d83d
--- /dev/null
+++ b/thirdparty/thekla_atlas/nvmesh/weld/Snap.cpp
@@ -0,0 +1,100 @@
+// 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;
+};
+