#5622: Implement fingerprinting of brush nodes (layer or grouping inf…

…ormation are disregarded)

radiantcore/brush/BrushNode.cpp

@@ -7,6 +7,7 @@
 #include "iclipper.h"
 #include "ientity.h"
 #include "math/Frustum.h"
+#include "math/Hash.h"
 #include <functional>
 
 // Constructor
@@ -60,6 +61,42 @@ const AABB& BrushNode::localAABB() const {
 	return m_brush.localAABB();
 }
 
+std::size_t BrushNode::getFingerprint()
+{
+    constexpr std::size_t SignificantDigits = 6;
+
+    if (m_brush.getNumFaces() == 0)
+    {
+        return 0; // empty brushes produce a zero fingerprint
+    }
+
+    auto hash = static_cast<std::size_t>(m_brush.getDetailFlag() + 1);
+
+    math::combineHash(hash, m_brush.getNumFaces());
+
+    // Combine all face plane equations
+    for (const auto& face : m_brush)
+    {
+        // Plane equation
+        math::combineHash(hash, math::hashVector3(face->getPlane3().normal(), SignificantDigits));
+        math::combineHash(hash, math::hashDouble(face->getPlane3().dist(), SignificantDigits));
+
+        // Material Name
+        math::combineHash(hash, std::hash<std::string>()(face->getShader()));
+
+        // Texture Matrix
+        auto texdef = face->getTexDefMatrix();
+        math::combineHash(hash, math::hashDouble(texdef.xx(), SignificantDigits));
+        math::combineHash(hash, math::hashDouble(texdef.yx(), SignificantDigits));
+        math::combineHash(hash, math::hashDouble(texdef.tx(), SignificantDigits));
+        math::combineHash(hash, math::hashDouble(texdef.xy(), SignificantDigits));
+        math::combineHash(hash, math::hashDouble(texdef.yy(), SignificantDigits));
+        math::combineHash(hash, math::hashDouble(texdef.ty(), SignificantDigits));
+    }
+
+    return hash;
+}
+
 // Snappable implementation
 void BrushNode::snapto(float snap) {
 	m_brush.snapto(snap);

radiantcore/brush/BrushNode.h

@@ -4,6 +4,7 @@
 #include "ibrush.h"
 #include "itraceable.h"
 #include "iscenegraph.h"
+#include "icomparablenode.h"
 
 #include "Brush.h"
 #include "scene/SelectableNode.h"
@@ -29,7 +30,8 @@ class BrushNode :
 	public PlaneSelectable,
 	public LitObject,
 	public Transformable,
-	public ITraceable
+	public ITraceable,
+    public scene::IComparableNode
 {
 	// The actual contained brush (NO reference)
 	Brush m_brush;
@@ -71,7 +73,7 @@ class BrushNode :
 
 	virtual ~BrushNode();
 
-	// IBrushNode implementtation
+	// IBrushNode implementation
 	virtual Brush& getBrush() override;
 	virtual IBrush& getIBrush() override;
 
@@ -82,6 +84,9 @@ class BrushNode :
 
 	Type getNodeType() const override;
 
+    // IComparable implementation
+    std::size_t getFingerprint() override;
+
 	// Bounded implementation
 	virtual const AABB& localAABB() const override;
 

radiantcore/map/algorithm/Import.cpp

@@ -376,18 +376,18 @@ void importFromStream(std::istream& stream)
 using Fingerprints = std::map<std::size_t, scene::INodePtr>;
 using FingerprintsByType = std::map<scene::INode::Type, Fingerprints>;
 
-FingerprintsByType collectFingerprints(const scene::INodePtr& node)
+FingerprintsByType collectFingerprints(const scene::INodePtr& root)
 {
     FingerprintsByType result;
 
-    node->foreachNode([&](const scene::INodePtr& node)
+    root->foreachNode([&](const scene::INodePtr& node)
     {
         auto comparable = std::dynamic_pointer_cast<scene::IComparableNode>(node);
 
         if (!comparable) return true; // skip
 
         // Find or insert the map for this node type
-        auto fingerprints = result.try_emplace(comparable->getNodeType()).first->second;
+        auto& fingerprints = result.try_emplace(comparable->getNodeType()).first->second;
 
         // Store the fingerprint and check for collisions
         auto insertResult = fingerprints.try_emplace(comparable->getFingerprint(), node);