demo: Move all metrics functions to the bottom of the file

This ensures they are more separate from the main processing, making the
former easier to read.

Author: zeux

demo/nanite.cpp

@@ -428,124 +428,7 @@ static std::vector<unsigned int> simplify(const std::vector<Vertex>& vertices, c
 	return lod;
 }
 
-static int follow(std::vector<int>& parents, int index)
-{
-	while (index != parents[index])
-	{
-		int parent = parents[index];
-		parents[index] = parents[parent];
-		index = parent;
-	}
-
-	return index;
-}
-
-static int measureComponents(std::vector<int>& parents, const std::vector<unsigned int>& indices, const std::vector<unsigned int>& remap)
-{
-	assert(parents.size() == remap.size());
-
-	for (size_t i = 0; i < indices.size(); ++i)
-	{
-		unsigned int v = remap[indices[i]];
-		parents[v] = v;
-	}
-
-	for (size_t i = 0; i < indices.size(); ++i)
-	{
-		int v0 = remap[indices[i]];
-		int v1 = remap[indices[i + (i % 3 == 2 ? -2 : 1)]];
-
-		v0 = follow(parents, v0);
-		v1 = follow(parents, v1);
-
-		parents[v0] = v1;
-	}
-
-	for (size_t i = 0; i < indices.size(); ++i)
-	{
-		unsigned int v = remap[indices[i]];
-		parents[v] = follow(parents, v);
-	}
-
-	int roots = 0;
-	for (size_t i = 0; i < indices.size(); ++i)
-	{
-		unsigned int v = remap[indices[i]];
-		roots += parents[v] == int(v);
-		parents[v] = -1; // make sure we only count each root once
-	}
-
-	return roots;
-}
-
-static int measureUnique(std::vector<int>& used, const std::vector<unsigned int>& indices, const std::vector<unsigned char>* locks = NULL)
-{
-	for (size_t i = 0; i < indices.size(); ++i)
-	{
-		unsigned int v = indices[i];
-		used[v] = 1;
-	}
-
-	size_t vertices = 0;
-
-	for (size_t i = 0; i < indices.size(); ++i)
-	{
-		unsigned int v = indices[i];
-		vertices += used[v] && (!locks || (*locks)[v]);
-		used[v] = 0;
-	}
-
-	return int(vertices);
-}
-
-static void dumpMetrics(int level, const std::vector<Cluster>& queue, const std::vector<std::vector<int> >& groups, const std::vector<unsigned int>& remap, const std::vector<unsigned char>& locks, const std::vector<int>& retry)
-{
-	std::vector<int> parents(remap.size());
-
-	int clusters = 0;
-	int triangles = 0;
-	int full_clusters = 0;
-	int components = 0;
-	int xformed = 0;
-	int boundary = 0;
-
-	for (size_t i = 0; i < groups.size(); ++i)
-	{
-		for (size_t j = 0; j < groups[i].size(); ++j)
-		{
-			const Cluster& cluster = queue[groups[i][j]];
-
-			clusters++;
-			triangles += int(cluster.indices.size() / 3);
-			full_clusters += cluster.indices.size() == kClusterSize * 3;
-			components += measureComponents(parents, cluster.indices, remap);
-			xformed += measureUnique(parents, cluster.indices);
-			boundary += kUseLocks ? measureUnique(parents, cluster.indices, &locks) : 0;
-		}
-	}
-
-	int stuck_clusters = 0;
-	int stuck_triangles = 0;
-
-	for (size_t i = 0; i < retry.size(); ++i)
-	{
-		const Cluster& cluster = queue[retry[i]];
-
-		stuck_clusters++;
-		stuck_triangles += int(cluster.indices.size() / 3);
-	}
-
-	double avg_group = double(clusters) / double(groups.size());
-	double inv_clusters = 1.0 / double(clusters);
-
-	printf("lod %d: %d clusters (%.1f%% full, %.1f tri/cl, %.1f vtx/cl, %.2f connected, %.1f boundary, %.1f partition), %d triangles",
-	    level, clusters,
-	    double(full_clusters) * inv_clusters * 100, double(triangles) * inv_clusters, double(xformed) * inv_clusters, double(components) * inv_clusters, double(boundary) * inv_clusters, avg_group,
-	    int(triangles));
-	if (stuck_clusters)
-		printf("; stuck %d clusters (%d triangles)", stuck_clusters, stuck_triangles);
-	printf("\n");
-}
+static void dumpMetrics(int level, const std::vector<Cluster>& queue, const std::vector<std::vector<int> >& groups, const std::vector<unsigned int>& remap, const std::vector<unsigned char>& locks, const std::vector<int>& retry);
 
 static bool loadMetis()
 {
@@ -581,10 +464,6 @@ void nanite(const std::vector<Vertex>& vertices, const std::vector<unsigned int>
 
 	static const char* dump = getenv("DUMP");
 
-#ifndef NDEBUG
-	std::vector<std::pair<int, int> > dag_debug;
-#endif
-
 	int depth = 0;
 	std::vector<unsigned char> locks(vertices.size());
 
@@ -669,13 +548,6 @@ void nanite(const std::vector<Vertex>& vertices, const std::vector<unsigned int>
 				clusters[groups[i][j]].parent = groupb;
 			}
 
-#ifndef NDEBUG
-			// record DAG edges for validation during the cut
-			for (size_t j = 0; j < groups[i].size(); ++j)
-				for (size_t k = 0; k < split.size(); ++k)
-					dag_debug.push_back(std::make_pair(groups[i][j], int(clusters.size()) + int(k)));
-#endif
-
 			for (size_t j = 0; j < split.size(); ++j)
 			{
 				split[j].self = groupb;
@@ -730,19 +602,6 @@ void nanite(const std::vector<Vertex>& vertices, const std::vector<unsigned int>
 		if (boundsError(clusters[i].self, maxx, maxy, maxz, proj, znear) <= threshold && boundsError(clusters[i].parent, maxx, maxy, maxz, proj, znear) > threshold)
 			cut.insert(cut.end(), clusters[i].indices.begin(), clusters[i].indices.end());
 
-#ifndef NDEBUG
-	for (size_t i = 0; i < dag_debug.size(); ++i)
-	{
-		int j = dag_debug[i].first, k = dag_debug[i].second;
-		float ej = boundsError(clusters[j].self, maxx, maxy, maxz, proj, znear);
-		float ejp = boundsError(clusters[j].parent, maxx, maxy, maxz, proj, znear);
-		float ek = boundsError(clusters[k].self, maxx, maxy, maxz, proj, znear);
-
-		assert(ej <= ek);
-		assert(ejp >= ej);
-	}
-#endif
-
 	printf("cut (%.3f): %d triangles\n", threshold, int(cut.size() / 3));
 
 	if (dump && -1 == atoi(dump))
@@ -754,3 +613,125 @@ void nanite(const std::vector<Vertex>& vertices, const std::vector<unsigned int>
 				dumpObj("cluster", clusters[i].indices);
 	}
 }
+
+// What follows is code that is helpful for collecting metrics, visualizing cuts, etc.
+// This code is not used in the actual clustering implementation and can be ignored.
+
+static int follow(std::vector<int>& parents, int index)
+{
+	while (index != parents[index])
+	{
+		int parent = parents[index];
+		parents[index] = parents[parent];
+		index = parent;
+	}
+
+	return index;
+}
+
+static int measureComponents(std::vector<int>& parents, const std::vector<unsigned int>& indices, const std::vector<unsigned int>& remap)
+{
+	assert(parents.size() == remap.size());
+
+	for (size_t i = 0; i < indices.size(); ++i)
+	{
+		unsigned int v = remap[indices[i]];
+		parents[v] = v;
+	}
+
+	for (size_t i = 0; i < indices.size(); ++i)
+	{
+		int v0 = remap[indices[i]];
+		int v1 = remap[indices[i + (i % 3 == 2 ? -2 : 1)]];
+
+		v0 = follow(parents, v0);
+		v1 = follow(parents, v1);
+
+		parents[v0] = v1;
+	}
+
+	for (size_t i = 0; i < indices.size(); ++i)
+	{
+		unsigned int v = remap[indices[i]];
+		parents[v] = follow(parents, v);
+	}
+
+	int roots = 0;
+	for (size_t i = 0; i < indices.size(); ++i)
+	{
+		unsigned int v = remap[indices[i]];
+		roots += parents[v] == int(v);
+		parents[v] = -1; // make sure we only count each root once
+	}
+
+	return roots;
+}
+
+static int measureUnique(std::vector<int>& used, const std::vector<unsigned int>& indices, const std::vector<unsigned char>* locks = NULL)
+{
+	for (size_t i = 0; i < indices.size(); ++i)
+	{
+		unsigned int v = indices[i];
+		used[v] = 1;
+	}
+
+	size_t vertices = 0;
+
+	for (size_t i = 0; i < indices.size(); ++i)
+	{
+		unsigned int v = indices[i];
+		vertices += used[v] && (!locks || (*locks)[v]);
+		used[v] = 0;
+	}
+
+	return int(vertices);
+}
+
+static void dumpMetrics(int level, const std::vector<Cluster>& queue, const std::vector<std::vector<int> >& groups, const std::vector<unsigned int>& remap, const std::vector<unsigned char>& locks, const std::vector<int>& retry)
+{
+	std::vector<int> parents(remap.size());
+
+	int clusters = 0;
+	int triangles = 0;
+	int full_clusters = 0;
+	int components = 0;
+	int xformed = 0;
+	int boundary = 0;
+
+	for (size_t i = 0; i < groups.size(); ++i)
+	{
+		for (size_t j = 0; j < groups[i].size(); ++j)
+		{
+			const Cluster& cluster = queue[groups[i][j]];
+
+			clusters++;
+			triangles += int(cluster.indices.size() / 3);
+			full_clusters += cluster.indices.size() == kClusterSize * 3;
+			components += measureComponents(parents, cluster.indices, remap);
+			xformed += measureUnique(parents, cluster.indices);
+			boundary += kUseLocks ? measureUnique(parents, cluster.indices, &locks) : 0;
+		}
+	}
+
+	int stuck_clusters = 0;
+	int stuck_triangles = 0;
+
+	for (size_t i = 0; i < retry.size(); ++i)
+	{
+		const Cluster& cluster = queue[retry[i]];
+
+		stuck_clusters++;
+		stuck_triangles += int(cluster.indices.size() / 3);
+	}
+
+	double avg_group = double(clusters) / double(groups.size());
+	double inv_clusters = 1.0 / double(clusters);
+
+	printf("lod %d: %d clusters (%.1f%% full, %.1f tri/cl, %.1f vtx/cl, %.2f connected, %.1f boundary, %.1f partition), %d triangles",
+	    level, clusters,
+	    double(full_clusters) * inv_clusters * 100, double(triangles) * inv_clusters, double(xformed) * inv_clusters, double(components) * inv_clusters, double(boundary) * inv_clusters, avg_group,
+	    int(triangles));
+	if (stuck_clusters)
+		printf("; stuck %d clusters (%d triangles)", stuck_clusters, stuck_triangles);
+	printf("\n");
+}