Custom MinHeap

Pathtracer.vcxproj

@@ -299,6 +299,7 @@
     <ClInclude Include="Src\Util\Parser.h" />
     <ClInclude Include="Src\Util\PerfTest.h" />
     <ClInclude Include="Src\Util\PMJ.h" />
+    <ClInclude Include="Src\Util\MinHeap.h" />
     <ClInclude Include="Src\Util\ScopeTimer.h" />
     <ClInclude Include="Src\Util\Shader.h" />
     <ClInclude Include="Src\Util\String.h" />

Pathtracer.vcxproj.filters

@@ -343,5 +343,8 @@
     <ClInclude Include="Src\Util\Mutex.h">
       <Filter>Util</Filter>
     </ClInclude>
+    <ClInclude Include="Src\Util\MinHeap.h">
+      <Filter>Util</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

Src/BVH/BVHOptimizer.cpp

@@ -1,12 +1,12 @@
 #include "BVHOptimizer.h"
 
-#include <queue>
 #include <random>
 
 #include "Config.h"
 
 #include "Util/Util.h"
 #include "Util/Array.h"
+#include "Util/MinHeap.h"
 #include "Util/ScopeTimer.h"
 
 static std::default_random_engine random_engine;
@@ -105,18 +105,20 @@ static void select_nodes_measure(const BVH & bvh, const int parent_indices[], in
 static void find_reinsertion(const BVH & bvh, const BVHNode2 & node_reinsert, float & min_cost, int & min_index) {
 	float node_reinsert_area = node_reinsert.aabb.surface_area();
 
-	// Compare based on induced cost
-	auto cmp = [](const std::pair<int, float> & a, const std::pair<int, float> & b) {
-		return a.second < b.second;
-	};
+	struct Pair {
+		int   node_index;
+		float induced_cost;
 
-	std::priority_queue<std::pair<int, float>, Array<std::pair<int, float>>, decltype(cmp)> priority_queue(cmp);
+		bool operator<(Pair other) const {
+			return induced_cost < other.induced_cost; // Compare based on induced cost
+		}
+	};
 
+	MinHeap<Pair> priority_queue;
 	priority_queue.emplace(0, 0.0f); // Push BVH root with 0 induced cost
 
 	while (priority_queue.size() > 0) {
-		auto [node_index, induced_cost] = priority_queue.top();
-		priority_queue.pop();
+		auto [node_index, induced_cost] = priority_queue.pop();
 
 		const BVHNode2 & node = bvh.nodes_2[node_index];
 

Src/Util/Array.h

@@ -18,7 +18,7 @@ struct Array {
 	size_t count    = 0;
 	size_t capacity = 0;
 
-	constexpr Array(int initial_count = 0) {
+	constexpr Array(size_t initial_count = 0) {
 		resize(initial_count);
 	}
 
@@ -167,12 +167,12 @@ struct Array {
 		return reinterpret_cast<const T *>(buffer);
 	}
 
-	constexpr T & operator[](int index) {
+	constexpr T & operator[](size_t index) {
 		assert(0 <= index && index < count);
 		return data()[index];
 	}
 
-	constexpr const T & operator[](int index) const {
+	constexpr const T & operator[](size_t index) const {
 		assert(0 <= index && index < count);
 		return data()[index];
 	}