[#73] perf(mesh): use sorted vector instead of unordered_set for …

…leaf polys

This patch improves performance for MinGW-w64 specifically. Vanilla GCC and Clang are unaffected by this patch apart from debug builds with sanitizers enabled which are slightly slower.

Closes: #71

include/phoenix/mesh.hh

@@ -88,7 +88,7 @@ namespace phoenix {
 		/// \throws parser_error if parsing fails.
 		/// \see #parse(buffer&&, const std::vector<std::uint32_t>&)
 		[[nodiscard]] PHOENIX_API static mesh
-		parse(buffer& buf, std::optional<std::unordered_set<std::uint32_t>> const& include_polygons = std::nullopt);
+		parse(buffer& buf, std::vector<uint32_t> const& include_polygons = {});
 
 		/// \brief Parses a mesh from the data in the given buffer.
 		///
@@ -103,7 +103,7 @@ namespace phoenix {
 		/// \throws parser_error if parsing fails.
 		/// \see #parse(buffer&, const std::vector<std::uint32_t>&)
 		[[nodiscard]] PHOENIX_API inline static mesh
-		parse(buffer&& buf, std::optional<std::unordered_set<std::uint32_t>> const& include_polygons = std::nullopt) {
+		parse(buffer&& buf, std::vector<std::uint32_t> const & include_polygons = {}) {
 			return mesh::parse(buf, include_polygons);
 		}
 

include/phoenix/world/bsp_tree.hh

@@ -79,7 +79,7 @@ namespace phoenix {
 		std::vector<std::uint32_t> polygon_indices;
 
 		/// \brief All BSP leaf polygon indices.
-		std::unordered_set<std::uint32_t> leaf_polygons;
+		std::vector<std::uint32_t> leaf_polygons;
 
 		/// \brief All BSP light points.
 		std::vector<glm::vec3> light_points;

source/mesh.cc

@@ -19,7 +19,7 @@ namespace phoenix {
 		end = 0xB060
 	};
 
-	mesh mesh::parse(buffer& buf, std::optional<std::unordered_set<std::uint32_t>> const& leaf_polygons) {
+	mesh mesh::parse(buffer& buf, std::vector<std::uint32_t> const& leaf_polygons) {
 		mesh msh {};
 
 		std::uint16_t version {};
@@ -125,7 +125,7 @@ namespace phoenix {
 					//       This presents a problem: Taking the leaf polygons as a parameter makes creating a unified
 					//       parsing function for world meshes impossible. Instead, there should be a function to remove
 					//       this extra data which would grant the user more freedom in how they use _phoenix_.
-					if (leaf_polygons && leaf_polygons->find(i) == leaf_polygons->end()) {
+					if (!leaf_polygons.empty() && !std::binary_search(leaf_polygons.begin(), leaf_polygons.end(), i)) {
 						// If the current polygon is not a leaf polygon, skip it.
 						chunk.skip((version == mesh_version_g2 ? 8 : 6) * vertex_count);
 						continue;

source/world/bsp_tree.cc

@@ -95,9 +95,10 @@ namespace phoenix {
 					auto& node = bsp.nodes[idx];
 
 					for (uint32_t i = 0; i < node.polygon_count; ++i) {
-						bsp.leaf_polygons.insert(bsp.polygon_indices[node.polygon_index + i]);
+						bsp.leaf_polygons.push_back(bsp.polygon_indices[node.polygon_index + i]);
 					}
 				}
+				std::sort(bsp.leaf_polygons.begin(), bsp.leaf_polygons.end());
 
 				assert(node_count == bsp.nodes.size());
 				assert(leaf_count == bsp.leaf_node_indices.size());