Move SMaterial std::hash impl to its header

irr/include/SMaterial.h

@@ -230,14 +230,14 @@ const c8 *const ZWriteNames[] = {
 /** SMaterial might ignore some textures in most function, like assignment and comparison,
 	when SIrrlichtCreationParameters::MaxTextureUnits is set to a lower number.
 */
-const u32 MATERIAL_MAX_TEXTURES = 4;
+constexpr static u32 MATERIAL_MAX_TEXTURES = 4;
 
 //! Struct for holding parameters for a material renderer
 // Note for implementors: Serialization is in CNullDriver
 class SMaterial
 {
 public:
-	//! Default constructor. Creates a solid, lit material with white colors
+	//! Default constructor. Creates a solid material
 	SMaterial() :
 			MaterialType(EMT_SOLID), ColorParam(0, 0, 0, 0),
 			MaterialTypeParam(0.0f), Thickness(1.0f), ZBuffer(ECFN_LESSEQUAL),
@@ -257,7 +257,7 @@ public:
 	E_MATERIAL_TYPE MaterialType;
 
 	//! Custom color parameter, can be used by custom shader materials.
-	// See MainShaderConstantSetter in Minetest.
+	// See MainShaderConstantSetter in Luanti.
 	SColor ColorParam;
 
 	//! Free parameter, dependent on the material type.
@@ -427,10 +427,13 @@ public:
 				PolygonOffsetDepthBias != b.PolygonOffsetDepthBias ||
 				PolygonOffsetSlopeScale != b.PolygonOffsetSlopeScale ||
 				UseMipMaps != b.UseMipMaps;
-		for (u32 i = 0; (i < MATERIAL_MAX_TEXTURES) && !different; ++i) {
-			different |= (TextureLayers[i] != b.TextureLayers[i]);
+		if (different)
+			return true;
+		for (u32 i = 0; i < MATERIAL_MAX_TEXTURES; ++i) {
+			if (TextureLayers[i] != b.TextureLayers[i])
+				return true;
 		}
-		return different;
+		return false;
 	}
 
 	//! Equality operator
@@ -477,5 +480,19 @@ public:
 
 //! global const identity Material
 IRRLICHT_API extern SMaterial IdentityMaterial;
+
 } // end namespace video
 } // end namespace irr
+
+template<>
+struct std::hash<irr::video::SMaterial>
+{
+	/// @brief std::hash specialization for video::SMaterial
+	std::size_t operator()(const irr::video::SMaterial &m) const noexcept
+	{
+		// basic implementation that hashes the two things most likely to differ
+		auto h1 = std::hash<irr::video::ITexture*>{}(m.getTexture(0));
+		auto h2 = std::hash<int>{}(m.MaterialType);
+		return (h1 << 1) ^ h2;
+	}
+};

irr/src/CSceneManager.cpp

@@ -469,14 +469,12 @@ void CSceneManager::drawAll()
 	if (!Driver)
 		return;
 
-	u32 i; // new ISO for scoping problem in some compilers
-
 	// reset all transforms
 	Driver->setMaterial(video::SMaterial());
 	Driver->setTransform(video::ETS_PROJECTION, core::IdentityMatrix);
 	Driver->setTransform(video::ETS_VIEW, core::IdentityMatrix);
 	Driver->setTransform(video::ETS_WORLD, core::IdentityMatrix);
-	for (i = video::ETS_COUNT - 1; i >= video::ETS_TEXTURE_0; --i)
+	for (u32 i = video::ETS_COUNT - 1; i >= video::ETS_TEXTURE_0; --i)
 		Driver->setTransform((video::E_TRANSFORMATION_STATE)i, core::IdentityMatrix);
 	// TODO: This should not use an attribute here but a real parameter when necessary (too slow!)
 	Driver->setAllowZWriteOnTransparent(Parameters->getAttributeAsBool(ALLOW_ZWRITE_ON_TRANSPARENT));

irr/src/CSceneManager.h

@@ -193,21 +193,21 @@ private:
 		}
 
 		DefaultNodeEntry(ISceneNode *n) :
-				Node(n), TextureValue(0)
+				Node(n)
 		{
 			if (n->getMaterialCount())
-				TextureValue = (n->getMaterial(0).getTexture(0));
+				Hash = std::hash<video::SMaterial>{}(n->getMaterial(0));
 		}
 
-		bool operator<(const DefaultNodeEntry &other) const
+		bool operator<(const DefaultNodeEntry &other) const noexcept
 		{
-			return (TextureValue < other.TextureValue);
+			return Hash < other.Hash;
 		}
 
-		ISceneNode *Node;
+		ISceneNode *Node = nullptr;
 
 	private:
-		void *TextureValue;
+		size_t Hash = 0;
 	};
 
 	//! sort on distance (center) to camera
@@ -223,42 +223,15 @@ private:
 			Distance = Node->getAbsoluteTransformation().getTranslation().getDistanceFromSQ(camera);
 		}
 
-		bool operator<(const TransparentNodeEntry &other) const
+		bool operator<(const TransparentNodeEntry &other) const noexcept
 		{
 			return Distance > other.Distance;
 		}
 
-		ISceneNode *Node;
+		ISceneNode *Node = nullptr;
 
 	private:
-		f64 Distance;
-	};
-
-	//! sort on distance (sphere) to camera
-	struct DistanceNodeEntry
-	{
-		DistanceNodeEntry(ISceneNode *n, const core::vector3df &cameraPos) :
-				Node(n)
-		{
-			setNodeAndDistanceFromPosition(n, cameraPos);
-		}
-
-		bool operator<(const DistanceNodeEntry &other) const
-		{
-			return Distance < other.Distance;
-		}
-
-		void setNodeAndDistanceFromPosition(ISceneNode *n, const core::vector3df &fromPosition)
-		{
-			Node = n;
-			Distance = Node->getAbsoluteTransformation().getTranslation().getDistanceFromSQ(fromPosition);
-			Distance -= Node->getBoundingBox().getExtent().getLengthSQ() * 0.5;
-		}
-
-		ISceneNode *Node;
-
-	private:
-		f64 Distance;
+		f32 Distance = 0;
 	};
 
 	//! video driver

src/client/clientmap.cpp

@@ -25,19 +25,10 @@ namespace {
 	// A helper struct
 	struct MeshBufListMaps
 	{
-		struct MaterialHash
-		{
-			size_t operator()(const video::SMaterial &m) const noexcept
-			{
-				// Only hash first texture. Simple and fast.
-				return std::hash<video::ITexture *>{}(m.TextureLayers[0].Texture);
-			}
-		};
-
 		using MeshBufListMap = std::unordered_map<
 				video::SMaterial,
-				std::vector<std::pair<v3s16, scene::IMeshBuffer *>>,
-				MaterialHash>;
+				std::vector<std::pair<v3s16, scene::IMeshBuffer *>>
+				>;
 
 		std::array<MeshBufListMap, MAX_TILE_LAYERS> maps;