ColladaExporter does now cache material-names on export by default which leads...

ColladaExporter does now cache material-names on export by default which leads to smaller .dae files.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4279 dfc29bdd-3216-0410-991c-e03cc46cb475

include/IColladaMeshWriter.h

@@ -82,7 +82,9 @@ namespace scene
 		//! Default - write each mesh exactly once to collada. Optimal but will not work with many tools.
 		ECGI_PER_MESH,	
 
-		//! Write each mesh as often as it's used with different materials in the scene.
+		//! Write each mesh as often as it's used with different materials-names in the scene.
+		//! Material names which are used here are created on export, so using the IColladaMeshWriterNames
+		//! interface you have some control over how many geometries are written.
 		ECGI_PER_MESH_AND_MATERIAL,
 
 		// not yet supported, but might be useful as well
@@ -205,7 +207,8 @@ namespace scene
 
 		IColladaMeshWriter() 
 			: Properties(0), DefaultProperties(0), NameGenerator(0), DefaultNameGenerator(0)
-			, WriteTextures(true), WriteDefaultScene(true), AmbientLight(0.f, 0.f, 0.f, 1.f)
+			, WriteTextures(true), WriteDefaultScene(true), ExportSMaterialOnce(true)
+			, AmbientLight(0.f, 0.f, 0.f, 1.f)
 		{
 		}
 
@@ -285,6 +288,24 @@ namespace scene
 			return GeometryWriting;
 		}
 
+		//! Make certain there is only one collada material generated per Irrlicht material
+		/** Checks before creating a collada material-name if an identical 
+		irr:::video::SMaterial has been exported already. If so don't export it with 
+		another name. This is set by default and leads to way smaller .dae files.
+		Note that if you need to disable this flag for some reason you can still 
+		get a similar effect using the IColladaMeshWriterNames::nameForMaterial
+		by returning identical names for identical materials there.
+		*/
+		virtual void setExportSMaterialsOnlyOnce(bool exportOnce)
+		{
+			ExportSMaterialOnce = exportOnce;
+		}
+
+		virtual bool getExportSMaterialsOnlyOnce() const
+		{
+			return ExportSMaterialOnce;
+		}
+
 		//! Set properties to use by the meshwriter instead of it's default properties.
 		/** Overloading properties with an own class allows modifying the writing process in certain ways. 
 		By default properties are set to the DefaultProperties. */
@@ -374,6 +395,7 @@ namespace scene
 		IColladaMeshWriterNames * DefaultNameGenerator;
 		bool WriteTextures;
 		bool WriteDefaultScene;
+		bool ExportSMaterialOnce;
 		video::SColorf AmbientLight;
 		E_COLLADA_GEOMETRY_WRITING GeometryWriting;
 	};

source/Irrlicht/CColladaMeshWriter.cpp

@@ -263,6 +263,7 @@ void CColladaMeshWriter::reset()
 	LightNodes.clear();
 	MaterialsWritten.clear();
 	EffectsWritten.clear();
+	MaterialNameCache.clear();
 }
 
 //! Returns the type of the mesh writer
@@ -996,14 +997,27 @@ irr::core::stringw CColladaMeshWriter::nameForNode(const scene::ISceneNode* node
 	return irr::core::stringw(L"missing_name_generator");
 }
 
-irr::core::stringw CColladaMeshWriter::nameForMaterial(const video::SMaterial & material, int materialId, const scene::IMesh* mesh, const scene::ISceneNode* node) const
+irr::core::stringw CColladaMeshWriter::nameForMaterial(const video::SMaterial & material, int materialId, const scene::IMesh* mesh, const scene::ISceneNode* node)
 {
+	irr::core::stringw matName;
+	if ( getExportSMaterialsOnlyOnce() )
+	{
+		matName = findCachedMaterialName(material);
+		if ( !matName.empty() )
+			return matName;
+	}
+
 	IColladaMeshWriterNames * nameGenerator = getNameGenerator();
 	if ( nameGenerator )
 	{
-		return nameGenerator->nameForMaterial(material, materialId, mesh, node);
+		matName = nameGenerator->nameForMaterial(material, materialId, mesh, node);
 	}
-	return irr::core::stringw(L"missing_name_generator");
+	else
+		matName = irr::core::stringw(L"missing_name_generator");
+
+	if ( getExportSMaterialsOnlyOnce() )
+		MaterialNameCache.push_back (MaterialName(material, matName));
+	return matName;
 }
 
 // Each mesh-material has one symbol which is replaced on instantiation
@@ -1014,6 +1028,16 @@ irr::core::stringw CColladaMeshWriter::nameForMaterialSymbol(const scene::IMesh*
 	return irr::core::stringw(buf);
 }
 
+irr::core::stringw CColladaMeshWriter::findCachedMaterialName(const irr::video::SMaterial& material) const
+{
+	for ( u32 i=0; i<MaterialNameCache.size(); ++i )
+	{
+		if ( MaterialNameCache[i].Material == material )
+			return MaterialNameCache[i].Name;
+	}
+	return irr::core::stringw();
+}
+
 irr::core::stringw CColladaMeshWriter::minTexfilterToString(bool bilinear, bool trilinear) const
 {
 	if ( trilinear )

source/Irrlicht/CColladaMeshWriter.h

@@ -109,9 +109,9 @@ protected:
 	inline irr::core::stringw toRef(const irr::core::stringw& source) const;
 	irr::core::stringw nameForMesh(const scene::IMesh* mesh, int instance) const;
 	irr::core::stringw nameForNode(const scene::ISceneNode* node) const;
-	irr::core::stringw nameForMaterial(const video::SMaterial & material, int materialId, const scene::IMesh* mesh, const scene::ISceneNode* node) const;
+	irr::core::stringw nameForMaterial(const video::SMaterial & material, int materialId, const scene::IMesh* mesh, const scene::ISceneNode* node);
 	irr::core::stringw nameForMaterialSymbol(const scene::IMesh* mesh, int materialId) const;
-	irr::core::stringw nameForPtr(const void* ptr) const;
+	irr::core::stringw findCachedMaterialName(const irr::video::SMaterial& material) const;
 	irr::core::stringw minTexfilterToString(bool bilinear, bool trilinear) const;
 	irr::core::stringw magTexfilterToString(bool bilinear, bool trilinear) const;
 	irr::core::stringw pathToURI(const irr::io::path& path) const;
@@ -241,6 +241,17 @@ protected:
 	// TODO: second parameter not needed, we just don't have a core::set class yet in Irrlicht
 	core::map<irr::core::stringw, bool> MaterialsWritten;
 	core::map<irr::core::stringw, bool> EffectsWritten;
+
+	// Cache material names
+	struct MaterialName
+	{
+		MaterialName(const irr::video::SMaterial & material, const irr::core::stringw& name) 
+			: Material(material), Name(name) 
+		{}
+		irr::video::SMaterial Material;
+		irr::core::stringw Name;
+	};
+	irr::core::array< MaterialName > MaterialNameCache;
 };