luanti/irr/include/IMeshCache.h

// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#pragma once

#include "IReferenceCounted.h"
#include "path.h"

namespace irr
{

namespace scene
{
class IMesh;
class IAnimatedMesh;
class IAnimatedMeshSceneNode;
class IMeshLoader;

//! The mesh cache stores already loaded meshes and provides an interface to them.
/** You can access it using ISceneManager::getMeshCache(). All existing
scene managers will return a pointer to the same mesh cache, because it
is shared between them. With this interface, it is possible to manually
add new loaded meshes (if ISceneManager::getMesh() is not sufficient),
to remove them and to iterate through already loaded meshes. */
class IMeshCache : public virtual IReferenceCounted
{
public:
	//! Destructor
	virtual ~IMeshCache() {}

	//! Adds a mesh to the internal list of loaded meshes.
	/** Usually, ISceneManager::getMesh() is called to load a mesh
	from a file. That method searches the list of loaded meshes if
	a mesh has already been loaded and returns a pointer to if it
	is in that list and already in memory. Otherwise it loads the
	mesh. With IMeshCache::addMesh(), it is possible to pretend
	that a mesh already has been loaded. This method can be used
	for example by mesh loaders who need to load more than one mesh
	with one call. They can add additional meshes with this method
	to the scene manager. The COLLADA loader for example uses this
	method.
	\param name Name of the mesh. When calling
	ISceneManager::getMesh() with this name it will return the mesh
	set by this method.
	\param mesh Pointer to a mesh which will now be referenced by
	this name. */
	virtual void addMesh(const io::path &name, IAnimatedMesh *mesh) = 0;

	//! Removes the mesh from the cache.
	/** After loading a mesh with getMesh(), the mesh can be
	removed from the cache using this method, freeing a lot of
	memory.
	\param mesh Pointer to the mesh which shall be removed. */
	virtual void removeMesh(const IMesh *const mesh) = 0;

	//! Returns amount of loaded meshes in the cache.
	/** You can load new meshes into the cache using getMesh() and
	addMesh(). If you ever need to access the internal mesh cache,
	you can do this using removeMesh(), getMeshNumber(),
	getMeshByIndex() and getMeshName().
	\return Number of meshes in cache. */
	virtual u32 getMeshCount() const = 0;

	//! Returns current index number of the mesh or -1 when not found.
	/** \param mesh Pointer to the mesh to search for.
	\return Index of the mesh in the cache, or -1 if not found. */
	virtual s32 getMeshIndex(const IMesh *const mesh) const = 0;

	//! Returns a mesh based on its index number.
	/** \param index: Index of the mesh, number between 0 and
	getMeshCount()-1.
	Note that this number is only valid until a new mesh is loaded
	or removed.
	\return Pointer to the mesh or 0 if there is none with this
	number. */
	virtual IAnimatedMesh *getMeshByIndex(u32 index) = 0;

	//! Returns a mesh based on its name.
	/** \param name Name of the mesh. Usually a filename.
	\return Pointer to the mesh or 0 if there is none with this number. */
	virtual IAnimatedMesh *getMeshByName(const io::path &name) = 0;

	//! Get the name of a loaded mesh, based on its index.
	/** \param index: Index of the mesh, number between 0 and getMeshCount()-1.
	\return The name if mesh was found and has a name, else the path is empty. */
	virtual const io::SNamedPath &getMeshName(u32 index) const = 0;

	//! Get the name of the loaded mesh if there is any.
	/** \param mesh Pointer to mesh to query.
	\return The name if mesh was found and has a name, else the path is empty. */
	virtual const io::SNamedPath &getMeshName(const IMesh *const mesh) const = 0;

	//! Renames a loaded mesh.
	/** Note that renaming meshes might change the ordering of the
	meshes, and so the index of the meshes as returned by
	getMeshIndex() or taken by some methods will change.
	\param index The index of the mesh in the cache.
	\param name New name for the mesh.
	\return True if mesh was renamed. */
	virtual bool renameMesh(u32 index, const io::path &name) = 0;

	//! Renames the loaded mesh
	/** Note that renaming meshes might change the ordering of the
	meshes, and so the index of the meshes as returned by
	getMeshIndex() or taken by some methods will change.
	\param mesh Mesh to be renamed.
	\param name New name for the mesh.
	\return True if mesh was renamed. */
	virtual bool renameMesh(const IMesh *const mesh, const io::path &name) = 0;

	//! Check if a mesh was already loaded.
	/** \param name Name of the mesh. Usually a filename.
	\return True if the mesh has been loaded, else false. */
	virtual bool isMeshLoaded(const io::path &name) = 0;

	//! Clears the whole mesh cache, removing all meshes.
	/** All meshes will be reloaded completely when using ISceneManager::getMesh()
	after calling this method.
	Warning: If you have pointers to meshes that were loaded with ISceneManager::getMesh()
	and you did not grab them, then they may become invalid. */
	virtual void clear() = 0;

	//! Clears all meshes that are held in the mesh cache but not used anywhere else.
	/** Warning: If you have pointers to meshes that were loaded with ISceneManager::getMesh()
	and you did not grab them, then they may become invalid. */
	virtual void clearUnusedMeshes() = 0;
};

} // end namespace scene
} // end namespace irr