Add a method to get a relative filename, based on an given base directory.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3529 dfc29bdd-3216-0410-991c-e03cc46cb475

include/IFileSystem.h

@@ -232,6 +232,9 @@ public:
 	//! flatten a path and file name for example: "/you/me/../." becomes "/you"
 	virtual path& flattenFilename(path& directory, const path& root="/") const =0;
 
+	//! Get the relative filename, relative to the given directory
+	virtual path getRelativeFilename(const path& filename, const path& directory) const =0;
+
 	//! Creates a list of files and directories in the current working directory and returns it.
 	/** \return a Pointer to the created IFileList is returned. After the list has been used
 	it has to be deleted using its IFileList::drop() method.

source/Irrlicht/CFileSystem.cpp

@@ -21,6 +21,7 @@
 #include "CAttributes.h"
 #include "CMemoryFile.h"
 #include "CLimitReadFile.h"
+#include "irrList.h"
 
 #if defined (_IRR_WINDOWS_API_)
 	#if !defined ( _WIN32_WCE )
@@ -592,6 +593,42 @@ io::path& CFileSystem::flattenFilename(io::path& directory, const io::path& root
 }
 
 
+//! Get the relative filename, relative to the given directory
+path CFileSystem::getRelativeFilename(const path& filename, const path& directory) const
+{
+		io::path path, file, ext;
+		core::splitFilename(getAbsolutePath(filename), &path, &file, &ext);
+		io::path path2(getAbsolutePath(directory));
+		core::list<io::path> list1, list2;
+		path.split(list1, "/\\", 2);
+		path2.split(list2, "/\\", 2);
+		u32 i=0;
+		core::list<io::path>::ConstIterator it1,it2;
+		it1=list1.begin();
+		it2=list2.begin();
+		for (; i<list1.size() && (*it1==*it2); ++i)
+		{
+			++it1;
+			++it2;
+		}
+		path="";
+		for (; i<list2.size(); ++i)
+			path += "../";
+		while (it1 != list1.end())
+		{
+			path += *it1++;
+			path += "/";
+		}
+		path += file;
+		if (ext.size())
+		{
+			path += ".";
+			path += ext;
+		}
+		return path;
+}
+
+
 //! Sets the current file systen type
 EFileSystemType CFileSystem::setFileListSystem(EFileSystemType listType)
 {

source/Irrlicht/CFileSystem.h

@@ -92,6 +92,9 @@ public:
 	//! flatten a path and file name for example: "/you/me/../." becomes "/you"
 	virtual io::path& flattenFilename( io::path& directory, const io::path& root = "/" ) const;
 
+	//! Get the relative filename, relative to the given directory
+	virtual path getRelativeFilename(const path& filename, const path& directory) const;
+
 	virtual EFileSystemType setFileListSystem(EFileSystemType listType);
 
 	//! Creates a list of files and directories in the current working directory

tests/filesystem.cpp

@@ -101,6 +101,27 @@ static bool testFlattenFilename(io::IFileSystem* fs)
 	return result;
 }
 
+static bool testgetRelativeFilename(io::IFileSystem* fs)
+{
+	bool result=true;
+	io::path apath = fs->getAbsolutePath("media");
+	io::path cwd = fs->getWorkingDirectory();
+	if (fs->getRelativeFilename(apath, cwd) != "media")
+	{
+		logTestString("getRelativePath failed on %s\n", apath.c_str());
+		result = false;
+	}
+
+	apath = fs->getAbsolutePath("../media/");
+	if (fs->getRelativeFilename(apath, cwd) != "../media/")
+	{
+		logTestString("getRelativePath failed on %s\n", apath.c_str());
+		result = false;
+	}
+
+	return result;
+}
+
 bool filesystem(void)
 {
 	IrrlichtDevice * device = irr::createDevice(video::EDT_NULL, dimension2d<u32>(1, 1));
@@ -151,7 +172,7 @@ bool filesystem(void)
 
 	result &= testFlattenFilename(fs);
 	result &= testgetAbsoluteFilename(fs);
-
+	result &= testgetRelativeFilename(fs);
 
 	device->closeDevice();
 	device->run();