Copy irrlichtmt to <root>/irr/

irr/src/CLimitReadFile.cpp

@@ -0,0 +1,115 @@
+// 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
+
+#include "CLimitReadFile.h"
+#include "irrMath.h"
+#include "irrString.h"
+
+namespace irr
+{
+namespace io
+{
+
+CLimitReadFile::CLimitReadFile(IReadFile *alreadyOpenedFile, long pos,
+		long areaSize, const io::path &name) :
+		Filename(name),
+		AreaStart(0), AreaEnd(0), Pos(0),
+		File(alreadyOpenedFile)
+{
+#ifdef _DEBUG
+	setDebugName("CLimitReadFile");
+#endif
+
+	if (File) {
+		File->grab();
+		AreaStart = pos;
+		AreaEnd = AreaStart + areaSize;
+	}
+}
+
+CLimitReadFile::~CLimitReadFile()
+{
+	if (File)
+		File->drop();
+}
+
+//! returns how much was read
+size_t CLimitReadFile::read(void *buffer, size_t sizeToRead)
+{
+	if (0 == File)
+		return 0;
+
+#if 1
+	long r = AreaStart + Pos;
+	long toRead = core::min_(AreaEnd, r + (long)sizeToRead) - core::max_(AreaStart, r);
+	if (toRead < 0)
+		return 0;
+	File->seek(r);
+	r = (long)File->read(buffer, toRead);
+	Pos += r;
+	return r;
+#else
+	const long pos = File->getPos();
+
+	if (pos >= AreaEnd)
+		return 0;
+
+	if (pos + (long)sizeToRead >= AreaEnd)
+		sizeToRead = AreaEnd - pos;
+
+	return File->read(buffer, sizeToRead);
+#endif
+}
+
+//! changes position in file, returns true if successful
+bool CLimitReadFile::seek(long finalPos, bool relativeMovement)
+{
+#if 1
+	Pos = core::s32_clamp(finalPos + (relativeMovement ? Pos : 0), 0, AreaEnd - AreaStart);
+	return true;
+#else
+	const long pos = File->getPos();
+
+	if (relativeMovement) {
+		if (pos + finalPos > AreaEnd)
+			finalPos = AreaEnd - pos;
+	} else {
+		finalPos += AreaStart;
+		if (finalPos > AreaEnd)
+			return false;
+	}
+
+	return File->seek(finalPos, relativeMovement);
+#endif
+}
+
+//! returns size of file
+long CLimitReadFile::getSize() const
+{
+	return AreaEnd - AreaStart;
+}
+
+//! returns where in the file we are.
+long CLimitReadFile::getPos() const
+{
+#if 1
+	return Pos;
+#else
+	return File->getPos() - AreaStart;
+#endif
+}
+
+//! returns name of file
+const io::path &CLimitReadFile::getFileName() const
+{
+	return Filename;
+}
+
+IReadFile *createLimitReadFile(const io::path &fileName, IReadFile *alreadyOpenedFile, long pos, long areaSize)
+{
+	return new CLimitReadFile(alreadyOpenedFile, pos, areaSize, fileName);
+}
+
+} // end namespace io
+} // end namespace irr