Initial source commit

minorGems/io/file/UniversalFileIO.h

@@ -0,0 +1,138 @@
+// Jason Rohrer
+// UniversalFileIO.h
+
+/**
+*
+*	Object that handles universal file reading and writing
+*	Writes files as big endian, even on little endian machines
+*
+*	Assumes that longs and floats are 32-bits
+*
+*	Created 1-12-99
+*	Mods:
+*		Jason Rohrer	1-30-2000	Fixed fwrite functions to work on little endian machines
+*/
+
+
+
+#ifndef UNIVERSAL_FILE_IO_INCLUDED
+#define UNIVERSAL_FILE_IO_INCLUDED
+
+
+#include <stdio.h>
+
+
+
+class UniversalFileIO {
+
+	public:
+		
+		UniversalFileIO();
+		
+		long freadLong( FILE *f );
+		float freadFloat( FILE *f );
+		
+		void fwriteLong( FILE *f, long x );
+		void fwriteFloat( FILE *f, float x );
+		
+	private:
+	
+		char machineBigEndian;
+		
+		char bytesInLong;
+		char bytesInFloat;
+
+	};
+	
+	
+inline UniversalFileIO::UniversalFileIO()
+	: machineBigEndian( true ),
+	bytesInLong( 4 ), bytesInFloat( 4 )
+	{
+	
+	// test whether machine is big endian
+	long test = 1;
+	char testChopped = (*(char*)&test);
+	if( testChopped == 1 ) machineBigEndian = false;
+	}
+
+
+
+
+inline long UniversalFileIO::freadLong( FILE *f ) {
+	if( machineBigEndian ) {
+		long returnVal;
+		fread((void *)&returnVal, sizeof(long), 1, f);
+		return returnVal;
+		}
+	else {
+		unsigned char *buffer = new unsigned char[bytesInLong];
+
+		fread((void *)buffer, sizeof(char), bytesInLong, f);
+		
+		// now put the bytes into a long
+		long returnVal = (long)( buffer[0] << 24 | buffer[1] << 16 | buffer[2] << 8 | buffer[3] );
+			
+		delete [] buffer;
+		
+		return returnVal;
+		}
+	}
+	
+inline float UniversalFileIO::freadFloat( FILE *f ) {
+	if( machineBigEndian ) {
+		float returnVal;
+		fread( (void *)&returnVal, sizeof(float), 1, f );
+		return returnVal;
+		}
+	else {
+		unsigned char *buffer = new unsigned char[bytesInFloat];
+
+		fread( (void *)buffer, sizeof(char), bytesInFloat, f );
+
+		// now put the bytes into a long
+		long temp = (long)(buffer[0] << 24 | buffer[1] << 16 | buffer[2] << 8 | buffer[3]);
+		
+		delete [] buffer;
+		
+		return *((float *) &temp);		// convert long into a float
+		}
+	}
+
+
+inline void UniversalFileIO::fwriteLong( FILE *f, long x ) {
+	if( machineBigEndian ) {
+		fwrite( (void *)&x, sizeof(long), 1, f );
+		}
+	else {
+		unsigned char *buffer = new unsigned char[bytesInLong];
+		
+		buffer[0] = (unsigned char)(x >> 24);		// put bytes from long into char buffer
+		buffer[1] = (unsigned char)(x >> 16);
+		buffer[2] = (unsigned char)(x >> 8);
+		buffer[3] = (unsigned char)(x);
+		
+		fwrite( (void *)buffer, sizeof(char), bytesInLong, f );
+		}
+	}
+	
+inline void UniversalFileIO::fwriteFloat( FILE *f, float x ) {
+	if( machineBigEndian ) {
+		fwrite( (void *)&x, sizeof(float), 1, f );
+		}
+	else {
+		unsigned char *buffer = new unsigned char[bytesInFloat];
+		
+		long temp = *((long*)&x);		// convert float into long so that bit-wise ops can be performed
+		
+		buffer[0] = (unsigned char)(temp >> 24);		// put bytes from float into char buffer
+		buffer[1] = (unsigned char)(temp >> 16);
+		buffer[2] = (unsigned char)(temp >> 8);
+		buffer[3] = (unsigned char)(temp);
+		
+		fwrite( (void *)buffer, sizeof(char), bytesInFloat, f );
+		}
+	}
+
+
+#endif