#include "SwapEndian.h"

static long _TestEndian=1;

int IsLittleEndian(void) {
	return *(char*)&_TestEndian;
}

/******************************************************************************
  FUNCTION: SwapEndian
  PURPOSE: Swap the byte order of a structure
  EXAMPLE: float F=123.456;; SWAP_FLOAT(F);
******************************************************************************/

void *SwapEndian(void* Addr, const int Nb) {
	static char Swapped[16];
	switch (Nb) {
		case 2:	Swapped[0]=*((char*)Addr+1);
				Swapped[1]=*((char*)Addr  );
				break;
		case 3:	// As far as I know, 3 is used only with RGB images
				Swapped[0]=*((char*)Addr+2);
				Swapped[1]=*((char*)Addr+1);
				Swapped[2]=*((char*)Addr  );
				break;
		case 4:	Swapped[0]=*((char*)Addr+3);
				Swapped[1]=*((char*)Addr+2);
				Swapped[2]=*((char*)Addr+1);
				Swapped[3]=*((char*)Addr  );
				break;
		case 8:	Swapped[0]=*((char*)Addr+7);
				Swapped[1]=*((char*)Addr+6);
				Swapped[2]=*((char*)Addr+5);
				Swapped[3]=*((char*)Addr+4);
				Swapped[4]=*((char*)Addr+3);
				Swapped[5]=*((char*)Addr+2);
				Swapped[6]=*((char*)Addr+1);
				Swapped[7]=*((char*)Addr  );
				break;
		case 16:Swapped[0]=*((char*)Addr+15);
				Swapped[1]=*((char*)Addr+14);
				Swapped[2]=*((char*)Addr+13);
				Swapped[3]=*((char*)Addr+12);
				Swapped[4]=*((char*)Addr+11);
				Swapped[5]=*((char*)Addr+10);
				Swapped[6]=*((char*)Addr+9);
				Swapped[7]=*((char*)Addr+8);
				Swapped[8]=*((char*)Addr+7);
				Swapped[9]=*((char*)Addr+6);
				Swapped[10]=*((char*)Addr+5);
				Swapped[11]=*((char*)Addr+4);
				Swapped[12]=*((char*)Addr+3);
				Swapped[13]=*((char*)Addr+2);
				Swapped[14]=*((char*)Addr+1);
				Swapped[15]=*((char*)Addr  );
				break;
	}
	return (void*)Swapped;
}