#include <windows.h>
#include <stdio.h>

// cod4 1.7 mp hack for geforce fx 5x00

size_t offset = 0x1f36f5;
unsigned char const newBytes[] = { 
	0x81, 0x4b, 0x20, 0x00, 0x00, 0x02, 0x00,		// or dword [ebx+0x20], 0x20000
	0x5f,											// pop edi
	0x5e,											// pop esi
	0x5d,											// pop ebp
	0x5b,											// pop ebx
	0xc3 };											// ret

unsigned char const oldBytes[] = {
	0x7d, 0x2a, 0x6a, 0x64, 0xff, 0x15, 0xb8,		//orig
	0x11, 0x69, 0x00, 0x83, 0xc7 };					

int main( void )
{
	HANDLE h = CreateFile( L"iw3mp.exe", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, 0, OPEN_EXISTING, 0, 0 );
	unsigned char buf[sizeof(newBytes)];
	DWORD crap;

	if (INVALID_HANDLE_VALUE == h)
	{
		printf( "failed opening iw3mp.exe -- error=%x\n", GetLastError() );
		return 1;
	}

	SetFilePointer( h, offset, 0, FILE_BEGIN );
	ReadFile( h, buf, sizeof(buf), &crap, 0 );

	if (!memcmp( buf, newBytes, sizeof(newBytes) ))
	{
		printf( "patch already applied.\n" ); return 2;
	}

	if (memcmp( buf, oldBytes, sizeof(oldBytes) ))
	{
		printf( "wrong file -- requires cod4 1.7\n" ); return 3;
	}

	SetFilePointer( h, offset, 0, FILE_BEGIN );
	WriteFile( h, newBytes, sizeof(buf), &crap, 0 );

	printf( "patched %u bytes at 0x%x\n", sizeof(buf), offset );

	CloseHandle( h );
	return 0;
}