Modified GetTile Function

From OPU Wiki

This code modifies GetTile to allow you to see if a tile has the blight on it.

// These are used to let us access more information about a tile than OP2 wants us to.
unsigned char *setTileLoc = (unsigned char *)0x00476D32;
unsigned char oldSetTile[] =
{
	0x25, 0xE0, 0xFF, 0x00, 0x00,   // and eax, 0FFE0h
	0xC1, 0xE8, 0x05                // shr eax, 5
};
unsigned char newSetTile[] =
{
    0x90, 0x90, 0x90, 0x90, 0x90,   // nop * 5
    0x90, 0x90, 0x90                // nop * 3
};
struct mapCell
{
    int cellType:5;
    int tileIndex:11;
    int unitID:11;
    int lava:1;
    int lavaPossible:1;
    int expand:1;
    int microbe:1;
    int wallBuilding:1;
};

BOOL APIENTRY DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
    DWORD oldAttr;
	if (fdwReason == DLL_PROCESS_ATTACH)
	{
		DisableThreadLibraryCalls(hinstDLL);

		// Modify the SetTile code for our purposes
		VirtualProtect(setTileLoc, sizeof(newSetTile), PAGE_EXECUTE_READWRITE, &oldAttr);
		memcpy(setTileLoc, newSetTile, sizeof(newSetTile));
	}
	else if (fdwReason == DLL_PROCESS_DETACH)
	{
		// Put the old SetTile code back
		memcpy(setTileLoc, oldSetTile, sizeof(newSetTile));
	}

    return TRUE;
}

/*
In order to use this, after calling GetTile, add this code:
  "memcpy(&cell, &tile, 4);"

To determine if the blight is on the tile, use:
  "if (cell.expand || cell.microbe)"
*/