Function ChangeDirDiff

src/direction_func.h:88–92

* Applies two differences together * * This function adds two differences together and returns the resulting * difference. So adding two DIRDIFF_REVERSE together results in the * DIRDIFF_SAME difference. * * @param d The first difference * @param delta The second difference to add on * @return The resulting difference */

 * @return The resulting difference
 */
inline DirDiff ChangeDirDiff(DirDiff d, DirDiff delta)
{
	/* Cast to uint so compiler can use bitmask. Result can never be negative. */
	return static_cast<DirDiff>((static_cast<uint>(d) + static_cast<uint>(delta)) % 8);
}

/**
 * Change a direction by a given difference