  This paper introduces a novel algorithm for solving the point-to-point
shortest path problem in a static regular 8-neighbor connectivity (G8) grid.
This algorithm can be seen as a generalization of Hadlock algorithm to G8
grids, and is shown to be theoretically equivalent to the relaxed $A^*$
($RA^*$) algorithm in terms of the provided solution's path length, but with
substantial time and memory savings, due to a completely different computation
strategy, based on defining a set of lookup matrices. Through an experimental
study on grid maps of various types and sizes (1290 runs on 43 maps), it is
proven to be 2.25 times faster than $RA^*$ and 17 times faster than the
original $A^*$, in average. Moreover, it is more memory-efficient, since it
does not need to store a G score matrix.
