; random_walker — attacks adjacent enemies, otherwise splits or wanders at random.

    lea  r8, [rdi + VIEW_CELLS]
    cmp  byte [r8 + 7], CELL_ENEMY
    je   .atk_up
    cmp  byte [r8 + 13], CELL_ENEMY
    je   .atk_right
    cmp  byte [r8 + 17], CELL_ENEMY
    je   .atk_down
    cmp  byte [r8 + 11], CELL_ENEMY
    je   .atk_left

    movzx eax, byte [rdi + VIEW_RAND]
    mov  cl, al
    and  cl, ACT_DIR_MASK            ; random direction
    cmp  rsi, SPLIT_MIN + 4
    jb   .maybe_move
    cmp  al, 160                     ; ~62%: split when able
    jae  .maybe_move
    mov  al, ACT_SPLIT
    or   al, cl
    ret
.maybe_move:
    cmp  al, 96                      ; ~37%: move
    jae  .rest
    cmp  rsi, 10                     ; don't walk ourselves to death
    jb   .rest
    mov  al, ACT_MOVE
    or   al, cl
    ret
.rest:
    mov  al, ACT_REST
    ret
.atk_up:    mov al, ACT_ATTACK + DIR_UP
            ret
.atk_right: mov al, ACT_ATTACK + DIR_RIGHT
            ret
.atk_down:  mov al, ACT_ATTACK + DIR_DOWN
            ret
.atk_left:  mov al, ACT_ATTACK + DIR_LEFT
            ret