diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/enemies.s | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/src/enemies.s b/src/enemies.s index 07578b7..25f041b 100644 --- a/src/enemies.s +++ b/src/enemies.s @@ -439,7 +439,7 @@ ;; ;; |TTTT KK-D|; where: ;; | - ;; |- D: downwards if 1; upwards if 0 (just like the 'diagonal' algorithm). + ;; |- D: downwards if 1; upwards if 0. ;; |- K: movement kind (see the constants FALLING_VELOCITY_*). ;; |- T: timer. Whenever it reaches zero, then a vertical movement is done. ;; @@ -471,10 +471,17 @@ and #$F0 bne @update_extra_state - ;; Move downwards and reset the 'extra' state depending on the enemy - ;; kind. + ;; Move upwards/downwards and reset the 'extra' state depending on the + ;; enemy kind. + tya + and #$01 + beq @up inc Enemies::zp_enemies_pool_base + 1, x + jmp @compute_next_counter + @up: + dec Enemies::zp_enemies_pool_base + 1, x + @compute_next_counter: ;; Yes, doing an index on a pre-computed ROM table would've been faster, ;; but I need the 'x' register and I didn't feel like doing funny ;; dances when it's not so bad. @@ -716,7 +723,7 @@ ;; ;; |TTTT -AAD|; where: ;; | - ;; |- D: downwards if 1; upwards if 0 (just like the 'diagonal' algorithm). + ;; |- D: downwards if 1; upwards if 0. ;; |- AA: current algorithm: 00/11: stop; 01: horizontal; 10: diagonal. ;; |- T: timer for algorithm. Whenever it reaches zero the algorithm is changed. ;; @@ -870,7 +877,7 @@ ;; ;; |TTTT ttSD|; where: ;; | - ;; |- D: downwards if 1; upwards if 0 (just like the 'diagonal' algorithm). + ;; |- D: downwards if 1; upwards if 0. ;; |- S: state: 0: moving up/down; 01: homing. ;; |- tt: number of times TT has run out. When it reaches '11', then we ;; | change from the zero state to homing. |