diff options
Diffstat (limited to 'src/enemies.s')
| -rw-r--r-- | src/enemies.s | 103 |
1 files changed, 30 insertions, 73 deletions
diff --git a/src/enemies.s b/src/enemies.s index c93f1c2..07578b7 100644 --- a/src/enemies.s +++ b/src/enemies.s @@ -559,19 +559,12 @@ lda Enemies::zp_enemies_pool_base, x and #$80 beq @move_left - lda Enemies::zp_enemies_pool_base + 2, x - clc - adc Enemies::zp_enemy_arg + inc Enemies::zp_enemies_pool_base + 2, x jmp @do_vertical @move_left: - lda Enemies::zp_enemies_pool_base + 2, x - sec - sbc Enemies::zp_enemy_arg + dec Enemies::zp_enemies_pool_base + 2, x @do_vertical: - ;; Set the previous computation regardless of the branch. - sta Enemies::zp_enemies_pool_base + 2, x - ;; The vertical movement works the same way, but taking into account its ;; direction via the 'extra' state. Note that we mask it, which is not ;; needed for the main enemies which use this algorithm, but it is for @@ -579,21 +572,13 @@ lda Enemies::zp_enemies_pool_base + 3, x and #$01 beq @move_up - lda Enemies::zp_enemies_pool_base + 1, x - clc - adc Enemies::zp_enemy_arg + inc Enemies::zp_enemies_pool_base + 1, x jmp @check_collision @move_up: - lda Enemies::zp_enemies_pool_base + 1, x - sec - sbc Enemies::zp_enemy_arg - - @check_collision: - ;; Set the previous computation regardless of the branch. - sta Enemies::zp_enemies_pool_base + 1, x + dec Enemies::zp_enemies_pool_base + 1, x ;; Collision checking. - + @check_collision: ;; Translate the Y axis into tile coordinates. lda Enemies::zp_enemies_pool_base + 1, x lsr @@ -633,10 +618,7 @@ ;; Move downwards once, which cancels the movement set at the beginning ;; of the function. - lda Enemies::zp_enemies_pool_base + 1, x - clc - adc Enemies::zp_enemy_arg - sta Enemies::zp_enemies_pool_base + 1, x + inc Enemies::zp_enemies_pool_base + 1, x rts @@ -682,16 +664,10 @@ ;; stucked or other weird situations. and #$80 beq @bounce_left - lda Enemies::zp_enemies_pool_base + 2, x - clc - adc Enemies::zp_enemy_arg - jmp @set_bounce + inc Enemies::zp_enemies_pool_base + 2, x + rts @bounce_left: - lda Enemies::zp_enemies_pool_base + 2, x - sec - sbc Enemies::zp_enemy_arg - @set_bounce: - sta Enemies::zp_enemies_pool_base + 2, x + dec Enemies::zp_enemies_pool_base + 2, x rts ;; Last but not least, let's see if the enemy collides on its bottom @@ -729,10 +705,7 @@ sta Enemies::zp_enemies_pool_base + 3, x ;; Make it bounce up. - lda Enemies::zp_enemies_pool_base + 1, x - sec - sbc Enemies::zp_enemy_arg - sta Enemies::zp_enemies_pool_base + 1, x + dec Enemies::zp_enemies_pool_base + 1, x rts .endproc @@ -789,7 +762,7 @@ clc adc Globals::zp_tmp0 sta Enemies::zp_enemies_pool_base + 3, x - jmp @end + rts @do: ;; Blindly increase the timer as overflows will be covered when entering @@ -801,9 +774,13 @@ ;; Now switch what to do depending on the algorithm. and #%00000110 - beq @end + bne @next_algo_1 + rts + @next_algo_1: cmp #%00000110 - beq @end + bne @next_algo_2 + rts + @next_algo_2: and #%00000100 beq @horizontal @@ -824,17 +801,12 @@ beq @move_left iny iny - lda Enemies::zp_enemies_pool_base + 2, x - clc - adc Enemies::zp_enemy_arg - jmp @set_horizontal + inc Enemies::zp_enemies_pool_base + 2, x + jmp @after_horizontal @move_left: - lda Enemies::zp_enemies_pool_base + 2, x - sec - sbc Enemies::zp_enemy_arg - @set_horizontal: - sta Enemies::zp_enemies_pool_base + 2, x + dec Enemies::zp_enemies_pool_base + 2, x + @after_horizontal: ;; We store in a temporary value how much the X tile coordinates will ;; have to be increased in order to point to the right face. sty Globals::zp_tmp0 @@ -870,7 +842,8 @@ ;; Bottom. inc Globals::zp_arg0 jsr Background::collides - beq @end + bne @horizontal_collision + rts @horizontal_collision: ;; Restore the 'x' register from a previous 'Background::collides' call. @@ -885,18 +858,10 @@ ;; stucked or other weird situations. and #$80 beq @bounce_left - lda Enemies::zp_enemies_pool_base + 2, x - clc - adc Enemies::zp_enemy_arg - jmp @set_bounce + inc Enemies::zp_enemies_pool_base + 2, x + rts @bounce_left: - lda Enemies::zp_enemies_pool_base + 2, x - sec - sbc Enemies::zp_enemy_arg - @set_bounce: - sta Enemies::zp_enemies_pool_base + 2, x - - @end: + dec Enemies::zp_enemies_pool_base + 2, x rts .endproc @@ -969,20 +934,12 @@ and #$01 beq @go_down - lda Enemies::zp_enemies_pool_base + 1, x - clc - adc Enemies::zp_enemy_arg - jmp @set_vertical + inc Enemies::zp_enemies_pool_base + 1, x + jmp @increase_timer @go_down: - lda Enemies::zp_enemies_pool_base + 1, x - sec - sbc Enemies::zp_enemy_arg - - @set_vertical: - ;; Set the new Y position. - sta Enemies::zp_enemies_pool_base + 1, x + dec Enemies::zp_enemies_pool_base + 1, x - ;; And increase the timer. + @increase_timer: tya clc adc #$10 |