diff options
Diffstat (limited to 'src/driver.s')
| -rw-r--r-- | src/driver.s | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/driver.s b/src/driver.s index bb0303f..00e807c 100644 --- a/src/driver.s +++ b/src/driver.s @@ -9,6 +9,11 @@ zp_player_timer = $30 PLAYER_TIMER_VALUE = HZ * 2 + .ifdef PAL + ;; Frame counter which resets every 5 frames. + zp_pal_counter = $31 + .endif + ;; Switch from the title screen to the main street. Note that this function ;; is to be called with the PPU disabled. If that's not the case, then it ;; will set the proper values to disable it on the next `nmi` call and set @@ -75,4 +80,31 @@ @game: JAL Player::update .endproc + + .ifdef PAL + ;; All the code that is needed to fix some values for PAL machines. + .proc pal_handler + ;; Check if 5 frames have passed since last counter reset. + lda Driver::zp_pal_counter + cmp #4 + beq @do_handle + + ;; Nope! Reset the player's step on PAL and increase the counter. + lda #1 + sta Player::zp_step_on_pal + inc Driver::zp_pal_counter + bne @end + + @do_handle: + ;; Increase the step just for this frame and reset the counter. + lda Player::zp_step_on_pal + clc + adc #2 + sta Player::zp_step_on_pal + lda #0 + sta Driver::zp_pal_counter + @end: + rts + .endproc + .endif .endscope |