A C64 Game - Step 96

And a nice little update, Richard Bayliss added sounds effects. Now there's a SFX mode, toggle in the title screen with left/right.



The effects are integrated in the player code as separate "songs". So we add a variable SFX_MODE and check it's value when we want to play an effect or start the music:

No music in title when SFX mode enabled:

          ;initialise music player
          ldx #0
          ldy #0
          lda SFX_MODE
          bne +

          lda #MUSIC_TITLE_TUNE
          jsr MUSIC_PLAYER

Play an effect is similar:

          lda SFX_MODE
          beq +

          lda #MUSIC_PICKUP
          jsr MUSIC_PLAYER

+

To toggle sfx mode move the joystick left/right in the title screen and display its state:

          ;switch through music/sfx mode
          lda #$04
          bit JOYSTICK_PORT_II
          bne .NotLeftPressed

          lda LEFT_RELEASED
          beq .LeftPressed

          lda SFX_MODE
          eor #$01
          sta SFX_MODE
          jsr DisplaySfxMode

          lda SFX_MODE
          beq +

          lda #MUSIC_PICKUP
          jmp ++

+
          lda #MUSIC_TITLE_TUNE
++
          jsr MUSIC_PLAYER
          lda #0
          jmp .LeftPressed

.NotLeftPressed
          lda #1

.LeftPressed
          sta LEFT_RELEASED
          lda #$08
          bit JOYSTICK_PORT_II
          bne .NotRightPressed

          lda RIGHT_RELEASED
          beq .RightPressed

          lda SFX_MODE
          eor #$01
          sta SFX_MODE
          jsr DisplaySfxMode

          lda SFX_MODE
          beq +

          lda #MUSIC_PICKUP
          jmp ++

+
          lda #MUSIC_TITLE_TUNE
++
          jsr MUSIC_PLAYER
          lda #0
          jmp .RightPressed

.NotRightPressed
          lda #1

.RightPressed
          sta RIGHT_RELEASED

!zone DisplaySfxMode
DisplaySfxMode
          lda SFX_MODE
          bne +

          lda #TEXT_MUSIC
          jmp .DisplaySfxMode

+
          lda #TEXT_SFX

.DisplaySfxMode
          sta ZEROPAGE_POINTER_1 + 1
          lda #34
          sta PARAM1
          lda #24
          sta PARAM2
          jmp DisplayText

Due to technical limitations in the player code there are not too many sounds, but there are enough to make it worthwile.


step96.zip