twoplayer: Fix demo when two players are enabled

As an easter egg, if one of the players moves with the controller that player would then be playing against the demo.
ejona86 · Mar 20, 2020 · bc164df · bc164df
1 parent da53266
commit bc164df
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Showing 2 changed files with 136 additions and 6 deletions.
diff --git a/twoplayer-tetris-PRG.s.diff b/twoplayer-tetris-PRG.s.diff
@@ -792,7 +792,7 @@
          lda     twoPlayerPieceDelayCounter
          cmp     #$00
          bne     @twoPlayerPieceDelay
-@@ -2803,24 +2950,30 @@ @notDelaying:
+@@ -2803,79 +2950,89 @@ @notDelaying:
          sta     tetriminoY
          lda     #$01
          sta     playState
@@ -826,11 +826,25 @@
          sta     autorepeatY
  @ret:   rts
 
-@@ -2839,43 +2992,47 @@ chooseNextTetrimino:
+ chooseNextTetrimino:
+         lda     gameMode
+         cmp     #$05
+         bne     pickRandomTetrimino
+-        ldx     demoIndex
+-        inc     demoIndex
++        .import chooseNextTetrimino_mod ; ldx     demoIndex
++        jsr     chooseNextTetrimino_mod ; inc     demoIndex
++        nop
+         lda     demoTetriminoTypeTable,x
+         lsr     a
+         lsr     a
+         lsr     a
+         lsr     a
+         and     #$07
          tax
          lda     spawnTable,x
          rts
- 
+-
  pickRandomTetrimino:
 -        jsr     @realStart
 -        rts
@@ -1021,6 +1035,30 @@
          adc     #$04
          tax
          lda     musicSelectionTable,x
+@@ -3477,19 +3660,19 @@ pollControllerButtons:
+
+ @demoGameMode:
+         lda     demo_recording
+         cmp     #$FF
+         beq     @recording
+-        jsr     pollController
++        .import demo_pollController_mod
++        jmp     demo_pollController_mod
+         lda     newlyPressedButtons_player1
+-        cmp     #$10
++@demo_pollController_mod_after: cmp     #$10
+         beq     @startButtonPressed
+-        lda     demo_repeats
++@demo_pollController_mod_skip:  lda     demo_repeats
+         beq     @finishedMove
+         dec     demo_repeats
+         jmp     @moveInProgress
+-
+ @finishedMove:
+         ldx     #$00
+         lda     (demoButtonsAddr,x)
+         sta     generalCounter
+         jsr     demoButtonsTable_indexIncr
 @@ -3830,11 +4013,11 @@ L9FE9:  ldy     #$00
          sty     PPUSCROLL
          sty     PPUSCROLL

diff --git a/twoplayer.s b/twoplayer.s
@@ -33,9 +33,13 @@
 
 .segment "GAMEBSS"
 
-.ifndef TOURNAMENT_MODE
-.res 1 ; must be at least size 1 to prevent init loop from breaking
-.else
+; 0 for both players demo
+demo_playingPlayer:
+        .res    1
+demoIndex_player2:
+        .res    1
+
+.ifdef TOURNAMENT_MODE
 tetrisCount_P1:
         .res    1
 tetrisCount_P2:
@@ -526,6 +530,94 @@ isStartNewlyPressed:
         cmp     #$10
         rts
 
+demo_pollController_mod_after := $9D66
+demo_pollController_mod_skip := $9D6A
+demo_pollController_mod:
+        .export demo_pollController_mod
+        jsr     pollController
+        lda     newlyPressedButtons_player1
+        ora     newlyPressedButtons_player2
+        and     #$10
+        bne     @ret
+
+        lda     numberOfPlayers
+        cmp     #$02
+        bne     @done
+        lda     demo_playingPlayer
+        cmp     #$01
+        beq     @player1Playing
+        cmp     #$02
+        beq     @player2Playing
+
+        ; check for starting player
+        lda     newlyPressedButtons_player1
+        bne     @startPlayer1
+        lda     newlyPressedButtons_player2
+        beq     @bothPlayersDemo
+
+@startPlayer2:
+        lda     #$02
+        sta     demo_playingPlayer
+@player2Playing:
+@done:
+        lda     #$00
+@ret:
+        jmp     demo_pollController_mod_after
+
+@startPlayer1:
+        inc     demo_playingPlayer
+@player1Playing:
+        ; copy player1 input to player2
+        lda     newlyPressedButtons_player1
+        sta     newlyPressedButtons_player2
+        lda     heldButtons_player1
+        sta     heldButtons_player2
+        jsr     demo_pollController_mod_skip
+        ; now swap player1 and player2 input
+        lda     newlyPressedButtons_player2
+        sta     tmp1
+        lda     newlyPressedButtons_player1
+        sta     newlyPressedButtons_player2
+        lda     tmp1
+        sta     newlyPressedButtons_player1
+
+        lda     heldButtons_player2
+        sta     tmp1
+        lda     heldButtons_player1
+        sta     heldButtons_player2
+        lda     tmp1
+        sta     heldButtons_player1
+        rts
+
+@bothPlayersDemo:
+        jsr     demo_pollController_mod_skip
+        lda     newlyPressedButtons_player1
+        sta     newlyPressedButtons_player2
+        lda     heldButtons_player1
+        sta     heldButtons_player2
+        rts
+
+
+chooseNextTetrimino_mod:
+        .export chooseNextTetrimino_mod
+        ; Assume that when demoIndex is 0/1, this is being called from
+        ; gameModeState_initGameState and that it applies to both players
+        lda     demoIndex
+        cmp     #$02
+        bmi     @bothPlayers
+        lda     activePlayer
+        cmp     #$01
+        bne     @player2
+        ldx     demoIndex
+        inc     demoIndex
+        rts
+@bothPlayers:
+        inc     demoIndex
+@player2:
+        ldx     demoIndex_player2
+        inc     demoIndex_player2
+        rts
+
 
 gameMode_levelMenu_nametable_mod:
         .export gameMode_levelMenu_nametable_mod