Fixed collision

diff --git a/main.asm b/main.asm
index f95014aa6e4539a04879c1b672c247b486cf431c..6cb3c6184d90b89c7aaeda0f94dc8b63f8cf6b35 100644 (file)
--- a/main.asm
+++ b/main.asm
@@ -37,7 +37,7 @@ DigitTens ds 2
 ScoreGfx ds 1
 TimerGfx ds 1
 
-Temp ds 1
+Temp ds 4 ; 4 bytes of temp storage
 
 ; object X positions in $89-8C
 ObjectX:        ds 4    ; player0, player1, missile0, missile1
@@ -63,6 +63,9 @@ Level: ds 1 ; level counter
 
 AnimationTimer ds 4 ; animation timer for p0, p1, m0, m1
 
+PreviousX ds 4
+PreviousY ds 4
+
        ; ---------- Constants
 
        SEG.U constants
@@ -101,8 +104,9 @@ Clear
        stx Level
        stx CurrentMap
 
+       ldx #15
        stx ObjectX
-  ldx #8
+  ldx #12
   stx ObjectX+1
   ldy #$30
   sty ObjectY
@@ -142,6 +146,8 @@ Sleep12 ; jsr here to sleep for 12 cycles
        rts
 
 VerticalBlank
+       ; game logic call
+       jsr ProcessJoystick
        jsr PositionObjects
        jsr SetObjectColours
        jsr PrepScoreForDisplay
@@ -226,6 +232,12 @@ scoreLoop
        ldx #0
        stx Temp ; store map counter in temp
 pfLoop
+       tya ; 2 29 - 2LK loop counter in A for testing
+       and #%11 ; 2 31 - test for every 4th time through the loop,
+       bne SkipMapCounter ; 2 33 (3 34) branch if not 4th time
+       inc Temp ; 2 35 - if 4th time, increase Temp so new playfield data is used
+SkipMapCounter
+
        ; continuation of line 2 of the 2LK
        ; this precalculates data that's used on line 1 of the 2LK
        lda #TURTLEHEIGHT-1 ; height of turtle sprite - 1
@@ -240,6 +252,9 @@ DoDrawGrp0 ;
 
        sta GRP0 ; update player0 to draw turtle
 
+       ; store current y in temp+1
+       sty Temp+1
+       ldy Temp ; load map counter
        ; draw playfield
        lda (MapPtr0),y ; playfiled pattern test
        sta PF0
@@ -248,6 +263,9 @@ DoDrawGrp0 ;
        lda (MapPtr2),y ; playfiled pattern test
        sta PF2
 
+       ; restore y
+       ldy Temp+1
+
        ; precalculate date for next line
        lda #TURTLEHEIGHT-1 ; height of gfx
        dcp BirdDraw ; decrement BirdDraw
@@ -278,10 +296,17 @@ Overscan
        lda #32 ; set time for 27 scanlines 32 = ((27 * 76) / 64)
        sta TIM64T ; timer will go off after 27 scanlines
 
-       ; game logic call
-       jsr ProcessJoystick
+       ldy #0 ; collision detection
+       ;sty Temp
+CollisionLoop
+       sty Temp
+       jsr CollisionDetection
+       iny
+       cpy #3
+       bne CollisionLoop
 
        lda #1
+       sta CXCLR ; clear collision
 overscanLoop
        sta WSYNC
        lda INTIM ; check timer
@@ -290,33 +315,51 @@ overscanLoop
 
 
 ProcessJoystick
-; game logic here
+       ; now we store old x and y
+       ldx ObjectX
+       stx PreviousX
+       ldx ObjectY
+       stx PreviousY
+
+       ldx ObjectX+1
+       stx PreviousX+1
+       ldx ObjectY+1
+       stx PreviousY+1
+
+       ; load Temp with 0 to enable collision
+       ldx #0
+       stx Temp
+       ; game logic here
        lda  SWCHA ; input registr
        asl  ; test bit 0, left joy - right input
        bcs Player1RightNotPressed ; this operation sets the carry for the fromer bit that fell off
        ldy #0 ; right presses
        ldx #0
-       jsr CollisionDetection
+       jsr MoveObject
 Player1RightNotPressed
        asl ; test bit 1, left joy - left input
        bcs Player1LeftNotPressed
        ldy #0 ; left presses
        ldx #1
-       jsr CollisionDetection
+       jsr MoveObject
 Player1LeftNotPressed
        asl ; test bit 1, left joy - down input
        bcs Player1DownNotPressed
        ldy #0
        ldx #2
-       jsr CollisionDetection
+       jsr MoveObject
 Player1DownNotPressed
        asl ; test bit 2, left joy - up input
        bcs Player1UpNotPressed
        ldy #0
        ldx #3
-       jsr CollisionDetection
+       jsr MoveObject
 Player1UpNotPressed
 
+       ; set Temp to 1 to disable collision for bird
+       ldx #1
+       stx Temp
+
        ; check left difficulty switch
        bit SWCHB       ; state of Right Difficult in N (negative flag)
                                                                        ; state of Left Difficult in V (overflow flag)
@@ -330,25 +373,25 @@ LeftIsBJoy
        bcs Player2RightNotPressed
        ldy #1
        ldx #0
-       jsr CollisionDetection
+       jsr MoveObject
 Player2RightNotPressed
        asl ; test bit 1, right joy - left input
        bcs Player2LeftNotPressed
        ldy #1
        ldx #1
-       jsr CollisionDetection
+       jsr MoveObject
 Player2LeftNotPressed
        asl ; test bit 1, right joy - down input
        bcs Player2DownNotPressed
        ldy #1
        ldx #2
-       jsr CollisionDetection
+       jsr MoveObject
 Player2DownNotPressed
        asl ; test bit 2, right joy - up input
        bcs Player2UpNotPressed
        ldy #1
        ldx #3
-       jsr CollisionDetection
+       jsr MoveObject
 Player2UpNotPressed
        rts
 
@@ -360,13 +403,15 @@ BirdAI
 ; Expected inputs:
 ; y - object's address offset, p0, p1, m0, m1
 ; x - move left, right, up, or down
+; set Temp memory address to 1 to ignore collision.
+; every other value will NOT ignore collision
 ; Retruns: 0, 1 or 2 in x
 ; 0 = no collision
 ; 1 = wall collision
 ; 2 = bird collision
 ; 3 = missile collision
-;;====================
-CollisionDetection
+;====================
+MoveObject ; for some reason the first frame of collision does not detect?
        cpx #0
        beq RightCollision
        cpx #1
@@ -385,7 +430,7 @@ SaveXRight
        stx ObjectX,y
        ldx #1
        stx REFP0,y ; makes turtle image face right
-       rts
+       jmp MoveDone
 LeftCollision
        ; left pressed code
        ldx ObjectX,y
@@ -397,7 +442,7 @@ SaveXLeft
        stx ObjectX,y
        ldx #0
        stx REFP0,y ; makes turtle image face left
-       rts
+       jmp MoveDone
 UpCollision
        ; down pressed code
        ldx ObjectY,y
@@ -407,7 +452,7 @@ UpCollision
        ldx #PFHEIGHT
 SaveYUp
        stx ObjectY,y
-       rts
+       jmp MoveDone
 DownCollision
        ; down pressed code
        ldx ObjectY,y
@@ -417,6 +462,42 @@ DownCollision
        ldx #0
 SaveYDown
        stx ObjectY,y
+
+MoveDone
+       rts
+
+       ;====================
+       ; This sub checks for collision based on inputs stored
+       ; Expected inputs:
+       ; y - object's address offset, p0, p1, m0, m1
+       ; set Temp memory address to 1 to ignore collision.
+       ; every other value will NOT ignore collision
+       ; Retruns: 0, 1 or 2 in x
+       ; 0 = no collision
+       ; 1 = wall collision
+       ; 2 = bird collision
+       ; 3 = missile collision
+       ;====================
+CollisionDetection
+       ldx Temp ; check if collision is enabled
+       cpx #1 ; if it is 1 just return no
+       beq CollisionDone
+       ; otherwise check collision
+       ldx CXP0FB,y ; load into x for bit operation
+       stx Temp+1 ; sotre for bit operation
+       bit Temp+1 ; N = player0/playfield, V=player0/ball
+       bpl NoPFCollision ; if N is off, then player did not collide with playfield
+       ; if collision restore position.
+       lda PreviousX,y
+       sta ObjectX,y
+       lda PreviousY,y
+       sta ObjectY,y
+
+       ldx #1 ; this means wall collision
+       jmp CollisionDone
+NoPFCollision
+       ldx #0
+CollisionDone
        rts
 
 ; Plays the Intro noise
@@ -753,50 +834,74 @@ DigitGfx:
 ; the room table holds pf information for each 1/2 scanline as a byte. 45 bytes
 ; All rooms require PF1 and PF2 tables as well
 Room1LayoutPF0:
-       REPEAT PFHEIGHT/12
-       .byte %11111111
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %10000000
-       .byte %11111111
-       REPEND
+       .byte %11110000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %00010000
+       .byte %11110000
 Room1LayoutPF1:
-       REPEAT PFHEIGHT/12
        .byte %11111111
-       .byte %00000001
-       .byte %00000001
-       .byte %00000001
-       .byte %00000001
        .byte %00000000
        .byte %00000000
+       .byte %00111000
+       .byte %00000000
+       .byte %00000000
+       .byte %00000000
+       .byte %11000000
+       .byte %01000000
+       .byte %01000000
+       .byte %01000001
+       .byte %01000001
+       .byte %01000000
+       .byte %01000000
+       .byte %11000000
+       .byte %00000000
        .byte %00000000
        .byte %00000000
+       .byte %00111000
        .byte %00000000
        .byte %00000000
        .byte %11111111
-       REPEND
 Room1LayoutPF2:
-       REPEAT PFHEIGHT/12
        .byte %11111111
+       .byte %10000000
+       .byte %00000000
+       .byte %00000000
        .byte %00000000
        .byte %00000000
+       .byte %00011100
+       .byte %00000100
        .byte %00000000
        .byte %00000000
        .byte %00000000
        .byte %00000000
        .byte %00000000
        .byte %00000000
+       .byte %00000100
+       .byte %00011100
        .byte %00000000
        .byte %00000000
+       .byte %00000000
+       .byte %00000000
+       .byte %10000000
        .byte %11111111
-       REPEND
 
 
 ; Table holding all the room start addresses next to each other