Merge pull request #120 from zohassadar/optimized_crunch

optimized crunch with crash mode accommodated

Author: kirjavascript

src/modes/crunch.asm

@@ -16,67 +16,53 @@
 ; E - 3 left 2 right
 ; F - 3 left 3 right
 
+; clobbers generalCounter3 & generalCounter4 (defined in playstate/util.asm)
+
 advanceGameCrunch:
-    lda #0
-    sta vramRow
-    lda #20
-advanceSides:
-    pha
-    sta tmp3
-    lda crunchModifier
-    lsr a
-    lsr a
-    ldx #0
-    jsr advanceSide
-    pla
-    sta tmp3
-    lda crunchModifier
-    and #%00000011
-    pha
-    eor #$FF
-    sec
-    adc #0
-    clc
-    adc #10
-    tax
-    pla
-    jsr advanceSide
+; initialize playfield row 19 to 0
+    ldx #$13
+@nextRow:
+    lda multBy10Table,x
+    sta playfieldAddr ; restored to 0 at end of loop
+    jsr advanceSides
+    dex
+    bpl @nextRow
+    inx ; x is FF, increase to store 0 in vramRow
+    stx vramRow
+crunchReturn:
     rts
 
-advanceSide:
-    cmp #0
-    beq @end
-    pha
-    ldy #0
-    txa
-    clc
-    adc #<playfield
-    sta tmp1
-    lda #>playfield
-    sta tmp2
-@rowLoop:
-    pla
-    pha
-    tax
-    beq @end
-@blockLoop:
+advanceSides:
+    ; called in playState_checkForCompletedRows and in advanceGameCrunch
+    ; draws to row defined in playfieldAddr, which defaults to 0
+    jsr unpackCrunchModifier
+
     lda #BLOCK_TILES
-    sta (tmp1), y
-    inc tmp1
-    dex
-    bne @blockLoop
-    pla
-    pha
-    eor #$FF
-    sec
-    adc #0
-    clc
-    adc tmp1
-    clc
-    adc #10
-    sta tmp1
-    dec tmp3
-    bne @rowLoop
-    pla
-@end:
+
+    ldy #$0
+@leftLoop:
+    dec crunchLeftColumns
+    bmi @initRight
+    sta (playfieldAddr),y
+    iny
+    bpl @leftLoop ; unconditional
+
+@initRight:
+    ldy #$9
+@rightLoop:
+    dec crunchRightColumns
+    bmi crunchReturn
+    sta (playfieldAddr),y
+    dey
+    bpl @rightLoop ; unconditional
+
+
+unpackCrunchModifier:
+    lda crunchModifier
+    lsr
+    lsr
+    sta crunchLeftColumns ; generalCounter3
+    lda crunchModifier
+    and #$03
+    sta crunchRightColumns ; generalCounter4
     rts

src/playstate/completedrows.asm

@@ -144,8 +144,7 @@ playState_checkForCompletedRows:
         lda practiseType
         cmp #MODE_CRUNCH
         bne @crunchEnd
-        lda #1
-        jsr advanceSides
+        jsr advanceSides ; clobbers generalCounter3 and generalCounter4
 @crunchEnd:
 
         lda completedLines

src/playstate/util.asm

@@ -77,10 +77,38 @@ updatePlayfield:
         sta vramRow
 @ret:   rts
 
+crunchLeftColumns = generalCounter3
+crunchRightColumns = generalCounter4
+
 updateMusicSpeed:
-        ldx #$05
-        lda multBy10Table,x ;this piece of code is parameterized for no reason but the crash checking code relies on the index being 50-59 so if you ever optimize this part out of the code please also adjust the crash test, specifically the part which handles cycles for allegro.
+
+        ; ldx #$05
+        ; lda multBy10Table,x ;this piece of code is parameterized for no reason but the crash checking code relies on the index being 50-59 so if you ever optimize this part out of the code please also adjust the crash test, specifically the part which handles cycles for allegro.
+        ; tay
+
+        ldy #50 ; replaces above
+
+; check if crunch mode
+        ldx practiseType
+        cpx #MODE_CRUNCH
+        bne @notCrunch
+
+        ; add crunch left columns to y
+        jsr unpackCrunchModifier
+        tya
+        clc
+        adc crunchLeftColumns ; offset y with left column count (generalCounter3)
         tay
+
+        ; set x to playable column count
+        lda #$0A
+        sec
+        sbc crunchLeftColumns ; generalCounter3
+        sbc crunchRightColumns ; generalCounter4
+        tax
+        bne @checkForBlockInRow ; unconditional, expected range 4 - 10
+
+@notCrunch:
         ldx #$0A
 @checkForBlockInRow:
         lda (playfieldAddr),y