target word animation

src/ui.common.a

@@ -3,6 +3,19 @@
 ;
 ; common graphics functions
 ;
+; Public functions:
+; - Home
+; - WaitForKeyWithTimeout
+; - ScrollDown
+; - ScrollDownBy
+; - ScrollUp
+; - ScrollUpBy
+; - LogicalColumnToPhysicalColumn
+; - ToASCIIString
+;
+; Public variables:
+; - GlobalLeftMargin
+;
 
 GlobalLeftMargin
          !byte $0A
@@ -69,11 +82,14 @@ WaitForKeyWithTimeout
 @exit    rts
 
 ScrollDown
+         lda   #$16
+ScrollDownBy
 ; in:    Y = logical column to scroll
+;        A = number of HGR rows to scroll
 ; out:   X/Y preserved
          stx   @x+1
          sty   @y+1
-         ldx   #$16
+         tax
          jsr   LogicalColumnToPhysicalColumn
          jsr   InitScrollStorage
          jsr   WaitForVBL
@@ -84,11 +100,14 @@ ScrollDown
          rts
 
 ScrollUp
+         lda   #$16
+ScrollUpBy
 ; in:    Y = logical column to scroll
+;        A = number of HGR rows to scroll
 ; out:   X/Y preserved
          stx   @x+1
          sty   @y+1
-         ldx   #$16
+         tax
          jsr   LogicalColumnToPhysicalColumn
          jsr   InitScrollStorage
          jsr   WaitForVBL
@@ -99,6 +118,7 @@ ScrollUp
          rts
 
 InitScrollStorage
+; out:   preserves X/Y
          lda   #$00
          sta   $FC
          sta   $FD

src/ui.play.a

@@ -199,7 +199,6 @@ PlayEventLetter
          rts                         ; puzzle is complete, return to caller with A = kCompletedPuzzle
 
 MarkTargetWord
-         ; TODO animation here?
          ldx   #4
          ldy   #0
 -        lda   puzzle_data4, y
@@ -207,6 +206,18 @@ MarkTargetWord
          iny
          cpy   puzzle_logical_width
          bne   -
+         ldy   #0
+-        lda   #1
+         jsr   ScrollUpBy
+         iny
+         cpy   puzzle_logical_width
+         bne   -
+         ldy   #0
+-        lda   #1
+         jsr   ScrollDownBy
+         iny
+         cpy   puzzle_logical_width
+         bne   -
          ; TODO sound here?
          rts