hud and menu housekeeping

2022-10-01 02:22:20 -05:00
parent 2d60b9654e
commit 55ed3943fd
4 changed files with 174 additions and 264 deletions
--- a/Menu/menu_scroll.asm
+++ b/Menu/menu_scroll.asm
@@ -0,0 +1,57 @@
+; -----------------------------------------------------------------------------
+
+Menu_CheckHScroll:
+{
+  LDA.b $F4
+  BIT.b #$10 : BNE .leave_menu
+  LDA.b $F6
+  BIT.b #$20 : BNE .left
+  BIT.b #$10 : BNE .right
+
+  RTS
+
+.left
+  REP #$20
+  LDA.w #$FFF8
+  BRA .merge
+
+.right
+  REP #$20
+  LDA.w #$0008
+
+.merge 
+  STA.w MenuScrollHDirection
+
+  SEP #$30
+  INC.w $0200
+  LDA.b #$06 : STA.w $012F
+  RTS
+
+.leave_menu
+  LDA.b #$08
+  STA.w $0200
+  RTS
+}
+
+; -----------------------------------------------------------------------------
+
+Menu_ScrollHorizontal:
+{
+  REP #$21                    ; set A to 16 bit, clear carry flag
+
+  LDA.w $E4                   ; BG3 Horizontal Scroll Value
+  ADC.w MenuScrollHDirection  ; Direction set by Menu_CheckHScroll
+  AND.w #$01FF                
+  STA.b $E4   
+  AND.w #$00FF
+  BNE .loop
+
+  SEC
+  RTS
+
+.loop
+  CLC 
+  RTS
+}
+
+; -----------------------------------------------------------------------------