4cade/src/ui.animation.a

;License:MIT
;(c) 2018-9 by 4am
;
; functions for animated title screens
;
; Public functions:
; - MaybeAnimateTitle
;

         ; /!\ execution falls through from ui.search.mode/FindMatchingTitle
;------------------------------------------------------------------------------
; MaybeAnimateTitle
; slow down to 1 Mhz (always), then check if there is an animation for the
; title screenshot we just displayed, and if so, load it and call it
;
; in:    none
; out:   C clear
;        all other flags clobbered
;        all registers clobbered
;------------------------------------------------------------------------------
MaybeAnimateTitle
         jsr   SwitchToBank2
         jsr   DisableAcceleratorAndSwitchToBank1

         lda   #$3F
         ldy   OffscreenPage
         bne   +
         eor   #$60
+        sta   SAVE+1
         and   #$60
         sta   @a+2
         eor   #$60
         sta   @b+2
         lda   #$FD
         sta   SAVE
         ldy   #0
         lda   (SAVE),y              ; see if there is a hidden JMP to an
         cmp   #$4C                  ; animation routine for this screen
                                     ; at +$1FFD (after the graphics data,
                                     ; in the last 3 bytes of a $2000 byte
                                     ; file -- this area part of a 'screen
                                     ; hole' and is not displayed on screen)
         bne   @exit                 ; if not, we're done here

         ; copy one HGR screen to the other
         ldx   #$20
@a       lda   $FD00,y               ; SMC
@b       sta   $FD00,y               ; SMC
         iny
         bne   @a
         inc   @a+2
         inc   @b+2
         dex
         bne   @a

         ; load the animation routine, which is stored in a subdirectory by filename
         jsr   GetGameToLaunch
         +STAY +
         jsr   LoadFile
         !word kAnimatedTitleDirectory
+        !word $FDFD
         !word 0

         ldx   #5                    ; copy prelaunch code
-        lda   @titleAnimPrelaunch,x
         sta   $106,x
         dex
         bpl   -

         jsr   Launch                ; execute the animation

         jsr   ResyncPage            ; we don't know which HGR page is showing
                                     ; when the animation returns, so resync
                                     ; the current one with our OffscreenPage
                                     ; variable

@exit    clc                         ; tell caller not to refresh screen
         rts

@titleAnimPrelaunch                  ; this is executed from $106/main by |Launch|
         bit   $C082
         jmp   (SAVE)