open-story-teller/story-editor/scripts/media.asm
2023-05-24 18:06:38 +02:00

49 lines
1.2 KiB
NASM

; Generic media choice manager
.media:
; Les adresses des différents medias sont dans la stack
; Arguments:
; r0: address d'une structure de type "media choice"
; Local:
; t0: loop counter
; t1: increment 1
; t2: increment 4
; t3: current media address
; t4: where to jump when OK button is pressed
.media_loop_start:
load t0, @r0, 4 ; Le premier élément est le nombre de choix possibles, t0 = 3 (exemple)
lcons t1, 1
lcons t2, 4
mov t3, r0
.media_loop:
add t3, t2 ; @++
; --------- We call a media transition node
push r0 ; save r0
load r0, @t3, 4 ; r0 = content in ram at address in T4
call r0 ; call subroutine
; Return argument in R0: the address of the node to call whe OK is pressed
; save it in t4
mov t4, r0
pop r0
; wait for event (OK or wheel)
syscall 2
; Event is stored in R0
; ----- Test if event is OK button
lcons r1, 1 ; mask for OK button
and r1, r0 ; r1 = r1 AND r0
skipz r1 ; not OK, skip jump
jumpr t4 ; we do not plan to return here, so a jump is enough
; all other events mean: next node
sub t0, t1 ; i--
skipnz t0 ; if (r0) goto start_loop;
jump .media_loop_start
jump .media_loop