prog8/examples/cx16/zsound/play-zsm.p8
2022-06-11 03:31:42 +02:00

73 lines
2.9 KiB
Lua

%import textio
%import cx16diskio
%zeropage basicsafe
%zpreserved $22,$28 ; zsound lib uses this region
;; Proof Of Concept ZSM player using a binary blob version of zsound library by ZeroByte relocated to something usable here.
; "issues":
; - prog8 (or rather, 64tass) cannot "link" other assembly object files so we have to incbin a binary blob.
; - zsound player ZP usage is only known after compilation of zsound lib. And then this has to be blocked off in the prog8 program.
; - zsound lib BSS section has to be expanded into real zeros as part of the included binary.
; - zsound binary starts with 2 byte prg header that shifts the jump table 2 bytes (not a big issue but a bit untidy)
; - prog8 always sticks main module at the beginning so can't create a container module to stick zsound in (if you want to load it at the beginning)
; - prog8 always has some bootstrap code after the basic launcher so we can only start loading stuff after that
; - prog8 main has to be set to a fixed address (in this case $0830) to which the special zsound binary has been compiled as well.
main $0830 {
zsound_lib:
; this has to be the first statement to make sure it loads at the specified module address $0830
%asmbinary "zsmplayer-0830.bin"
; note: jump table is offset by 2 from the load address (because of prg header)
romsub $0832 = zsm_init() clobbers(A)
romsub $0835 = zsm_play() clobbers(A, X, Y)
romsub $0838 = zsm_playIRQ() clobbers(A, X, Y)
romsub $083b = zsm_start(ubyte bank @A, uword song_address @XY) clobbers(A, X, Y) -> ubyte @Pc
romsub $083e = zsm_stop()
romsub $0841 = zsm_setspeed(uword hz @XY) clobbers(A, X, Y)
romsub $0844 = zsm_setloop(ubyte count @A)
romsub $0847 = zsm_forceloop(ubyte count @A)
romsub $084a = zsm_noloop()
romsub $084d = zsm_setcallback(uword address @XY)
romsub $0850 = zsm_clearcallback() clobbers(A)
romsub $0853 = zsm_get_music_speed() clobbers(A) -> uword @XY
const ubyte song_bank = 4
const uword song_address = $a000
sub start() {
txt.print("zsound demo program!\n")
if not cx16diskio.load_raw(8, "colony.zsm", song_bank, song_address) {
txt.print("?can't load song\n")
return
}
cx16.rambank(song_bank)
zsm_init()
zsm_setcallback(&end_of_song_cb)
if zsm_start(song_bank, song_address)==0 {
txt.print("music speed: ")
txt.print_uw(zsm_get_music_speed())
txt.print(" hz\nplaying song! hit enter to stop.\n")
; for IRQ based playback instead: cx16.set_irq(&zsm_playIRQ, true)
while cx16.joystick_get2(0)==$ffff {
sys.waitvsync()
zsm_play()
}
zsm_stop()
} else {
txt.print("?song start error\n")
}
}
sub end_of_song_cb() {
txt.print("end of song!\n")
}
}