REM > Layers.QTM.Source
REM > © Chris Rutter, 1996

ON ERROR OSCLI("Error "+REPORT$+" at line "+STR$(ERL))
DIM code% 32*1024

FOR pass%=4 TO 6 STEP 2
O%=code%
P%=0
[ Opt     pass%
  Equs    "QTML"
  Equd    007
  Equd    title
  Equd    author
  Equd    127
  Equd    recognise_filetypes
  Equd    title ;QTMPlayer will automatically load and kill our module

.jump_table
  LdmFd   r13!,{Pc} ;no start code
  LdmFd   r13!,{Pc} ;no initialise code
  B       finalise
  Equd    0 ;search through list of filetypes
  B       examine
  Equd    0 ;reserve OS_File,5 filesize amount of memory
  B       play_sample
  B       sound_quality
  B       tss
  B       sample_length
  B       current_position
  B       last_position
  B       set_position
  B       song_author
  B       song_name
  B       song_duration
  B       play_file
  B       pause
  B       restart
  B       stop
  B       set_volume
  B       read_volume
  B       read_sample_name

.title
  FNstring("QTMTracker")
.author
  FNstring("Stephen Harrison")
.finalise
  Swi     "XQTM_Clear"
  LdmFd   r13!,{Pc}
.recognise_filetypes
  Equd    &cb6
  Equd    &cc5
  Equd    &001
  Equd    -1
.examine ;called when the Tracker layer claims filetype 0xcb6
  Mov     r0,#1 ;r1=file handle already
  Mov     r2,#0
  Swi     "XOS_Args" ;set file position pointer to zero
  LdmVsFd r13!,{Pc}
  Mov     r0,#4
  Mov     r2,r12 ;r12=workspace address (256 bytes long)
  Mov     r3,#4 ;read in one word
  Swi     "XOS_GBPB"
  LdmVsFd r13!,{Pc}
  Ldr     r0,[r12] ;load in the word we read
  Ldr     r1,musx
  Teq     r0,r1
  MovNe   r0,#1
  MovEq   r0,#0 ;if the file starts with anything apart from "MUSX
  LdmFd   r13!,{Pc} ;assume it's ours
.musx
  Equs    "MUSX"
.play_sample
  Mov     r3,r2 ;volume
  Mov     r2,r1 ;note
  Mov     r1,r0 ;sample
  Mov     r0,#1 ;channel
  Swi     "XQTM_PlaySample"
  FNend
.sound_quality
  Swi     "XQTM_SetSampleSpeed"
  FNend
.tss
  Teq     r0,#1
  BEq     tss_on
.tss_off
  Mvn     r0,#0
  Mov     r1,#0
  Mvn     r2,#0
  Swi     "XQTM_SoundControl"
  FNend
.tss_on
  Mvn     r0,#0
  Mov     r1,#1
  Mvn     r2,#0
  Swi     "XQTM_SoundControl"
  FNend
.sample_length
  Swi     "XQTM_ReadSampleTable"
  Mov     r0,r1
  FNend
.current_position
  Mvn     r0,#0
  Mvn     r1,#0
  Swi     "XQTM_Pos"
  MovVs   r0,#0
  FNend
.last_position
  Swi     "XQTM_ReadSongLength"
  MovVs   r0,#0
  FNend
.set_position
  Swi     "XQTM_Pos"
  FNend
.song_author
  Swi     "XQTM_Info"
  MovVc   r0,r1
  FNend
.song_name
  Swi     "XQTM_Info"
  FNend
.song_duration
  Swi     "XQTM_ReadPlayingTime"
  MovVc   r0,r2
  FNend
.play_file
  Teq     r3,#0 ;WORK-AROUND for QTMTracker bug
  AdrEq   r0,error_zerolength
  LdmEqFd r13!,{r14}
  OrrEqS  Pc,r14,#1<<28
  Mov     r2,#0
  Mov     r3,#0
  Swi     "XQTM_Load"
  SwiVc   "XQTM_Start"
  MvnVc   r0,#0
  FNend
.pause
  Swi     "XQTM_Pause"
  FNend
.restart
  Swi     "XQTM_Start"
  FNend
.stop
  Swi     "XQTM_Stop"
  FNend
.set_volume
  Swi     "XQTM_Volume"
  FNend
.read_volume
  Mvn     r0,#0
  Swi     "XQTM_Volume"
  FNend
.read_sample_name
  Swi     "XQTM_ReadSampleTable"
  FNend

.error_zerolength
  Equd    0
  Equs    "QTMTracker will crash if asked to load a zero-length file, so QTMPlayer has a work-around for this"+CHR$0
  Align
]
NEXT pass%

SYS "OS_File",10,"<Obey$Dir>.Code",&FFD,,code%,O%
END

DEF FNstring(string$)
[ Opt     pass%
  Equs    string$
  Equb    0
  Align
]
=pass%

DEF FNend
[ Opt     pass%
  LdmFd   r13!,{Pc}
]
=pass%