require'vcs'
mappers['2K']()

local AUDC0s = 0x90
local AUDC1s, AUDF0s, AUDF1s, AUDV0s, AUDV1s = AUDC0s+1, AUDC0s+2, AUDC0s+3, AUDC0s+4, AUDC0s+5
local vubars = 0xA0
local tmp = 0xF0

local zic_filename = 'Ishtar.ttt'
local zic = ttt(zic_filename)
print(string.format('Using file %s (ttt version %d)\n  Name:   %s\n  Author: %s\n%s', zic_filename, zic.version, zic.name, zic.author, zic.comment))

-- debug printing of zic data
--[[
local printbytetable = function(v)
    local s = '  '
    for kk,vv in ipairs(v) do
        s = s .. string.format('%02x, ', vv)
        if #s >= 34 then print(s) s = '  ' end
    end
    if #s > 0 then print(s) end
end
for k,v in pairs(zic) do
    if type(v) ~= 'table' then
        print(k,v)
    elseif type(v[1]) == 'number' then
        print(k) printbytetable(v)
    elseif type(v[1]) == 'table' then
        for ek, e in ipairs(v) do
            print(k, ek, e.name) printbytetable(e)
        end
    end
end
]]

@@tt_InsCtrlTable byte(zic.insctrltable)
@@tt_InsADIndexes byte(zic.insadindexes)
@@tt_InsSustainIndexes byte(zic.inssustainindexes)
@@tt_InsReleaseIndexes byte(zic.insreleaseindexes)
@@tt_InsFreqVolTable byte(zic.insfreqvoltable)
@@tt_PercIndexes byte(zic.percindexes)
@@tt_PercFreqTable byte(zic.percfreqtable)
@@tt_PercCtrlVolTable byte(zic.percctrlvoltable)
local patterns = {}
for i,pattern in ipairs(zic.patterns) do
    table.insert(patterns, section("pattern"..i)) byte(pattern)
end
@@tt_PatternSpeeds byte(zic.patternspeeds)
@@tt_PatternPtrLo byte_lo(patterns)
@@tt_PatternPtrHi byte_hi(patterns)
@@tt_SequenceTable byte(zic.sequence[1]) byte(zic.sequence[2])

local tt = {
-- =====================================================================
-- Permanent variables. These are states needed by the player.
-- =====================================================================
    'timer',              -- current music timer value
    'cur_pat_index_c0',   -- current pattern index into tt_SequenceTable
    'cur_pat_index_c1',
    'cur_note_index_c0',  -- note index into current pattern
    'cur_note_index_c1',
    'envelope_index_c0',  -- index into ADSR envelope
    'envelope_index_c1',
    'cur_ins_c0',         -- current instrument
    'cur_ins_c1',
-- =====================================================================
-- Temporary variables. These will be overwritten during a call to the
-- player routine, but can be used between calls for other things.
-- =====================================================================
    'ptr', -- 2 bytes
}
for k,v in ipairs(tt) do tt[v] = k + 0x7F end

tt.FREQ_MASK    = 0b00011111
tt.INS_HOLD     = 8
tt.INS_PAUSE    = 16
tt.FIRST_PERC   = 17

tt.fetchCurrentNoteImpl = function()
@_constructPatPtr
        ldy tt.cur_pat_index_c0,x lda tt_SequenceTable,y
    if zic.usegoto then
        bpl _noPatternGoto
       ;and #0b01111111 sta tt.cur_pat_index_c0,x bpl _constructPatPtr
@_noPatternGoto
    end
        tay lda tt_PatternPtrLo,y sta tt.ptr lda tt_PatternPtrHi,y sta tt.ptr+1
    if zic.overlay then
        clv
        lda tt.cur_note_index_c0,x bpl _notPrefetched
       ;and #0b01111111 sta tt.cur_note_index_c0,x
        bit tt_Bit6Set
@_notPrefetched
        tay
    else
        ldy tt.cur_note_index_c0,x
    end
        lda (tt.ptr),y bne _noEndOfPattern
        sta tt.cur_note_index_c0,x
        inc tt.cur_pat_index_c0,x
        bne _constructPatPtr
@_noEndOfPattern
end
if zic.useoverlay then
    @@tt_fetchCurrentNoteSection tt.fetchCurrentNoteImpl() rts
    tt.fetchCurrentNote = function() jsr tt_fetchCurrentNoteSection end
else
    tt.fetchCurrentNote = tt.fetchCurrentNoteImpl
end

@@tt_CalcInsIndex
        lsr lsr lsr lsr lsr
        tay
@tt_Bit6Set
        rts

local function zic_tick()
        dec tt.timer bpl _noNewNote
        ldx #1
@_advanceLoop
        tt.fetchCurrentNote()
        cmp #tt.INS_PAUSE
    if zic.useslide then
        beq _pause
        bcs _newNote
        adc tt.cur_ins_c0,x sec sbc #8 sta tt.cur_ins_c0,x
        bcs _finishedNewNote
    else
        bcc _finishedNewNote	
        bne _newNote
    end
@_pause
        lda tt.cur_ins_c0,x jsr tt_CalcInsIndex
        lda tt_InsReleaseIndexes-1,y
        clc adc #1 bcc _storeADIndex
@_newNote
        sta tt.cur_ins_c0,x
        cmp #tt.FREQ_MASK+1 bcs _startInstrument
        tay
        lda tt_PercIndexes-tt.FIRST_PERC,y
        bne _storeADIndex
@_startInstrument
    if zic.useoverlay then
        bvs _finishedNewNote
    end
        jsr tt_CalcInsIndex
        lda tt_InsADIndexes-1,y
@_storeADIndex
        sta tt.envelope_index_c0,x      
@_finishedNewNote
        inc tt.cur_note_index_c0,x
@_sequencerNextChannel
        dex
        bpl _advanceLoop
    if zic.globalspeed then
        ldx #zic.speed-1
      if zic.usefunktempo then
        lda tt.cur_note_index_c0 lsr bcc _noOddFrame ldx #zic.oddspeed-1 @_noOddFrame
      end
        stx tt.timer
    else
        ldx tt.cur_pat_index_c0 ldy tt_SequenceTable,x
      if zic.usefunktempo then
        lda tt.cur_note_index_c0 lsr
        lda tt_PatternSpeeds,y
        bcc _evenFrame
       ;and #0x0f
        bcs _storeFunkTempo        
@_evenFrame
        lsr lsr lsr lsr
@_storeFunkTempo
        sta tt.timer
      else
        lda tt_PatternSpeeds,y sta tt.timer
      end
    end
@_noNewNote
        ldx #1
@_updateLoop
        lda tt.cur_ins_c0,x
    if not zic.startswithnotes then
        beq _afterAudioUpdate
    end
        cmp #tt.FREQ_MASK+1 bcs _instrument
        ldy tt.envelope_index_c0,x
        lda tt_PercCtrlVolTable-1,y beq _endOfPercussion inc tt.envelope_index_c0,x @_endOfPercussion
        sta AUDV0,x lsr lsr lsr lsr sta AUDC0,x
        lda tt_PercFreqTable-1,y
        sta AUDF0,x
        sta AUDF0s,x -- EXTRA for vumeter rendering
    if zic.useoverlay then
        bpl _afterAudioUpdate
        tt.fetchCurrentNote()
        cmp #tt.FREQ_MASK+1
        bcc _afterAudioUpdate
        sta tt.cur_ins_c0,x
        jsr tt_CalcInsIndex
        lda tt_InsSustainIndexes-1,y sta tt.envelope_index_c0,x      
        asl tt.cur_note_index_c0,x sec ror tt.cur_note_index_c0,x
        bmi _afterAudioUpdate
    else  
        jmp _afterAudioUpdate
    end
@_instrument
        jsr tt_CalcInsIndex
        lda tt_InsCtrlTable-1,y sta AUDC0,x
        sta AUDC0s,x -- EXTRA for vumeter rendering
        lda tt.envelope_index_c0,x cmp tt_InsReleaseIndexes-1,y bne _noEndOfSustain lda tt_InsSustainIndexes-1,y @_noEndOfSustain
        tay
        lda tt_InsFreqVolTable,y beq _endOfEnvelope iny @_endOfEnvelope
        sty tt.envelope_index_c0,x
        sta AUDV0,x
        sta AUDV0s,x -- EXTRA for vumeter rendering
        lsr lsr lsr lsr clc adc tt.cur_ins_c0,x sec sbc #8
        sta AUDF0,x
        sta AUDF0s,x -- EXTRA for vumeter rendering
@_afterAudioUpdate
        dex
        bpl _updateLoop
end

local function zic_init()
    if zic.c0init ~= 0 then lda#zic.c0init sta tt.cur_pat_index_c0 end
    if zic.c1init ~= 0 then lda#zic.c1init sta tt.cur_pat_index_c1 end
end


----------------------------------------------------------------------
-- equalizer anim
----------------------------------------------------------------------

-- convert to freq: http://atariage.com/forums/topic/257526-musicsound-programming-question-atari-2600/
-- maps AUDCi to 0-7 3 bits (<<5) value for wave length of: 1, 2, 6, 15, 31, 93, 465, 511
@@wavlen samepage
dc.b 0x00,0x60,0xC0,0xC0,0x20,0x20,0x80,0x80,
     0xF0,0x80,0x80,0x00,0x40,0x40,0xA0,0xA0
end
local wavelen_map = { 1, 2, 6, 15, 31, 93, 465, 511 }
local freq_ranges = { 30, 60, 120, 240, 480, 960, 1920, 9999999 }
local t = {}
for i=0,255 do
    local wavelen = wavelen_map[(i>>5)+1]
    local note = (i&31)+1
    local freq = 3546894 / 114 / wavelen / note
    for x=1,9 do
        if freq <= freq_ranges[x] then
            t[#t+1] = x-1
            break
        end
    end
end
section{'regfreq', align=256} byte(t)
@@vm_pf2 samepage
dc.b 0x00,0x80,0xC0,0xE0,0xF0,0xF8,0xFC,0xFE,
     0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF
end
@@vm_pf1 samepage
dc.b 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
     0x00,0x01,0x03,0x07,0x0F,0x1F,0x3F,0x7F
end
@@vm_col samepage
dc.b 0x3C,0x7C,0x9C,0xDC,0x2C,0x4C,0x6C,0xAC
end
local vumeter_tick = function()
    lda #0 ldy #15 @_vudec ldx vubars,y dex bmi _vudecskip stx vubars,y @_vudecskip dey bpl _vudec
    lda AUDF0s ldy AUDC0s ora wavlen,y tax ldy regfreq,x
    lda AUDV0s cmp vubars,y bmi _vuless0 sta vubars,y @_vuless0
    lda AUDF1s ldy AUDC1s ora wavlen,y tax ldy regfreq,x
    lda AUDV1s cmp vubars+8,y bmi _vuless1 sta vubars+8,y @_vuless1
end
local vumeter_draw = function()
    lda #ctrlpf.PF_MIRRORED sta CTRLPF
    ldy #7
@_vudraw
    samepage
        lda #21 sta tmp
@_vudraw1
        sta WSYNC
        lda vm_col,y sta COLUPF sleep(4)
        ldx vubars,y
        lda vm_pf1,x sta PF1
        lda vm_pf2,x sta PF2
        sleep(8)
        ldx vubars+8,y
        lda vm_pf2,x sta PF2
        lda vm_pf1,x sta PF1
        dec tmp bpl _vudraw1
        sta WSYNC lda #0 sta PF2 sta PF1
        sta WSYNC
        dey bpl _vudraw
    end
    lda #0 sta CTRLPF
    sta WSYNC sta WSYNC
end

local tick = function()
    zic_tick()
    vumeter_tick()
end

@@main
    init()
    zic_init()
@_frame
    overscan() vblank(tick) screen(vumeter_draw) jmp _frame

; -- needed if last instruction is implied
writebin(filename..'.bin')
writesym(filename..'.sym')
print(stats)