%import textio
%import syslib
%import psg

main {

    sub start() {

        txt.print("will play the music from boulderdash,\nmade in 1984 by peter liepa.\npress enter to start: ")
        void c64.CHRIN()
        txt.clear_screen()

        psg.voice(0, psg.LEFT, 63, psg.TRIANGLE, 0)
        psg.voice(1, psg.RIGHT, 63, psg.TRIANGLE, 0)
        cx16.set_irq(&psg.envelopes_irq, false)

        repeat {
            uword note
            for note in notes {
                ubyte note0 = lsb(note)
                ubyte note1 = msb(note)
                psg.freq(0, vera_freqs[note0])
                psg.freq(1, vera_freqs[note1])
                psg.envelope(0, 255, 6)
                psg.envelope(1, 255, 6)
                print_notes(note0, note1)
                sys.wait(10)
            }
        }

        psg.silent()
    }

    sub print_notes(ubyte n1, ubyte n2) {
        txt.nl()
        txt.plot(n1, txt.DEFAULT_HEIGHT-1)
        txt.color(7)
        txt.chrout('Q')
        txt.plot(n2, txt.DEFAULT_HEIGHT-1)
        txt.color(4)
        txt.chrout('Q')
    }


    ; details about the boulderdash music can be found here:
    ; https://www.elmerproductions.com/sp/peterb/sounds.html#Theme%20tune

    uword[] notes = [
        $1622, $1d26, $2229, $252e, $1424, $1f27, $2029, $2730,
        $122a, $122c, $1e2e, $1231, $202c, $3337, $212d, $3135,
        $1622, $162e, $161d, $1624, $1420, $1430, $1424, $1420,
        $1622, $162e, $161d, $1624, $1e2a, $1e3a, $1e2e, $1e2a,
        $142c, $142c, $141b, $1422, $1c28, $1c38, $1c2c, $1c28,
        $111d, $292d, $111f, $292e, $0f27, $0f27, $1633, $1627,
        $162e, $162e, $162e, $162e, $222e, $222e, $162e, $162e,
        $142e, $142e, $142e, $142e, $202e, $202e, $142e, $142e,
        $162e, $322e, $162e, $332e, $222e, $322e, $162e, $332e,
        $142e, $322e, $142e, $332e, $202c, $302c, $142c, $312c,
        $162e, $163a, $162e, $3538, $222e, $2237, $162e, $3135,
        $142c, $1438, $142c, $1438, $202c, $2033, $142c, $1438,
        $162e, $322e, $162e, $332e, $222e, $322e, $162e, $332e,
        $142e, $322e, $142e, $332e, $202c, $302c, $142c, $312c,
        $2e32, $292e, $2629, $2226, $2c30, $272c, $2427, $1420,
        $3532, $322e, $2e29, $2926, $2730, $242c, $2027, $1420
    ]

    uword[] vera_freqs = [
        0,0,0,0,0,0,0,0,0,0,   ; first 10 notes are not used
        120, 127, 135, 143, 152, 160, 170, 180, 191, 203,
        215, 227, 240, 255, 270, 287, 304, 320, 341, 360,
        383, 405, 429, 455, 479, 509, 541, 573, 607, 640,
        682, 720, 766, 810, 859, 910, 958, 1019, 1082, 1147,
        1215, 1280, 1364, 1440, 1532, 1621, 1718, 1820, 1917]

}