1068 lines
32 KiB
JavaScript
1068 lines
32 KiB
JavaScript
var xm; // contains all song data
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var audioctx; // AudioContext
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// Load font (ripped from FastTracker 2)
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var fontimg = new Image();
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fontimg.src = "ft2font.png";
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// canvas to render patterns onto
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var pat_canvas = document.createElement('canvas');
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//
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var _note_names = ["C-", "C#", "D-", "D#", "E-", "F-", "F#", "G-", "G#", "A-", "A#", "B-"];
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var f_smp = 44100; // updated by play callback, default value here
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var _fontmap_notes = [8*5, 8*22, 8*28];
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var _pattern_cellwidth = 16 + 4 + 8 + 4 + 8 + 16 + 4;
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var _scope_width = _pattern_cellwidth - 1;
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var _pattern_border = 20;
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var pat_canvas_patnum;
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function RenderPattern(canv, pattern) {
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// a pattern consists of NxM cells which look like
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// N-O II VV EFF
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var cellwidth = _pattern_cellwidth;
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canv.width = pattern[0].length * cellwidth + _pattern_border;
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canv.height = pattern.length * 8;
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var ctx = canv.getContext('2d');
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ctx.fillcolor='#000';
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ctx.fillRect(0, 0, canv.width, canv.height);
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for (var j = 0; j < pattern.length; j++) {
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var row = pattern[j];
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var dy = j * 8;
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// render row number
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ctx.drawImage(fontimg, 8*(j>>4), 0, 8, 8, 2, dy, 8, 8);
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ctx.drawImage(fontimg, 8*(j&15), 0, 8, 8, 10, dy, 8, 8);
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for (var i = 0; i < row.length; i++) {
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var dx = i*cellwidth + 2 + _pattern_border;
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var data = row[i];
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// render note
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var note = data[0];
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if (note < 0) {
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ctx.drawImage(fontimg, 0, 8*5, 16, 8, dx, dy, 16, 8);
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} else {
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var octave = (note/12)|0;
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var note_fontrow = _fontmap_notes[(octave/3)|0];
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note = (note % (12*3))|0;
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ctx.drawImage(fontimg, 16+16*note, note_fontrow, 16, 8, dx, dy, 16, 8);
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}
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dx += 20;
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// render instrument
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var inst = data[1];
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if (inst != -1) { // no instrument = render nothing
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if (inst > 15) {
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ctx.drawImage(fontimg, 8*(inst>>4), 4*8, 4, 8, dx, dy, 4, 8);
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}
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ctx.drawImage(fontimg, 8*(inst&15), 4*8, 4, 8, dx+4, dy, 4, 8);
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}
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dx += 12;
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// render volume
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var vol = data[2];
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if (vol < 0x10) {
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ctx.drawImage(fontimg, 312, 0, 8, 8, dx, dy, 8, 8);
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} else {
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ctx.drawImage(fontimg, 8*(vol>>4) + 56*8, 4*8, 8, 8, dx, dy, 8, 8);
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ctx.drawImage(fontimg, 8*(vol&15), 4*8, 4, 8, dx+4, dy, 4, 8);
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}
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dx += 8;
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// render effect
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var eff = data[3];
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var effdata = data[4];
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ctx.drawImage(fontimg, 8*eff + 16*8, 4*8, 8, 8, dx, dy, 8, 8);
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dx += 8;
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ctx.drawImage(fontimg, 8*(effdata>>4), 4*8, 4, 8, dx, dy, 4, 8);
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ctx.drawImage(fontimg, 8*(effdata&15), 4*8, 4, 8, dx+4, dy, 4, 8);
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}
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}
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}
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function prettify_note(note) {
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if (note < 0) return "---";
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if (note == 96) return "^^^";
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return _note_names[note%12] + ~~(note/12);
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}
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function prettify_number(num) {
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if (num == -1) return "--";
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if (num < 10) return "0" + num;
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return num;
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}
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function prettify_volume(num) {
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if (num < 0x10) return "--";
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return num.toString(16);
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}
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function prettify_effect(t, p) {
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if (t >= 10) t = String.fromCharCode(55 + t);
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if (p < 16) p = '0' + p.toString(16);
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else p = p.toString(16);
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return t + p
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}
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function prettify_notedata(data) {
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return (prettify_note(data[0]) + " " + prettify_number(data[1]) + " "
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+ prettify_volume(data[2]) + " "
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+ prettify_effect(data[3], data[4]));
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}
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function getstring(dv, offset, len) {
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var str = [];
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for (var i = offset; i < offset+len; i++) {
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var c = dv.getUint8(i);
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if (c == 0) break;
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str.push(String.fromCharCode(c));
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}
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return str.join('');
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}
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// Return 2-pole Butterworth lowpass filter coefficients for
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// center frequncy f_c (relative to sampling frequency)
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function FilterCoeffs(f_c) {
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if (f_c > 0.5) { // we can't lowpass above the nyquist frequency...
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f_c = 0.5;
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}
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var wct = Math.sqrt(2) * Math.PI * f_c;
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var e = Math.exp(-wct);
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var c = e * Math.cos(wct);
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var s = e * Math.sin(wct);
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var gain = (1 - 2*c + c*c + s*s) / 2;
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return [gain, 2*c, -c*c - s*s];
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}
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popfilter = FilterCoeffs(200.0 / 44100.0);
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popfilter_alpha = 0.9837;
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function UpdateChannelPeriod(ch, period) {
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var freq = 8363 * Math.pow(2, (1152.0 - period) / 192.0);
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if (isNaN(freq)) {
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console.log("invalid period!", period);
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return;
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}
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ch.doff = freq / f_smp;
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ch.filter = FilterCoeffs(ch.doff / 2);
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}
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function PeriodForNote(ch, note) {
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return 1920 - (note + ch.samp.note)*16 - ch.samp.fine / 8.0;
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}
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var audio_events = [];
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var shown_row = undefined;
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function RedrawScreen() {
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if (audio_events.length == 0) return;
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var e;
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var t = audioctx.currentTime;
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do {
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e = audio_events.shift();
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} while(e.t < t && audio_events.length > 0);
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if (e == undefined) return;
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var VU = e.vu;
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var scopes = e.scopes;
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if (e.scopes != undefined) {
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// update VU meters & oscilliscopes
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var canvas = document.getElementById("vu");
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var ctx = canvas.getContext("2d");
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ctx.fillStyle = '#000';
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ctx.fillRect(0, 0, canvas.width, 64);
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ctx.fillStyle = '#0f0';
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ctx.strokeStyle = '#55acff';
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for (var j = 0; j < xm.nchan; j++) {
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var x = _pattern_border + j * _pattern_cellwidth;
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// render channel number
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if (j >= 10) {
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ctx.drawImage(fontimg, 8*((j/10)|0), 4*8, 4, 8, x, 1, 4, 8);
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}
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ctx.drawImage(fontimg, 8*(j%10), 4*8, 4, 8, x+4, 1, 4, 8);
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// volume in dB as a green bar
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var vu_y = -Math.log(VU[j])*10;
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ctx.fillRect(x, vu_y, 2, 64-vu_y);
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// oscilloscope
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var scope = scopes[j];
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ctx.beginPath();
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for (var k = 0; k < _scope_width; k++) {
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ctx.lineTo(x + 1 + k, 32 - 16 * scope[k]);
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}
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ctx.stroke();
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}
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}
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var debug = document.getElementById("debug");
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debug.innerHTML = xm.songname + '<br>pat ' + e.pat + ' row ' + (e.row);
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if (e.row != shown_row) {
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var gfx = document.getElementById("gfxpattern");
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if (e.pat != pat_canvas_patnum) {
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var p = xm.patterns[e.pat];
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if (p != undefined) {
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RenderPattern(pat_canvas, xm.patterns[e.pat]);
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pat_canvas_patnum = e.pat;
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}
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}
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var ctx = gfx.getContext('2d');
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ctx.fillStyle = '#000';
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ctx.fillRect(0, 0, gfx.width, gfx.height);
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ctx.fillStyle = '#2a5684';
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ctx.fillRect(0, gfx.height/2 - 4, gfx.width, 8);
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ctx.globalCompositeOperation = 'lighten';
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ctx.drawImage(pat_canvas, 0, gfx.height / 2 - 4 - 8*(e.row));
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ctx.globalCompositeOperation = 'source-over';
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shown_row = e.row;
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}
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if (audio_events.length > 0) {
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var next_event = audio_events[0].t;
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setTimeout(RedrawScreen, 1000*(next_event - audioctx.currentTime));
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}
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}
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var cur_songpos = -1, cur_pat = -1, cur_row = 64, cur_ticksamp = 0;
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var cur_tick = 6;
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function next_row() {
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if (cur_pat == -1 || cur_row >= xm.patterns[cur_pat].length) {
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cur_row = 0;
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cur_songpos++;
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if (cur_songpos >= xm.songpats.length)
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cur_songpos = xm.song_looppos;
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cur_pat = xm.songpats[cur_songpos];
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}
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var p = xm.patterns[cur_pat];
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var r = p[cur_row];
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cur_row++;
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for (var i = 0; i < r.length; i++) {
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var ch = xm.channelinfo[i];
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var inst = ch.inst;
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var triggernote = false;
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// instrument trigger
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if (r[i][1] != -1) {
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inst = xm.instruments[r[i][1] - 1];
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if (inst && inst.samplemap) {
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ch.inst = inst;
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// retrigger unless overridden below
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triggernote = true;
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if (ch.note && inst.samplemap) {
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ch.samp = inst.samples[inst.samplemap[ch.note]];
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ch.vol = ch.samp.vol;
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ch.pan = ch.samp.pan;
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}
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} else {
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// console.log("invalid inst", r[i][1], instruments.length);
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}
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}
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// note trigger
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if (r[i][0] != -1) {
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if (r[i][0] == 96) {
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ch.release = 1;
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triggernote = false;
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} else {
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if (inst && inst.samplemap) {
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var note = r[i][0];
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ch.note = note;
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ch.samp = inst.samples[inst.samplemap[ch.note]];
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if (triggernote) {
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// if we were already triggering the note, reset vol/pan using
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// (potentially) new sample
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ch.pan = ch.samp.pan;
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ch.vol = ch.samp.vol;
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}
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triggernote = true;
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}
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}
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}
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ch.voleffectfn = undefined;
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if (r[i][2] != -1) { // volume column
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var v = r[i][2];
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ch.voleffectdata = v & 0x0f;
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if (v < 0x10) {
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console.log("channel", i, "invalid volume", v.toString(16));
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} else if (v <= 0x50) {
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ch.vol = v - 0x10;
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} else if (v >= 0x60 && v < 0x70) { // volume slide down
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ch.voleffectfn = function(ch) {
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ch.vol = Math.max(0, ch.vol - ch.voleffectdata);
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}
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} else if (v >= 0x70 && v < 0x80) { // volume slide up
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ch.voleffectfn = function(ch) {
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ch.vol = Math.min(64, ch.vol + ch.voleffectdata);
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}
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} else if (v >= 0x80 && v < 0x90) { // fine volume slide down
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ch.vol = Math.max(0, ch.vol - (v & 0x0f));
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} else if (v >= 0x90 && v < 0xa0) { // fine volume slide up
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ch.vol = Math.min(64, ch.vol + (v & 0x0f));
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} else if (v >= 0xc0 && v < 0xd0) { // set panning
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ch.pan = (v & 0x0f) * 0x11;
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} else {
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console.log("channel", i, "volume effect", v.toString(16));
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}
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}
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ch.effect = r[i][3];
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ch.effectdata = r[i][4];
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if (ch.effect < 36) {
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ch.effectfn = effects_t1[ch.effect];
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var eff_t0 = effects_t0[ch.effect];
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if (eff_t0 && eff_t0(ch, ch.effectdata)) {
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triggernote = false;
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}
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} else {
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console.log("channel", i, "effect > 36", ch.effect);
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}
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// special handling for portamentos: don't trigger the note
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if (ch.effect == 3 || ch.effect == 5) {
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if (r[i][0] != -1) {
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ch.periodtarget = PeriodForNote(ch, ch.note);
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}
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triggernote = false;
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if (inst && inst.samplemap) {
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if (ch.env_vol == undefined) {
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// note wasn't already playing; we basically have to ignore the
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// portamento and just trigger
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triggernote = true;
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} else if (ch.release) {
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// reset envelopes if note was released but leave offset/pitch/etc
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// alone
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ch.envtick = 0;
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ch.release = 0;
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ch.env_vol = new EnvelopeFollower(inst.env_vol);
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ch.env_pan = new EnvelopeFollower(inst.env_pan);
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}
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}
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}
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if (triggernote) {
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ch.off = 0;
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ch.release = 0;
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ch.envtick = 0;
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ch.vibratopos = 0;
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ch.env_vol = new EnvelopeFollower(inst.env_vol);
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ch.env_pan = new EnvelopeFollower(inst.env_pan);
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if (ch.note != undefined) {
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ch.period = PeriodForNote(ch, ch.note);
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}
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}
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}
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}
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function Envelope(points, type, sustain, loopstart, loopend) {
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this.points = points;
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this.type = type;
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this.sustain = sustain;
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this.loopstart = points[loopstart*2];
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this.loopend = points[loopend*2];
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}
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Envelope.prototype.Get = function(ticks) {
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// TODO: optimize follower with ptr
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// or even do binary search here
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var y0;
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var env = this.points;
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for (var i = 0; i < env.length; i += 2) {
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y0 = env[i+1];
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if (ticks < env[i]) {
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var x0 = env[i-2];
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var y0 = env[i-1];
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var dx = env[i] - x0;
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var dy = env[i+1] - y0;
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return y0 + (ticks - x0) * dy / dx;
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}
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}
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return y0;
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}
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function EnvelopeFollower(env) {
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this.env = env;
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this.tick = 0;
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}
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EnvelopeFollower.prototype.Tick = function(release) {
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var value = this.env.Get(this.tick);
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// if we're sustaining a note, stop advancing the tick counter
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if (!release && this.tick >= this.env.points[this.env.sustain*2]) {
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return this.env.points[this.env.sustain*2 + 1];
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}
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this.tick++;
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if (this.env.type & 4) { // envelope loop?
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if (!release &&
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this.tick >= this.env.loopend) {
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this.tick -= this.env.loopend - this.env.loopstart;
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}
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}
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return value;
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}
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function next_tick() {
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cur_tick++;
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if (cur_tick >= xm.tempo) {
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cur_tick = 0;
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next_row();
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}
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for (var j = 0; j < xm.nchan; j++) {
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var ch = xm.channelinfo[j];
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var inst = ch.inst;
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ch.periodoffset = 0;
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if (cur_tick != 0) {
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if(ch.voleffectfn) ch.voleffectfn(ch);
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if(ch.effectfn) ch.effectfn(ch);
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}
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if (isNaN(ch.period)) {
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console.log(prettify_notedata(xm.patterns[cur_pat][cur_row-1][j]),
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"set channel", j, "period to NaN");
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}
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if (inst == undefined) continue;
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if (ch.env_vol == undefined) {
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console.log(prettify_notedata(xm.patterns[cur_pat][cur_row-1][j]),
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"set channel", j, "env_vol to undefined, but note is playing");
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continue;
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}
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ch.volE = ch.env_vol.Tick(ch.release);
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ch.panE = ch.env_pan.Tick(ch.release);
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UpdateChannelPeriod(ch, ch.period + ch.periodoffset);
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}
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}
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// This function gradually brings the channel back down to zero if it isn't
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// already to avoid clicks and pops when samples end.
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function MixSilenceIntoBuf(ch, start, end, dataL, dataR) {
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var s = ch.filterstate[1];
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if (isNaN(s)) {
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console.log("NaN filterstate?", ch.filterstate, ch.filter);
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return;
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}
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for (var i = start; i < end; i++) {
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if (Math.abs(s) < 1.526e-5) { // == 1/65536.0
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s = 0;
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break;
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}
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dataL[i] += s * ch.vL;
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dataR[i] += s * ch.vR;
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s *= popfilter_alpha;
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}
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ch.filterstate[1] = s;
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ch.filterstate[2] = s;
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if (isNaN(s)) {
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console.log("NaN filterstate after adding silence?", ch.filterstate, ch.filter, i);
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return;
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}
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return 0;
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}
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function MixChannelIntoBuf(ch, start, end, dataL, dataR) {
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var inst = ch.inst;
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var instsamp = ch.samp;
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var loop = false;
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var looplen = 0, loopstart = 0;
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// nothing on this channel, just filter the last dc offset back down to zero
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if (instsamp == undefined || inst == undefined || ch.mute) {
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return MixSilenceIntoBuf(ch, start, end, dataL, dataR);
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}
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var samp = instsamp.sampledata;
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var sample_end = instsamp.len;
|
|
if ((instsamp.type & 3) == 1) { // todo: support pingpong
|
|
loop = true;
|
|
loopstart = instsamp.loop;
|
|
looplen = instsamp.looplen;
|
|
sample_end = loopstart + looplen;
|
|
}
|
|
var samplen = instsamp.len;
|
|
var volE = ch.volE / 64.0; // current volume envelope
|
|
var panE = 4*(ch.panE - 32); // current panning envelope
|
|
var p = panE + ch.pan - 128; // final pan
|
|
var volL = volE * (128 - p) * ch.vol / 8192.0;
|
|
var volR = volE * (128 + p) * ch.vol / 8192.0;
|
|
if (volL < 0) volL = 0;
|
|
if (volR < 0) volR = 0;
|
|
if (volR == 0 && volL == 0)
|
|
return;
|
|
if (isNaN(volR) || isNaN(volL)) {
|
|
console.log("NaN volume!?", ch.number, volL, volR, volE, panE, ch.vol);
|
|
return;
|
|
}
|
|
var k = ch.off;
|
|
var dk = ch.doff;
|
|
var Vrms = 0;
|
|
var f0 = ch.filter[0], f1 = ch.filter[1], f2 = ch.filter[2];
|
|
var fs0 = ch.filterstate[0], fs1 = ch.filterstate[1], fs2 = ch.filterstate[2];
|
|
|
|
// we also low-pass filter volume changes with a simple one-zero,
|
|
// one-pole filter to avoid pops and clicks when volume changes.
|
|
var vL = popfilter_alpha * ch.vL + (1 - popfilter_alpha) * (volL + ch.vLprev) * 0.5;
|
|
var vR = popfilter_alpha * ch.vR + (1 - popfilter_alpha) * (volR + ch.vRprev) * 0.5;
|
|
var pf_8 = Math.pow(popfilter_alpha, 8);
|
|
ch.vLprev = volL;
|
|
ch.vRprev = volR;
|
|
|
|
// we can mix up to this many bytes before running into a sample end/loop
|
|
var i = start;
|
|
var failsafe = 100;
|
|
while (i < end) {
|
|
if (failsafe-- == 0) {
|
|
console.log("failsafe in mixing loop!", k, sample_end, loopstart, looplen, dk);
|
|
break;
|
|
}
|
|
if (k >= sample_end) { // TODO: implement pingpong looping
|
|
if (loop) {
|
|
k = loopstart + (k - loopstart) % looplen;
|
|
} else {
|
|
// kill sample
|
|
ch.inst = undefined;
|
|
// fill rest of buf with filtered dc offset using loop above
|
|
return Vrms + MixSilenceIntoBuf(ch, i, end, dataL, dataR);
|
|
}
|
|
}
|
|
var next_event = Math.max(1, Math.min(end, i + (sample_end - k) / dk));
|
|
// this is the inner loop of the player
|
|
|
|
// unrolled 8x
|
|
for (; i + 7 < next_event; i+=8) {
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i] += vL * y;
|
|
dataR[i] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i+1] += vL * y;
|
|
dataR[i+1] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i+2] += vL * y;
|
|
dataR[i+2] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i+3] += vL * y;
|
|
dataR[i+3] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i+4] += vL * y;
|
|
dataR[i+4] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i+5] += vL * y;
|
|
dataR[i+5] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i+6] += vL * y;
|
|
dataR[i+6] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
var s = samp[k|0];
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
k += dk;
|
|
dataL[i+7] += vL * y;
|
|
dataR[i+7] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
|
|
vL = pf_8 * vL + (1 - pf_8) * volL;
|
|
vR = pf_8 * vR + (1 - pf_8) * volR;
|
|
}
|
|
|
|
for (; i < next_event; i++) {
|
|
var s = samp[k|0];
|
|
// we low-pass filter here since we are resampling some arbitrary
|
|
// frequency to f_smp; this is an anti-aliasing filter and is
|
|
// implemented as an IIR butterworth filter (usually we'd use an FIR
|
|
// brick wall filter, but this is much simpler computationally and
|
|
// sounds fine)
|
|
var y = f0 * (s + fs0) + f1*fs1 + f2*fs2;
|
|
fs2 = fs1; fs1 = y; fs0 = s;
|
|
dataL[i] += vL * y;
|
|
dataR[i] += vR * y;
|
|
Vrms += (vL + vR) * y * y;
|
|
k += dk;
|
|
}
|
|
}
|
|
ch.off = k;
|
|
ch.filterstate[0] = fs0;
|
|
ch.filterstate[1] = fs1;
|
|
ch.filterstate[2] = fs2;
|
|
ch.vL = vL;
|
|
ch.vR = vR;
|
|
return Vrms * 0.5;
|
|
}
|
|
|
|
function audio_cb(e) {
|
|
f_smp = audioctx.sampleRate;
|
|
var time_sound_started = undefined;
|
|
var buflen = e.outputBuffer.length;
|
|
var dataL = e.outputBuffer.getChannelData(0);
|
|
var dataR = e.outputBuffer.getChannelData(1);
|
|
|
|
for (var i = 0; i < buflen; i++) {
|
|
dataL[i] = 0;
|
|
dataR[i] = 0;
|
|
}
|
|
|
|
var offset = 0;
|
|
var ticklen = 0|(f_smp * 2.5 / xm.bpm);
|
|
|
|
while(buflen > 0) {
|
|
if (cur_pat == -1 || cur_ticksamp >= ticklen) {
|
|
next_tick(f_smp);
|
|
cur_ticksamp -= ticklen;
|
|
}
|
|
var tickduration = Math.min(buflen, ticklen - cur_ticksamp);
|
|
var VU = new Float32Array(xm.nchan);
|
|
var scopes = undefined;
|
|
for (var j = 0; j < xm.nchan; j++) {
|
|
var scope;
|
|
if (tickduration >= 4*_scope_width) {
|
|
scope = new Float32Array(_scope_width);
|
|
for (var k = 0; k < _scope_width; k++) {
|
|
scope[k] = -dataL[offset+k*4] - dataR[offset+k*4];
|
|
}
|
|
}
|
|
|
|
VU[j] = MixChannelIntoBuf(
|
|
xm.channelinfo[j], offset, offset + tickduration, dataL, dataR) /
|
|
tickduration;
|
|
|
|
if (tickduration >= 4*_scope_width) {
|
|
for (var k = 0; k < _scope_width; k++) {
|
|
scope[k] += dataL[offset+k*4] + dataR[offset+k*4];
|
|
}
|
|
if (scopes == undefined) scopes = [];
|
|
scopes.push(scope);
|
|
}
|
|
}
|
|
audio_events.push({
|
|
t: e.playbackTime + (0.0 + offset) / f_smp,
|
|
vu: VU,
|
|
scopes: scopes,
|
|
songpos: cur_songpos,
|
|
pat: cur_pat,
|
|
row: cur_row - 1
|
|
});
|
|
if (audio_events.length == 1) {
|
|
requestAnimationFrame(RedrawScreen);
|
|
}
|
|
offset += tickduration;
|
|
cur_ticksamp += tickduration;
|
|
buflen -= tickduration;
|
|
}
|
|
}
|
|
|
|
function ConvertSample(array, bits) {
|
|
var len = array.length;
|
|
var acc = 0;
|
|
if (bits == 0) { // 8 bit sample
|
|
var samp = new Float32Array(len);
|
|
for (var k = 0; k < len; k++) {
|
|
acc += array[k];
|
|
var b = acc&255;
|
|
if (b & 128) b = b-256;
|
|
samp[k] = b / 128.0;
|
|
}
|
|
return samp;
|
|
} else {
|
|
len /= 2;
|
|
var samp = new Float32Array(len);
|
|
for (var k = 0; k < len; k++) {
|
|
acc += array[k*2] + (array[k*2 + 1] << 8);
|
|
var b = acc&65535;
|
|
if (b & 32768) b = b-65536;
|
|
samp[k] = b / 32768.0;
|
|
}
|
|
return samp;
|
|
}
|
|
}
|
|
|
|
// optimization: unroll short sample loops so we can run our inner mixing loop
|
|
// uninterrupted for as long as possible; this also handles pingpong loops.
|
|
function UnrollSampleLoop(samp) {
|
|
var nloops = ((2048 + samp.looplen - 1) / samp.looplen) | 0;
|
|
console.log(samp.looplen, nloops);
|
|
var pingpong = samp.type & 2;
|
|
if (pingpong) {
|
|
// make sure we have an even number of loops if we are pingponging
|
|
nloops = (nloops + 1) & (~1);
|
|
}
|
|
var samplesiz = samp.loop + nloops * samp.looplen;
|
|
var data = new Float32Array(samplesiz);
|
|
for (var i = 0; i < samp.loop; i++) {
|
|
data[i] = samp.sampledata[i];
|
|
}
|
|
for (var j = 0; j < nloops; j++) {
|
|
if ((j&1) && pingpong) {
|
|
for (var k = samp.looplen - 1; k >= 0; k--) {
|
|
data[i++] = samp.sampledata[samp.loop + k];
|
|
}
|
|
} else {
|
|
for (var k = 0; k < samp.looplen; k++) {
|
|
data[i++] = samp.sampledata[samp.loop + k];
|
|
}
|
|
}
|
|
}
|
|
console.log("unrolled sample loop; looplen", samp.looplen, "x", nloops, " = ", samplesiz);
|
|
samp.sampledata = data;
|
|
samp.looplen = nloops * samp.looplen;
|
|
samp.type = 1;
|
|
}
|
|
|
|
function loadXM(arrayBuf) {
|
|
var dv = new DataView(arrayBuf);
|
|
var xm = {};
|
|
|
|
xm.songname = getstring(dv, 17, 20);
|
|
var hlen = dv.getUint32(0x3c, true) + 0x3c;
|
|
var songlen = dv.getUint16(0x40, true);
|
|
xm.song_looppos = dv.getUint16(0x42, true);
|
|
xm.nchan = dv.getUint16(0x44, true);
|
|
var npat = dv.getUint16(0x46, true);
|
|
var ninst = dv.getUint16(0x48, true);
|
|
xm.flags = dv.getUint16(0x4a, true);
|
|
xm.tempo = dv.getUint16(0x4c, true);
|
|
xm.bpm = dv.getUint16(0x4e, true);
|
|
xm.channelinfo = [];
|
|
|
|
for (var i = 0; i < xm.nchan; i++) {
|
|
xm.channelinfo.push({
|
|
number: i,
|
|
filterstate: new Float32Array(3),
|
|
vol: 0,
|
|
pan: 128,
|
|
period: 1920 - 48*16,
|
|
vL: 0, vR: 0, // left right volume envelope followers (changes per sample)
|
|
vLprev: 0, vRprev: 0,
|
|
mute: 0,
|
|
volE: 0, panE: 0,
|
|
retrig: 0,
|
|
vibratodepth: 1,
|
|
vibratospeed: 1,
|
|
})
|
|
}
|
|
console.log("header len " + hlen);
|
|
|
|
console.log("songlen %d, %d channels, %d patterns, %d instruments", songlen, xm.nchan, npat, ninst);
|
|
console.log("loop @%d", xm.song_looppos);
|
|
console.log("flags=%d tempo %d bpm %d", xm.flags, xm.tempo, xm.bpm);
|
|
|
|
xm.songpats = [];
|
|
for (var i = 0; i < songlen; i++) {
|
|
xm.songpats.push(dv.getUint8(0x50 + i));
|
|
}
|
|
console.log("song patterns: ", xm.songpats);
|
|
|
|
var idx = hlen;
|
|
xm.patterns = [];
|
|
for (var i = 0; i < npat; i++) {
|
|
var pattern = [];
|
|
var patheaderlen = dv.getUint32(idx, true);
|
|
var patrows = dv.getUint16(idx + 5, true);
|
|
var patsize = dv.getUint16(idx + 7, true);
|
|
console.log("pattern %d: %d bytes, %d rows", i, patsize, patrows);
|
|
idx += 9;
|
|
for (var j = 0; patsize > 0 && j < patrows; j++) {
|
|
row = [];
|
|
for (var k = 0; k < xm.nchan; k++) {
|
|
var byte0 = dv.getUint8(idx); idx++;
|
|
var note = -1, inst = -1, vol = -1, efftype = 0, effparam = 0;
|
|
if (byte0 & 0x80) {
|
|
if (byte0 & 0x01) {
|
|
note = dv.getUint8(idx) - 1; idx++;
|
|
}
|
|
if (byte0 & 0x02) {
|
|
inst = dv.getUint8(idx); idx++;
|
|
}
|
|
if (byte0 & 0x04) {
|
|
vol = dv.getUint8(idx); idx++;
|
|
}
|
|
if (byte0 & 0x08) {
|
|
efftype = dv.getUint8(idx); idx++;
|
|
}
|
|
if (byte0 & 0x10) {
|
|
effparam = dv.getUint8(idx); idx++;
|
|
}
|
|
} else {
|
|
// byte0 is note from 1..96 or 0 for nothing or 97 for release
|
|
// so we subtract 1 so that C-0 is stored as 0
|
|
note = byte0 - 1;
|
|
inst = dv.getUint8(idx); idx++;
|
|
vol = dv.getUint8(idx); idx++;
|
|
efftype = dv.getUint8(idx); idx++;
|
|
effparam = dv.getUint8(idx); idx++;
|
|
}
|
|
var notedata = [note, inst, vol, efftype, effparam];
|
|
row.push(notedata);
|
|
}
|
|
pattern.push(row);
|
|
}
|
|
xm.patterns.push(pattern);
|
|
}
|
|
|
|
xm.instruments = [];
|
|
// now load instruments
|
|
for (i = 0; i < ninst; i++) {
|
|
var hdrsiz = dv.getUint32(idx, true);
|
|
var instname = getstring(dv, idx+0x4, 22);
|
|
var nsamp = dv.getUint16(idx+0x1b, true);
|
|
var inst = {
|
|
'name': instname,
|
|
'number': i,
|
|
};
|
|
if (nsamp > 0) {
|
|
// return a slice so we have a fresh copy and don't retain pointers to
|
|
// the original xm file arraybuf forever
|
|
var samplemap = new Uint8Array(arrayBuf, idx+33, 96).slice();
|
|
|
|
var env_nvol = dv.getUint8(idx+225);
|
|
var env_vol_type = dv.getUint8(idx+233);
|
|
var env_vol_sustain = dv.getUint8(idx+227);
|
|
var env_vol_loop_start = dv.getUint8(idx+228);
|
|
var env_vol_loop_end = dv.getUint8(idx+229);
|
|
var env_npan = dv.getUint8(idx+226);
|
|
var env_pan_type = dv.getUint8(idx+234);
|
|
var env_pan_sustain = dv.getUint8(idx+230);
|
|
var env_pan_loop_start = dv.getUint8(idx+231);
|
|
var env_pan_loop_end = dv.getUint8(idx+232);
|
|
var vol_fadeout = dv.getUint16(idx+239, true);
|
|
var env_vol = [];
|
|
for (var j = 0; j < env_nvol*2; j++) {
|
|
env_vol.push(dv.getUint16(idx+129+j*2, true));
|
|
}
|
|
var env_pan = [];
|
|
for (var j = 0; j < env_npan*2; j++) {
|
|
env_pan.push(dv.getUint16(idx+177+j*2, true));
|
|
}
|
|
// FIXME: ignoring keymaps for now and assuming 1 sample / instrument
|
|
// var keymap = getarray(dv, idx+0x21);
|
|
var samphdrsiz = dv.getUint32(idx+0x1d, true);
|
|
console.log("hdrsiz %d; instrument %d: '%s' %d samples, samphdrsiz %d",
|
|
hdrsiz, i, instname, nsamp, samphdrsiz);
|
|
idx += hdrsiz;
|
|
var totalsamples = 0;
|
|
var samps = [];
|
|
for (var j = 0; j < nsamp; j++) {
|
|
var samplen = dv.getUint32(idx, true);
|
|
var samploop = dv.getUint32(idx+4, true);
|
|
var samplooplen = dv.getUint32(idx+8, true);
|
|
var sampvol = dv.getUint8(idx+12);
|
|
var sampfinetune = dv.getInt8(idx+13);
|
|
var samptype = dv.getUint8(idx+14);
|
|
var samppan = dv.getUint8(idx+15);
|
|
var sampnote = dv.getInt8(idx+16);
|
|
var sampname = getstring(dv, idx+18, 22);
|
|
var sampleoffset = idx + samphdrsiz + totalsamples;
|
|
console.log("sample %d: len %d name '%s' loop %d/%d vol %d",
|
|
j, samplen, sampname, samploop, samplooplen, sampvol);
|
|
console.log(" type %d note %s(%d) finetune %d pan %d",
|
|
samptype, prettify_note(sampnote + 12*4), sampnote, sampfinetune, samppan);
|
|
console.log(" vol env", env_vol, env_vol_sustain,
|
|
env_vol_loop_start, env_vol_loop_end, "type", env_vol_type,
|
|
"fadeout", vol_fadeout);
|
|
console.log(" pan env", env_pan, env_pan_sustain,
|
|
env_pan_loop_start, env_pan_loop_end, "type", env_pan_type);
|
|
var samp = {
|
|
'len': samplen, 'loop': samploop,
|
|
'looplen': samplooplen, 'note': sampnote, 'fine': sampfinetune,
|
|
'pan': samppan, 'type': samptype, 'vol': sampvol,
|
|
'fine': sampfinetune,
|
|
'sampledata': ConvertSample(
|
|
new Uint8Array(arrayBuf, sampleoffset, samplen), samptype & 16),
|
|
};
|
|
// length / pointers are all specified in bytes; fixup for 16-bit samples
|
|
if (samptype & 16) {
|
|
samp.len /= 2;
|
|
samp.loop /= 2;
|
|
samp.looplen /= 2;
|
|
}
|
|
|
|
// unroll short loops and any pingpong loops
|
|
if ((samp.type & 3) && (samp.looplen < 2048 || (samp.type & 2))) {
|
|
UnrollSampleLoop(samp);
|
|
}
|
|
samps.push(samp);
|
|
|
|
idx += samphdrsiz;
|
|
totalsamples += samplen;
|
|
}
|
|
idx += totalsamples;
|
|
inst.samplemap = samplemap;
|
|
inst.samples = samps;
|
|
if (env_vol_type) {
|
|
// insert an automatic fadeout to 0 at the end of the envelope
|
|
var env_end_tick = env_vol[env_vol.length-2];
|
|
if (!(env_vol_type & 2)) { // if there's no sustain point, create one
|
|
env_vol_sustain = env_vol.length / 2;
|
|
}
|
|
if (vol_fadeout > 0) {
|
|
var fadeout_ticks = 65536.0 / vol_fadeout;
|
|
env_vol.push(env_end_tick + fadeout_ticks);
|
|
env_vol.push(0);
|
|
}
|
|
inst.env_vol = new Envelope(
|
|
env_vol,
|
|
env_vol_type,
|
|
env_vol_sustain,
|
|
env_vol_loop_start,
|
|
env_vol_loop_end);
|
|
} else {
|
|
// no envelope, then just make a default full-volume envelope.
|
|
// i thought this would use fadeout, but apparently it doesn't.
|
|
inst.env_vol = new Envelope([0, 64, 1, 0], 2, 0, 0, 0);
|
|
}
|
|
if (env_pan_type) {
|
|
if (!(env_pan_type & 2)) { // if there's no sustain point, create one
|
|
env_pan_sustain = env_pan.length / 2;
|
|
}
|
|
inst.env_pan = new Envelope(
|
|
env_pan,
|
|
env_pan_type,
|
|
env_pan_sustain,
|
|
env_pan_loop_start,
|
|
env_pan_loop_end);
|
|
} else {
|
|
// create a default empty envelope
|
|
inst.env_pan = new Envelope([0, 32], 0, 0, 0, 0);
|
|
}
|
|
} else {
|
|
idx += hdrsiz;
|
|
console.log("empty instrument", i, hdrsiz, idx);
|
|
}
|
|
xm.instruments.push(inst);
|
|
}
|
|
|
|
var debug = document.getElementById("debug");
|
|
console.log("loaded \"" + xm.songname + "\"");
|
|
debug.innerHTML = xm.songname;
|
|
|
|
var instrlist = document.getElementById("instruments");
|
|
var namelist = [];
|
|
for (var j = 0; j < xm.instruments.length; j++) {
|
|
var n = (j+1).toString(16);
|
|
if (j < 15) n = ' ' + n;
|
|
namelist.push(n + " " + xm.instruments[j].name);
|
|
}
|
|
instrlist.innerHTML = namelist.join("\n");
|
|
|
|
return xm;
|
|
}
|
|
|
|
var playing = false;
|
|
var jsNode, gainNode;
|
|
var paused_events = [];
|
|
function InitAudio() {
|
|
audioContext = window.AudioContext || window.webkitAudioContext;
|
|
audioctx = new audioContext();
|
|
gainNode = audioctx.createGain();
|
|
gainNode.gain.value = 0.1; // master volume
|
|
jsNode = audioctx.createScriptProcessor(16384, 0, 2);
|
|
jsNode.onaudioprocess = audio_cb;
|
|
gainNode.connect(audioctx.destination);
|
|
}
|
|
|
|
function PlayXM() {
|
|
if (!playing) {
|
|
// put paused events back into action, if any
|
|
var t = audioctx.currentTime;
|
|
while (paused_events.length > 0) {
|
|
var e = paused_events.shift();
|
|
e.t += t;
|
|
audio_events.push(e);
|
|
}
|
|
// start playing
|
|
jsNode.connect(gainNode);
|
|
requestAnimationFrame(RedrawScreen);
|
|
}
|
|
playing = true;
|
|
}
|
|
|
|
function PauseXM() {
|
|
if (playing) {
|
|
jsNode.disconnect(gainNode);
|
|
// grab all the audio events
|
|
var t = audioctx.currentTime;
|
|
while (audio_events.length > 0) {
|
|
var e = audio_events.shift();
|
|
e.t -= t;
|
|
paused_events.push(e);
|
|
}
|
|
}
|
|
playing = false;
|
|
}
|
|
|
|
function main() {
|
|
InitAudio();
|
|
var xmReq = new XMLHttpRequest();
|
|
var uri = location.search.substr(1);
|
|
if (uri == "") {
|
|
uri = "kamel.xm";
|
|
}
|
|
xmReq.open("GET", uri, true);
|
|
xmReq.responseType = "arraybuffer";
|
|
xmReq.onload = function (xmEvent) {
|
|
var arrayBuffer = xmReq.response;
|
|
if (arrayBuffer) {
|
|
xm = loadXM(arrayBuffer);
|
|
} else {
|
|
console.log("unable to load", uri);
|
|
}
|
|
document.getElementById('vu').width = _pattern_border + _pattern_cellwidth * xm.nchan;
|
|
var gfxpattern = document.getElementById("gfxpattern");
|
|
gfxpattern.width = _pattern_cellwidth * xm.nchan + _pattern_border;
|
|
var playbutton = document.getElementById('playpause');
|
|
playbutton.onclick = function() {
|
|
if (playing) {
|
|
PauseXM();
|
|
playbutton.innerHTML='Play';
|
|
} else {
|
|
PlayXM();
|
|
playbutton.innerHTML='Pause';
|
|
}
|
|
}
|
|
playbutton.disabled = false;
|
|
// generate a fake audio event to render the initial paused screen
|
|
var scopes = [];
|
|
for (var i = 0; i < xm.nchan; i++) {
|
|
scopes.push(new Float32Array(_scope_width));
|
|
}
|
|
audio_events.push({
|
|
t: 0, row: 0, pat: xm.songpats[0],
|
|
vu: new Float32Array(xm.nchan),
|
|
scopes: scopes
|
|
});
|
|
RedrawScreen();
|
|
}
|
|
xmReq.send(null);
|
|
}
|
|
|