diff --git a/index.html b/index.html
index 788ef28..374ee2a 100644
--- a/index.html
+++ b/index.html
@@ -5,9 +5,13 @@
todo:
- - load instruments
- - load samples
- - open audio and start generating
+ - pan envelopes
+ - effects!
+ - arpeggio
+ - vibrato
+ - portamento / pitch slide
+ - volume slide (via Axy effect + volume effects)
+ - instrument vibrato
diff --git a/xm.js b/xm.js
index cf99105..8e677e1 100644
--- a/xm.js
+++ b/xm.js
@@ -12,17 +12,21 @@ function prettify_number(num) {
return num;
}
+function prettify_volume(num) {
+ if (num < 0x10) return "--";
+ return num.toString(16);
+}
+
function prettify_effect(t, p) {
- if (t == -1) t = "-"; else t = t.toString(16);
- if (p == -1) p = "--";
- else if (p < 16) p = '0' + p.toString(16);
+ t = t.toString(16);
+ if (p < 16) p = '0' + p.toString(16);
else p = p.toString(16);
- return "" + t + p
+ return t + p
}
function prettify_notedata(note, inst, vol, efftype, effparam) {
return (prettify_note(note) + " " + prettify_number(inst) + " "
- + prettify_number(vol) + " "
+ + prettify_volume(vol) + " "
+ prettify_effect(efftype, effparam));
}
@@ -78,8 +82,15 @@ function Filter(x, coef, state) {
return y;
}
+function UpdateChannelNote(ch, note, f_smp) {
+ var freq = 8363 * Math.pow(2, note/12.0 + ch.inst.fine/(12*128.0) - 4);
+ ch.doff = freq / f_smp;
+ ch.filter = FilterCoeffs(ch.doff / 2);
+}
+
var cur_songpos = -1, cur_pat = -1, cur_row = 64, cur_ticksamp = 0;
var cur_tick = 6;
+var patdisplay = [];
function next_row(f_smp) {
if (cur_row >= 64) {
cur_row = 0;
@@ -93,16 +104,17 @@ function next_row(f_smp) {
cur_row++;
pretty_row = [];
for (var i = 0; i < r.length; i++) {
+ var ch = channelinfo[i];
pretty_row.push(prettify_notedata(r[i][0], r[i][1], r[i][2], r[i][3], r[i][4]));
// instrument trigger
if (r[i][1] != -1) {
var inst = instruments[r[i][1] - 1];
if (inst !== undefined) {
- channelinfo[i].inst = inst;
+ ch.inst = inst;
// retrigger?
- channelinfo[i].off = 0;
- channelinfo[i].release = 0;
- channelinfo[i].envtick = 0;
+ ch.off = 0;
+ ch.release = 0;
+ ch.envtick = 0;
// new instrument doesn ot reset volume!
} else {
// console.log("invalid inst", r[i][1], instruments.length);
@@ -112,11 +124,11 @@ function next_row(f_smp) {
if (r[i][0] != -1) {
if (r[i][0] == 96) {
// release note, FIXME once envelopes are implemented
- channelinfo[i].release = 1;
+ ch.release = 1;
} else {
// assume linear frequency table (flags header & 1 == 1)
// is this true in kamel.xm?
- var inst = channelinfo[i].inst;
+ var inst = ch.inst;
if (inst === undefined) {
continue;
}
@@ -124,36 +136,45 @@ function next_row(f_smp) {
// var period = 7680 - r[i][0]*64 - inst.fine*0.5;
// var freq = 8363 * Math.pow(2, (4608 - period) / 768);
var note = r[i][0] + inst.note;
- var freq = 8363 * Math.pow(2, note/12.0 + inst.fine/(12*128.0) - 4);
- channelinfo[i].doff = freq / f_smp;
- channelinfo[i].off = 0;
- channelinfo[i].release = 0;
- channelinfo[i].envtick = 0;
- channelinfo[i].filter = FilterCoeffs(channelinfo[i].doff / 2);
- // console.log("channel", i, r[i][0], channelinfo[i]);
+ ch.note = note;
+ ch.off = 0;
+ ch.release = 0;
+ ch.envtick = 0;
+ UpdateChannelNote(ch, note, f_smp);
+ // console.log("channel", i, r[i][0], ch);
// if there's an instrument and a note, set the volume
if (r[i][0] != -1) {
- channelinfo[i].volL = inst.vol;
- channelinfo[i].volR = inst.vol;
+ var p = (inst.pan - 128) / 128.0;
+ ch.volL = Math.sqrt(1 - p) * inst.vol;
+ ch.volR = Math.sqrt(1 + p) * inst.vol;
}
}
}
- if (r[i][2] != -1) {
+ if (r[i][2] != -1) { // volume column
// FIXME: panning
var v = r[i][2];
if (v < 0x10) {
console.log("channel", i, "invalid volume", v.toString(16));
} else if (v <= 0x50) {
- channelinfo[i].volL = v - 0x10;
- channelinfo[i].volR = v - 0x10;
- } else {
- console.log("channel", i, "volume effect", v.toString(16));
+ ch.volL = v - 0x10;
+ ch.volR = v - 0x10;
}
}
+
+ ch.effect = r[i][3];
+ ch.effectdata = r[i][4];
+ // TODO: process initial effect tick for effects which need it
+
}
- console.log(pretty_row.join(" "));
var debug = document.getElementById("debug");
debug.innerHTML = 'pat ' + cur_pat + ' row ' + (cur_row-1);
+
+ var pat = document.getElementById("pattern");
+ patdisplay.push(pretty_row.join(" "));
+ if (patdisplay.length > 16) {
+ patdisplay.shift();
+ }
+ pat.innerHTML = patdisplay.join("\n");
}
function next_tick(f_smp) {
@@ -165,6 +186,12 @@ function next_tick(f_smp) {
for (var j = 0; j < nchan; j++) {
var ch = channelinfo[j];
var inst = ch.inst;
+ // process effects
+ if (ch.effect == 0 && ch.effectdata != 0) {
+ var arpeggio = [0, ch.effectdata>>4, ch.effectdata&15];
+ var note = ch.note + arpeggio[cur_tick % 3];
+ UpdateChannelNote(ch, note, f_smp);
+ }
if (inst === undefined) continue;
if (inst.env_vol !== undefined) {
ch.env_vol = GetEnvelope(inst.env_vol, ch.envtick);
@@ -338,7 +365,7 @@ function playXM(arrayBuf) {
pretty_row = [];
for (var k = 0; k < nchan; k++) {
var byte0 = dv.getUint8(idx); idx++;
- var note = -1, inst = -1, vol = -1, efftype = -1, effparam = -1;
+ var note = -1, inst = -1, vol = -1, efftype = 0, effparam = 0;
if (byte0 & 0x80) {
if (byte0 & 0x01) {
note = dv.getUint8(idx) - 1; idx++;