diff --git a/index.html b/index.html index d6b1431..ba17192 100644 --- a/index.html +++ b/index.html @@ -9,13 +9,10 @@ tune: my dirty old kamel - Zalza todo: - instrument fadeout - pingpong loops - - volume effects - - 8x - - others? - - various other XM effects are missing but nonessential + - various XM effects are missing - oscilloscopes - +
diff --git a/xm.js b/xm.js
index 62ae088..211f522 100644
--- a/xm.js
+++ b/xm.js
@@ -139,6 +139,15 @@ function next_row() {
console.log("channel", i, "invalid volume", v.toString(16));
} else if (v <= 0x50) {
ch.vol = v - 0x10;
+ } else if (v >= 0x80 && v < 0x90) { // fine volume slide down
+ ch.vol = Math.max(0, ch.vol - (v & 0x0f));
+ } else if (v >= 0x90 && v < 0xa0) { // fine volume slide up
+ ch.vol = Math.min(64, ch.vol + (v & 0x0f));
+ } else if (v >= 0xc0 && v < 0xd0) { // set panning
+ ch.pan = 16 * (v & 0x0f);
+ console.log("channel", i, "pan", ch.pan);
+ } else {
+ console.log("channel", i, "volume effect", v.toString(16));
}
}
@@ -221,9 +230,9 @@ function EnvelopeFollower(env) {
this.tick = 0;
}
-EnvelopeFollower.prototype.Tick = function(release) {
+EnvelopeFollower.prototype.Tick = function(release, defaultval) {
if (this.env === undefined) {
- return 64;
+ return defaultval;
}
var value = this.env.Get(this.tick);
if (this.env.type & 1) { // sustain?
@@ -256,8 +265,8 @@ function next_tick() {
ch.effectfn(ch);
}
if (inst === undefined) continue;
- ch.volE = ch.env_vol.Tick(ch.release);
- ch.panE = ch.env_pan.Tick(ch.release);
+ ch.volE = ch.env_vol.Tick(ch.release, 64);
+ ch.panE = ch.env_pan.Tick(ch.release, 32);
}
}
@@ -296,9 +305,9 @@ function MixChannelIntoBuf(ch, start, end, dataL, dataR) {
sample_end = looplen + inst.loop;
}
var samplen = inst.len;
- var volE = ch.volE / 64.0;
- var panE = (ch.panE - 32);
- var p = panE + ch.pan - 128;
+ 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;
@@ -309,7 +318,9 @@ function MixChannelIntoBuf(ch, start, end, dataL, dataR) {
var dk = ch.doff;
var Vrms = 0;
for (var i = start; i < end; i++) {
- var s = samp[k|0];
+ var s = 0;
+ // if ((k|0) != (k-dk)|0)
+ 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
@@ -327,7 +338,7 @@ function MixChannelIntoBuf(ch, start, end, dataL, dataR) {
ch.vRprev = volR;
dataL[i] += ch.vL * si;
dataR[i] += ch.vR * si;
- Vrms += ch.vL * ch.vR * si * si;
+ Vrms += (ch.vL + ch.vR) * si * si;
k += dk;
if (k >= sample_end) { // TODO: implement pingpong looping
if (loop) {
@@ -342,7 +353,7 @@ function MixChannelIntoBuf(ch, start, end, dataL, dataR) {
}
ch.off = k;
ch.doff = dk;
- return Vrms;
+ return Vrms * 0.5;
}
function audio_cb(e) {
@@ -686,6 +697,8 @@ function playXM(arrayBuf) {
samptype, prettify_note(sampnote), sampfinetune, samppan);
console.log(" vol env", env_vol, env_vol_sustain,
env_vol_loop_start, env_vol_loop_end, "type", env_vol_type);
+ console.log(" pan env", env_pan, env_pan_sustain,
+ env_pan_loop_start, env_pan_loop_end, "type", env_pan_type);
idx += samplen + samphdrsiz;
}
inst = {