fixed NES audio; use setTimeout for animation loop; famitracker

presets/nes/shoot2.c

@@ -391,10 +391,10 @@ void draw_next_row() {
 #define FLIPXY 0xc0
 
 const byte DIR_TO_CODE[32] = {
-  0, 1, 2, 3, 4, 5, 6, 6,
-  6|FLIPY, 6|FLIPY, 5|FLIPY, 4|FLIPY, 3|FLIPY, 2|FLIPY, 1|FLIPY, 0|FLIPY,
   0|FLIPXY, 1|FLIPXY, 2|FLIPXY, 3|FLIPXY, 4|FLIPXY, 5|FLIPXY, 6|FLIPXY, 6|FLIPXY,
   6|FLIPX, 6|FLIPX, 5|FLIPX, 4|FLIPX, 3|FLIPX, 2|FLIPX, 1|FLIPX, 0|FLIPX,
+  0, 1, 2, 3, 4, 5, 6, 6,
+  6|FLIPY, 6|FLIPY, 5|FLIPY, 4|FLIPY, 3|FLIPY, 2|FLIPY, 1|FLIPY, 0|FLIPY,
 };
 
 const byte SINTBL[32] = {

src/audio.ts

@@ -299,7 +299,7 @@ var SampleAudio = function(clockfreq) {
     }
     self.context = new AudioContext();
     self.sr=self.context.sampleRate;
-    self.bufferlen=(self.sr > 44100) ? 4096 : 2048;
+    self.bufferlen=2048;
 
     // Amiga 500 fixed filter at 6kHz. WebAudio lowpass is 12dB/oct, whereas
     // older Amigas had a 6dB/oct filter at 4900Hz.
@@ -361,9 +361,9 @@ var SampleAudio = function(clockfreq) {
       bufpos = 0;
       bufferlist[ifill] = buffer;
       var inext = (ifill + 1) % bufferlist.length;
-      //if (inext != idrain) ifill = inext;
       if (inext == idrain) {
-        ifill = (idrain + bufferlist.length/2) % bufferlist.length;
+        ifill = Math.floor(idrain + nbuffers/2) % bufferlist.length;
+        //console.log('audio skipped', idrain, ifill);
       } else {
         ifill = inext;
       }
@@ -375,7 +375,7 @@ var SampleAudio = function(clockfreq) {
     while (count-- > 0) {
       accum += value;
       sfrac += sinc;
-      if (sfrac >= 1) {
+      while (sfrac >= 1) {
         sfrac -= 1;
         value *= sfrac;
         this.addSingleSample(accum - value);

src/emu.ts

@@ -216,21 +216,27 @@ var AnimationTimer = function(frequencyHz:number, callback:() => void) {
   var intervalMsec = 1000.0 / frequencyHz;
   var running;
   var lastts = 0;
-  var useReqAnimFrame = window.requestAnimationFrame ? (frequencyHz>40) : false;
+  var useReqAnimFrame = false; //window.requestAnimationFrame ? (frequencyHz>40) : false;
   var nframes, startts; // for FPS calc
   this.frameRate = frequencyHz;
 
-  function scheduleFrame() {
+  function scheduleFrame(msec:number) {
     if (useReqAnimFrame)
       window.requestAnimationFrame(nextFrame);
     else
-      setTimeout(nextFrame, intervalMsec);
+      setTimeout(nextFrame, msec);
   }
-  function nextFrame(ts) {
-    if (running) {
-      scheduleFrame();
+  function nextFrame(ts:number) {
+    if (!ts) ts = Date.now();
+    if (ts - lastts < intervalMsec*10) {
+      lastts += intervalMsec;
+    } else {
+      lastts = ts + intervalMsec; // frames skipped, catch up
     }
-    if (!useReqAnimFrame || ts - lastts > intervalMsec/2) {
+    if (running) {
+      scheduleFrame(lastts - ts);
+    }
+    if (!useReqAnimFrame || lastts - ts > intervalMsec/2) {
       if (running) {
         try {
           callback();
@@ -239,11 +245,6 @@ var AnimationTimer = function(frequencyHz:number, callback:() => void) {
           throw e;
         }
       }
-      if (ts - lastts < intervalMsec*30) {
-        lastts += intervalMsec;
-      } else {
-        lastts = ts;
-      }
       if (nframes == 0) startts = ts;
       if (nframes++ == 300) {
         console.log("Avg framerate: " + nframes*1000/(ts-startts) + " fps");
@@ -258,7 +259,7 @@ var AnimationTimer = function(frequencyHz:number, callback:() => void) {
       running = true;
       lastts = 0;
       nframes = 0;
-      scheduleFrame();
+      scheduleFrame(0);
     }
   }
   this.stop = function() {

src/platform/nes.js

@@ -12,6 +12,7 @@ var JSNES_PRESETS = [
   {id:'neslib4.c', name:'Metasprites'},
   {id:'neslib5.c', name:'RLE Unpack'},
   {id:'music.c', name:'Music Player'},
+  {id:'musicdemo.asm', name:'Famitone Demo'},
   {id:'siegegame.c', name:'Siege Game'},
   {id:'shoot2.c', name:'Solarian Game'},
 ];
@@ -61,8 +62,9 @@ var JSNESPlatform = function(mainElement) {
   var nes;
   var rom;
   var video, audio, timer;
-  var audioFrequency = 44100;
+  var audioFrequency = 44030; //44100
   var frameindex = 0;
+  var nsamples = 0;
 
   this.getPresets = function() { return JSNES_PRESETS; }
 
@@ -78,17 +80,19 @@ var JSNESPlatform = function(mainElement) {
         video.updateFrame();
         self.restartDebugState();
         frameindex++;
+        //if (frameindex == 2000) console.log(nsamples*60/frameindex,'Hz');
       },
       onAudioSample: function(left, right) {
         if (frameindex < 10)
           audio.feedSample(0, 1); // avoid popping at powerup
         else
           audio.feedSample(left+right, 1);
+        //nsamples++;
       },
       onStatusUpdate: function(s) {
         console.log(s);
       },
-      //onBatteryRamWrite
+      //TODO: onBatteryRamWrite
     });
     nes.stop = function() {
       // TODO: trigger breakpoint