Merge pull request #705 from JerwuQu/jwq_tick-aware-apu

✨ Make APU tick aware ✨

Author: aduros

runtimes/native/src/apu.c

@@ -29,6 +29,9 @@ typedef struct {
     /** Time the tone should end. */
     unsigned long long releaseTime;
 
+    /** The tick the tone should end. */
+    unsigned long long endTick;
+
     /** Sustain volume level. */
     int16_t sustainVolume;
 
@@ -59,8 +62,9 @@ typedef struct {
 
 static Channel channels[4] = { 0 };
 
-/** The current time, in samples. */
+/** The current time in samples and ticks respectively. */
 static unsigned long long time = 0;
+static unsigned long long ticks = 0;
 
 static int w4_min (int a, int b) {
     return a < b ? a : b;
@@ -71,6 +75,7 @@ static int lerp (int value1, int value2, float t) {
 }
 
 static int ramp (int value1, int value2, unsigned long long time1, unsigned long long time2) {
+    if (time >= time2) return value2;
     float t = (float)(time - time1) / (time2 - time1);
     return lerp(value1, value2, t);
 }
@@ -84,7 +89,7 @@ static uint16_t getCurrentFrequency (const Channel* channel) {
 }
 
 static int16_t getCurrentVolume (const Channel* channel) {
-    if (time >= channel->sustainTime) {
+    if (time >= channel->sustainTime && channel->releaseTime != channel->sustainTime) {
         // Release
         return ramp(channel->sustainVolume, 0, channel->sustainTime, channel->releaseTime);
     } else if (time >= channel->decayTime) {
@@ -115,6 +120,10 @@ void w4_apuInit () {
     channels[3].noise.seed = 0x0001;
 }
 
+void w4_apuTick () {
+    ticks++;
+}
+
 void w4_apuTone (int frequency, int duration, int volume, int flags) {
     int freq1 = frequency & 0xffff;
     int freq2 = (frequency >> 16) & 0xffff;
@@ -135,7 +144,7 @@ void w4_apuTone (int frequency, int duration, int volume, int flags) {
     Channel* channel = &channels[channelIdx];
 
     // Restart the phase if this channel wasn't already playing
-    if (time > channel->releaseTime) {
+    if (time > channel->releaseTime && ticks != channel->endTick) {
         channel->phase = (channelIdx == 2) ? 0.25 : 0;
     }
 
@@ -146,6 +155,7 @@ void w4_apuTone (int frequency, int duration, int volume, int flags) {
     channel->decayTime = channel->attackTime + SAMPLE_RATE*decay/60;
     channel->sustainTime = channel->decayTime + SAMPLE_RATE*sustain/60;
     channel->releaseTime = channel->sustainTime + SAMPLE_RATE*release/60;
+    channel->endTick = ticks + attack + decay + sustain + release;
     int16_t maxVolume = (channelIdx == 2) ? MAX_VOLUME_TRIANGLE : MAX_VOLUME;
     channel->sustainVolume = maxVolume * sustainVolume/100;
     channel->peakVolume = peakVolume ? maxVolume * peakVolume/100 : maxVolume;
@@ -179,7 +189,7 @@ void w4_apuWriteSamples (int16_t* output, unsigned long frames) {
         for (int channelIdx = 0; channelIdx < 4; ++channelIdx) {
             Channel* channel = &channels[channelIdx];
 
-            if (time < channel->releaseTime) {
+            if (time < channel->releaseTime || ticks == channel->endTick) {
                 uint16_t freq = getCurrentFrequency(channel);
                 int16_t volume = getCurrentVolume(channel);
                 int16_t sample;

runtimes/native/src/apu.h

@@ -5,6 +5,8 @@
 
 void w4_apuInit ();
 
+void w4_apuTick ();
+
 void w4_apuTone (int frequency, int duration, int volume, int flags);
 
 void w4_apuWriteSamples (int16_t* output, unsigned long frames);

runtimes/native/src/runtime.c

@@ -184,6 +184,7 @@ void w4_runtimeUpdate () {
         w4_framebufferClear();
     }
     w4_wasmCallUpdate();
+    w4_apuTick();
     uint32_t palette[4] = {
         w4_read32LE(&memory->palette[0]),
         w4_read32LE(&memory->palette[1]),

runtimes/web/src/apu-worklet.ts

@@ -27,6 +27,9 @@ class Channel {
     /** Time the tone should end. */
     releaseTime = 0;
 
+    /** The tick the tone should end. */
+    endTick = 0;
+
     /** Sustain volume level. */
     sustainVolume = 0;
 
@@ -67,25 +70,32 @@ function polyblep (phase: number, phaseInc: number) {
 
 class APUProcessor extends AudioWorkletProcessor {
     time: number;
+    ticks: number;
     channels: Channel[];
 
     constructor () {
         super();
 
         this.time = 0;
+        this.ticks = 0;
         this.channels = new Array(4);
         for (let ii = 0; ii < 4; ++ii) {
             this.channels[ii] = new Channel();
         }
 
         if (this.port != null) {
-            this.port.onmessage = (event: MessageEvent<[number, number, number, number]>) => {
-                this.tone(...event.data);
+            this.port.onmessage = (event: MessageEvent<'tick' | [number, number, number, number]>) => {
+                if (event.data === 'tick') {
+                    this.tick();
+                } else {
+                    this.tone(...event.data);
+                }
             };
         }
     }
 
     ramp (value1: number, value2: number, time1: number, time2: number) {
+        if (this.time >= time2) return value2;
         const t = (this.time - time1) / (time2 - time1);
         return lerp(value1, value2, t);
     }
@@ -100,7 +110,7 @@ class APUProcessor extends AudioWorkletProcessor {
 
     getCurrentVolume (channel: Channel) {
         const time = this.time;
-        if (time >= channel.sustainTime) {
+        if (time >= channel.sustainTime && channel.releaseTime != channel.sustainTime) {
             // Release
             return this.ramp(channel.sustainVolume, 0, channel.sustainTime, channel.releaseTime);
         } else if (time >= channel.decayTime) {
@@ -115,6 +125,10 @@ class APUProcessor extends AudioWorkletProcessor {
         }
     }
 
+    tick () {
+        this.ticks++;
+    }
+
     tone (frequency: number, duration: number, volume: number, flags: number) {
         const freq1 = frequency & 0xffff;
         const freq2 = (frequency >> 16) & 0xffff;
@@ -134,7 +148,7 @@ class APUProcessor extends AudioWorkletProcessor {
         const channel = this.channels[channelIdx];
 
         // Restart the phase if this channel wasn't already playing
-        if (this.time > channel.releaseTime) {
+        if (this.time > channel.releaseTime && this.ticks != channel.endTick) {
             channel.phase = (channelIdx == 2) ? 0.25 : 0;
         }
 
@@ -145,6 +159,7 @@ class APUProcessor extends AudioWorkletProcessor {
         channel.decayTime = channel.attackTime + ((SAMPLE_RATE*decay/60) >>> 0);
         channel.sustainTime = channel.decayTime + ((SAMPLE_RATE*sustain/60) >>> 0);
         channel.releaseTime = channel.sustainTime + ((SAMPLE_RATE*release/60) >>> 0);
+        channel.endTick = this.ticks + attack + decay + sustain + release;
         channel.pan = pan;
 
         const maxVolume = (channelIdx == 2) ? MAX_VOLUME_TRIANGLE : MAX_VOLUME;
@@ -179,7 +194,7 @@ class APUProcessor extends AudioWorkletProcessor {
             for (let channelIdx = 0; channelIdx < 4; ++channelIdx) {
                 const channel = this.channels[channelIdx];
 
-                if (this.time < channel.releaseTime) {
+                if (this.time < channel.releaseTime || this.ticks == channel.endTick) {
                     const freq = this.getCurrentFrequency(channel);
                     const volume = this.getCurrentVolume(channel);
                     let sample;

runtimes/web/src/apu.ts

@@ -55,12 +55,18 @@ export class APU {
         }
     }
 
+    tick() {
+        if (this.processorPort != null) {
+            this.processorPort.postMessage('tick');
+        } else {
+            this.processor.tick();
+        }
+    }
+
     tone (frequency: number, duration: number, volume: number, flags: number) {
-        const processorPort = this.processorPort;
-        if (processorPort != null) {
+        if (this.processorPort != null) {
             // Send params out to the worker
-            processorPort.postMessage([frequency, duration, volume, flags]);
-
+            this.processorPort.postMessage([frequency, duration, volume, flags]);
         } else {
             // For the ScriptProcessorNode fallback, just call tone() directly
             this.processor.tone(frequency, duration, volume, flags);

runtimes/web/src/runtime.ts

@@ -334,6 +334,7 @@ export class Runtime {
         let update_function = this.wasm!.exports["update"];
         if (typeof update_function === "function") {
             this.bluescreenOnError(update_function);
+            this.apu.tick();
         }
     }