From 451c35f41ba990a011f4d62e16ee4d92489aca5b Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Tue, 8 Jun 2021 23:16:29 -0500
Subject: [PATCH] PCE: sample playback

---
 src/engine/platform/pce.cpp | 41 +++++++++++++++++++++++++++++++++++++
 src/engine/platform/pce.h   |  4 +++-
 src/engine/playback.cpp     |  3 +++
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/src/engine/platform/pce.cpp b/src/engine/platform/pce.cpp
index 1afe9014..4daecd8f 100644
--- a/src/engine/platform/pce.cpp
+++ b/src/engine/platform/pce.cpp
@@ -14,6 +14,29 @@
 #define FREQ_BASE 1712.0f*2
 
 void DivPlatformPCE::acquire(int& l, int& r) {
+  // PCM part
+  for (int i=0; i<6; i++) {
+    if (chan[i].pcm && chan[i].dacSample!=-1) {
+      if (--chan[i].dacPeriod<1) {
+        DivSample* s=parent->song.sample[chan[i].dacSample];
+        chWrite(i,0x07,0);
+        if (s->depth==8) {
+          printf("Screw your 8 bit samples\n");
+          //writes.emplace(0x2a,(unsigned char)s->rendData[chan[i].dacPos++]+0x80);
+        } else {
+          chWrite(i,0x04,0xdf);
+          chWrite(i,0x06,(((unsigned short)s->rendData[chan[i].dacPos++]+0x8000)>>11));
+          //writes.emplace(0x2a,((unsigned short)s->rendData[chan[i].dacPos++]+0x8000)>>8);
+        }
+        if (chan[i].dacPos>=s->rendLength) {
+          chan[i].dacSample=-1;
+        }
+        chan[i].dacPeriod=chan[i].dacRate;
+      }
+    }
+  }
+
+  // PCE part
   while (!writes.empty()) {
     QueuedWrite w=writes.front();
     pce->Write(cycles,w.addr,w.val);
@@ -45,6 +68,10 @@ static unsigned char noiseFreq[12]={
   4,13,15,18,21,23,25,27,29,31,0,2  
 };
 
+static int dacRates[6]={
+  224,224,162,112,81,56
+};
+
 void DivPlatformPCE::tick() {
   for (int i=0; i<6; i++) {
     chan[i].std.next();
@@ -106,6 +133,17 @@ void DivPlatformPCE::tick() {
 int DivPlatformPCE::dispatch(DivCommand c) {
   switch (c.cmd) {
     case DIV_CMD_NOTE_ON:
+      if (chan[c.chan].pcm) {
+        chan[c.chan].dacSample=c.value%12;
+        if (chan[c.chan].dacSample>=parent->song.sampleLen) {
+          chan[c.chan].dacSample=-1;
+          break;
+        }
+        chan[c.chan].dacPos=0;
+        chan[c.chan].dacPeriod=0;
+        chan[c.chan].dacRate=dacRates[parent->song.sample[chan[c.chan].dacSample]->rate];
+        break;
+      }
       chan[c.chan].baseFreq=round(FREQ_BASE/pow(2.0f,((float)c.value/12.0f)));
       chan[c.chan].freqChanged=true;
       chan[c.chan].note=c.value;
@@ -176,6 +214,9 @@ int DivPlatformPCE::dispatch(DivCommand c) {
       chan[c.chan].noise=c.value;
       chWrite(c.chan,0x07,chan[c.chan].noise?(0x80|chan[c.chan].note):0);
       break;
+    case DIV_CMD_SAMPLE_MODE:
+      chan[c.chan].pcm=c.value;
+      break;
     case DIV_CMD_PANNING: {
       chan[c.chan].pan=c.value;
       chWrite(c.chan,0x05,chan[c.chan].pan);
diff --git a/src/engine/platform/pce.h b/src/engine/platform/pce.h
index 1cf9ecdd..0d981d9d 100644
--- a/src/engine/platform/pce.h
+++ b/src/engine/platform/pce.h
@@ -9,8 +9,9 @@
 class DivPlatformPCE: public DivDispatch {
   struct Channel {
     int freq, baseFreq, pitch;
+    int dacPeriod, dacRate, dacPos, dacSample;
     unsigned char ins, note, pan;
-    bool active, insChanged, freqChanged, keyOn, keyOff, inPorta, noise;
+    bool active, insChanged, freqChanged, keyOn, keyOff, inPorta, noise, pcm;
     signed char vol, outVol, wave;
     DivMacroInt std;
     Channel():
@@ -27,6 +28,7 @@ class DivPlatformPCE: public DivDispatch {
       keyOff(false),
       inPorta(false),
       noise(false),
+      pcm(false),
       vol(31),
       outVol(31),
       wave(-1) {}
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 5c01f9db..bc58400d 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -117,6 +117,9 @@ bool DivEngine::perSystemEffect(int ch, unsigned char effect, unsigned char effe
         case 0x11: // noise mode
           dispatchCmd(DivCommand(DIV_CMD_STD_NOISE_MODE,ch,effectVal));
           break;
+        case 0x17: // PCM enable
+          dispatchCmd(DivCommand(DIV_CMD_SAMPLE_MODE,ch,(effectVal>0)));
+          break;
         default:
           return false;
       }