From 591cd633d7d380496e529ae8c857de7becd8e2f3 Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Sun, 19 Mar 2023 16:49:31 -0500
Subject: [PATCH] SegaPCM: implement getSamplePos()

---
 src/engine/platform/segapcm.cpp       | 11 +++++++++++
 src/engine/platform/segapcm.h         |  1 +
 src/engine/platform/sound/segapcm.cpp | 14 +++++++++++++-
 src/engine/platform/sound/segapcm.h   |  2 ++
 4 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/engine/platform/segapcm.cpp b/src/engine/platform/segapcm.cpp
index 0b02bb40..a4003a2b 100644
--- a/src/engine/platform/segapcm.cpp
+++ b/src/engine/platform/segapcm.cpp
@@ -382,6 +382,17 @@ DivMacroInt* DivPlatformSegaPCM::getChanMacroInt(int ch) {
   return &chan[ch].std;
 }
 
+DivSamplePos DivPlatformSegaPCM::getSamplePos(int ch) {
+  if (ch>=16) return DivSamplePos();
+  if (chan[ch].pcm.sample<0 || chan[ch].pcm.sample>=parent->song.sampleLen) return DivSamplePos();
+  if (!pcm.is_playing(ch)) return DivSamplePos();
+  return DivSamplePos(
+    chan[ch].pcm.sample,
+    pcm.get_addr(ch)-sampleOffSegaPCM[chan[ch].pcm.sample],
+    122*(chan[ch].pcm.freq+1)
+  );
+}
+
 DivDispatchOscBuffer* DivPlatformSegaPCM::getOscBuffer(int ch) {
   return oscBuf[ch];
 }
diff --git a/src/engine/platform/segapcm.h b/src/engine/platform/segapcm.h
index f99a24df..9e2ad5df 100644
--- a/src/engine/platform/segapcm.h
+++ b/src/engine/platform/segapcm.h
@@ -87,6 +87,7 @@ class DivPlatformSegaPCM: public DivDispatch {
     int dispatch(DivCommand c);
     void* getChanState(int chan);
     DivMacroInt* getChanMacroInt(int ch);
+    DivSamplePos getSamplePos(int ch);
     DivDispatchOscBuffer* getOscBuffer(int chan);
     unsigned char* getRegisterPool();
     int getRegisterPoolSize();
diff --git a/src/engine/platform/sound/segapcm.cpp b/src/engine/platform/sound/segapcm.cpp
index 4dd58eb2..d469e3a1 100644
--- a/src/engine/platform/sound/segapcm.cpp
+++ b/src/engine/platform/sound/segapcm.cpp
@@ -134,6 +134,18 @@ uint8_t* segapcm_device::get_ram() {
   return m_ram;
 }
 
+unsigned int segapcm_device::get_addr(int ch) {
+  uint8_t *regs = &m_ram[8*ch];
+  int offset = (regs[0x86] & m_bankmask) << m_bankshift;
+  uint32_t addr = (regs[0x85] << 8) | (regs[0x84]) | offset;
+  return addr;
+}
+
+bool segapcm_device::is_playing(int ch) {
+  uint8_t *regs = &m_ram[8*ch];
+  return !(regs[0x86]&1);
+}
+
 void segapcm_device::mute(int ch, bool doMute) {
   m_muted[ch&15]=doMute;
-}
\ No newline at end of file
+}
diff --git a/src/engine/platform/sound/segapcm.h b/src/engine/platform/sound/segapcm.h
index 40ca35a4..819202cd 100644
--- a/src/engine/platform/sound/segapcm.h
+++ b/src/engine/platform/sound/segapcm.h
@@ -34,6 +34,8 @@ public:
 	void write(unsigned int offset, uint8_t data);
 	uint8_t read(unsigned int offset);
   uint8_t* get_ram();
+  unsigned int get_addr(int ch);
+  bool is_playing(int ch);
   void mute(int ch, bool doMute);
 
 	// device-level overrides