From aaf972453113aa78931b104537096fafcc32241c Mon Sep 17 00:00:00 2001
From: scawful <justin.scofield@outlook.com>
Date: Wed, 24 Apr 2024 12:32:09 -0400
Subject: [PATCH] Move Apu cycling from SNES to Apu class

---
 src/app/emu/audio/apu.cc | 16 ++++++++--------
 src/app/emu/audio/apu.h  |  6 +++---
 src/app/emu/snes.cc      |  9 +--------
 src/app/emu/snes.h       |  1 +
 4 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/src/app/emu/audio/apu.cc b/src/app/emu/audio/apu.cc
index 79704e35..1be425aa 100644
--- a/src/app/emu/audio/apu.cc
+++ b/src/app/emu/audio/apu.cc
@@ -17,6 +17,9 @@ namespace app {
 namespace emu {
 namespace audio {
 
+static const double apuCyclesPerMaster = (32040 * 32) / (1364 * 262 * 60.0);
+static const double apuCyclesPerMasterPal = (32040 * 32) / (1364 * 312 * 50.0);
+
 static const uint8_t bootRom[0x40] = {
     0xcd, 0xef, 0xbd, 0xe8, 0x00, 0xc6, 0x1d, 0xd0, 0xfc, 0x8f, 0xaa,
     0xf4, 0x8f, 0xbb, 0xf5, 0x78, 0xcc, 0xf4, 0xd0, 0xfb, 0x2f, 0x19,
@@ -59,17 +62,14 @@ void Apu::Update() {
   }
 }
 
-int Apu::RunCycles(uint32_t wanted_cycles) {
-  int run_cycles = 0;
-  uint32_t start_cycles = cycles_;
+void Apu::RunCycles(uint64_t cycles) {
+  uint64_t sync_to =
+      (uint64_t)cycles *
+      (memory_.pal_timing() ? apuCyclesPerMasterPal : apuCyclesPerMaster);
 
-  while (run_cycles < wanted_cycles) {
+  while (cycles_ < sync_to) {
     spc700_.RunOpcode();
-
-    run_cycles += (uint32_t)cycles_ - start_cycles;
-    start_cycles = cycles_;
   }
-  return run_cycles;
 }
 
 void Apu::Cycle() {
diff --git a/src/app/emu/audio/apu.h b/src/app/emu/audio/apu.h
index 0f37bf49..d3bb7857 100644
--- a/src/app/emu/audio/apu.h
+++ b/src/app/emu/audio/apu.h
@@ -56,14 +56,13 @@ typedef struct Timer {
  */
 class Apu {
  public:
-  Apu(MemoryImpl &memory, Clock &clock)
-      : clock_(clock), memory_(memory) {}
+  Apu(MemoryImpl &memory, Clock &clock) : clock_(clock), memory_(memory) {}
 
   void Init();
   void Reset();
   void Update();
 
-  int RunCycles(uint32_t wanted_cycles);
+  void RunCycles(uint64_t cycles);
   uint8_t SpcRead(uint16_t address);
   void SpcWrite(uint16_t address, uint8_t data);
   void SpcIdle(bool waiting);
@@ -76,6 +75,7 @@ class Apu {
   void UpdateClock(int delta_time) { clock_.UpdateClock(delta_time); }
 
   auto dsp() -> Dsp & { return dsp_; }
+  auto spc700() -> Spc700 & { return spc700_; }
 
   // Port buffers (equivalent to $2140 to $2143 for the main CPU)
   uint8_t in_ports_[6];  // includes 2 bytes of ram
diff --git a/src/app/emu/snes.cc b/src/app/emu/snes.cc
index 507447d8..90dbe245 100644
--- a/src/app/emu/snes.cc
+++ b/src/app/emu/snes.cc
@@ -87,18 +87,13 @@ void SNES::RunFrame() {
   while (!in_vblank_ && frame == frames_) {
     cpu_.RunOpcode();
   }
-  CatchUpApu();
 }
 
 void SNES::CatchUpApu() {
-  int catchup_cycles = (int)apu_catchup_cycles_;
-  int ran_cycles = apu_.RunCycles(catchup_cycles);
-  apu_catchup_cycles_ -= ran_cycles;
+  apu_.RunCycles(cycles_);
 }
 
 namespace {
-static const double apuCyclesPerMaster = (32040 * 32) / (1364 * 262 * 60.0);
-static const double apuCyclesPerMasterPal = (32040 * 32) / (1364 * 312 * 50.0);
 
 void input_latch(Input* input, bool value) {
   input->latchLine = value;
@@ -132,8 +127,6 @@ void SNES::HandleInput() {
 }
 
 void SNES::RunCycle() {
-  apu_catchup_cycles_ +=
-      (memory_.pal_timing() ? apuCyclesPerMasterPal : apuCyclesPerMaster) * 2.0;
   cycles_ += 2;
 
   // check for h/v timer irq's
diff --git a/src/app/emu/snes.h b/src/app/emu/snes.h
index dd84b318..c0728ded 100644
--- a/src/app/emu/snes.h
+++ b/src/app/emu/snes.h
@@ -69,6 +69,7 @@ class SNES {
   bool running() const { return running_; }
   auto cpu() -> Cpu& { return cpu_; }
   auto ppu() -> video::Ppu& { return ppu_; }
+  auto apu() -> audio::Apu& { return apu_; }
   auto Memory() -> memory::MemoryImpl& { return memory_; }
 
  private: