Switch FM sound emulator to ymfm

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "deps/fmgen"]
-	path = deps/fmgen
-	url = https://github.com/kichikuou/fmgen.git
+[submodule "deps/ymfm"]
+	path = deps/ymfm
+	url = https://github.com/aaronsgiles/ymfm.git

src/CMakeLists.txt

@@ -17,7 +17,12 @@ if (MSVC)
   set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
 endif ()
 
-add_subdirectory(../deps/fmgen fmgen)
+add_library(ymfm
+  ../deps/ymfm/src/ymfm_opn.cpp
+  ../deps/ymfm/src/ymfm_adpcm.cpp
+  ../deps/ymfm/src/ymfm_ssg.cpp)
+target_include_directories(ymfm PUBLIC ../deps/ymfm/src)
+
 
 if (ANDROID)
   add_library(system3 SHARED)
@@ -27,7 +32,7 @@ if (ANDROID)
     android/mako.cpp
     sys/mako_midi.cpp
     )
-  target_link_libraries(system3 PRIVATE SDL2 SDL2_ttf fmgen)
+  target_link_libraries(system3 PRIVATE SDL2 SDL2_ttf ymfm)
 
 elseif (EMSCRIPTEN)
   add_executable(system3)
@@ -39,7 +44,7 @@ elseif (EMSCRIPTEN)
   set(LIBS "SHELL:-s USE_SDL=2" "SHELL:-s USE_SDL_TTF=2")
   target_compile_options(system3 PRIVATE ${LIBS})
   target_link_options(system3 PRIVATE ${LIBS})
-  target_link_libraries(system3 PRIVATE idbfs.js fmgen)
+  target_link_libraries(system3 PRIVATE idbfs.js ymfm)
 
   # Without optimizations, Asyncify generates very large code.
   list(APPEND CMAKE_EXE_LINKER_FLAGS_DEBUG "-O1")
@@ -55,7 +60,7 @@ elseif (EMSCRIPTEN)
 
 else()  # NOT (ANDROID OR EMSCRIPTEN)
   add_executable(system3)
-  target_link_libraries(system3 PRIVATE fmgen)
+  target_link_libraries(system3 PRIVATE ymfm)
 
   if (MSVC)
     if (CMAKE_VS_PLATFORM_NAME STREQUAL "Win32")
@@ -151,7 +156,7 @@ target_sources(system3 PRIVATE
   encoding.cpp
   texthook.cpp
   fm/makofm.cpp
-  fm/mako_fmgen.cpp
+  fm/mako_ymfm.cpp
   sys/ags.cpp
   sys/ags_bmp.cpp
   sys/ags_cursor.cpp

src/android/mako.cpp

@@ -6,7 +6,7 @@
 #include "dri.h"
 #include "mako.h"
 #include "mako_midi.h"
-#include "fm/mako_fmgen.h"
+#include "fm/mako_ymfm.h"
 
 namespace {
 
@@ -14,11 +14,11 @@ const int SAMPLE_RATE = 44100;
 
 MAKO *g_mako;
 SDL_mutex* fm_mutex;
-std::unique_ptr<MakoFMgen> fm;
+std::unique_ptr<MakoYmfm> fm;
 
 void audio_callback(void*, Uint8* stream, int len) {
 	SDL_LockMutex(fm_mutex);
-	fm->Process(reinterpret_cast<int16*>(stream), len/ 4);
+	fm->Process(reinterpret_cast<int16_t*>(stream), len/ 4);
 	SDL_UnlockMutex(fm_mutex);
 }
 
@@ -82,7 +82,7 @@ void MAKO::play_music(int page)
 			return;
 
 		SDL_LockMutex(fm_mutex);
-		fm = std::make_unique<MakoFMgen>(SAMPLE_RATE, data, true);
+		fm = std::make_unique<MakoYmfm>(SAMPLE_RATE, data, true);
 		SDL_UnlockMutex(fm_mutex);
 		SDL_PauseAudio(0);
 	} else {

src/emscripten/mako.cpp

@@ -6,13 +6,13 @@
 #include <memory>
 #include <emscripten.h>
 #include "mako.h"
-#include "fm/mako_fmgen.h"
+#include "fm/mako_ymfm.h"
 #include "dri.h"
 
 namespace {
 
 MAKO *g_mako;
-std::unique_ptr<MakoFMgen> fm;
+std::unique_ptr<MakoYmfm> fm;
 
 } // namespace
 
@@ -48,7 +48,7 @@ void MAKO::play_music(int page)
 		if (!data)
 			return;
 		int rate = EM_ASM_INT({ return xsystem35.audio.enable_audio_hook(); });
-		fm = std::make_unique<MakoFMgen>(rate, data, true);
+		fm = std::make_unique<MakoYmfm>(rate, data, true);
 	}
 
 	current_music = page;
@@ -101,7 +101,7 @@ EMSCRIPTEN_KEEPALIVE
 bool audio_callback(Uint8 *stream, int len) {
 	if (!fm)
 		return false;
-	fm->Process(reinterpret_cast<int16*>(stream), len);
+	fm->Process(reinterpret_cast<int16_t*>(stream), len);
 	return true;
 }
 

src/fm/mako_fmgen.cpp

@@ -1,67 +0,0 @@
-#include "mako_fmgen.h"
-#include <algorithm>
-#include <assert.h>
-#include <string.h>
-
-const int OPNA_CLOCK = 3993600 * 2;
-
-MakoFMgen::MakoFMgen(int rate, const uint8_t* data, bool free_data) :
-	MakoFM(data, free_data),
-	sample_rate(rate),
-	sync_ms(0),
-	samples_left(0) {
-	bool ok = opna.Init(OPNA_CLOCK, sample_rate, false);
-	assert(ok);
-	opna.SetVolumePSG(-14);
-	opna.Reset();
-}
-
-void MakoFMgen::Process(int16* stream, int len) {
-	output = stream;
-	out_samples = len;
-
-	if (samples_left > 0) {
-		int samples = samples_left;
-		samples_left = 0;
-		Mix(samples);
-	}
-	while (out_samples > 0) {
-		MainLoop();
-		Sync();
-	}
-}
-
-void MakoFMgen::SetReg(RegType type, uint8_t addr, uint8_t val) {
-	opna.SetReg(addr + (type == OPNA_SLAVE ? 0x100 : 0), val);
-}
-
-void MakoFMgen::Sync() {
-	int t = static_cast<int>(GetTime());
-	if (t == sync_ms)
-		return;
-	int ms = t - sync_ms;
-	sync_ms = t;
-	Mix(sample_rate * ms / 1000);
-}
-
-void MakoFMgen::Mix(int samples) {
-	assert(samples_left == 0);
-	if (samples > out_samples) {
-		samples_left = samples - out_samples;
-		samples = out_samples;
-	}
-	FM_SAMPLETYPE* buf = (FM_SAMPLETYPE*)alloca(samples * 2 * sizeof(FM_SAMPLETYPE));
-	memset(buf, 0, samples * sizeof(FM_SAMPLETYPE) * 2);
-	opna.Mix(buf, samples);
-	for (int i = 0; i < samples * 2; i += 2) {
-		output[i] = std::max(-0x7fff, std::min(0x7fff, buf[i]));
-		output[i+1] = std::max(-0x7fff, std::min(0x7fff, buf[i+1]));
-	}
-	out_samples -= samples;
-	output += samples * 2;
-}
-
-void MakoFMgen::get_mark(int* mark, int* loop) {
-	*mark = GetMark();
-	*loop = Looped() ? 1 : 0;
-}

src/fm/mako_fmgen.h

@@ -1,26 +0,0 @@
-#ifndef MAKOFMGEN_H_
-#define MAKOFMGEN_H_
-
-#include "fmgen/opna.h"
-#include "makofm.h"
-
-class MakoFMgen : private MakoFM {
-public:
-	MakoFMgen(int rate, const uint8_t* data, bool free_data);
-	void Process(int16* stream, int len);
-	void get_mark(int* mark, int* loop);
-
-private:
-	void SetReg(RegType type, uint8_t addr, uint8_t val) override;
-	void Sync();
-	void Mix(int samples);
-
-	const int sample_rate;
-	FM::OPNA opna;
-	int sync_ms;
-	int16* output;
-	int out_samples;
-	int samples_left;
-};
-
-#endif // MAKOFMGEN_H_

src/fm/mako_ymfm.cpp

@@ -0,0 +1,71 @@
+#include "mako_ymfm.h"
+#include <algorithm>
+
+const int OPNA_CLOCK = 3993600 * 2;
+
+int16_t mixSample(int32_t fm, int32_t ssg) {
+	return ymfm::clamp(fm * 2 + ssg / 2, -32768, 32767);
+}
+
+MakoYmfm::MakoYmfm(int rate, const uint8_t* data, bool free_data) :
+	MakoFM(data, free_data),
+	sample_rate(rate),
+	opna(*this)
+{
+	opna.set_fidelity(ymfm::OPN_FIDELITY_MIN);
+	opna.reset();
+}
+
+void MakoYmfm::Process(int16_t* stream, int len) {
+	int16_t* buf = stream;
+
+	if (samples_left > 0) {
+		Generate(buf, samples_left);
+		buf += samples_left * 2;
+		len -= samples_left;
+		samples_left = 0;
+	}
+	while (len > 0) {
+		MainLoop();
+		int t = static_cast<int>(GetTime());
+		int dt = t - last_sync;
+		last_sync = t;
+		int samples = sample_rate * dt / 1000;
+		if (samples > len) {
+			samples_left = samples - len;
+			samples = len;
+		}
+		Generate(buf, samples);
+		buf += samples * 2;
+		len -= samples;
+	}
+}
+
+void MakoYmfm::SetReg(RegType type, uint8_t addr, uint8_t val) {
+	uint32_t offset = type == OPNA_SLAVE ? 2 : 0;
+	opna.write(offset, addr);
+	opna.write(offset + 1, val);
+}
+
+void MakoYmfm::Generate(int16_t* buf, int samples) {
+	const emulated_time output_step = 0x100000000ull / sample_rate;
+	const emulated_time opna_step   = 0x100000000ull / opna.sample_rate(OPNA_CLOCK);
+
+	for (int i = 0; i < samples * 2; i += 2) {
+		ymfm::ym2608::output_data opna_output;
+		// generate at the appropriate sample rate
+		assert(opna_pos <= output_pos);
+		while (opna_pos <= output_pos) {
+			opna.generate(&opna_output);
+			opna_pos += opna_step;
+		}
+		buf[i] = mixSample(opna_output.data[0], opna_output.data[2]);
+		buf[i+1] = mixSample(opna_output.data[1], opna_output.data[2]);
+		output_pos += output_step;
+	}
+}
+
+void MakoYmfm::get_mark(int* mark, int* loop) {
+	*mark = GetMark();
+	*loop = Looped() ? 1 : 0;
+}

src/fm/mako_ymfm.h

@@ -0,0 +1,28 @@
+#ifndef MAKOYMFM_H_
+#define MAKOYMFM_H_
+
+#include "ymfm_opn.h"
+#include "makofm.h"
+
+class MakoYmfm : private MakoFM, private ymfm::ymfm_interface {
+public:
+	MakoYmfm(int rate, const uint8_t* data, bool free_data);
+	void Process(int16_t* stream, int len);
+	void get_mark(int* mark, int* loop);
+
+private:
+	// we use an int64_t as emulated time, as a 32.32 fixed point value
+	using emulated_time = int64_t;
+
+	void SetReg(RegType type, uint8_t addr, uint8_t val) override;
+	void Generate(int16_t* buf, int samples);
+
+	const int sample_rate;
+	ymfm::ym2608 opna;
+	emulated_time opna_pos = 0;
+	emulated_time output_pos = 0;
+	int last_sync = 0;
+	int samples_left = 0;
+};
+
+#endif // MAKOYMFM_H_

src/linux/mako.cpp

@@ -10,7 +10,7 @@
 
 #include "mako.h"
 #include "mako_midi.h"
-#include "fm/mako_fmgen.h"
+#include "fm/mako_ymfm.h"
 #include "../config.h"
 #include "dri.h"
 
@@ -27,11 +27,11 @@ std::vector<uint8> smf;
 Mix_Music *mix_music;
 Mix_Chunk *mix_chunk;
 SDL_mutex* fm_mutex;
-std::unique_ptr<MakoFMgen> fm;
+std::unique_ptr<MakoYmfm> fm;
 
 void FMHook(void *udata, Uint8 *stream, int len) {
 	SDL_LockMutex(fm_mutex);
-	fm->Process(reinterpret_cast<int16*>(stream), len / 4);
+	fm->Process(reinterpret_cast<int16_t*>(stream), len / 4);
 	SDL_UnlockMutex(fm_mutex);
 }
 
@@ -119,7 +119,7 @@ void MAKO::play_music(int page)
 			fm_mutex = SDL_CreateMutex();
 
 		SDL_LockMutex(fm_mutex);
-		fm = std::make_unique<MakoFMgen>(SAMPLE_RATE, data, true);
+		fm = std::make_unique<MakoYmfm>(SAMPLE_RATE, data, true);
 		Mix_HookMusic(&FMHook, this);
 		SDL_UnlockMutex(fm_mutex);
 	} else {

src/win/mako.cpp

@@ -6,13 +6,15 @@
 
 #include <windows.h>
 #undef ERROR
+#undef min
+#undef max
 #include <memory>
 #include <string>
 #include <SDL.h>
 #include <SDL_syswm.h>
 #include "mako.h"
 #include "mako_midi.h"
-#include "fm/mako_fmgen.h"
+#include "fm/mako_ymfm.h"
 #include "../config.h"
 #include "dri.h"
 #include "crc32.h"
@@ -232,11 +234,11 @@ private:
 Music* music;
 uint8* wav_buffer;
 SDL_mutex* fm_mutex;
-std::unique_ptr<MakoFMgen> fm;
+std::unique_ptr<MakoYmfm> fm;
 
 void audio_callback(void*, Uint8* stream, int len) {
 	SDL_LockMutex(fm_mutex);
-	fm->Process(reinterpret_cast<int16*>(stream), len/ 4);
+	fm->Process(reinterpret_cast<int16_t*>(stream), len/ 4);
 	SDL_UnlockMutex(fm_mutex);
 }
 
@@ -332,7 +334,7 @@ void MAKO::play_music(int page)
 			return;
 
 		SDL_LockMutex(fm_mutex);
-		fm = std::make_unique<MakoFMgen>(SAMPLE_RATE, data, true);
+		fm = std::make_unique<MakoYmfm>(SAMPLE_RATE, data, true);
 		SDL_UnlockMutex(fm_mutex);
 		SDL_PauseAudio(0);
 	} else {