Basic audio system start

CMakeLists.txt

@@ -83,7 +83,11 @@ source_group("dusk" FILES ${DUSK_FILES})
 
 # game_debug is for game code files that we know work when compiled with DEBUG=1
 # Of course, if building a release build, this distinction is irrelevant
-add_library(game_debug STATIC ${JSYSTEM_DEBUG_FILES} ${SSYSTEM_FILES})
+add_library(game_debug STATIC ${JSYSTEM_DEBUG_FILES} ${SSYSTEM_FILES}
+        src/dusk/audio/DuskAudioSystem.cpp
+        src/dusk/audio/JASCriticalSection.cpp
+        src/dusk/audio/DuskDsp.hpp
+        src/dusk/audio/DuskDsp.cpp)
 target_compile_definitions(game_debug PRIVATE TARGET_PC AVOID_UB=1 VERSION=0 $<$<CONFIG:Debug>:DEBUG=1>)
 
 # Make these properties PUBLIC so that the regular game target also sees them.

include/dusk/audio/DuskAudioSystem.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void DuskAudioInitialize();

libs/JSystem/src/JAudio2/JAUInitializer.cpp

@@ -15,6 +15,8 @@
 #include "JSystem/JKernel/JKRSolidHeap.h"
 #include "JSystem/JKernel/JKRThread.h"
 
+#include "dusk/audio/DuskAudioSystem.h"
+
 JAU_JASInitializer::JAU_JASInitializer() {
     audioMemory_ = 0;
     audioMemSize_ = 0;
@@ -60,7 +62,11 @@ void JAU_JASInitializer::initJASystem(JKRSolidHeap* heap) {
         }
 
         JASDvd::createThread(dvdThreadPriority_, 0x80, 0x1000);
+#if TARGET_PC
+        DuskAudioInitialize();
+#else
         JASAudioThread::create(audioThreadPriority_);
+#endif
         JKRThreadSwitch* threadSwitch = JKRThreadSwitch::getManager();
         if (threadSwitch) {
             if (dvdThreadId_ >= 0) {

src/dusk/audio/DuskAudioSystem.cpp

@@ -0,0 +1,82 @@
+#include "dusk/audio/DuskAudioSystem.h"
+
+#include <SDL3/SDL_init.h>
+#include <array>
+
+#include "JSystem/JAudio2/JASAiCtrl.h"
+#include "JSystem/JAudio2/JASChannel.h"
+#include "JSystem/JAudio2/JASCriticalSection.h"
+#include "JSystem/JAudio2/JASDSPChannel.h"
+#include "JSystem/JAudio2/JASHeapCtrl.h"
+
+#include "DuskDsp.hpp"
+
+static DspSubframe AllSubframeBuffers[DSP_OUTPUT_CHANNELS];
+
+static SDL_AudioStream* PlaybackStream;
+
+static void SDLCALL GetNewAudio(
+    void *userdata,
+    SDL_AudioStream *stream,
+    int additional_amount,
+    int total_amount);
+
+static int RenderNewAudioFrame();
+static void RenderAudioSubframe();
+
+static void InitSDL3Output() {
+    SDL_Init(SDL_INIT_AUDIO);
+
+    constexpr SDL_AudioSpec spec = {
+        SDL_AUDIO_S16,
+        1,
+        32000,
+    };
+    PlaybackStream = SDL_OpenAudioDeviceStream(
+        SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK,
+        &spec,
+        &GetNewAudio,
+        nullptr);
+}
+
+void DuskAudioInitialize() {
+    InitSDL3Output();
+
+    JASDsp::initBuffer();
+    JASDSPChannel::initAll();
+
+    JASPoolAllocObject_MultiThreaded<JASChannel>::newMemPool(0x48);
+
+    SDL_ResumeAudioStreamDevice(PlaybackStream);
+}
+
+void SDLCALL GetNewAudio(
+    void*,
+    SDL_AudioStream*,
+    int,
+    int total_amount) {
+    while (total_amount > 0) {
+        const int rendered = RenderNewAudioFrame();
+        total_amount -= rendered;
+    }
+}
+
+int RenderNewAudioFrame() {
+    JASCriticalSection section;
+    const u32 countSubframes = JASDriver::getSubFrames();
+
+    for (u32 i = 0; i < countSubframes; i++) {
+        RenderAudioSubframe();
+    }
+
+    return static_cast<u16>(countSubframes) * DSP_SUBFRAME_SIZE;
+}
+
+void RenderAudioSubframe() {
+    DspSubframe& subFrame = AllSubframeBuffers[0];
+
+    JASDriver::updateDSP();
+    DuskDspRender(subFrame);
+
+    SDL_PutAudioStreamData(PlaybackStream, &subFrame, sizeof(subFrame));
+}

src/dusk/audio/DuskDsp.cpp

@@ -0,0 +1,16 @@
+#include "DuskDsp.hpp"
+
+#include <limits>
+
+static float SinePos;
+
+void DuskDspRender(DspSubframe& subframe) {
+    subframe.fill(0);
+
+    for (auto& elem : subframe) {
+        elem = static_cast<s16>(sinf(SinePos) * std::numeric_limits<s16>::max() * 0.2);
+        SinePos += 0.05f;
+    }
+
+    auto& channels = *reinterpret_cast<std::array<JASDsp::TChannel, DSP_CHANNELS>*>(JASDsp::CH_BUF);
+}

src/dusk/audio/DuskDsp.hpp

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "JSystem/JAudio2/JASDSPInterface.h"
+
+#include <array>
+
+using DspSubframe = std::array<s16, DSP_SUBFRAME_SIZE>;
+
+void DuskDspRender(DspSubframe& subframe);