Refactor audio handling in Controller; replace LoadAudioDevice with backend audio initialization and shutdown methods

src/app/core/controller.cc

@@ -22,7 +22,12 @@ absl::Status Controller::OnEntry(std::string filename) {
   RETURN_IF_ERROR(CreateWindow())
   RETURN_IF_ERROR(CreateRenderer())
   RETURN_IF_ERROR(CreateGuiContext())
-  RETURN_IF_ERROR(LoadAudioDevice())
+  backend_.init_audio();
+  // cast to Sdl2backend to access audio buffer and device
+  auto &sdl2_backend = static_cast<Sdl2Backend &>(backend_);
+  editor_manager_.emulator().set_audio_buffer(
+      sdl2_backend.audio_buffer().get());
+  editor_manager_.emulator().set_audio_device_id(sdl2_backend.audio_device());
   Initialize(filename);
   return absl::OkStatus();
 }
@@ -108,10 +113,6 @@ absl::Status Controller::OnLoad() {
   return absl::OkStatus();
 }
 
-
-
-
-
 void Controller::DoRender() const {
   ImGui::Render();
   SDL_RenderClear(Renderer::GetInstance().renderer());
@@ -121,8 +122,7 @@ void Controller::DoRender() const {
 }
 
 void Controller::OnExit() {
-  SDL_PauseAudioDevice(audio_device_, 1);
-  SDL_CloseAudioDevice(audio_device_);
+  backend_.shutdown_audio();
   ImGui_ImplSDLRenderer2_Shutdown();
   ImGui_ImplSDL2_Shutdown();
   ImGui::DestroyContext();
@@ -180,32 +180,11 @@ absl::Status Controller::CreateGuiContext() {
   gui::ColorsYaze();
 
   // Build a new ImGui frame
-  ImGui_ImplSDLRenderer2_NewFrame();
-  ImGui_ImplSDL2_NewFrame();
+  backend_.new_frame();
 
   return absl::OkStatus();
 }
 
-absl::Status Controller::LoadAudioDevice() {
-  SDL_AudioSpec want, have;
-  SDL_memset(&want, 0, sizeof(want));
-  want.freq = audio_frequency_;
-  want.format = AUDIO_S16;
-  want.channels = 2;
-  want.samples = 2048;
-  want.callback = NULL;  // Uses the queue
-  audio_device_ = SDL_OpenAudioDevice(NULL, 0, &want, &have, 0);
-  if (audio_device_ == 0) {
-    return absl::InternalError(
-        absl::StrFormat("Failed to open audio: %s\n", SDL_GetError()));
-  }
-  audio_buffer_ = std::make_shared<int16_t>(audio_frequency_ / 50 * 4);
-  SDL_PauseAudioDevice(audio_device_, 0);
-  editor_manager_.emulator().set_audio_buffer(audio_buffer_.get());
-  editor_manager_.emulator().set_audio_device_id(audio_device_);
-  return absl::OkStatus();
-}
-
 absl::Status Controller::LoadConfigFiles() {
   // Create and load a dotfile for the application
   // This will store the user's preferences and settings

src/app/core/controller.h

@@ -6,9 +6,9 @@
 #include <memory>
 
 #include "absl/status/status.h"
+#include "app/core/platform/backend.h"
 #include "app/core/platform/file_dialog.h"
 #include "app/core/platform/renderer.h"
-#include "app/editor/editor.h"
 #include "app/editor/editor_manager.h"
 #include "imgui/backends/imgui_impl_sdl2.h"
 #include "imgui/backends/imgui_impl_sdlrenderer2.h"
@@ -39,7 +39,6 @@ class Controller {
   absl::Status CreateWindow();
   absl::Status CreateRenderer();
   absl::Status CreateGuiContext();
-  absl::Status LoadAudioDevice();
   absl::Status LoadConfigFiles();
 
   auto window() -> SDL_Window * { return window_.get(); }
@@ -51,11 +50,8 @@ class Controller {
 
   bool active_ = false;
   editor::EditorManager editor_manager_;
-
-  int audio_frequency_ = 48000;
-  SDL_AudioDeviceID audio_device_;
-  std::shared_ptr<int16_t> audio_buffer_;
   std::shared_ptr<SDL_Window> window_;
+  core::PlatformBackend<Sdl2Backend> backend_;
 };
 
 }  // namespace core

src/app/core/platform/backend.h

@@ -0,0 +1,125 @@
+#ifndef YAZE_APP_CORE_PLATFORM_BACKEND_H
+#define YAZE_APP_CORE_PLATFORM_BACKEND_H
+
+#include <SDL.h>
+
+#include <memory>
+#include <stdexcept>
+
+#include "app/core/platform/renderer.h"
+#include "app/core/platform/sdl_deleter.h"
+#include "imgui/backends/imgui_impl_sdl2.h"
+#include "imgui/backends/imgui_impl_sdlrenderer2.h"
+
+namespace yaze {
+namespace core {
+
+template <typename Derived>
+class PlatformBackend {
+ public:
+  PlatformBackend() = default;
+  ~PlatformBackend() = default;
+
+  void init() { static_cast<Derived *>(this)->init(); }
+  void init_audio() { static_cast<Derived *>(this)->init_audio(); }
+  void shutdown_audio() { static_cast<Derived *>(this)->shutdown_audio(); }
+  void shutdown() { static_cast<Derived *>(this)->shutdown(); }
+  void new_frame() { static_cast<Derived *>(this)->new_frame(); }
+  void render() { static_cast<Derived *>(this)->render(); }
+};
+
+class Sdl2Backend : public PlatformBackend<Sdl2Backend> {
+ public:
+  Sdl2Backend() = default;
+  ~Sdl2Backend() = default;
+
+  void init() {
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) !=
+        0) {
+      throw std::runtime_error("Failed to initialize SDL2");
+    }
+
+    SDL_DisplayMode display_mode;
+    SDL_GetCurrentDisplayMode(0, &display_mode);
+    int screen_width = display_mode.w * 0.8;
+    int screen_height = display_mode.h * 0.8;
+
+    window = std::unique_ptr<SDL_Window, core::SDL_Deleter>(
+        SDL_CreateWindow("Yet Another Zelda3 Editor",  // window title
+                         SDL_WINDOWPOS_UNDEFINED,      // initial x position
+                         SDL_WINDOWPOS_UNDEFINED,      // initial y position
+                         screen_width,                 // width, in pixels
+                         screen_height,                // height, in pixels
+                         SDL_WINDOW_RESIZABLE),
+        core::SDL_Deleter());
+    if (!window) {
+      throw std::runtime_error("Failed to create window");
+    }
+
+    if (!Renderer::GetInstance().CreateRenderer(window.get()).ok()) {
+      throw std::runtime_error("Failed to create renderer");
+    }
+
+    ImGui_ImplSDL2_InitForSDLRenderer(window.get(),
+                                      Renderer::GetInstance().renderer());
+    ImGui_ImplSDLRenderer2_Init(Renderer::GetInstance().renderer());
+  }
+
+  void init_audio() {
+    const int audio_frequency = 48000;
+    SDL_AudioSpec want, have;
+    SDL_memset(&want, 0, sizeof(want));
+    want.freq = audio_frequency;
+    want.format = AUDIO_S16;
+    want.channels = 2;
+    want.samples = 2048;
+    want.callback = NULL;  // Uses the queue
+    audio_device_ = SDL_OpenAudioDevice(NULL, 0, &want, &have, 0);
+    if (audio_device_ == 0) {
+      throw std::runtime_error(
+          absl::StrFormat("Failed to open audio: %s\n", SDL_GetError()));
+    }
+    audio_buffer_ = std::make_shared<int16_t>(audio_frequency / 50 * 4);
+    SDL_PauseAudioDevice(audio_device_, 0);
+  }
+
+  void shutdown_audio() {
+    SDL_PauseAudioDevice(audio_device_, 1);
+    SDL_CloseAudioDevice(audio_device_);
+  }
+
+  void shutdown() {
+    ImGui_ImplSDL2_Shutdown();
+    ImGui_ImplSDLRenderer2_Shutdown();
+    SDL_DestroyRenderer(Renderer::GetInstance().renderer());
+    SDL_DestroyWindow(window.get());
+    SDL_Quit();
+  }
+
+  void new_frame() {
+    ImGui_ImplSDLRenderer2_NewFrame();
+    ImGui_ImplSDL2_NewFrame();
+  }
+
+  void render() {
+    ImGui::Render();
+    SDL_RenderClear(Renderer::GetInstance().renderer());
+    ImGui_ImplSDLRenderer2_RenderDrawData(ImGui::GetDrawData(),
+                                          Renderer::GetInstance().renderer());
+    SDL_RenderPresent(Renderer::GetInstance().renderer());
+  }
+
+  auto window_ptr() -> SDL_Window * { return window.get(); }
+  auto audio_device() -> SDL_AudioDeviceID { return audio_device_; }
+  auto audio_buffer() -> std::shared_ptr<int16_t> { return audio_buffer_; }
+
+ private:
+  SDL_AudioDeviceID audio_device_;
+  std::shared_ptr<int16_t> audio_buffer_;
+  std::unique_ptr<SDL_Window, SDL_Deleter> window;
+};
+
+}  // namespace core
+}  // namespace yaze
+
+#endif  // YAZE_APP_CORE_PLATFORM_BACKEND_H