Return of the Qt frontend

CMakeLists.txt

@@ -2,10 +2,15 @@ cmake_minimum_required(VERSION 3.2)
 project(NanoBoyAdvance)
 
 option(PLATFORM_SDL2 "Build SDL2 frontend" ON)
+option(PLATFORM_QT "Build Qt frontend" ON)
 
 add_subdirectory(src/nba)
 add_subdirectory(src/platform/core)
 
 if (PLATFORM_SDL2)
   add_subdirectory(src/platform/sdl ${CMAKE_CURRENT_BINARY_DIR}/bin/sdl/)
+endif()
+
+if (PLATFORM_QT)
+  add_subdirectory(src/platform/qt ${CMAKE_CURRENT_BINARY_DIR}/bin/qt/)
 endif()

src/platform/core/CMakeLists.txt

@@ -6,6 +6,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 set(SOURCES
   src/emulator.cpp
+  src/frame_limiter.cpp
   src/game_db.cpp
 )
 
@@ -15,6 +16,7 @@ set(HEADERS
 
 set(HEADERS_PUBLIC
   include/platform/emulator.hpp
+  include/platform/frame_limiter.hpp
 )
 
 add_library(platform-core STATIC ${SOURCES} ${HEADERS} ${HEADERS_PUBLIC})

src/platform/core/include/platform/frame_limiter.hpp

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2021 fleroviux
+ *
+ * Licensed under GPLv3 or any later version.
+ * Refer to the included LICENSE file.
+ */
+
+#pragma once
+
+#include <chrono>
+#include <functional>
+#include <thread>
+
+namespace nba {
+
+struct FrameLimiter {
+  FrameLimiter(float fps = 60.0) {
+    Reset(fps);
+  }
+
+  void Reset();
+  void Reset(float fps);
+  void SetFastForward(bool value);
+
+  void Run(
+    std::function<void(void)> frame_advance,
+    std::function<void(float)> update_fps
+  );
+
+private:
+  static constexpr int kMillisecondsPerSecond = 1000;
+  static constexpr int kMicrosecondsPerSecond = 1000000;
+
+  int frame_count = 0;
+  int frame_duration;
+  float frames_per_second;
+  bool fast_forward = false;
+
+  std::chrono::time_point<std::chrono::steady_clock> timestamp_target;
+  std::chrono::time_point<std::chrono::steady_clock> timestamp_fps_update;
+};
+
+} // namespace nba

src/platform/core/src/frame_limiter.cpp

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2021 fleroviux
+ *
+ * Licensed under GPLv3 or any later version.
+ * Refer to the included LICENSE file.
+ */
+
+#include <platform/frame_limiter.hpp>
+
+namespace nba {
+
+void FrameLimiter::Reset() {
+  Reset(frames_per_second);
+}
+
+void FrameLimiter::Reset(float fps) {
+  frame_count = 0;
+  frame_duration = int(kMicrosecondsPerSecond / fps);
+  frames_per_second = fps;
+  fast_forward = false;
+  timestamp_target = std::chrono::steady_clock::now();
+  timestamp_fps_update = std::chrono::steady_clock::now();
+}
+
+void FrameLimiter::SetFastForward(bool value) {
+  if (fast_forward != value) {
+    fast_forward = value;
+    if (!fast_forward) {
+      timestamp_target = std::chrono::steady_clock::now();
+    }
+  }
+}
+
+void FrameLimiter::Run(
+  std::function<void(void)> frame_advance,
+  std::function<void(float)> update_fps
+) {
+  timestamp_target += std::chrono::microseconds(frame_duration);
+
+  frame_advance();
+  frame_count++;
+
+  auto now = std::chrono::steady_clock::now(); 
+  auto fps_update_delta = std::chrono::duration_cast<std::chrono::milliseconds>(
+    now - timestamp_fps_update).count();
+
+  if (fps_update_delta >= kMillisecondsPerSecond) {
+    update_fps(frame_count * float(kMillisecondsPerSecond) / fps_update_delta);
+    frame_count = 0;
+    timestamp_fps_update = std::chrono::steady_clock::now();
+  }
+
+  if (!fast_forward) {
+    std::this_thread::sleep_until(timestamp_target);
+  }
+}
+
+} // namespace nba

src/platform/qt/CMakeLists.txt

@@ -0,0 +1,34 @@
+project(NanoBoyAdvance-Qt CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR}/CMakeModules)
+
+set(SOURCES
+  main.cpp
+  screen.cpp
+  main_window.cpp
+)
+
+set(HEADERS
+  screen.hpp
+  main_window.hpp
+)
+
+# CHECKME: dunno, is this required?
+set(CMAKE_AUTOMOC ON)
+
+# CHECKME: possibly we can get rid of all OpenGL dependencies here.
+find_package(OpenGL REQUIRED)
+find_package(Qt5Gui REQUIRED)
+find_package(Qt5Widgets REQUIRED)
+find_package(Qt5OpenGL REQUIRED)
+set(QT_DEPS Qt5::Gui Qt5::Widgets Qt5::OpenGL)
+
+include(FindSDL2 REQUIRED)
+find_package(SDL2 REQUIRED)
+include_directories(${SDL2_INCLUDE_DIR})
+
+add_executable(NanoBoyAdvance-Qt ${SOURCES} ${HEADERS})
+target_link_libraries(NanoBoyAdvance-Qt platform-core ${QT_DEPS} ${OPENGL_gl_LIBRARY} ${SDL2_LIBRARY})
+set_target_properties(NanoBoyAdvance-Qt PROPERTIES OUTPUT_NAME "NanoBoyAdvance")

src/platform/qt/main.cpp

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2021 fleroviux
+ *
+ * Licensed under GPLv3 or any later version.
+ * Refer to the included LICENSE file.
+ */
+
+#include <QApplication>
+
+#include "main_window.hpp"
+
+int main(int argc, char** argv) {
+  QApplication app{ argc, argv };
+  MainWindow window{ &app };
+
+  QCoreApplication::setOrganizationName("fleroviux");
+  QCoreApplication::setApplicationName("NanoboyAdvance");
+
+  window.show();
+  return app.exec();
+}