Merge pull request #15 from audetto/retro2

Implement a libretro core.

CMakeLists.txt

@@ -12,6 +12,9 @@ MESSAGE("CMAKE_CXX_FLAGS_RELEASE:         ${CMAKE_CXX_FLAGS_RELEASE}")
 MESSAGE("CMAKE_CXX_FLAGS_DEBUG:           ${CMAKE_CXX_FLAGS_DEBUG}")
 MESSAGE("CMAKE_CXX_FLAGS_RELWITHDEBINFO:  ${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
 
+# this only affects common2, the others are already build with fPIC by default
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR})
 
 execute_process(COMMAND uname -n
@@ -35,4 +38,5 @@ add_subdirectory(source/frontends/common2)
 add_subdirectory(source/frontends/ncurses)
 add_subdirectory(source/frontends/qapple)
 add_subdirectory(source/frontends/sa2)
+add_subdirectory(source/frontends/retro)
 add_subdirectory(test/TestCPU6502)

linux.md

@@ -6,6 +6,7 @@
   * [applen](#applen)
   * [qapple](#qapple)
   * [sa2](#sa2)
+  * [libretro](#ra2)
 * [Build](#build)
   * [Checkout](#checkout)
   * [Fedora](#fedora)
@@ -88,6 +89,20 @@ This is based on Qt, currently tested with 5.10
 
 See [sa2](source/frontends/sa2/README.md).
 
+### ra2
+
+There is an initial [libretro](https://docs.libretro.com/development/cores/developing-cores/) core.
+
+Keyboard works, but a lot of keys overlap with RetroArch shortcuts.
+
+Video works, but the vertical flip is done in software.
+
+Must be manually configured:
+``cmake -DLIBRETRO_PATH=/path/to/libretro-common``
+
+Easiest way to run from the ``build`` folder:
+``retroarch -L source/frontends/retro/libra2.so ../Disks/NoSlotClockTest.dsk``
+
 ## Build
 
 The project can be built using cmake from the top level directory.

source/frontends/common2/CMakeLists.txt

@@ -18,7 +18,7 @@ target_include_directories(common2 PRIVATE
   ${Boost_INCLUDE_DIRS}
   )
 
-target_link_libraries(common2 PRIVATE
+target_link_libraries(common2 PUBLIC
   Boost::program_options
 )
 

source/frontends/common2/config.h.in

@@ -1,3 +1,6 @@
 // relative path from executable to resources
 #cmakedefine ROOT_PATH "@ROOT_PATH@"
 #cmakedefine SHARE_PATH "@SHARE_PATH@"
+
+// this one is a bit of a hack, until resources are embedded in the retro core
+#cmakedefine CMAKE_SOURCE_DIR "@CMAKE_SOURCE_DIR@"

source/frontends/common2/resources.cpp

@@ -27,6 +27,8 @@ namespace
 
   std::string getResourcePathImpl()
   {
+    std::vector<std::string> paths;
+
     char self[1024] = {0};
     const int ch = readlink("/proc/self/exe", self,  sizeof(self));
     if (ch != -1)
@@ -34,21 +36,24 @@ namespace
       const char * path = dirname(self);
 
       // case 1: run from the build folder
-      const std::string path1 = std::string(path) + '/'+ ROOT_PATH + "/resource/";
+      paths.emplace_back(std::string(path) + '/'+ ROOT_PATH);
-      if (dirExists(path1))
-      {
-	return path1;
-      }
-
       // case 2: run from the installation folder
-      const std::string path2 = std::string(path) + '/'+ SHARE_PATH + "/resource/";
+      paths.emplace_back(std::string(path) + '/'+ SHARE_PATH);
-      if (dirExists(path2))
+    }
+
+    // case 3: use the source folder
+    paths.emplace_back(CMAKE_SOURCE_DIR);
+
+    for (const std::string & path : paths)
+    {
+      const std::string resourcePath = path + "/resource/";
+      if (dirExists(resourcePath))
       {
-	return path2;
+	return resourcePath;
       }
     }
-    // else?
+
-    return std::string();
+    throw std::runtime_error("Cannot found the resource path");
   }
 
 }

source/frontends/retro/CMakeLists.txt

@@ -0,0 +1,27 @@
+# there is no simple package for libretro-common
+# this requires user input
+set(LIBRETRO_PATH NONE CACHE PATH "path to libretro-common")
+
+if (IS_DIRECTORY ${LIBRETRO_PATH})
+  message("Using LIBRETRO_PATH=${LIBRETRO_PATH}")
+
+  add_library(ra2 SHARED
+    environment.cpp
+    libretro.cpp
+    bitmaps.cpp
+    rdirectsound.cpp
+    interface.cpp
+    game.cpp
+    )
+
+  target_include_directories(ra2 PRIVATE
+    ${LIBRETRO_PATH}/include
+    )
+
+  target_link_libraries(ra2 PRIVATE
+    appleii
+    common2
+    )
+else()
+  message("Bad LIBRETRO_PATH=${LIBRETRO_PATH}, skipping libretro code")
+endif()

source/frontends/retro/bitmaps.cpp

@@ -0,0 +1,151 @@
+#include "frontends/retro/environment.h"
+
+#include <linux/interface.h>
+#include <linux/windows/misc.h>
+#include <frontends/common2/resources.h>
+
+#include <fstream>
+#include <cstring>
+
+namespace
+{
+
+  void readFileToBuffer(const std::string & filename, std::vector<char> & buffer)
+  {
+    std::ifstream file(filename.c_str(), std::ios::binary | std::ios::ate);
+    const std::streamsize size = file.tellg();
+    file.seekg(0, std::ios::beg);
+
+    buffer.resize(size);
+    file.read(buffer.data(), size);
+  }
+
+  template<typename T>
+  T getAs(const std::vector<char> & buffer, const size_t offset)
+  {
+    if (offset + sizeof(T) > buffer.size())
+    {
+      throw std::runtime_error("Invalid bitmap");
+    }
+    const T * ptr = reinterpret_cast<const T *>(buffer.data() + offset);
+    return * ptr;
+  }
+
+  // libretro cannot parse BMP with 1 bpp
+  // simple version implemented here
+  bool getBitmapData(const std::vector<char> & buffer, int32_t & width, int32_t & height, uint16_t & bpp, const char * & data, uint32_t & size)
+  {
+    if (buffer.size() < 2)
+    {
+      return false;
+    }
+
+    if (buffer[0] != 0x42 || buffer[1] != 0x4D)
+    {
+      return false;
+    }
+
+    const uint32_t fileSize = getAs<uint32_t>(buffer, 2);
+    if (fileSize != buffer.size())
+    {
+      return false;
+    }
+
+    const uint32_t offset = getAs<uint32_t>(buffer, 10);
+    const uint32_t header = getAs<uint32_t>(buffer, 14);
+    if (header != 40)
+    {
+      return false;
+    }
+
+    width = getAs<int32_t>(buffer, 18);
+    height = getAs<int32_t>(buffer, 22);
+    bpp = getAs<uint16_t>(buffer, 28);
+    const uint32_t imageSize = getAs<uint32_t>(buffer, 34);
+    if (offset + imageSize > fileSize)
+    {
+      return false;
+    }
+    data = buffer.data() + offset;
+    size = imageSize;
+    return true;
+  }
+
+}
+
+struct CBITMAP : public CHANDLE
+{
+  std::vector<char> image;
+};
+
+std::string getFilename(const std::string & resource)
+{
+  if (resource == "CHARSET40") return "CHARSET4.BMP";
+  if (resource == "CHARSET82") return "CHARSET82.bmp";
+  if (resource == "CHARSET8M") return "CHARSET8M.bmp";
+  if (resource == "CHARSET8C") return "CHARSET8C.bmp";
+
+  return resource;
+}
+
+HBITMAP LoadBitmap(HINSTANCE hInstance, const char * resource)
+{
+  if (resource)
+  {
+    const std::string filename = getFilename(resource);
+    const std::string path = getResourcePath() + filename;
+
+    std::vector<char> buffer;
+    readFileToBuffer(path, buffer);
+
+    if (!buffer.empty())
+    {
+      int32_t width, height;
+      uint16_t bpp;
+      const char * data;
+      uint32_t size;
+      const bool res = getBitmapData(buffer, width, height, bpp, data, size);
+
+      log_cb(RETRO_LOG_INFO, "RA2: %s. %s = %dx%d, %dbpp\n", __FUNCTION__, path.c_str(),
+	     width, height, bpp);
+
+      if (res && height > 0)
+      {
+	CBITMAP * bitmap = new CBITMAP;
+	bitmap->image.resize(size);
+	const size_t length = size / height;
+	// rows are stored upside down
+	for (size_t row = 0; row < height; ++row)
+	{
+	  const char * src = data + row * length;
+	  char * dst = bitmap->image.data() + (height - row - 1) * length;
+	  memcpy(dst, src, length);
+	}
+	return bitmap;
+      }
+    }
+    else
+    {
+      log_cb(RETRO_LOG_INFO, "RA2: %s. Cannot load: %s with path: %s\n", __FUNCTION__, resource, path.c_str());
+      return nullptr;
+    }
+  }
+
+  log_cb(RETRO_LOG_INFO, "RA2: %s. Cannot load invaid resource\n", __FUNCTION__);
+  return nullptr;
+}
+
+LONG GetBitmapBits(HBITMAP hbit, LONG cb, LPVOID lpvBits)
+{
+  const CBITMAP & bitmap = dynamic_cast<CBITMAP&>(*hbit);
+  const char * bits = bitmap.image.data();
+  const size_t size = bitmap.image.size();
+  const size_t requested = cb;
+
+  const size_t copied = std::min(requested, size);
+
+  char * dest = static_cast<char *>(lpvBits);
+  memcpy(dest, bits, copied);
+
+  return copied;
+}

source/frontends/retro/environment.cpp

@@ -0,0 +1,28 @@
+#include "frontends/retro/environment.h"
+
+#include <cstdarg>
+#include <iostream>
+
+
+void fallback_log(enum retro_log_level level, const char *fmt, ...)
+{
+  (void)level;
+  va_list va;
+  va_start(va, fmt);
+  vfprintf(stderr, fmt, va);
+  va_end(va);
+}
+
+retro_log_callback logging;
+retro_log_printf_t log_cb = fallback_log;
+retro_input_poll_t input_poll_cb;
+retro_input_state_t input_state_cb;
+
+retro_environment_t environ_cb;
+retro_video_refresh_t video_cb;
+retro_audio_sample_t audio_cb;
+retro_audio_sample_batch_t audio_batch_cb;
+
+std::string retro_base_directory;
+
+unsigned int retro_devices[RETRO_DEVICES] = {};

source/frontends/retro/environment.h

@@ -0,0 +1,19 @@
+#include "libretro.h"
+
+#include <string>
+
+void fallback_log(enum retro_log_level level, const char *fmt, ...);
+extern retro_log_callback logging;
+extern retro_log_printf_t log_cb;
+extern retro_input_poll_t input_poll_cb;
+extern retro_input_state_t input_state_cb;
+extern retro_environment_t environ_cb;
+extern retro_video_refresh_t video_cb;
+extern retro_audio_sample_t audio_cb;
+extern  retro_audio_sample_batch_t audio_batch_cb;
+
+extern std::string retro_base_directory;
+
+#define RETRO_DEVICES 5
+
+extern unsigned int retro_devices[RETRO_DEVICES];

source/frontends/retro/game.cpp

@@ -0,0 +1,297 @@
+#include "StdAfx.h"
+#include "frontends/retro/game.h"
+
+#include "Frame.h"
+#include "Video.h"
+
+#include "Common.h"
+#include "CardManager.h"
+#include "Core.h"
+#include "Disk.h"
+#include "Mockingboard.h"
+#include "SoundCore.h"
+#include "Harddisk.h"
+#include "Speaker.h"
+#include "Log.h"
+#include "CPU.h"
+#include "Memory.h"
+#include "LanguageCard.h"
+#include "MouseInterface.h"
+#include "ParallelPrinter.h"
+#include "NTSC.h"
+#include "SaveState.h"
+#include "RGBMonitor.h"
+#include "Riff.h"
+#include "Utilities.h"
+
+#include "linux/videobuffer.h"
+#include "linux/keyboard.h"
+#include "linux/paddle.h"
+#include "frontends/common2/programoptions.h"
+#include "frontends/common2/configuration.h"
+#include "frontends/retro/environment.h"
+
+#include "libretro.h"
+
+namespace
+{
+
+  void initialiseEmulator()
+  {
+#ifdef RIFF_SPKR
+    RiffInitWriteFile("/tmp/Spkr.wav", SPKR_SAMPLE_RATE, 1);
+#endif
+#ifdef RIFF_MB
+    RiffInitWriteFile("/tmp/Mockingboard.wav", 44100, 2);
+#endif
+
+    g_nAppMode = MODE_RUNNING;
+    LogFileOutput("Initialisation\n");
+
+    g_bFullSpeed = false;
+
+    LoadConfiguration();
+    SetCurrentCLK6502();
+    GetAppleWindowTitle();
+
+    DSInit();
+    MB_Initialize();
+    SpkrInitialize();
+
+    MemInitialize();
+    VideoBufferInitialize();
+    VideoSwitchVideocardPalette(RGB_GetVideocard(), GetVideoType());
+
+    GetCardMgr().GetDisk2CardMgr().Reset();
+    HD_Reset();
+    Snapshot_Startup();
+  }
+
+  void uninitialiseEmulator()
+  {
+    Snapshot_Shutdown();
+    CMouseInterface* pMouseCard = GetCardMgr().GetMouseCard();
+    if (pMouseCard)
+    {
+      pMouseCard->Reset();
+    }
+    VideoBufferDestroy();
+    MemDestroy();
+
+    SpkrDestroy();
+    MB_Destroy();
+    DSUninit();
+
+    HD_Destroy();
+    PrintDestroy();
+    CpuDestroy();
+
+    GetCardMgr().GetDisk2CardMgr().Destroy();
+    LogDone();
+    RiffFinishWriteFile();
+  }
+
+  void runOneFrame(Speed & speed)
+  {
+    if (g_nAppMode == MODE_RUNNING)
+    {
+      const size_t cyclesToExecute = speed.getCyclesTillNext(16);
+
+      const bool bVideoUpdate = true;
+      const UINT dwClksPerFrame = NTSC_GetCyclesPerFrame();
+
+      const DWORD executedCycles = CpuExecute(cyclesToExecute, bVideoUpdate);
+      //      log_cb(RETRO_LOG_INFO, "RA2: %s %d\n", __FUNCTION__, executedCycles);
+
+      g_dwCyclesThisFrame = (g_dwCyclesThisFrame + executedCycles) % dwClksPerFrame;
+      GetCardMgr().GetDisk2CardMgr().UpdateDriveState(executedCycles);
+      MB_PeriodicUpdate(executedCycles);
+      SpkrUpdate(executedCycles);
+    }
+  }
+
+}
+
+Game::Game()
+  : mySpeed(true)
+  , myWidth(GetFrameBufferWidth())
+  , myHeight(GetFrameBufferHeight())
+{
+  EmulatorOptions options;
+  options.memclear = g_nMemoryClearType;
+  options.log = true;
+
+  if (options.log)
+  {
+    LogInit();
+  }
+
+  InitializeRegistry(options);
+  initialiseEmulator();
+
+  const size_t size = myWidth * myHeight * sizeof(bgra_t);
+  myVideoBuffer.resize(size);
+}
+
+Game::~Game()
+{
+  uninitialiseEmulator();
+}
+
+void Game::executeOneFrame()
+{
+  runOneFrame(mySpeed);
+}
+
+void Game::processInputEvents()
+{
+  input_poll_cb();
+}
+
+void Game::keyboardCallback(bool down, unsigned keycode, uint32_t character, uint16_t key_modifiers)
+{
+  if (down)
+  {
+    processKeyDown(keycode, character, key_modifiers);
+  }
+  else
+  {
+    processKeyUp(keycode, character, key_modifiers);
+  }
+}
+
+void Game::processKeyDown(unsigned keycode, uint32_t character, uint16_t key_modifiers)
+{
+  BYTE ch = 0;
+  switch (keycode)
+  {
+  case RETROK_RETURN:
+    {
+      ch = 0x0d;
+      break;
+    }
+  case RETROK_BACKSPACE: // same as AppleWin
+  case RETROK_LEFT:
+    {
+      ch = 0x08;
+      break;
+    }
+  case RETROK_RIGHT:
+    {
+      ch = 0x15;
+      break;
+    }
+  case RETROK_UP:
+    {
+      ch = 0x0b;
+      break;
+    }
+  case RETROK_DOWN:
+    {
+      ch = 0x0a;
+      break;
+    }
+  case RETROK_DELETE:
+    {
+      ch = 0x7f;
+      break;
+    }
+  case RETROK_ESCAPE:
+    {
+      ch = 0x1b;
+      break;
+    }
+  case RETROK_TAB:
+    {
+      ch = 0x09;
+      break;
+    }
+  case RETROK_LALT:
+    {
+      Paddle::setButtonPressed(Paddle::ourOpenApple);
+      break;
+    }
+  case RETROK_RALT:
+    {
+      Paddle::setButtonPressed(Paddle::ourSolidApple);
+      break;
+    }
+  case RETROK_a ... RETROK_z:
+    {
+      ch = (keycode - RETROK_a) + 0x01;
+      if (key_modifiers & RETROKMOD_CTRL)
+      {
+	// ok
+      }
+      else if (key_modifiers & RETROKMOD_SHIFT)
+      {
+	ch += 0x60;
+      }
+      else
+      {
+	ch += 0x40;
+      }
+      break;
+    }
+  }
+
+  if (!ch)
+  {
+    switch (character) {
+    case 0x20 ... 0x40:
+    case 0x5b ... 0x60:
+    case 0x7b ... 0x7e:
+      {
+	// not the letters
+	// this is very simple, but one cannot handle CRTL-key combination.
+	ch = character;
+	break;
+      }
+    }
+  }
+
+  if (ch)
+  {
+    addKeyToBuffer(ch);
+    log_cb(RETRO_LOG_INFO, "RA2: %s - %02x\n", __FUNCTION__, ch);
+  }
+}
+
+void Game::processKeyUp(unsigned keycode, uint32_t character, uint16_t key_modifiers)
+{
+  switch (keycode)
+  {
+  case RETROK_LALT:
+    {
+      Paddle::setButtonReleased(Paddle::ourOpenApple);
+      break;
+    }
+  case RETROK_RALT:
+    {
+      Paddle::setButtonReleased(Paddle::ourSolidApple);
+      break;
+    }
+  }
+}
+
+void Game::drawVideoBuffer()
+{
+  const size_t pitch = myWidth * sizeof(bgra_t);
+  // this should not be necessary
+  // either libretro handles it
+  // or we should change AW
+  // but for now, there is no alternative
+  for (size_t row = 0; row < myHeight; ++row)
+  {
+    const uint8_t * src = g_pFramebufferbits + row * pitch;
+    uint8_t * dst = myVideoBuffer.data() + (myHeight - row - 1) * pitch;
+    memcpy(dst, src, pitch);
+  }
+  video_cb(myVideoBuffer.data(), myWidth, myHeight, pitch);
+}
+
+bool Game::loadGame(const char * path)
+{
+  const bool ok = DoDiskInsert(SLOT6, DRIVE_1, path);
+  return ok;
+}

source/frontends/retro/game.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "frontends/common2/speed.h"
+
+class Game
+{
+public:
+  Game();
+  ~Game();
+
+  bool loadGame(const char * path);
+
+  void executeOneFrame();
+  void processInputEvents();
+
+  void drawVideoBuffer();
+
+  static void keyboardCallback(bool down, unsigned keycode, uint32_t character, uint16_t key_modifiers);
+
+private:
+  Speed mySpeed;  // fixed speed
+
+  const size_t myHeight;
+  const size_t myWidth;
+
+  static void processKeyDown(unsigned keycode, uint32_t character, uint16_t key_modifiers);
+  static void processKeyUp(unsigned keycode, uint32_t character, uint16_t key_modifiers);
+
+  std::vector<uint8_t> myVideoBuffer;
+};

source/frontends/retro/interface.cpp

@@ -0,0 +1,22 @@
+#include "linux/interface.h"
+
+#include "frontends/retro/environment.h"
+#include "linux/win.h"
+
+int MessageBox(HWND, const char * text, const char * caption, UINT type)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s: %s - %s\n", __FUNCTION__, caption, text);
+  return IDOK;
+}
+
+void FrameDrawDiskLEDS(HDC x)
+{
+}
+
+void FrameDrawDiskStatus(HDC x)
+{
+}
+
+void FrameRefreshStatus(int x, bool)
+{
+}

source/frontends/retro/libretro.cpp

@@ -0,0 +1,231 @@
+#include "libretro.h"
+#include <memory>
+#include <cstring>
+
+#include "StdAfx.h"
+#include "Frame.h"
+
+#include "linux/version.h"
+
+#include "frontends/retro/game.h"
+#include "frontends/retro/environment.h"
+
+namespace
+{
+  std::unique_ptr<Game> game;
+}
+
+void retro_init(void)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  const char *dir = NULL;
+  if (environ_cb(RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY, &dir) && dir)
+  {
+    retro_base_directory = dir;
+  }
+}
+
+void retro_deinit(void)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+}
+
+unsigned retro_api_version(void)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return RETRO_API_VERSION;
+}
+
+void retro_set_controller_port_device(unsigned port, unsigned device)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  log_cb(RETRO_LOG_INFO, "Plugging device %u into port %u.\n", device, port);
+
+  if (port < RETRO_DEVICES)
+    retro_devices[port] = device;
+}
+
+void retro_get_system_info(retro_system_info *info)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  static std::string version = getVersion();
+
+  memset(info, 0, sizeof(*info));
+  info->library_name     = "AppleWin";
+  info->library_version  = version.c_str();
+  info->need_fullpath    = true;
+  info->valid_extensions = "bin|do|dsk|nib|po|gz|woz|zip|2mg|2img|iie|apl|hdv";
+}
+
+
+void retro_get_system_av_info(retro_system_av_info *info)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+
+  info->geometry.base_width   = GetFrameBufferWidth();
+  info->geometry.base_height  = GetFrameBufferHeight();
+  info->geometry.max_width    = GetFrameBufferWidth();
+  info->geometry.max_height   = GetFrameBufferHeight();
+  info->geometry.aspect_ratio = 0;
+
+  info->timing.fps            = 60;
+  info->timing.sample_rate    = 0;
+}
+
+void retro_set_environment(retro_environment_t cb)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  environ_cb = cb;
+
+  if (cb(RETRO_ENVIRONMENT_GET_LOG_INTERFACE, &logging))
+    log_cb = logging.log;
+  else
+    log_cb = fallback_log;
+  /*
+  static const retro_controller_description controllers[] =
+    {
+     { "Apple Keyboard", RETRO_DEVICE_SUBCLASS(RETRO_DEVICE_KEYBOARD, 0) },
+    };
+
+  static const retro_controller_info ports[] =
+    {
+     { controllers, 1 },
+     { NULL, 0 },
+    };
+
+    cb(RETRO_ENVIRONMENT_SET_CONTROLLER_INFO, (void*)ports);*/
+  retro_keyboard_callback callback = {&Game::keyboardCallback};
+  cb(RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK, &callback);
+}
+
+void retro_set_audio_sample(retro_audio_sample_t cb)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  audio_cb = cb;
+}
+
+void retro_set_audio_sample_batch(retro_audio_sample_batch_t cb)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  audio_batch_cb = cb;
+}
+
+void retro_set_input_poll(retro_input_poll_t cb)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  input_poll_cb = cb;
+}
+
+void retro_set_input_state(retro_input_state_t cb)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  input_state_cb = cb;
+}
+
+void retro_set_video_refresh(retro_video_refresh_t cb)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  video_cb = cb;
+}
+
+void retro_run(void)
+{
+  game->processInputEvents();
+  game->executeOneFrame();
+  game->drawVideoBuffer();
+}
+
+bool retro_load_game(const retro_game_info *info)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+
+  enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_XRGB8888;
+  if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt))
+  {
+    log_cb(RETRO_LOG_INFO, "XRGB8888 is not supported.\n");
+    return false;
+  }
+
+  try
+  {
+    game.reset(new Game);
+    const bool ok = game->loadGame(info->path);
+
+    log_cb(RETRO_LOG_INFO, "Game path: %s:%d\n", info->path, ok);
+
+    return ok;
+  }
+  catch (const std::exception & e)
+  {
+    log_cb(RETRO_LOG_INFO, "Exception: %s\n", e.what());
+  }
+  catch (const std::string & s)
+  {
+    log_cb(RETRO_LOG_INFO, "Exception: %s\n", s.c_str());
+  }
+
+  return false;
+}
+
+void retro_unload_game(void)
+{
+  game.reset();
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+}
+
+unsigned retro_get_region(void)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return RETRO_REGION_NTSC;
+}
+
+void retro_reset(void)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+}
+
+bool retro_load_game_special(unsigned type, const struct retro_game_info *info, size_t num)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return false;
+}
+
+size_t retro_serialize_size(void)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return 0;
+}
+
+bool retro_serialize(void *data, size_t size)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return false;
+}
+
+bool retro_unserialize(const void *data, size_t size)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return false;
+}
+
+void retro_cheat_reset(void)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+}
+
+void retro_cheat_set(unsigned index, bool enabled, const char *code)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+}
+
+void *retro_get_memory_data(unsigned id)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return nullptr;
+}
+
+size_t retro_get_memory_size(unsigned id)
+{
+  log_cb(RETRO_LOG_INFO, "RA2: %s\n", __FUNCTION__);
+  return 0;
+}

source/frontends/retro/rdirectsound.cpp

@@ -0,0 +1,10 @@
+#include <linux/interface.h>
+
+// Mockingboard
+void registerSoundBuffer(IDirectSoundBuffer * buffer)
+{
+}
+
+void unregisterSoundBuffer(IDirectSoundBuffer * buffer)
+{
+}

source/frontends/retro/run

@@ -0,0 +1 @@
+retroarch -L source/frontends/retro/libra2.so ../Disks/NoSlotClockTest.dsk

source/frontends/sa2/CMakeLists.txt

@@ -9,23 +9,17 @@ add_executable(sa2
   utils.cpp
   )
 
-find_package(Boost REQUIRED
-  COMPONENTS program_options
-  )
-
 find_package(SDL2 REQUIRED)
 pkg_search_module(SDL2_IMAGE REQUIRED SDL2_image)
 
 target_compile_features(sa2 PUBLIC cxx_std_17)
 
 target_include_directories(sa2 PRIVATE
-  ${Boost_INCLUDE_DIRS}
   ${SDL2_INCLUDE_DIRS}
   ${SDL2_IMAGE_INCLUDE_DIRS}
   )
 
 target_link_libraries(sa2 PRIVATE
-  Boost::program_options
   ${SDL2_LIBRARIES}
   ${SDL2_IMAGE_LIBRARIES}
   appleii

source/linux/build.sh

@@ -2,8 +2,10 @@
 
 set -euxo pipefail
 
+wget https://raw.githubusercontent.com/libretro/RetroArch/master/libretro-common/include/libretro.h -P build/libretro-common/include
+
 mkdir -p build
 cd build
 
-cmake -DCMAKE_BUILD_TYPE=RELEASE ..
+cmake -DCMAKE_BUILD_TYPE=RELEASE -DLIBRETRO_PATH=libretro-common ..
 make