sdl: convert keyboard mapping from keycodes to scancode on first load

core/input/mapping.cpp

@@ -142,6 +142,7 @@ void InputMapping::load(FILE* fp)
 	int dz = mf.get_int("emulator", "dead_zone", 10);
 	dz = std::min(dz, 100);
 	dz = std::max(dz, 0);
+	version = mf.get_int("emulator", "version", 1);
 
 	this->dead_zone = (float)dz / 100.f;
 
@@ -236,6 +237,7 @@ bool InputMapping::save(const char *name)
 
 	mf.set("emulator", "mapping_name", this->name);
 	mf.set_int("emulator", "dead_zone", (int)std::round(this->dead_zone * 100.f));
+	mf.set_int("emulator", "version", version);
 
 	for (int port = 0; port < 4; port++)
 	{

core/input/mapping.h

@@ -41,6 +41,7 @@ public:
 
 	std::string name;
 	float dead_zone = 0.1f;
+	int version = 2;
 
 	DreamcastKey get_button_id(u32 port, u32 code)
 	{

core/sdl/sdl_keyboard.h

@@ -7,7 +7,35 @@ class SDLKeyboardDevice : public KeyboardDeviceTemplate<SDL_Scancode>
 public:
 	SDLKeyboardDevice(int maple_port) : KeyboardDeviceTemplate(maple_port, "SDL") {
 		_unique_id = "sdl_keyboard";
-		loadMapping();
+		if (find_mapping())
+		{
+			if (input_mapper->version == 1)
+			{
+				// Convert keycodes to scancode
+				SDL_Scancode scancodes[4][26] {};
+				for (int i = 0; i < 26; i++)
+				{
+					DreamcastKey key = (DreamcastKey)(1 << i);
+					for (int port = 0; port < 4; port++)
+					{
+						SDL_Keycode keycode = (SDL_Keycode)input_mapper->get_button_code(port, key);
+						if ((int)keycode != -1)
+							scancodes[port][i] = SDL_GetScancodeFromKey(keycode);
+					}
+				}
+				for (int i = 0; i < 26; i++)
+				{
+					DreamcastKey key = (DreamcastKey)(1 << i);
+					for (int port = 0; port < 4; port++)
+						if (scancodes[port][i] != 0)
+							input_mapper->set_button(port, key, (u32)scancodes[port][i]);
+				}
+				input_mapper->version = 2;
+				save_mapping();
+			}
+		}
+		else
+			input_mapper = getDefaultMapping();
 	}
 
 	const char *get_button_name(u32 code) override