Let ROMs set their default mode. Default implementation returns the f…

…irst mode in the available mode list

src/environment/stella_environment.cpp

@@ -46,6 +46,9 @@ StellaEnvironment::StellaEnvironment(OSystem* osystem, RomSettings* settings)
   m_num_reset_steps = 4;
   m_cartridge_md5 = m_osystem->console().properties().get(Cartridge_MD5);
 
+  // Set current mode to the ROM's default mode
+  m_state.setCurrentMode(settings->getDefaultMode());
+
   m_max_num_frames_per_episode =
       m_osystem->settings().getInt("max_num_frames_per_episode");
   m_colour_averaging = m_osystem->settings().getBool("color_averaging");

src/games/RomSettings.cpp

@@ -63,6 +63,16 @@ void RomSettings::setMode(game_mode_t m, System&, std::unique_ptr<StellaEnvironm
   }
 }
 
+game_mode_t RomSettings::getDefaultMode() {
+  // By default, return the first available mode, or 0 if none are listed
+  ModeVect available_modes = getAvailableModes();
+  if (available_modes.empty()) {
+    return 0;
+  } else {
+    return available_modes[0];
+  }
+}
+
 DifficultyVect RomSettings::getAvailableDifficulties() {
   return DifficultyVect(1, 0);
 }

src/games/RomSettings.hpp

@@ -115,6 +115,9 @@ class RomSettings {
       game_mode_t, System& system,
       std::unique_ptr<StellaEnvironmentWrapper> environment);
 
+  // Return the default mode for the game.
+  virtual game_mode_t getDefaultMode();
+
   // Returns a list of difficulties that the game can be played in.
   // By default, there is only one available difficulty.
   virtual DifficultyVect getAvailableDifficulties();

src/games/supported/AirRaid.cpp

@@ -97,9 +97,6 @@ ModeVect AirRaidSettings::getAvailableModes() {
 void AirRaidSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 1; // the default mode is not valid in this game
-  }
   if (m >= 1 && m <= getNumModes()) {
     //open the mode selection panel
     environment->pressSelect(20);

src/games/supported/BattleZone.cpp

@@ -139,9 +139,6 @@ ModeVect BattleZoneSettings::getAvailableModes() {
 void BattleZoneSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 1; // the default mode is not valid here
-  }
   if (m >= 1 && m <= 3) {
     // read the mode we are currently in
     unsigned char mode = readRam(&system, 0xA1);

src/games/supported/Berzerk.cpp

@@ -127,9 +127,6 @@ ModeVect BerzerkSettings::getAvailableModes() {
 void BerzerkSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 1; // The mode 0, which is the default, is not available in this game.
-  }
   if (m >= 1 && (m <= 9 || m == 0x10 || m == 0x11 || m == 0x12)) {
     // we wait that the game is ready to change mode
     for (unsigned int i = 0; i < 20; i++) {

src/games/supported/Centipede.cpp

@@ -124,9 +124,6 @@ ModeVect CentipedeSettings::getAvailableModes() {
 void CentipedeSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 0x16; // The default mode doesn't work here.
-  }
   if (m == 0x16 || m == 0x56) {
     // read the mode we are currently in
     unsigned char mode = readRam(&system, 0xA7);

src/games/supported/Defender.cpp

@@ -130,9 +130,6 @@ ModeVect DefenderSettings::getAvailableModes() {
 void DefenderSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 1; // The default mode (0) is not valid here.
-  }
   if (m >= 1 && (m <= 9 || m == 16)) {
     // read the mode we are currently in
     unsigned char mode = readRam(&system, 0x9B);

src/games/supported/DemonAttack.cpp

@@ -116,9 +116,6 @@ ModeVect DemonAttackSettings::getAvailableModes() {
 void DemonAttackSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 1; // The default mode is not valid here
-  }
   if (m == 1 || m == 3 || m == 5 || m == 7) {
     // read the mode we are currently in
     unsigned char mode = readRam(&system, 0xEA);

src/games/supported/Galaxian.cpp

@@ -121,9 +121,6 @@ ModeVect GalaxianSettings::getAvailableModes() {
 void GalaxianSettings::setMode(
     game_mode_t mode, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (mode == 0)
-    mode = 1;
-
   if (mode >= 1 && mode <= 9) {
     // press select until the correct mode is reached
     while (mode != static_cast<unsigned>(readRam(&system, 0xB3))) {

src/games/supported/NameThisGame.cpp

@@ -106,9 +106,6 @@ ModeVect NameThisGameSettings::getAvailableModes() {
 void NameThisGameSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 0x08; // the default mode is not valid here
-  }
   if (m == 0x08 || m == 0x18 || m == 0x28) {
     // read the mode we are currently in
     unsigned char mode = readRam(&system, 0xDE);

src/games/supported/Pooyan.cpp

@@ -109,9 +109,6 @@ ModeVect PooyanSettings::getAvailableModes() {
 void PooyanSettings::setMode(
     game_mode_t m, System& system,
     std::unique_ptr<StellaEnvironmentWrapper> environment) {
-  if (m == 0) {
-    m = 0x0A; // The default mode (0) is not valid here.
-  }
   if (m == 0x0A || m == 0x1E || m == 0x32 || m == 0x46) {
     environment->pressSelect(2);
     // read the mode we are currently in