Streamlined instance management for Game and derived classes

7 files changed, 43 insertions, 37 deletions

diff --git a/StarsEx/Game.cpp b/StarsEx/Game.cpp
index 272dd17..3d3315e 100644
--- a/StarsEx/Game.cpp
+++ b/StarsEx/Game.cpp
@@ -23,40 +23,34 @@
 #include "WndProc.h"
 #include "SoundCard.h"
 
-// +--------------------------------------------------------------------+
 
-Game*    game           = 0;
+Game* Game::instance {nullptr};
 
-// +--------------------------------------------------------------------+
 
 Game::Game() :
-    world(0),
-    status(Game::OK),
-    exit_code(0),
-    game_mode(MENU_MODE)
+    world {nullptr},
+    status {OK},
+    exit_code {0},
+    game_mode {MENU_MODE},
+    active {false},
+    paused {false},
+    server {false},
+    show_mouse {false},
+    frame_number {0}
 {
+    if (instance != nullptr)
+        throw "Game may have only one instance";
+    instance = this;
     Clock::Init();
-    if (!game) {
-        game = this;
-
-        active         = false;
-        paused         = false;
-        server         = false;
-        show_mouse     = false;
-        frame_number   = 0;
-    }
-    else
-    status = TOO_MANY;
 }
 
+
 Game::~Game()
 {
-    if (game == this)
-    game = 0;
-
     Clock::Close();
-
-    delete world;
+    if (world) delete world;
+    if (instance == this)
+        instance = nullptr;
 }
 
 // +--------------------------------------------------------------------+
@@ -184,7 +178,7 @@ Game::UpdateScreen()
 Game*
 Game::GetInstance()
 {
-    return game;
+    return instance;
 }
 
 // +--------------------------------------------------------------------+
diff --git a/StarsEx/Game.h b/StarsEx/Game.h
index 2aa1df7..48629c6 100644
--- a/StarsEx/Game.h
+++ b/StarsEx/Game.h
@@ -85,6 +85,9 @@ protected:
     bool              server;
     bool              show_mouse;
     DWORD             frame_number;
+
+private:
+    static Game* instance;
 };
 
 // +--------------------------------------------------------------------+
diff --git a/StarsEx/GameWinDX9.cpp b/StarsEx/GameWinDX9.cpp
index 4b5b2d8..7099b90 100644
--- a/StarsEx/GameWinDX9.cpp
+++ b/StarsEx/GameWinDX9.cpp
@@ -24,7 +24,7 @@
 #include "VideoSettings.h"
 
 
-GameWinDX9* GameWinDX9::instance = nullptr;
+GameWinDX9* GameWinDX9::instance {nullptr};
 
 
 GameWinDX9*
@@ -56,7 +56,7 @@ GameWinDX9::GameWinDX9() :
     is_device_restored {false}
 {
     if (instance != nullptr)
-        Panic::Panic("Multiple instances of GameWinDX9");
+        throw "GameWinDX9 may have only one instance";
     instance = this;
     video_settings = new VideoSettings;
 }
@@ -64,13 +64,13 @@ GameWinDX9::GameWinDX9() :
 
 GameWinDX9::~GameWinDX9()
 {
-    if (instance != nullptr)
-        instance = nullptr;
     if (screen) delete screen;
     if (video_factory) delete video_factory;
     if (video) delete video;
     if (soundcard) delete soundcard;
     if (video_settings) delete video_settings;
+    if (instance == this)
+        instance = nullptr;
 }
 
 
diff --git a/StarsEx/StarServer.cpp b/StarsEx/StarServer.cpp
index fa0743d..eea6784 100644
--- a/StarsEx/StarServer.cpp
+++ b/StarsEx/StarServer.cpp
@@ -57,7 +57,7 @@
 
 // +--------------------------------------------------------------------+
 
-StarServer*       StarServer::instance = 0;
+StarServer*       StarServer::instance {nullptr};
 
 static Mission*   current_mission      = 0;
 static double     time_til_change      = 0;
@@ -69,7 +69,8 @@ StarServer::StarServer()
 : loader(0), time_mark(0), minutes(0),
 admin_server(0), lobby_server(0)
 {
-    if (!instance)
+    if (instance != nullptr)
+        throw "StarServer may have only one instance";
     instance = this;
 
     server      = true;
@@ -96,6 +97,7 @@ admin_server(0), lobby_server(0)
     loader->EnableMedia(false);
 }
 
+
 StarServer::~StarServer()
 {
     delete admin_server;
@@ -124,9 +126,10 @@ StarServer::~StarServer()
     NetServerConfig::Close();
     ModConfig::Close();
 
-    instance = 0;
-
     server = false;
+
+    if (instance == this)
+        instance = nullptr;
 }
 
 // +--------------------------------------------------------------------+
diff --git a/StarsEx/StarServer.h b/StarsEx/StarServer.h
index fa4828d..f1562bc 100644
--- a/StarsEx/StarServer.h
+++ b/StarsEx/StarServer.h
@@ -54,13 +54,15 @@ protected:
     virtual void      UpdateWorld();
     virtual void      InstantiateMission();
 
-    static StarServer*      instance;
     NetServer*              admin_server;
     NetLobbyServer*         lobby_server;
     DataLoader*             loader;
 
     DWORD                   time_mark;
     DWORD                   minutes;
+
+private:
+    static StarServer* instance;
 };
 
 #endif  // StarServer_h
diff --git a/StarsEx/Starshatter.cpp b/StarsEx/Starshatter.cpp
index 65c7d13..23ba839 100644
--- a/StarsEx/Starshatter.cpp
+++ b/StarsEx/Starshatter.cpp
@@ -121,7 +121,7 @@ Mission*       quick_mission = 0;
 
 int            Starshatter::keymap[256];
 int            Starshatter::keyalt[256];
-Starshatter*   Starshatter::instance = 0;
+Starshatter*   Starshatter::instance {nullptr};
 
 static Mission*   current_mission   = 0;
 static Mission*   cutscene_mission  = 0;
@@ -158,7 +158,8 @@ lens_flare(true), corona(true), nebula(true), dust(0),
 load_step(0), load_progress(0),
 chat_mode(0), exit_time(1.2), cutscene(0)
 {
-    if (!instance)
+    if (instance != nullptr)
+        throw "Starshatter may have only one instance";
     instance = this;
 
     app_name     = "Starshatter: The Open Source Project";
@@ -311,7 +312,8 @@ Starshatter::~Starshatter()
     delete input;
     delete head_tracker;
 
-    instance = 0;
+    if (instance == this)
+        instance = nullptr;
 }
 
 void
diff --git a/StarsEx/Starshatter.h b/StarsEx/Starshatter.h
index ca30124..ecd1a62 100644
--- a/StarsEx/Starshatter.h
+++ b/StarsEx/Starshatter.h
@@ -132,7 +132,6 @@ protected:
     virtual bool      ResizeVideo();
     virtual void      InitMouse();
 
-    static Starshatter*     instance;
     Window*                 gamewin;
     MenuScreen*             menuscreen;
     LoadScreen*             loadscreen;
@@ -200,6 +199,9 @@ protected:
     NetLobby*               net_lobby;
     int                     chat_mode;
     Text                    chat_text;
+
+private:
+    static Starshatter* instance;
 };
 
 #endif  // Starshatter_h