Texture & mouse functions; refactoring & fixes

- cleaned up and added documentation to engine.h
- refactored CEngine interface and associated structs
- added mouse handling functions in CApplication & CEngine
- fixed bugs in projection matrix setting
- changed texture loading & handling
- added const-values in CDevice & CGLDevice
- changed event management in CApplication
- other minor changes & bugfixes

3 files changed, 13 insertions, 8 deletions

diff --git a/src/common/event.h b/src/common/event.h
index 70b110d..6ce1a79 100644
--- a/src/common/event.h
+++ b/src/common/event.h
@@ -36,6 +36,7 @@ enum EventType
 
 // TODO: document the meaning of each value
 
+    //! Invalid event / no event
     EVENT_NULL              = 0,
 
     //! Event sent on user or system quit request
@@ -638,6 +639,9 @@ struct Event
     //! Type of event (EVENT_*)
     EventType type;
 
+    //! If true, the event was produced by system (SDL); else, it has come from user interface
+    bool systemEvent;
+
     //! Additional data for EVENT_KEY_DOWN and EVENT_KEY_UP
     KeyEventData key;
     //! Additional data for EVENT_MOUSE_BUTTON_DOWN and EVENT_MOUSE_BUTTON_UP
@@ -657,7 +661,8 @@ struct Event
     //? short        keyState;   // state of the keyboard (KS_ *)
     //? float        rTime;      // relative time
 
-    Event(EventType aType = EVENT_NULL) : type(aType) {}
+    Event(EventType aType = EVENT_NULL)
+        : type(aType), systemEvent(false) {}
 };
 
 
diff --git a/src/common/key.h b/src/common/key.h
index 0ed6b54..de31c09 100644
--- a/src/common/key.h
+++ b/src/common/key.h
@@ -27,8 +27,8 @@
 
 // Key symbol defined as concatenation to SDLK_...
 // If need arises, it can be changed to custom function or anything else
-#define KEY(x) SDLK_ # x
+#define KEY(x) SDLK_ ## x
 
 // Key modifier defined as concatenation to KMOD_...
 // If need arises, it can be changed to custom function or anything else
-#define KEY_MOD(x) KMOD_ # x
+#define KEY_MOD(x) KMOD_ ## x
diff --git a/src/common/singleton.h b/src/common/singleton.h
index ee01b24..4df7878 100644
--- a/src/common/singleton.h
+++ b/src/common/singleton.h
@@ -29,21 +29,21 @@ template<typename T> class CSingleton
 
     public:
         static T& GetInstance() {
-            aserrt(mInstance);
+            assert(mInstance != NULL);
             return *mInstance;
         }
 
-        static T& GetInstancePointer() {
-            aserrt(mInstance);
+        static T* GetInstancePointer() {
+            assert(mInstance != NULL);
             return mInstance;
         }
 
         static bool IsCreated() {
-            return mInstance != NULL; 
+            return mInstance != NULL;
         }
 
         CSingleton() {
-            assert(!mInstance);
+            assert(mInstance == NULL);
             mInstance = static_cast<T *>(this);
         }