+// ----------------------------------------------------------------------------
+// wxGLModule is responsible for unregistering wxGLCanvasClass Windows class
+// ----------------------------------------------------------------------------
+
+class wxGLModule : public wxModule
+{
+public:
+ bool OnInit() { return true; }
+ void OnExit() { UnregisterClasses(); }
+
+ // register the GL classes if not done yet, return true if ok, false if
+ // registration failed
+ static bool RegisterClasses();
+
+ // unregister the classes, done automatically on program termination
+ static void UnregisterClasses();
+
+private:
+ // wxGLCanvas is only used from the main thread so this is MT-ok
+ static bool ms_registeredGLClasses;
+
+ DECLARE_DYNAMIC_CLASS(wxGLModule)
+};
+
+IMPLEMENT_DYNAMIC_CLASS(wxGLModule, wxModule)
+
+bool wxGLModule::ms_registeredGLClasses = false;
+
+/* static */
+bool wxGLModule::RegisterClasses()
+{
+ if (ms_registeredGLClasses)
+ return true;
+
+ // We have to register a special window class because we need the CS_OWNDC
+ // style for GLCanvas.
+
+ /*
+ From Angel Popov <jumpo@bitex.com>
+
+ Here are two snips from a dicussion in the OpenGL Gamedev list that explains
+ how this problem can be fixed:
+
+ "There are 5 common DCs available in Win95. These are aquired when you call
+ GetDC or GetDCEx from a window that does _not_ have the OWNDC flag.
+ OWNDC flagged windows do not get their DC from the common DC pool, the issue
+ is they require 800 bytes each from the limited 64Kb local heap for GDI."
+
+ "The deal is, if you hold onto one of the 5 shared DC's too long (as GL apps
+ do), Win95 will actually "steal" it from you. MakeCurrent fails,
+ apparently, because Windows re-assigns the HDC to a different window. The
+ only way to prevent this, the only reliable means, is to set CS_OWNDC."
+ */
+
+ WNDCLASS wndclass;
+
+ // the fields which are common to all classes
+ wndclass.lpfnWndProc = (WNDPROC)wxWndProc;
+ wndclass.cbClsExtra = 0;
+ wndclass.cbWndExtra = sizeof( DWORD ); // VZ: what is this DWORD used for?
+ wndclass.hInstance = wxhInstance;
+ wndclass.hIcon = (HICON) NULL;
+ wndclass.hCursor = ::LoadCursor((HINSTANCE)NULL, IDC_ARROW);
+ wndclass.lpszMenuName = NULL;
+
+ // Register the GLCanvas class name
+ wndclass.hbrBackground = (HBRUSH)NULL;
+ wndclass.lpszClassName = wxGLCanvasClassName;
+ wndclass.style = CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS | CS_OWNDC;
+
+ if ( !::RegisterClass(&wndclass) )
+ {
+ wxLogLastError(wxT("RegisterClass(wxGLCanvasClass)"));
+ return false;
+ }
+
+ // Register the GLCanvas class name for windows which don't do full repaint
+ // on resize
+ wndclass.lpszClassName = wxGLCanvasClassNameNoRedraw;
+ wndclass.style &= ~(CS_HREDRAW | CS_VREDRAW);
+
+ if ( !::RegisterClass(&wndclass) )
+ {
+ wxLogLastError(wxT("RegisterClass(wxGLCanvasClassNameNoRedraw)"));
+
+ ::UnregisterClass(wxGLCanvasClassName, wxhInstance);
+
+ return false;
+ }
+
+ ms_registeredGLClasses = true;
+
+ return true;
+}
+
+/* static */
+void wxGLModule::UnregisterClasses()
+{
+ // we need to unregister the classes in case we're in a DLL which is
+ // unloaded and then loaded again because if we don't, the registration is
+ // going to fail in wxGLCanvas::Create() the next time we're loaded
+ if ( ms_registeredGLClasses )
+ {
+ ::UnregisterClass(wxGLCanvasClassName, wxhInstance);
+ ::UnregisterClass(wxGLCanvasClassNameNoRedraw, wxhInstance);
+
+ ms_registeredGLClasses = false;
+ }
+}
+
projects / wxWidgets.git / blobdiff