win32-improve opengl display method, i hope.

desmume/src/windows/main.cpp

@@ -1433,7 +1433,7 @@ struct GLDISPLAY
 	{
 		//do we need to use another HDC?
 		if(init) return true;
-		init = initContext(MainWindow->getHWnd(),&privateContext, &privateDC);
+		init = initContext(MainWindow->getHWnd(),&privateContext);
 		return init;
 	}
 
@@ -1441,8 +1441,6 @@ struct GLDISPLAY
 	{
 		if(!init) return;
 		wglDeleteContext(privateContext);
-		DeleteObject(privateDC);
-		privateDC = NULL;
 		privateContext = NULL;
 		init = false;
 	}
@@ -1460,11 +1458,18 @@ struct GLDISPLAY
 			if(!initialize()) return false;
 		}
 
-		if(wglGetCurrentContext() != privateContext)
+		privateDC = GetDC(MainWindow->getHWnd());
 		wglMakeCurrent(privateDC,privateContext);
 		return true;
 	}
 
+	void end()
+	{
+		wglMakeCurrent(NULL,privateContext);
+		ReleaseDC(MainWindow->getHWnd(),privateDC);
+		privateDC = NULL;
+	}
+
 	void showPage()
 	{
 			SwapBuffers(privateDC);
@@ -1634,6 +1639,8 @@ static void OGL_DoDisplay()
 	glEnd();
 
 	gldisplay.showPage();
+
+	gldisplay.end();
 }
 
 //the directdraw final presentation portion of display, including rotating

desmume/src/windows/ogl.cpp

@@ -63,10 +63,9 @@ int CheckHardwareSupport(HDC hdc)
 	return -1; // check error
 }
 
-bool initContext(HWND hwnd, HGLRC *hRC, HDC *hdc)
+bool initContext(HWND hwnd, HGLRC *hRC)
 {
 	*hRC = NULL;
-	*hdc = NULL;
 
 	HDC oglDC = GetDC (hwnd);
 
@@ -91,7 +90,7 @@ bool initContext(HWND hwnd, HGLRC *hRC, HDC *hdc)
 		return false;
 	}
 
-	*hdc = oglDC;
+	wglMakeCurrent(NULL,NULL);
 
 	return true;
 }

desmume/src/windows/ogl.h

@@ -18,4 +18,4 @@
 #pragma once
 
 bool windows_opengl_init();
-bool initContext(HWND hwnd, HGLRC *hRC, HDC *hdc);
+bool initContext(HWND hwnd, HGLRC *hRC);