new API: IsMemDC

include/gdi.h

@@ -1389,6 +1389,20 @@ MG_EXPORT HDC GUIAPI CreateCompatibleDCEx (HDC hdc, int width, int height);
  */
 MG_EXPORT BOOL GUIAPI IsCompatibleDC (HDC hdc1, HDC hdc2);
 
+/**
+ * \fn BOOL GUIAPI IsMemDC (HDC hdc1)
+ * \brief Check whether a given DC is a memory DC.
+ *
+ * This function checks whether a give DC \a hdc is a memory DC.
+ *
+ * \param hdc The handle to the DC.
+ *
+ * \return TRUE for memory DC, otherwise FALSE.
+ *
+ * \sa CreateMemDCEx
+ */
+MG_EXPORT BOOL GUIAPI IsMemDC (HDC hdc);
+
 /**
  * \fn HDC GUIAPI CreateMemDCEx (int width, int height, int depth, DWORD flags, \
  Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask,

src/newgdi/gdi.c

@@ -3731,3 +3731,9 @@ MG_EXPORT BOOL GUIAPI SyncUpdateDC (HDC hdc)
 #endif
 }
 
+MG_EXPORT BOOL GUIAPI IsMemDC (HDC hdc)
+{
+    PDC pdc = dc_HDC2PDC(hdc);
+    return dc_IsMemDC (pdc);
+}
+