X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/cf1eeea343cda634290bb95432f75802aa9d2783..a51fb6427c1036779a67b92ff0976c0a735ab0c3:/src/msw/utils.cpp

diff --git a/src/msw/utils.cpp b/src/msw/utils.cpp
index f5217d22f9..e035e05457 100644
--- a/src/msw/utils.cpp
+++ b/src/msw/utils.cpp
@@ -437,7 +437,7 @@ bool wxDirExists(const wxString& dir)
 {
 #if defined(__WIN32__)
     DWORD attribs = GetFileAttributes(dir);
-    return ((attribs != -1) && (attribs & FILE_ATTRIBUTE_DIRECTORY));
+    return ((attribs != (DWORD)-1) && (attribs & FILE_ATTRIBUTE_DIRECTORY));
 #else // Win16
     #ifdef __BORLANDC__
         struct ffblk fileInfo;
@@ -990,10 +990,22 @@ void wxGetMousePosition( int* x, int* y )
 // Return TRUE if we have a colour display
 bool wxColourDisplay()
 {
-    ScreenHDC dc;
-    int noCols = GetDeviceCaps(dc, NUMCOLORS);
+    // this function is called from wxDC ctor so it is called a *lot* of times
+    // hence we optimize it a bit but doign the check only once
+    //
+    // this should be MT safe as only the GUI thread (holding the GUI mutex)
+    // can call us
+    static int s_isColour = -1;
+
+    if ( s_isColour == -1 )
+    {
+        ScreenHDC dc;
+        int noCols = ::GetDeviceCaps(dc, NUMCOLORS);
+
+        s_isColour = (noCols == -1) || (noCols > 2);
+    }
 
-    return (noCols == -1) || (noCols > 2);
+    return s_isColour != 0;
 }
 
 // Returns depth of screen