implemented wxDisplaySizeMM for gtk, msw & motif.

used wxDisplaySize and wxDisplaySizeMM to calculate real screen PPI in
wxPostScriptPrinter.
documented wxDisplaySize and wxDisplaySizeMM.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@8414 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/function.tex

@@ -849,6 +849,22 @@ Returns TRUE if the display is colour, FALSE otherwise.
 
 Returns the depth of the display (a value of 1 denotes a monochrome display).
 
+\membersection{::wxDisplaySize}
+
+\func{void}{wxDisplaySize}{\param{int *}{width}, \param{int *}{height}}
+
+\func{wxSize}{wxGetDisplaySize}{\void}
+
+Returns the display size in pixels.
+
+\membersection{::wxDisplaySizeMM}
+
+\func{void}{wxDisplaySizeMM}{\param{int *}{width}, \param{int *}{height}}
+
+\func{wxSize}{wxGetDisplaySizeMM}{\void}
+
+Returns the display size in millimeters.
+
 \membersection{::wxMakeMetafilePlaceable}\label{wxmakemetafileplaceable}
 
 \func{bool}{wxMakeMetafilePlaceable}{\param{const wxString\& }{filename}, \param{int }{minX}, \param{int }{minY},