fix Xcode project generation via cmake

Move Objective-C++ Mac code for Wx into macsupport.mm with stub methods
in panel.cpp, and stop compiling all C++ as Objective-C++.

cmake -G Xcode # now works fine

CMakeLists.txt

@@ -97,9 +97,6 @@ IF(APPLE)
     ELSEIF(EXISTS /sw/bin)
         SET(CMAKE_PROGRAM_PATH "${CMAKE_PROGRAM_PATH};/sw/bin")
     ENDIF()
-
-    # and compile as Objective-C++ for ObjectiveC #ifdefs
-    SET(CMAKE_CXX_COMPILE_OBJECT "<CMAKE_CXX_COMPILER> -x objective-c++ <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT> -c <SOURCE>")
 ENDIF(APPLE)
 
 # We do not support amd64 asm yet

src/wx/CMakeLists.txt

@@ -153,6 +153,10 @@ SET( SRC_WX
    xrc/vbam.xpm
 )
 
+IF(APPLE)
+    SET(SRC_WX ${SRC_WX} macsupport.mm)
+ENDIF(APPLE)
+
 SET( HDR_WX
    wxvbam.h
    drawing.h

src/wx/macsupport.mm

@@ -0,0 +1,29 @@
+#import <Foundation/Foundation.h>
+#import <Cocoa/Cocoa.h>
+
+#include "wxvbam.h"
+
+double HiDPIAware::HiDPIScaleFactor()
+{
+    if (hidpi_scale_factor == 0) {
+        NSWindow* window = [(NSView*)GetWindow()->GetHandle() window];
+
+        if ([window respondsToSelector:@selector(backingScaleFactor)]) {
+            hidpi_scale_factor = [window backingScaleFactor];
+        }
+        else {
+            hidpi_scale_factor = 1.0;
+        }
+    }
+
+    return hidpi_scale_factor;
+}
+
+void HiDPIAware::RequestHighResolutionOpenGLSurface()
+{
+    NSView* view = (NSView*)(GetWindow()->GetHandle());
+
+    if ([view respondsToSelector:@selector(setWantsBestResolutionOpenGLSurface:)]) {
+        [view setWantsBestResolutionOpenGLSurface:YES];
+    }
+}

src/wx/panel.cpp

@@ -1,10 +1,5 @@
 #include <wx/dcbuffer.h>
 
-#ifdef __WXMAC__
-#import <Foundation/Foundation.h>
-#import <Cocoa/Cocoa.h>
-#endif
-
 #include "../../version.h"
 #include "../common/ConfigManager.h"
 #include "../common/Patch.h"
@@ -18,26 +13,6 @@
 
 int emulating;
 
-double HiDPIAware::HiDPIScaleFactor()
-{
-    if (hidpi_scale_factor == 0) {
-#ifdef __WXMAC__
-        NSWindow* window = [(NSView*)GetWindow()->GetHandle() window];
-
-        if ([window respondsToSelector:@selector(backingScaleFactor)]) {
-            hidpi_scale_factor = [window backingScaleFactor];
-        }
-        else {
-            hidpi_scale_factor = 1.0;
-        }
-#else
-        hidpi_scale_factor = 1.0;
-#endif
-    }
-
-    return hidpi_scale_factor;
-}
-
 IMPLEMENT_DYNAMIC_CLASS(GameArea, wxPanel)
 
 GameArea::GameArea()
@@ -2023,13 +1998,7 @@ GLDrawingPanel::GLDrawingPanel(wxWindow* parent, int _width, int _height)
           wxFULL_REPAINT_ON_RESIZE | wxWANTS_CHARS)
     , DrawingPanel(_width, _height)
 {
-#ifdef __WXMAC__
-    NSView* view = (NSView*)GetHandle();
-
-    if ([view respondsToSelector:@selector(setWantsBestResolutionOpenGLSurface:)]) {
-        [view setWantsBestResolutionOpenGLSurface:YES];
-    }
-#endif
+    RequestHighResolutionOpenGLSurface();
 #if wxCHECK_VERSION(2, 9, 0)
     ctx = new wxGLContext(this);
     SetCurrent(*ctx);
@@ -2479,3 +2448,19 @@ void GameArea::HidePointer()
             panel->GetWindow()->SetCursor(wxCursor(wxCURSOR_BLANK));
     }
 }
+
+// stub HiDPI methods, see macsupport.mm for the Mac support
+#ifndef __WXMAC__
+double HiDPIAware::HiDPIScaleFactor()
+{
+    if (hidpi_scale_factor == 0) {
+        hidpi_scale_factor = 1.0;
+    }
+
+    return hidpi_scale_factor;
+}
+
+void HiDPIAware::RequestHighResolutionOpenGLSurface()
+{
+}
+#endif // HiDPI stubs

src/wx/wxvbam.h

@@ -345,7 +345,8 @@ private:
 // helper class to add HiDPI awareness (mostly for Mac OS X)
 class HiDPIAware {
 public:
-    double HiDPIScaleFactor();
+    virtual double HiDPIScaleFactor();
+    virtual void RequestHighResolutionOpenGLSurface();
     virtual wxWindow* GetWindow() = 0;
 private:
     double hidpi_scale_factor = 0;