Make Fl_Gl_Window::pixels_per_unit() return a float (rather than int) value.

This is compatible with future scaling factors applicable to the GUI.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@11787 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

src/Fl_Gl_Device_Plugin.cxx

@@ -53,7 +53,7 @@ static Fl_RGB_Image* capture_gl_rectangle(Fl_Gl_Window *glw, int x, int y, int w
 {
 #if defined(__APPLE__)
   const int bytesperpixel = 4;
-  int factor = glw->pixels_per_unit();
+  float factor = glw->pixels_per_unit();
   if (factor > 1) {
     w *= factor; h *= factor; x *= factor; y *= factor;
   }

src/Fl_Gl_Window.cxx

@@ -96,7 +96,7 @@ void Fl_Gl_Window::show() {
 
 #if defined(__APPLE__)
 
-int Fl_Gl_Window::pixels_per_unit()
+float Fl_Gl_Window::pixels_per_unit()
 {
   return (fl_mac_os_version >= 100700 && Fl::use_high_res_GL() && Fl_X::i(this) && Fl_X::i(this)->mapped_to_retina()) ? 2 : 1;
 }

src/glut_compatability.cxx

@@ -83,9 +83,9 @@ int Fl_Glut_Window::handle(int event) {
   make_current();
   int ex = Fl::event_x();
   int ey = Fl::event_y();
-  int factor = pixels_per_unit();
-  ex *= factor;
-  ey *= factor;
+  float factor = pixels_per_unit();
+  ex = int(ex * factor + 0.5);
+  ey = int(ey * factor + 0.5);
   int button;
   switch (event) {