HiDPI support for WIN32 platform: begin to support screen-specific scale factor.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12280 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 10 insertions, 1 deletions

diff --git a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
index 0229f3cce..079ca743d 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
+++ b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
@@ -48,6 +48,7 @@ Fl_WinAPI_Window_Driver::Fl_WinAPI_Window_Driver(Fl_Window *win)
   icon_ = new icon_data;
   memset(icon_, 0, sizeof(icon_data));
   cursor = NULL;
+  screen_num_ = -1;
 }
 
 
@@ -60,6 +61,13 @@ Fl_WinAPI_Window_Driver::~Fl_WinAPI_Window_Driver()
   delete icon_;
 }
 
+int Fl_WinAPI_Window_Driver::screen_num() {
+  if (pWindow->parent()) {
+    screen_num_ = pWindow->top_window()->driver()->screen_num();
+  }
+  return screen_num_ >= 0 ? screen_num_ : 0;
+}
+
 
 RECT // frame of the decorated window in screen coordinates
   Fl_WinAPI_Window_Driver::border_width_title_bar_height(
@@ -395,7 +403,7 @@ void Fl_WinAPI_Window_Driver::make_current() {
 #endif // USE_COLORMAP
   
   fl_graphics_driver->clip_region(0);
-  fl_graphics_driver->scale(Fl::screen_driver()->scale(0));
+  fl_graphics_driver->scale(Fl::screen_driver()->scale(screen_num()));
   fl_graphics_driver->line_style(FL_SOLID); // scale also default line width
 }
 
@@ -489,6 +497,7 @@ void Fl_WinAPI_Window_Driver::hide() {
   if (pWindow->non_modal() && Fl::first_window() && Fl::first_window()->shown())
     Fl::first_window()->show();
   delete ip;
+  screen_num_ = -1;
 }