Advancing HiDPI support for the WIN32 platform - still incomplete.

It's still necessary to compile with -DFLTK_HIDPI_SUPPORT
to activate the new HiDPI support.
Default builds get the same HiDPI support as in FLTK 1.3

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12265 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

4 files changed, 54 insertions, 26 deletions

diff --git a/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H b/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H
index 503eb308d..e81120fea 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H
+++ b/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.H
@@ -40,6 +40,8 @@ protected:
 
   static BOOL CALLBACK screen_cb(HMONITOR mon, HDC, LPRECT r, LPARAM);
   BOOL screen_cb(HMONITOR mon, HDC, LPRECT r);
+  int screen_num_unscaled(int x, int y);
+  int get_mouse_unscaled(int &mx, int &my);
 
 public:
   Fl_WinAPI_Screen_Driver() : Fl_Screen_Driver() { scale_ = 1; }
@@ -53,7 +55,7 @@ public:
   virtual int h();
   virtual void screen_xywh(int &X, int &Y, int &W, int &H, int n);
   virtual void screen_dpi(float &h, float &v, int n=0);
-  static float desktop_scaling_factor();
+  float DWM_scaling_factor(int screen_num);
   virtual void screen_work_area(int &X, int &Y, int &W, int &H, int n);
   // --- audible output
   virtual void beep(int type);
@@ -74,6 +76,7 @@ public:
   virtual int dnd(int unused);
   virtual int compose(int &del);
   virtual Fl_RGB_Image *read_win_rectangle(uchar *p, int X, int Y, int w, int h, int alpha);
+  Fl_RGB_Image *read_win_rectangle_unscaled(uchar *p, int X, int Y, int w, int h, int alpha);
   virtual int get_mouse(int &x, int &y);
   virtual void enable_im();
   virtual void disable_im();
diff --git a/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.cxx b/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.cxx
index e9ca9d2fb..e4a3361f5 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.cxx
+++ b/src/drivers/WinAPI/Fl_WinAPI_Screen_Driver.cxx
@@ -159,10 +159,10 @@ void Fl_WinAPI_Screen_Driver::screen_work_area(int &X, int &Y, int &W, int &H, i
 {
   if (num_screens < 0) init();
   if (n < 0 || n >= num_screens) n = 0;
-  X = work_area[n].left;
-  Y = work_area[n].top;
-  W = work_area[n].right - X;
-  H = work_area[n].bottom - Y;
+  X = work_area[n].left/scale_;
+  Y = work_area[n].top/scale_;
+  W = (work_area[n].right - X)/scale_;
+  H = (work_area[n].bottom - Y)/scale_;
 }
 
 
@@ -174,10 +174,10 @@ void Fl_WinAPI_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H, int n)
     n = 0;
 
   if (num_screens > 0) {
-    X = screens[n].left;
-    Y = screens[n].top;
-    W = screens[n].right - screens[n].left;
-    H = screens[n].bottom - screens[n].top;
+    X = screens[n].left/scale_;
+    Y = screens[n].top/scale_;
+    W = (screens[n].right - screens[n].left)/scale_;
+    H = (screens[n].bottom - screens[n].top)/scale_;
   } else {
     /* Fallback if something is broken... */
     X = 0;
@@ -512,7 +512,7 @@ int Fl_WinAPI_Screen_Driver::compose(int &del) {
 }
 
 
-Fl_RGB_Image *				// O - image or NULL if failed
+Fl_RGB_Image *                                                  // O - image or NULL if failed
 Fl_WinAPI_Screen_Driver::read_win_rectangle(uchar *p,		// I - Pixel buffer or NULL to allocate
                                             int   X,		// I - Left position
                                             int   Y,		// I - Top position
@@ -520,6 +520,12 @@ Fl_WinAPI_Screen_Driver::read_win_rectangle(uchar *p,		// I - Pixel buffer or NU
                                             int   h,		// I - Height of area to read
                                             int   alpha) 	// I - Alpha value for image (0 for none)
 {
+  float s = Fl_Surface_Device::surface()->driver()->scale();
+  return read_win_rectangle_unscaled(p, X*s, Y*s, w*s, h*s, alpha);
+}
+
+Fl_RGB_Image *Fl_WinAPI_Screen_Driver::read_win_rectangle_unscaled(uchar *p, int X, int Y, int w, int h, int alpha)
+{
   int	d;			// Depth of image
   
   // Allocate the image data array as needed...
@@ -614,11 +620,11 @@ Fl_WinAPI_Screen_Driver::read_win_rectangle(uchar *p,		// I - Pixel buffer or NU
   return rgb;
 }
 
-/** Returns the current desktop scaling factor (1.75 for example)
+/* Returns the current desktop scaling factor for screen_num (1.75 for example)
  */
-float Fl_WinAPI_Screen_Driver::desktop_scaling_factor() {
+float Fl_WinAPI_Screen_Driver::DWM_scaling_factor(int screen_num) {
 #ifdef FLTK_HIDPI_SUPPORT
-  return 1;// this becomes useless if FLTK app are made DPI-aware by calling SetProcessDpiAwareness()
+  return scale(screen_num);
 #else
   // Compute the global desktop scaling factor: 1, 1.25, 1.5, 1.75, etc...
   // This factor can be set in Windows 10 by
@@ -651,6 +657,20 @@ void Fl_WinAPI_Screen_Driver::offscreen_size(Fl_Offscreen off, int &width, int &
   }
 }
 
+int Fl_WinAPI_Screen_Driver::screen_num_unscaled(int x, int y)
+{
+  int screen = 0;
+  if (num_screens < 0) init();
+  for (int i = 0; i < num_screens; i ++) {
+    if (x >= screens[i].left && x < screens[i].right &&
+        y >= screens[i].top && y < screens[i].bottom) {
+      screen = i;
+      break;
+    }
+  }
+  return screen;
+}
+
 //
 // End of "$Id$".
 //
diff --git a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.H b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.H
index 59ced3e37..acd8f7603 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.H
+++ b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.H
@@ -62,7 +62,6 @@ class FL_EXPORT Fl_WinAPI_Window_Driver : public Fl_Window_Driver
     HICON small_icon;
   };
 private:
-  RECT border_width_title_bar_height(int &bx, int &by, int &bt, float *pscaling = NULL);
   void shape_bitmap_(Fl_Image* b);
   void shape_alpha_(Fl_Image* img, int offset);
 public:
@@ -70,6 +69,7 @@ public:
   ~Fl_WinAPI_Window_Driver();
   static inline Fl_WinAPI_Window_Driver* driver(Fl_Window *w) {return (Fl_WinAPI_Window_Driver*)w->driver();}
   HDC private_dc; // used for OpenGL
+  RECT border_width_title_bar_height(int &bx, int &by, int &bt);
 
   struct icon_data *icon_;
   HCURSOR cursor;
diff --git a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
index 1d496edff..e39a2ed5a 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
+++ b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
@@ -59,14 +59,11 @@ Fl_WinAPI_Window_Driver::~Fl_WinAPI_Window_Driver()
 }
 
 
-// --- private
-
 RECT // frame of the decorated window in screen coordinates
   Fl_WinAPI_Window_Driver::border_width_title_bar_height(
                                                          int &bx, // left and right border width
                                                          int &by, // bottom border height (=bx)
-                                                         int &bt, // height of window title bar
-                                                         float *pscaling // display scaling factor
+                                                         int &bt  // height of window title bar
                                                          )
 {
   Fl_Window *win = pWindow;
@@ -83,14 +80,12 @@ RECT // frame of the decorated window in screen coordinates
       const DWORD DWMWA_EXTENDED_FRAME_BOUNDS = 9;
       if ( DwmGetWindowAttribute(fl_xid(win), DWMWA_EXTENDED_FRAME_BOUNDS, &r, sizeof(RECT)) == S_OK ) {
         need_r = 0;
-        scaling = Fl_WinAPI_Screen_Driver::desktop_scaling_factor();
+        scaling = ((Fl_WinAPI_Screen_Driver*)Fl::screen_driver())->DWM_scaling_factor(screen_num());
       }
     }
     if (need_r) {
       GetWindowRect(fl_xid(win), &r);
     }
-    if (pscaling) *pscaling = scaling;
-
     bx = (r.right - r.left - int(win->w() * scaling))/2;
     if (bx < 1) bx = 1;
     by = bx;
@@ -105,16 +100,24 @@ RECT // frame of the decorated window in screen coordinates
 int Fl_WinAPI_Window_Driver::decorated_w()
 {
   int bt, bx, by;
+  float s = Fl::screen_driver()->scale(screen_num());
   border_width_title_bar_height(bx, by, bt);
-  return w() + 2 * bx;
+  int mini_bx = bx/s; if (mini_bx < 1) mini_bx = 1;
+  return w() + 2 * mini_bx;
 }
 
 int Fl_WinAPI_Window_Driver::decorated_h()
 {
   int bt, bx, by;
-  float scaling = 1;
-  border_width_title_bar_height(bx, by, bt, &scaling);
-  return h() + bt/scaling + 2 * by;
+  border_width_title_bar_height(bx, by, bt);
+#ifdef FLTK_HIDPI_SUPPORT
+  float s = Fl::screen_driver()->scale(screen_num());
+  int mini_by = by/s; if (mini_by < 1) mini_by = 1;
+  return h() + (bt + by)/s + mini_by;
+#else
+  float scaling = ((Fl_WinAPI_Screen_Driver*)Fl::screen_driver())->DWM_scaling_factor(0);
+  return h() + bt/scaling + 2 * by +1;
+#endif
 }
 
 
@@ -596,7 +599,7 @@ int Fl_WinAPI_Window_Driver::scroll(int src_x, int src_y, int src_w, int src_h,
   static fl_GetRandomRgn_func fl_GetRandomRgn = 0L;
   static char first_time = 1;
   // We will have to do some Region magic now, so let's see if the
-  // required function is available (and it should be staring w/Win95)
+  // required function is available (and it should be starting w/Win95)
   if (first_time) {
     HMODULE hMod = GetModuleHandle("GDI32.DLL");
     if (hMod) {
@@ -604,6 +607,8 @@ int Fl_WinAPI_Window_Driver::scroll(int src_x, int src_y, int src_w, int src_h,
     }
     first_time = 0;
   }
+  float s = Fl::screen_driver()->scale(screen_num());
+  src_x *= s; src_y *= s; src_w *= s; src_h *= s; dest_x *= s; dest_y *= s;
   // Now check if the source scrolling area is fully visible.
   // If it is, we will do a quick scroll and just update the
   // newly exposed area. If it is not, we go the safe route and