Fix a case when fl_read_window() did not capture subwindows correctly.

The case was under macOS with a non-GL parent window mapped to a retina display
containing a GL subwindow and if the app did not call Fl::use_high_res_GL(1).

2 files changed, 5 insertions, 3 deletions

diff --git a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
index 2b329367b..faf5b8520 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
+++ b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
@@ -99,7 +99,7 @@ public:
   virtual APP_SCALING_CAPABILITY rescalable() { return SYSTEMWIDE_APP_SCALING; }
   virtual float scale(int n) {return scale_;}
   virtual void scale(int n, float f) { scale_ = f;}
-  virtual Fl_RGB_Image *read_win_rectangle(int X, int Y, int w, int h, Fl_Window *win);
+  virtual Fl_RGB_Image *read_win_rectangle(int X, int Y, int w, int h, Fl_Window *win, bool may_capture_subwins, bool *did_capture_subwins);
 private:
   float scale_;
 };
diff --git a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx
index d3ec31fdf..34e1c80fd 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx
+++ b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx
@@ -339,7 +339,8 @@ void Fl_Cocoa_Screen_Driver::offscreen_size(Fl_Offscreen off, int &width, int &h
   height = CGBitmapContextGetHeight(off);
 }
 
-Fl_RGB_Image *Fl_Cocoa_Screen_Driver::read_win_rectangle(int X, int Y, int w, int h, Fl_Window *window)
+Fl_RGB_Image *Fl_Cocoa_Screen_Driver::read_win_rectangle(int X, int Y, int w, int h, Fl_Window *window,
+                                                         bool may_capture_subwins, bool *did_capture_subwins)
 {
   int bpp, bpr, depth = 4;
   uchar *base, *p;
@@ -374,7 +375,8 @@ Fl_RGB_Image *Fl_Cocoa_Screen_Driver::read_win_rectangle(int X, int Y, int w, in
     bpr = 0;
   } else { // read from window
     Fl_Cocoa_Window_Driver *d = Fl_Cocoa_Window_Driver::driver(window);
-    CGImageRef cgimg = d->CGImage_from_window_rect(X, Y, w, h, false);
+    CGImageRef cgimg = d->CGImage_from_window_rect(X, Y, w, h, may_capture_subwins);
+    if (did_capture_subwins) *did_capture_subwins = may_capture_subwins;
     if (!cgimg) {
       return NULL;
     }