STR#3444: Add MacOS support for application rescaling (not quite complete)

With this, most MacOS FLTK app can be scaled with command/+/-/0/ keystrokes.
A scaling problem remains, visible in test/cube, where the "Test" string is not positioned correctly.

GLUT apps can also be scaled (across platforms).

SVG images are re-rasterized after app scaling for optimal drawing.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.4@12594 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

3 files changed, 16 insertions, 7 deletions

diff --git a/src/drivers/Cocoa/Fl_Cocoa_Printer_Driver.mm b/src/drivers/Cocoa/Fl_Cocoa_Printer_Driver.mm
index 38c3075c5..607aed8fc 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Printer_Driver.mm
+++ b/src/drivers/Cocoa/Fl_Cocoa_Printer_Driver.mm
@@ -19,6 +19,7 @@
 #include <FL/Fl_Printer.H>
 #include <FL/Fl_Shared_Image.H>
 #include <FL/Fl_Window_Driver.H>
+#include <FL/Fl_Screen_Driver.H>
 #include "../Quartz/Fl_Quartz_Graphics_Driver.H"
 #include "../Darwin/Fl_Darwin_System_Driver.H"
 #include "Fl_Cocoa_Window_Driver.H"
@@ -401,8 +402,9 @@ void Fl_Cocoa_Printer_Driver::draw_decorated_window(Fl_Window *win, int x_offset
       CGContextRef gc = (CGContextRef)driver()->gc();
       CGContextSaveGState(gc);
       CGContextTranslateCTM(gc, x_offset - 0.5, y_offset + bt - 0.5);
-      CGContextScaleCTM(gc, 1, -1);
-      Fl_Cocoa_Window_Driver::draw_layer_to_context(layer, gc, win->w(), bt);
+      float s = Fl::screen_driver()->scale(win->driver()->screen_num());
+      CGContextScaleCTM(gc, 1/s, -1/s);
+      Fl_Cocoa_Window_Driver::draw_layer_to_context(layer, gc, win->w() * s, bt);
       CGContextRestoreGState(gc);
     }
     else {
diff --git a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
index 3335a39ff..5e318a2e3 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
+++ b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.H
@@ -4,7 +4,7 @@
 // Definition of Apple Cocoa Screen interface
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2016 by Bill Spitzak and others.
+// Copyright 2010-2017 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -97,6 +97,12 @@ public:
   // --- compute dimensions of an Fl_Offscreen
   virtual void offscreen_size(Fl_Offscreen o, int &width, int &height);
   virtual float retina_factor() { return 2; }
+  
+  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;}
+private:
+  float scale_;
 };
 
 
diff --git a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx
index 7c8119ca1..e4f86aa90 100644
--- a/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx
+++ b/src/drivers/Cocoa/Fl_Cocoa_Screen_Driver.cxx
@@ -99,10 +99,11 @@ void Fl_Cocoa_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H, int n)
   if ((n < 0) || (n >= num_screens))
     n = 0;
 
-  X = screens[n].x;
-  Y = screens[n].y;
-  W = screens[n].width;
-  H = screens[n].height;
+  float s = scale(0);
+  X = screens[n].x/s;
+  Y = screens[n].y/s;
+  W = screens[n].width/s;
+  H = screens[n].height/s;
 }