Mac OS: support for high resolution OpenGL windows.

Methods Fl::event_x_pixel() and Fl::event_y_pixel() committed at r.10941
are removed. Instead method Fl_Gl_Window::pixels_per_unit() is added.

The documentation explains in more detail how to write cross-platform
FLTK code supporting high resolution OpenGL windows on retina displays.

The examples/OpenGL3test.cxx app exercises Fl_Gl_Window::pixels_per_unit().

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10945 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

13 files changed, 38 insertions, 97 deletions

diff --git a/CHANGES b/CHANGES
index 8dcf5d84d..5efc7dbbf 100644
--- a/CHANGES
+++ b/CHANGES
@@ -34,8 +34,8 @@ CHANGES IN FLTK 1.3.4					RELEASED: ??? ?? ????
 	  (Apple GL library) to draw OpenGL data. Instead, it uses standard
 	  cocoa APIs. This allows FLTK to support drawing GL scenes at high
 	  resolution when an Fl_Gl_Window is mapped to a 'retina' display.
-	- Added Fl_Gl_Window::pixel_w(), Fl_Gl_Window::pixel_h(), Fl::event_x_pixel(),
-	  and Fl::event_y_pixel() useful for high resolution OpenGL windows.
+	- Added Fl_Gl_Window::pixel_w(), Fl_Gl_Window::pixel_h(), and
+	  Fl_Gl_Window::pixels_per_unit() useful for high resolution OpenGL windows.
 	- fl_read_image() now captures all pixels within the rectangle
 	  described by its arguments, whether they belong to a GL scene
 	  or not (STR #3142). It also captures subwindows of GL windows.
diff --git a/FL/Fl.H b/FL/Fl.H
index 3d04838c8..674873637 100644
--- a/FL/Fl.H
+++ b/FL/Fl.H
@@ -135,9 +135,6 @@ public: // should be private!
   static int e_y;
   static int e_x_root;
   static int e_y_root;
-#ifdef __APPLE__
-  static Fl_Window *e_window_;
-#endif
   static int e_dx;
   static int e_dy;
   static int e_state;
@@ -604,29 +601,6 @@ public:
     event_x(),event_y().
   */
   static int event_y_root()	{return e_y_root;}
-#ifdef __APPLE__
-  static int event_x_pixel();
-  static int event_y_pixel();
-#else
-  /** Horizontal position in pixels of the mouse event relative to the Fl_Window it was passed to.
-   Generally identical with Fl::event_x(), but for OpenGL windows of macintosh computers
-   with a 'retina' display, and if Fl::use_high_res_GL(bool) is set to true,
-   the returned position, measured in pixels, differs from Fl::event_x(), measured in FLTK units.
-   \version 1.3.4
-   */
-  static int event_x_pixel()	{
-    return e_x;
-  }
-  /** Vertical position in pixels of the mouse event relative to the Fl_Window it was passed to.
-   Generally identical with Fl::event_y(), but for OpenGL windows of macintosh computers
-   with a 'retina' display, and if Fl::use_high_res_GL(bool) is set to true,
-   the returned position, measured in pixels, differs from Fl::event_y(), measured in FLTK units.
-   \version 1.3.4
-   */
-  static int event_y_pixel()	{
-    return e_y;
-  }
-#endif
   /**
     Returns the current horizontal mouse scrolling associated with the
     FL_MOUSEWHEEL event. Right is positive.
diff --git a/FL/Fl_Gl_Window.H b/FL/Fl_Gl_Window.H
index e8bd11aff..543aa41f3 100644
--- a/FL/Fl_Gl_Window.H
+++ b/FL/Fl_Gl_Window.H
@@ -229,10 +229,20 @@ public:
   // Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
   virtual Fl_Gl_Window* as_gl_window() {return this;}
   
-#if defined(__APPLE__)
-  int pixel_w();
-  int pixel_h();
+#ifdef __APPLE__
+  int pixels_per_unit();
 #else
+  /** The number of pixels per FLTK unit of length for the window.
+   Returns 1, except for a window mapped to
+   an Apple 'retina' display, and if Fl::use_high_res_GL(bool) is set to true,
+   when it returns 2. This method dynamically adjusts its value when the window
+   is moved to/from a retina display. This method is useful, e.g., to convert,
+   in a window's handle() method, the FLTK units returned by Fl::event_x() and
+   Fl::event_y() to the pixel units used by the OpenGL source code.
+   \version 1.3.4
+   */
+  int pixels_per_unit() { return 1; }
+#endif
   /** Gives the window width in OpenGL pixels.
    Generally identical with the result of the w() function, but for a window mapped to
    an Apple 'retina' display, and if Fl::use_high_res_GL(bool) is set to true,
@@ -240,7 +250,7 @@ public:
    between low and high resolution displays and automatically adjusts the returned value.
    \version 1.3.4
    */
-  int pixel_w() { return w(); }
+  int pixel_w() { return pixels_per_unit() * w(); }
   /** Gives the window height in OpenGL pixels.
    Generally identical with the result of the h() function, but for a window mapped to
    an Apple 'retina' display, and if Fl::use_high_res_GL(bool) is set to true,
@@ -248,8 +258,7 @@ public:
    between low and high resolution displays and automatically adjusts the returned value.
    \version 1.3.4
    */
-  int pixel_h() { return h(); }
-#endif
+  int pixel_h() { return pixels_per_unit() * h(); }
   
   ~Fl_Gl_Window();
   /**
diff --git a/FL/mac.H b/FL/mac.H
index 219a23c44..a8a6fc271 100644
--- a/FL/mac.H
+++ b/FL/mac.H
@@ -181,7 +181,6 @@ public:
   static void q_begin_image(CGRect&, int x, int y, int w, int h);
   static void q_end_image();
   // Cocoa additions
-  static int resolution_scaling_factor(Fl_Window*);
   static NSOpenGLPixelFormat *mode_to_NSOpenGLPixelFormat(int mode, const int*); // computes NSOpenGLPixelFormat from Gl window's mode
   static NSOpenGLContext* create_GLcontext_for_window(NSOpenGLPixelFormat *pixelformat, NSOpenGLContext *shared_ctx, Fl_Window *window);
   static void GLcontext_update(NSOpenGLContext*);
diff --git a/documentation/src/osissues.dox b/documentation/src/osissues.dox
index 80edb3624..829c3d5e7 100644
--- a/documentation/src/osissues.dox
+++ b/documentation/src/osissues.dox
@@ -839,16 +839,21 @@ by
 \verbatim
 glViewport(0, 0, pixel_w(), pixel_h());
 \endverbatim
-making use of the Fl_Gl_Window::pixel_w() and Fl_Gl_Window::pixel_h() functions that return the width and height of
-the GL scene in pixels: if the Fl_Gl_Window is mapped on a retina display, these functions return twice as much as 
-reported by Fl_Widget::w() and Fl_Widget::h(); if it's mapped on a regular display, they return the same values as w() and h().
-If you don't call Fl::use_high_res_GL(1), your Fl_Gl_Window 's will be drawn with low resolution.
-These functions are synonyms of w() and h() on non-Mac OS X platforms, so your source code remains cross-platform.
+making use of the Fl_Gl_Window::pixel_w() and Fl_Gl_Window::pixel_h() methods that return the width and height of
+the GL scene in pixels: if the Fl_Gl_Window is mapped on a retina display, these methods return twice as much as
+reported by Fl_Widget::w() and Fl_Widget::h(); if it's mapped on a regular display, they return the same values
+as w() and h(). These methods dynamically change their values if the window is moved into/out from a retina
+display. If Fl::use_high_res_GL(1) is not called, all Fl_Gl_Window 's are drawn at low resolution.
+These methods are synonyms of w() and h() on non-Mac OS X platforms, so the source code remains cross-platform.
 
-Fl_Double_Window
+The Fl_Gl_Window::pixels_per_unit() method is useful when the OpenGL code depends on the pixel dimension
+of the GL scene. This occurs, e.g., if a window's handle() method uses Fl::event_x() and Fl::event_y()
+whose returned values should be multiplied by Fl_Gl_Window::pixels_per_unit() to obtain the adequate pixel units.
+This method may also be useful, for example, to adjust the width of a line in a high resolution GL scene.
 
-OS X double-buffers all windows automatically. On OS X,
-Fl_Window and Fl_Double_Window are handled
+\subsection double_window Fl_Double_Window
+
+OS X double-buffers all windows automatically. On OS X, Fl_Window and Fl_Double_Window are handled
 internally in the same way.
 
 \subsection osissues_mac_files Mac File System Specifics
diff --git a/examples/OpenGL3test.cxx b/examples/OpenGL3test.cxx
index 8c293f81f..5ce620445 100644
--- a/examples/OpenGL3test.cxx
+++ b/examples/OpenGL3test.cxx
@@ -149,7 +149,7 @@ public:
       data[0] *= factor;
       glBufferSubData(GL_ARRAY_BUFFER, 24*sizeof(GLfloat), 4*sizeof(GLfloat), data);
       redraw();
-      add_output("push Fl::event_x_pixel()=%d  Fl::event_y_pixel()=%d\n",Fl::event_x_pixel(), Fl::event_y_pixel());
+      add_output("push  Fl_Gl_Window::pixels_per_unit()=%d\n", pixels_per_unit());
       return 1;
     }
     return Fl_Gl_Window::handle(event);
diff --git a/src/Fl.cxx b/src/Fl.cxx
index 4f4b263fe..357fb55f0 100644
--- a/src/Fl.cxx
+++ b/src/Fl.cxx
@@ -86,9 +86,6 @@ Fl_Widget	*Fl::belowmouse_,
 		*Fl::pushed_,
 		*Fl::focus_,
 		*Fl::selection_owner_;
-#ifdef __APPLE__
-Fl_Window       *Fl::e_window_; // the window relative to which Fl::e_x and Fl::e_y are measured
-#endif
 int		Fl::damage_,
 		Fl::e_number,
 		Fl::e_x,
@@ -1093,9 +1090,6 @@ void fl_fix_focus() {
 	// send a FL_MOVE event so the enter/leave state is up to date
 	Fl::e_x = Fl::e_x_root-fl_xmousewin->x();
 	Fl::e_y = Fl::e_y_root-fl_xmousewin->y();
-#ifdef __APPLE__
-        Fl::e_window_ = fl_xmousewin;
-#endif
         int old_event = Fl::e_number;
 	w->handle(Fl::e_number = FL_MOVE);
 	Fl::e_number = old_event;
@@ -1186,19 +1180,10 @@ static int send_event(int event, Fl_Widget* to, Fl_Window* window) {
     if (w->type()>=FL_WINDOW) {dx -= w->x(); dy -= w->y();}
   int save_x = Fl::e_x; Fl::e_x += dx;
   int save_y = Fl::e_y; Fl::e_y += dy;
-#ifdef __APPLE__
-  Fl_Window *save_e_window = Fl::e_window_;
-  if (dx || dy) {
-    Fl::e_window_ = (to->as_window() ? to->as_window() : to->window());
-  }
-#endif
   int ret = to->handle(Fl::e_number = event);
   Fl::e_number = old_event;
   Fl::e_y = save_y;
   Fl::e_x = save_x;
-#ifdef __APPLE__
-  Fl::e_window_ = save_e_window;
-#endif
   return ret;
 }
 
diff --git a/src/Fl_Gl_Device_Plugin.cxx b/src/Fl_Gl_Device_Plugin.cxx
index e9b43d1cf..94c355349 100644
--- a/src/Fl_Gl_Device_Plugin.cxx
+++ b/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 = Fl_X::resolution_scaling_factor(glw);
+  int factor = glw->pixels_per_unit();
   if (factor > 1) {
     w *= factor; h *= factor; x *= factor; y *= factor;
   }
diff --git a/src/Fl_Gl_Window.cxx b/src/Fl_Gl_Window.cxx
index 7fa0a4004..46e7ebbb7 100644
--- a/src/Fl_Gl_Window.cxx
+++ b/src/Fl_Gl_Window.cxx
@@ -96,14 +96,9 @@ void Fl_Gl_Window::show() {
 
 #if defined(__APPLE__)
 
-int Fl_Gl_Window::pixel_w()
+int Fl_Gl_Window::pixels_per_unit()
 {
-  return Fl_X::resolution_scaling_factor(this) * w();
-}
-
-int Fl_Gl_Window::pixel_h()
-{
-  return Fl_X::resolution_scaling_factor(this) * h();
+  return (fl_mac_os_version >= 100700 && Fl::use_high_res_GL() && Fl_X::i(this) && Fl_X::i(this)->mapped_to_retina()) ? 2 : 1;
 }
 
 #endif // __APPLE__
diff --git a/src/Fl_Group.cxx b/src/Fl_Group.cxx
index 3ac752613..7b10dc9f3 100644
--- a/src/Fl_Group.cxx
+++ b/src/Fl_Group.cxx
@@ -105,16 +105,9 @@ static int send(Fl_Widget* o, int event) {
   }
   int save_x = Fl::e_x; Fl::e_x -= o->x();
   int save_y = Fl::e_y; Fl::e_y -= o->y();
-#ifdef __APPLE__
-  Fl_Window *save_e_window = Fl::e_window_;
-  Fl::e_window_ = o->as_window();
-#endif
   int ret = o->handle(event);
   Fl::e_y = save_y;
   Fl::e_x = save_x;
-#ifdef __APPLE__
-  Fl::e_window_ = save_e_window;
-#endif
   switch ( event )
   {
   case FL_ENTER: /* FALLTHROUGH */
diff --git a/src/Fl_cocoa.mm b/src/Fl_cocoa.mm
index ed9872f91..02b8e7ce1 100644
--- a/src/Fl_cocoa.mm
+++ b/src/Fl_cocoa.mm
@@ -972,7 +972,6 @@ static void update_e_xy_and_e_xy_root(NSWindow *nsw)
 {
   NSPoint pt;
   pt = [nsw mouseLocationOutsideOfEventStream];
-  Fl::e_window_ = [(FLWindow*)nsw getFl_Window];
   Fl::e_x = int(pt.x);
   Fl::e_y = int([[nsw contentView] frame].size.height - pt.y);
   pt = [NSEvent mouseLocation];
@@ -980,13 +979,6 @@ static void update_e_xy_and_e_xy_root(NSWindow *nsw)
   Fl::e_y_root = int(main_screen_height - pt.y);
 }
 
-int Fl::event_x_pixel()	{
-  return e_x * Fl_X::resolution_scaling_factor(Fl::e_window_);
-}
-
-int Fl::event_y_pixel()	{
-  return e_y * Fl_X::resolution_scaling_factor(Fl::e_window_);
-}
 
 /*
  * Cocoa Mousewheel handler
@@ -2740,13 +2732,6 @@ static FLTextInputContext* fltextinputcontext_instance = nil;
 @end
 
 
-// For Fl_Gl_Window on retina display, returns 2, otherwise 1
-int Fl_X::resolution_scaling_factor(Fl_Window* win)
-{
-  return (fl_mac_os_version >= 100700 && win && win->as_gl_window() && Fl::use_high_res_GL() && win->i && win->i->mapped_to_retina()) ? 2 : 1;
-}
-
-
 NSOpenGLPixelFormat* Fl_X::mode_to_NSOpenGLPixelFormat(int m, const int *alistp)
 {
   NSOpenGLPixelFormatAttribute attribs[32];
diff --git a/src/gl_draw.cxx b/src/gl_draw.cxx
index 6f88d0637..1c31f4174 100644
--- a/src/gl_draw.cxx
+++ b/src/gl_draw.cxx
@@ -520,7 +520,7 @@ static gl_texture_fifo *gl_fifo = NULL; // points to the texture pile class inst
 // draws a utf8 string using pre-computed texture if available
 static void gl_draw_textures(const char* str, int n) 
 {
-  gl_scale = Fl_X::resolution_scaling_factor(Fl_Window::current());
+  gl_scale = Fl_Window::current()->as_gl_window()->pixels_per_unit();
   //fprintf(stderr,"gl_scale=%d\n",gl_scale);
   if (! gl_fifo) gl_fifo = new gl_texture_fifo();
   if (!gl_fifo->textures_generated) {
diff --git a/src/glut_compatability.cxx b/src/glut_compatability.cxx
index 1f1d6a6ff..9b1f9e6dd 100644
--- a/src/glut_compatability.cxx
+++ b/src/glut_compatability.cxx
@@ -83,13 +83,9 @@ int Fl_Glut_Window::handle(int event) {
   make_current();
   int ex = Fl::event_x();
   int ey = Fl::event_y();
-#ifdef __APPLE__
-  if (shown()) {
-    int factor = Fl_X::resolution_scaling_factor(this);
-    ex *= factor;
-    ey *= factor;
-  }
-#endif
+  int factor = pixels_per_unit();
+  ex *= factor;
+  ey *= factor;
   int button;
   switch (event) {