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

3 files changed, 15 insertions, 33 deletions

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*);