Changed OpenGL support for the Mac OS X platform: use cocoa instead of deprecated AGL.

All changes are mac-specific, except a very minor change in file src/gl_draw.cxx
where string drawing wrongly claimed to support @symbol, not possible
because symbols are drawn using non-GL primitives.

Unchanged application code can use the new FLTK code.
In addition, the new code allows mac applications to draw OpenGL scenes
at high resolution on so-called 'retina' displays, but this requires some
support from app code. They must call, before opening GL windows,
Fl::use_high_resolution(1);
and change their glViewport() calls as follows
glViewport(0, 0, pxel_w(), pixel_h());
This uses 2 new member functions of the Fl_Gl_Window class,
pixel_w() and pixel_h() returning the window dimensions in pixel
units, that is, twice the w() and h() when the window is mapped
on a retina display.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10498 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

3 files changed, 42 insertions, 3 deletions

diff --git a/FL/Fl.H b/FL/Fl.H
index cc223dba8..259e14371 100644
--- a/FL/Fl.H
+++ b/FL/Fl.H
@@ -125,6 +125,9 @@ typedef void (*Fl_Clipboard_Notify_Handler)(int source, void *data);
 class FL_EXPORT Fl {
   Fl() {}; // no constructor!
   
+private:
+  static int use_high_res_GL_;
+  
 public: // should be private!
 #ifndef FL_DOXYGEN
   static int e_number;
@@ -1206,6 +1209,16 @@ public:
   static void release_widget_pointer(Fl_Widget *&w);
   static void clear_widget_pointer(Fl_Widget const *w);
   /** @} */
+  
+  /**  sets whether GL windows should be drawn at high resolution on Apple
+   computers with retina displays
+   */
+  static void use_high_res_GL(int val) { use_high_res_GL_ = val; }
+  /**  returns whether GL windows should be drawn at high resolution on Apple
+   computers with retina displays.
+   Default is no.
+   */
+  static int use_high_res_GL() { return use_high_res_GL_; }
 
 #ifdef FLTK_HAVE_CAIRO
   /** \defgroup group_cairo Cairo support functions and classes 
diff --git a/FL/Fl_Gl_Window.H b/FL/Fl_Gl_Window.H
index 47fe04939..7bec39877 100644
--- a/FL/Fl_Gl_Window.H
+++ b/FL/Fl_Gl_Window.H
@@ -89,7 +89,7 @@ public:
     \code
     void mywindow::draw() {
      if (!valid()) {
-       glViewport(0,0,w(),h());
+       glViewport(0,0,pixel_w(),pixel_h());
        glFrustum(...);
        ...other initialization...
      }
@@ -168,7 +168,8 @@ public:
   int mode(int a) {return mode(a,0);}
   /** See Fl_Mode mode() const */
   int mode(const int *a) {return mode(0, a);}
-  /** void See void context(void* v, int destroy_flag) */
+  /** Returns a pointer to the GLContext that this window is using.
+   \see void context(void* v, int destroy_flag) */
   void* context() const {return context_;}
   void context(void*, int destroy_flag = 0);
   void make_current();
@@ -201,6 +202,24 @@ public:
   // Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
   virtual Fl_Gl_Window* as_gl_window() {return this;}
   
+#if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
+  int pixel_w();
+  int pixel_h();
+#else
+  /** Gives the window width in OpenGL pixels.
+   Generally identical with the result of the w() function, but on macintosh computers
+   with a 'retina' display, and if Fl::use_high_res_GL(bool) is set to true, 
+   pixel_w() returns 2 * w().
+   */
+  int pixel_w() { return w(); }
+  /** Gives the window height in OpenGL pixels.
+   Generally identical with the result of the h() function, but on macintosh computers
+   with a 'retina' display, and if Fl::use_high_res_GL(bool) is set to true,
+   pixel_h() returns 2 * h().
+   */
+  int pixel_h() { return h(); }
+#endif
+  
   ~Fl_Gl_Window();
   /**
     Creates a new Fl_Gl_Window widget using the given size, and label string. 
diff --git a/FL/mac.H b/FL/mac.H
index 85e40c12b..df234710f 100644
--- a/FL/mac.H
+++ b/FL/mac.H
@@ -74,8 +74,10 @@ typedef CGContextRef Fl_Offscreen;
 
 #ifdef __OBJC__
 @class NSCursor;
+@class NSOpenGLPixelFormat;
 #else
 class NSCursor;
+class NSOpenGLPixelFormat;
 #endif // __OBJC__
 
 typedef CGContextRef Fl_Offscreen;
@@ -151,6 +153,8 @@ public:
 #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7
   bool mapped_to_retina();      // is window mapped to retina display?
   void mapped_to_retina(bool);  // sets whether window is mapped to retina display
+  bool changed_resolution();      // did window just moved to display with another resolution?
+  void changed_resolution(bool);// sets whether window just moved to display with another resolution
 #endif
   // Quartz additions:
   CGContextRef gc;                 // graphics context (NULL when using QD)
@@ -160,6 +164,8 @@ 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
   void destroy(void);
   void map(void);
   void unmap(void);
@@ -183,7 +189,8 @@ public:
 private:
 #if FLTK_ABI_VERSION >= 10304
   CGRect* subRect_;           // makes sure subwindow remains inside its parent window
-  unsigned mapped_to_retina_; // stores whether window is mapped to retina display
+  // stores 2 binary flags: whether window is mapped to retina display; whether resolution just changed
+  unsigned mapped_to_retina_;
 #else
   bool subwindow;     // for ABI compatibility, useless with true subwindows
 #endif