From bfb7e3a6973c4807d33ca6e96cef9924271a00ac Mon Sep 17 00:00:00 2001
From: Jonathan Moore Liles <j.liles@unix.net>
Date: Sun, 18 Mar 2012 17:32:11 -0700
Subject: [PATCH] Keep Cairo clipping in sync with FLTK/Xlib clipping.

---
 FL/Fl_Device.H                   | 44 +++-----------------------------
 src/Fl_Cairo_Graphics_Driver.cxx | 40 +++++++++++------------------
 2 files changed, 19 insertions(+), 65 deletions(-)

diff --git a/FL/Fl_Device.H b/FL/Fl_Device.H
index ed5898c..7f68f5c 100644
--- a/FL/Fl_Device.H
+++ b/FL/Fl_Device.H
@@ -344,7 +344,7 @@ protected:
   /** \brief see fl_clip_region(Fl_Region r). */
   void clip_region(Fl_Region r);
   /** \brief see fl_restore_clip(). */
-  void restore_clip();
+  virtual void restore_clip();
   
   // Images
   /** \brief see fl_draw_image(const uchar* buf, int X,int Y,int W,int H, int D, int L). */
@@ -502,23 +502,6 @@ FL_EXPORT Fl_Color fl_color_add_alpha ( Fl_Color c, uchar alpha );
 
 class Fl_Cairo_Graphics_Driver : public Fl_Xlib_Graphics_Driver {
 
-struct ClipRect 
-{
-    int x, y, w, h;
-
-    ClipRect ( int X, int Y, int W, int H )
-        {
-            x = X;
-            y = Y;
-            w = W;
-            h = H;
-        }
-};
-
-    int rstackptr;
-    static const int region_stack_max = FL_REGION_STACK_SIZE - 1;
-    ClipRect *rstack[FL_REGION_STACK_SIZE];
-    
 public:
 
     Fl_Cairo_Graphics_Driver ( );
@@ -534,41 +517,22 @@ public:
 
     void line_style(int style, int width=0, char* dashes=0);
 
-    void end_points ( void );
+    
+    void restore_clip ( void );
 
-    void push_clip ( int x, int y, int w, int h );
-    void pop_clip ( void );
     void arc( int x, int y, int w, int h, double a1, double a2 );
     void pie( int x, int y, int w, int h, double a1, double a2 );
     void arc( double x, double y, double r, double a1, double a2 );
     void line( int x1, int y1, int x2, int y2 );
     void line( int x1, int y1, int x2, int y2, int x3, int y3 );
     void rect ( int x, int y, int w, int h );
-    /* void rect ( int x, int y, int w, int h, Fl_Color c ); */
+    void end_points ( void );
     void rectf ( int x, int y, int w, int h );
-    /* void rectf ( int x, int y, int w, int h, Fl_Color c ); */
-    /* void scale ( double x, double y ); */
-    /* void scale ( double x ); */
     void circle ( double x, double y, double r );
-
-    /* void translate ( double x, double y ); */
-    /* void rotate ( double r ); */
-
-    /* void begin_line ( void ); */
-
-    /* void vertex ( double x, double y ); */
-
-    /* void gap ( void ); */
     void end_line ( void );
-    /* void begin_loop ( void ); */
     void end_loop ( void );
-    /* void begin_complex_polygon ( void ); */
     void end_complex_polygon ( void );
-    /* void begin_polygon ( void ); */
     void end_polygon ( void );
-    /* void push_matrix ( void ); */
-    /* void pop_matrix ( void ); */
-    void push_no_clip ( void );
     void curve( double x, double y, double x1, double y1, double x2, double y2, double x3, double y3 );
 
     void loop ( int x, int y, int x1, int y1, int x2, int y2 );
diff --git a/src/Fl_Cairo_Graphics_Driver.cxx b/src/Fl_Cairo_Graphics_Driver.cxx
index 7f4730d..ad10de3 100644
--- a/src/Fl_Cairo_Graphics_Driver.cxx
+++ b/src/Fl_Cairo_Graphics_Driver.cxx
@@ -61,40 +61,30 @@ static double line_width = 0.5;
 
 Fl_Cairo_Graphics_Driver::Fl_Cairo_Graphics_Driver ( )   : Fl_Xlib_Graphics_Driver ()
 {
-    rstackptr = 0;
+//    rstackptr = 0;
 }
 
-void Fl_Cairo_Graphics_Driver::push_no_clip ( void )
+void Fl_Cairo_Graphics_Driver::restore_clip ( void )
 {
     cairo_t *cr = Fl::cairo_cc();
 
-    Fl_Xlib_Graphics_Driver::push_no_clip();
+    if ( ! cr )
+        return;
 
-    cairo_save( cr );
-
-    cairo_reset_clip( cr );
-}
+    Fl_Xlib_Graphics_Driver::restore_clip();
 
-void Fl_Cairo_Graphics_Driver::push_clip ( int x, int y, int w, int h )
-{
-    cairo_t *cr = Fl::cairo_cc();
-
-    Fl_Xlib_Graphics_Driver::push_clip( x, y, w, h );
-
-    cairo_save( cr );
-
-    cairo_rectangle( cr, x, y, w, h );
+    Fl_Region r = clip_region();
 
-    cairo_clip( cr );
-}
-
-void Fl_Cairo_Graphics_Driver::pop_clip ( void )
-{
-    cairo_t *cr = Fl::cairo_cc();
-
-    Fl_Xlib_Graphics_Driver::pop_clip();
+    cairo_reset_clip( cr );
 
-    cairo_restore( cr );
+    if ( r )
+    {
+        XRectangle rect;
+        XClipBox(r, &rect);
+        
+        cairo_rectangle( cr, rect.x, rect.y, rect.width, rect.height );
+        cairo_clip( cr );
+    }
 }
 
 void Fl_Cairo_Graphics_Driver::line_style ( int style, int t, char* )