provide C API for rounded rectangle cairo utility

git-svn-id: svn://localhost/ardour2/branches/3.0@10310 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/gtkmm2ext/gtkmm2ext/utils.h

@@ -98,6 +98,7 @@ namespace Gtkmm2ext {
 
         void container_clear (Gtk::Container&);
         void rounded_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, double y, double w, double h, double r=10);
+        void rounded_rectangle (cairo_t*, double x, double y, double w, double h, double r=10);
 };
 
 #endif /*  __gtkmm2ext_utils_h__ */

libs/gtkmm2ext/utils.cc

@@ -399,15 +399,29 @@ Gtkmm2ext::rounded_rectangle (Cairo::RefPtr<Cairo::Context> context, double x, d
       G    D
       F****E
 */
-        context->move_to(x+r,y); // Move to A
-        context->line_to(x+w-r,y); // Straight line to B
-        context->curve_to(x+w,y,x+w,y,x+w,y+r); // Curve to C, Control points are both at Q
-        context->line_to(x+w,y+h-r); // Move to D
-        context->curve_to(x+w,y+h,x+w,y+h,x+w-r,y+h); // Curve to E
-        context->line_to(x+r,y+h); // Line to F
-        context->curve_to(x,y+h,x,y+h,x,y+h-r); // Curve to G
-        context->line_to(x,y+r); // Line to H
-        context->curve_to(x,y,x,y,x+r,y); // Curve to A
+	rounded_rectangle (context->cobj(), x, y, w, h, r);
+}
+
+void
+Gtkmm2ext::rounded_rectangle (cairo_t* cr, double x, double y, double w, double h, double r)
+{
+        /* renders small shapes better than most others */
+
+/*    A****BQ
+      H    C
+      *    *
+      G    D
+      F****E
+*/
+	cairo_move_to (cr, x+r,y); // Move to A
+	cairo_line_to (cr, x+w-r,y); // Straight line to B
+	cairo_curve_to (cr, x+w,y,x+w,y,x+w,y+r); // Curve to C, Control points are both at Q
+	cairo_line_to (cr, x+w,y+h-r); // Move to D
+	cairo_curve_to (cr, x+w,y+h,x+w,y+h,x+w-r,y+h); // Curve to E
+	cairo_line_to (cr, x+r,y+h); // Line to F
+	cairo_curve_to (cr, x,y+h,x,y+h,x,y+h-r); // Curve to G
+	cairo_line_to (cr, x,y+r); // Line to H
+	cairo_curve_to (cr, x,y,x,y,x+r,y); // Curve to A
 }
 
 #else