fix up some issues with precise placement of ArdourCanvas::Rectangle frame/outline

diff --git a/libs/canvas/rectangle.cc b/libs/canvas/rectangle.cc
index 4c5304aafd4f5925922054aad6d10a3ee4387195..e2c0b974c03a890b32fb5574b4b54568717e3385 100644 (file)
--- a/libs/canvas/rectangle.cc
+++ b/libs/canvas/rectangle.cc
@@ -78,24 +78,18 @@ Rectangle::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) con
 
                setup_outline_context (context);
                
+               /* see the cairo FAQ on single pixel lines to see why we do
+                * the 0.5 pixel additions.
+                */
+
                if (_outline_what == What (LEFT|RIGHT|BOTTOM|TOP)) {
                        
-                       /* outline must be on pixels (hence 0.5 offset) and
-                          must be WITHIN coordinates of rect, not outside it
-                          (hence the -2.0 size adjustment, since we use 1
-                          pixel on each side for the outline)
-                       */
-
                        context->rectangle (self.x0 + 0.5, self.y0 + 0.5, self.width() - 1.0, self.height() - 1.0);
 
                } else {
 
                        // context->set_line_cap (Cairo::LINE_CAP_SQUARE);
                        
-                       /* see the cairo FAQ on single pixel lines to see why we do
-                        * this expansion of the perimeter.
-                        */
-
                        if (_outline_what & LEFT) {
                                /* vertical line: move x-coordinate by 0.5 pixels */
                                context->move_to (self.x0 + 0.5, self.y0);
@@ -104,14 +98,14 @@ Rectangle::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) con
                        
                        if (_outline_what & BOTTOM) {
                                /* horizontal line: move y-coordinate by 0.5 pixels */
-                               context->move_to (self.x0, self.y1 - 0.5);
-                               context->line_to (self.x1, self.y1 - 0.5);
+                               context->move_to (self.x0, self.y1 + 0.5);
+                               context->line_to (self.x1, self.y1 + 0.5);
                        }
                        
                        if (_outline_what & RIGHT) {
                                /* vertical line: move x-coordinate by 0.5 pixels */
-                               context->move_to (self.x1 - 0.5, self.y0);
-                               context->line_to (self.x1 - 0.5, self.y1);
+                               context->move_to (self.x1 + 0.5, self.y0);
+                               context->line_to (self.x1 + 0.5, self.y1);
                        }
                        
                        if (_outline_what & TOP) {