more changes for rectangle outlining

[ardour.git] / libs / canvas / rectangle.cc

diff --git a/libs/canvas/rectangle.cc b/libs/canvas/rectangle.cc
index d79518e7f6d86138ae34a00438b7d3ca3766c1b9..8ee83195919e9ef51c0be9efab46a707bddb142f 100644 (file)
--- a/libs/canvas/rectangle.cc
+++ b/libs/canvas/rectangle.cc
@@ -88,53 +88,52 @@ Rectangle::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) con
 
                setup_outline_context (context);
                
+               /* the goal here is that if the border is 1 pixel
+                * thick, it will precisely align with the corner
+                * coordinates of the rectangle. So if the rectangle
+                * has a left edge at 0 and a right edge at 10, then
+                * the left edge must span -0.5..+0.5, the right edge
+                * must span 9.5..10.5 (i.e. the single full color
+                * pixel is precisely aligned with 0 and 10
+                * respectively).
+                *
+                * we have to shift left/up in all cases, which means
+                * subtraction along both axes (i.e. edge at
+                * N, outline must start at N-0.5). 
+                *
+                * see the cairo FAQ on single pixel lines to see why we do
+                * the 0.5 pixel additions.
+                */
+
+               self = self.translate (Duple (-0.5, -0.5));
+
+               std::cerr << "Outline using " << self << " from " << _rect << std::endl;
+               
                if (_outline_what == What (LEFT|RIGHT|BOTTOM|TOP)) {
                        
-                       context->rectangle (self.x0 + 0.5, self.y0 + 0.5, self.width() - 1.0, self.height() - 1.0);
+                       context->rectangle (self.x0, self.y0, self.width(), self.height());
 
                } else {
 
-                       /* the goal here is that if the border is 1 pixel
-                        * thick, it will precisely align with the corner
-                        * coordinates of the rectangle. So if the rectangle
-                        * has a left edge at 0 and a right edge at 10, then
-                        * the left edge must span -0.5..+0.5, the right edge
-                        * must span 9.5..10.5 (i.e. the single full color
-                        * pixel is precisely aligned with 0 and 10
-                        * respectively).
-                        *
-                        * we have to shift left/up in all cases, which means
-                        * subtraction along both axes (i.e. edge at
-                        * N, outline must start at N-0.5). 
-                        *
-                        * see the cairo FAQ on single pixel lines to see why we do
-                        * the 0.5 pixel additions.
-                        */
-
                        if (_outline_what & LEFT) {
-                               /* vertical line: move x-coordinate left by 0.5 pixels */
-                               context->move_to (self.x0 - 0.5, self.y0);
-                               context->line_to (self.x0 - 0.5, self.y1);
+                               context->move_to (self.x0, self.y0);
+                               context->line_to (self.x0, self.y1);
                        }
                        
                        if (_outline_what & TOP) {
-                               /* horizontal line: move y-coordinate up by 0.5 pixels */
-                               context->move_to (self.x0, self.y0 - 0.5);
-                               context->line_to (self.x1, self.y0 - 0.5);
+                               context->move_to (self.x0, self.y0);
+                               context->line_to (self.x1, self.y0);
                        }
 
                        if (_outline_what & BOTTOM) {
-                               /* horizontal line: move y-coordinate up 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);
+                               context->line_to (self.x1, self.y1);
                        }
                        
                        if (_outline_what & RIGHT) {
-                               /* vertical line: move x-coordinate left 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, self.y0);
+                               context->line_to (self.x1, self.y1);
                        }
-                       
                }
                
                context->stroke ();
@@ -146,12 +145,12 @@ Rectangle::compute_bounding_box () const
 {
        if (!_rect.empty()) {
                Rect r = _rect.fix ();
+
                /* take into acount the 0.5 addition to the bounding
                   box for the right and bottom edges, see ::render() above
                */
 
-               r.x1 += 1.0; // XXX this makes no sense but is necessary
-               r.y1 += 0.5;
+               r = r.expand (1.0);
 
                _bounding_box = r;
        }