X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fcanvas%2Frectangle.cc;h=232da178935b083720b8db64d2334087ee993eff;hb=f1e6b28ab7759f9bc93eb965cbe7740f1bafb2d3;hp=ac05003693970325153322f44ce843049ea8e30f;hpb=590882f3c8e063528452d71daffb36d3151da05e;p=ardour.git

diff --git a/libs/canvas/rectangle.cc b/libs/canvas/rectangle.cc
index ac05003693..232da17893 100644
--- a/libs/canvas/rectangle.cc
+++ b/libs/canvas/rectangle.cc
@@ -43,28 +43,34 @@ Rectangle::Rectangle (Canvas* c, Rect const & rect)
 {
 }
 
-Rectangle::Rectangle (Group* g)
-	: Item (g)
+Rectangle::Rectangle (Item* parent)
+	: Item (parent)
 	, _outline_what ((What) (LEFT | RIGHT | TOP | BOTTOM))
 {
 }
 
-Rectangle::Rectangle (Group* g, Rect const & rect)
-	: Item (g)
+Rectangle::Rectangle (Item* parent, Rect const & rect)
+	: Item (parent)
 	, _rect (rect)
 	, _outline_what ((What) (LEFT | RIGHT | TOP | BOTTOM))
 {
 }
 
-void
-Rectangle::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
+Rect
+Rectangle::get_self_for_render () const
 {
 	/* In general, a Rectangle will have a _position of (0,0) within its
 	   parent, and its extent is actually defined by _rect. But in the
 	   unusual case that _position is set to something other than (0,0),
 	   we should take that into account when rendering.
 	*/
-	Rect self = item_to_window (_rect.translate (_position));
+
+	return item_to_window (_rect.translate (_position));
+}
+
+void
+Rectangle::render_self (Rect const & area, Cairo::RefPtr<Cairo::Context> context, Rect self) const
+{
 	boost::optional<Rect> r = self.intersection (area);
 
 	if (!r) {
@@ -88,57 +94,73 @@ 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 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));
+
 		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 {
 
 			if (_outline_what & LEFT) {
-				/* vertical line: move x-coordinate 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 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 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 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 ();
 	}
 }
 
+void
+Rectangle::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
+{
+	render_self (area, context, get_self_for_render ());
+}
+
 void
 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;
 	}
@@ -226,3 +248,37 @@ Rectangle::set_outline_what (What what)
 	}
 }
 
+
+/*-------------------*/
+
+void
+TimeRectangle::compute_bounding_box () const
+{
+	Rectangle::compute_bounding_box ();
+
+	if (_bounding_box) {
+		Rect r = _bounding_box.get ();
+		
+		/* This is a TimeRectangle, so its right edge is drawn 1 pixel beyond
+		 * (larger x-axis coordinates) than a normal Rectangle.
+		 */
+		
+		r.x1 += 1.0; /* this should be using safe_add() */
+		
+		_bounding_box = r;
+	}
+}
+
+void 
+TimeRectangle::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
+{
+	Rect self = get_self_for_render ();
+
+
+	/* This is a TimeRectangle, so its right edge is drawn 1 pixel beyond
+	 * (larger x-axis coordinates) than a normal Rectangle.
+	 */
+
+	self.x1 += 1.0; /* this should be using safe_add() */
+	render_self (area, context, self);
+}