diff options
| author | Paul Davis <paul@linuxaudiosystems.com> | 2014-11-05 16:57:37 -0500 |
|---|---|---|
| committer | Paul Davis <paul@linuxaudiosystems.com> | 2014-11-05 19:45:23 -0500 |
| commit | ecd618c343d4fc41e95f0c58795271c2ab3b1980 (patch) | |
| tree | d4ac161ea7378369165e8c51061a805deb741b94 /libs/canvas/rectangle.cc | |
| parent | 857719f2e12bdfbb6f770afe75c0f968b2c4fa2c (diff) | |
correct the rendering of Rectangle outlines, and the computation of their bounding box
Diffstat (limited to 'libs/canvas/rectangle.cc')
| -rw-r--r-- | libs/canvas/rectangle.cc | 27 |
1 files changed, 6 insertions, 21 deletions
diff --git a/libs/canvas/rectangle.cc b/libs/canvas/rectangle.cc index 232da17893..a4540ccbac 100644 --- a/libs/canvas/rectangle.cc +++ b/libs/canvas/rectangle.cc @@ -98,20 +98,13 @@ Rectangle::render_self (Rect const & area, Cairo::RefPtr<Cairo::Context> context * 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. + * the left edge must span 0..1, the right edge + * must span 9..10 because the first and final pixels + * to be colored are actually "at" 0.5 and 9.5 (midway + * between the integer coordinates. */ - self = self.translate (Duple (0.5, 0.5)); + self = self.shrink (0.5); if (_outline_what == What (LEFT|RIGHT|BOTTOM|TOP)) { @@ -155,13 +148,6 @@ 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 = r.expand (1.0); - _bounding_box = r; } @@ -273,8 +259,7 @@ 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. */ |