X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fcanvas%2Frectangle.cc;h=1ef783479b102613ab230924f86d625fc60cf84f;hb=4ee8a0e9fc2a35441e2bb016f173adf5e521660d;hp=bc4ad0c9609862e34903d251a6b2fe458d33af65;hpb=a8bd6ecc4fe4016090fad92daf6d9a572941d035;p=ardour.git diff --git a/libs/canvas/rectangle.cc b/libs/canvas/rectangle.cc index bc4ad0c960..1ef783479b 100644 --- a/libs/canvas/rectangle.cc +++ b/libs/canvas/rectangle.cc @@ -56,22 +56,28 @@ Rectangle::Rectangle (Item* parent, Rect const & rect) { } -void -Rectangle::render (Rect const & area, Cairo::RefPtr 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)); - boost::optional r = self.intersection (area); + + return item_to_window (_rect.translate (_position), false); +} + +void +Rectangle::render_self (Rect const & area, Cairo::RefPtr context, Rect self) const +{ + Rect r = self.intersection (area); if (!r) { return; } - Rect draw = r.get (); + Rect draw = r; if (_fill && !_transparent) { if (_stops.empty()) { @@ -82,65 +88,100 @@ Rectangle::render (Rect const & area, Cairo::RefPtr context) con context->rectangle (draw.x0, draw.y0, draw.width(), draw.height()); context->fill (); - } - - if (_outline) { + } + + if (_outline && _outline_width && _outline_what) { setup_outline_context (context); - - /* see the cairo FAQ on single pixel lines to see why we do - * the 0.5 pixel additions. + + /* 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..1, the right edge + * must span 10..11 because the first and final pixels + * to be colored are actually "at" 0.5 and 10.5 (midway + * between the integer coordinates). + * + * See the Cairo FAQ on single pixel lines for more + * detail. */ + if (fmod (_outline_width, 2.0) != 0.0) { + const double shift = _outline_width * 0.5; + self = self.translate (Duple (shift, shift)); + } + 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 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; + /* if the outline is 1 pixel, then the actual + bounding box is 0.5 pixels outside the stated + corners of the rectangle. + + if the outline is 2 pixels, then the actual + bounding box is 1.0 pixels outside the stated + corners of the rectangle (so that the middle + of the 2 pixel wide border passes through + the corners, alternatively described as 1 row + of pixels outside of the corners, and 1 row + inside). + + if the outline is 3 pixels, then the actual + bounding box is 1.5 outside the stated corners + of the rectangle (so that the middle row of + pixels of the border passes through the corners). + + if the outline is 4 pixels, then the actual bounding + box is 2.0 pixels outside the stated corners + of the rectangle, so that the border consists + of 2 pixels outside the corners and 2 pixels inside. + + hence ... the bounding box is width * 0.5 larger + than the rectangle itself. + */ - _bounding_box = r; + _bounding_box = r.expand (1.0 + _outline_width * 0.5); } _bounding_box_dirty = false; @@ -154,11 +195,11 @@ Rectangle::set (Rect const & r) */ if (r != _rect) { - + begin_change (); - + _rect = r; - + _bounding_box_dirty = true; end_change (); } @@ -169,9 +210,9 @@ Rectangle::set_x0 (Coord x0) { if (x0 != _rect.x0) { begin_change (); - + _rect.x0 = x0; - + _bounding_box_dirty = true; end_change (); } @@ -182,9 +223,9 @@ Rectangle::set_y0 (Coord y0) { if (y0 != _rect.y0) { begin_change (); - + _rect.y0 = y0; - + _bounding_box_dirty = true; end_change(); } @@ -195,9 +236,9 @@ Rectangle::set_x1 (Coord x1) { if (x1 != _rect.x1) { begin_change (); - + _rect.x1 = x1; - + _bounding_box_dirty = true; end_change (); } @@ -208,9 +249,9 @@ Rectangle::set_y1 (Coord y1) { if (y1 != _rect.y1) { begin_change (); - + _rect.y1 = y1; - + _bounding_box_dirty = true; end_change (); } @@ -226,3 +267,25 @@ Rectangle::set_outline_what (What what) } } +double +Rectangle::vertical_fraction (double y) const +{ + /* y is in canvas coordinates */ + + Duple i (canvas_to_item (Duple (0, y))); + Rect r = bounding_box(); + if (!r) { + return 0; /* not really correct, but what else can we do? */ + } + + Rect bbox (r); + + if (i.y < bbox.y0 || i.y >= bbox.y1) { + return 0; + } + + /* convert to fit Cairo origin model (origin at upper left) + */ + + return 1.0 - ((i.y - bbox.y0) / bbox.height()); +}