using namespace std;
using namespace ArdourCanvas;
-Line::Line (Group* parent)
- : Item (parent)
- , Outline (parent)
+Line::Line (Canvas* c)
+ : Item (c)
{
+}
+Line::Line (Item* parent)
+ : Item (parent)
+{
}
void
Line::compute_bounding_box () const
{
Rect bbox;
-
+
bbox.x0 = min (_points[0].x, _points[1].x);
bbox.y0 = min (_points[0].y, _points[1].y);
bbox.x1 = max (_points[0].x, _points[1].x);
Duple p0 = item_to_window (Duple (_points[0].x, _points[0].y));
Duple p1 = item_to_window (Duple (_points[1].x, _points[1].y));
- /* See Cairo FAQ on single pixel lines to understand why we add 0.5
- */
+ if (_outline_width <= 1.0) {
+ /* See Cairo FAQ on single pixel lines to understand why we add 0.5
+ */
+
+ const Duple half_a_pixel (0.5, 0.5);
+ p0 = p0.translate (half_a_pixel);
+ p1 = p1.translate (half_a_pixel);
+ }
- context->move_to (p0.x + 0.5, p0.y + 0.5);
- context->line_to (p1.x + 0.5, p1.y + 0.5);
+ context->move_to (p0.x, p0.y);
+ context->line_to (p1.x, p1.y);
context->stroke ();
}
void
Line::set (Duple a, Duple b)
{
- begin_change ();
-
- _points[0] = a;
- _points[1] = b;
+ if (a != _points[0] || b != _points[1]) {
+ begin_change ();
- _bounding_box_dirty = true;
- end_change ();
+ _points[0] = a;
+ _points[1] = b;
- DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
+ _bounding_box_dirty = true;
+ end_change ();
+ }
}
void
Line::set_x (Coord x0, Coord x1)
{
- begin_change ();
-
- _points[0].x = x0;
- _points[1].x = x1;
+ if (x0 != _points[0].x || x1 != _points[1].x) {
+ begin_change ();
- _bounding_box_dirty = true;
- end_change ();
+ _points[0].x = x0;
+ _points[1].x = x1;
- DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
-}
+ _bounding_box_dirty = true;
+ end_change ();
+ }
+}
void
Line::set_x0 (Coord x0)
{
- begin_change ();
-
- _points[0].x = x0;
+ if (x0 != _points[0].x) {
+ begin_change ();
- _bounding_box_dirty = true;
- end_change ();
+ _points[0].x = x0;
- DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
+ _bounding_box_dirty = true;
+ end_change ();
+ }
}
void
Line::set_y0 (Coord y0)
{
- begin_change ();
+ if (y0 != _points[0].y) {
+ begin_change ();
- _points[0].y = y0;
+ _points[0].y = y0;
- _bounding_box_dirty = true;
- end_change ();
+ _bounding_box_dirty = true;
+ end_change ();
+ }
DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
}
void
Line::set_x1 (Coord x1)
{
- begin_change ();
+ if (x1 != _points[1].x) {
+ begin_change ();
- _points[1].x = x1;
+ _points[1].x = x1;
- _bounding_box_dirty = true;
- end_change ();
-
- DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
+ _bounding_box_dirty = true;
+ end_change ();
+ }
}
void
Line::set_y1 (Coord y1)
{
- begin_change ();
-
- _points[1].y = y1;
+ if (y1 != _points[1].y) {
+ begin_change ();
- _bounding_box_dirty = true;
- end_change ();
+ _points[1].y = y1;
- DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
+ _bounding_box_dirty = true;
+ end_change ();
+ }
}
bool
Line::covers (Duple const & point) const
{
- Duple p = canvas_to_item (point);
+ const Duple p = window_to_item (point);
+ static const Distance threshold = 2.0;
+
+ /* this quick check works for vertical and horizontal lines, which are
+ * common.
+ */
- /* compute area of triangle computed by the two line points and the one
- we are being asked about. If zero (within a given tolerance), the
- points are co-linear and the argument is on the line.
+ if (_points[0].x == _points[1].x) {
+ /* line is vertical, just check x coordinate */
+ return fabs (_points[0].x - p.x) <= threshold;
+ }
+
+ if (_points[0].y == _points[1].y) {
+ /* line is horizontal, just check y coordinate */
+ return fabs (_points[0].y - p.y) <= threshold;
+ }
+
+ Duple at;
+ double t;
+ Duple a (_points[0]);
+ Duple b (_points[1]);
+ const Rect visible (window_to_item (_canvas->visible_area()));
+
+ /*
+ Clamp the line endpoints to the visible area of the canvas. If we do
+ not do this, we have a line segment extending to COORD_MAX and our
+ math goes wrong.
*/
- double area = fabs (_points[0].x * (_points[0].y - p.y)) +
- (_points[1].x * (p.y - _points[0].y)) +
- (p.x * (_points[0].y - _points[1].y));
+ a.x = min (a.x, visible.x1);
+ a.y = min (a.y, visible.y1);
+ b.x = min (b.x, visible.x1);
+ b.y = min (b.y, visible.y1);
+
+ double d = distance_to_segment_squared (p, a, b, t, at);
+
+ if (t < 0.0 || t > 1.0) {
+ return false;
+ }
- if (area < 0.001) {
+ if (d < threshold) {
return true;
}