diff options
author | Paul Davis <paul@linuxaudiosystems.com> | 2013-12-09 17:24:34 -0500 |
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committer | Paul Davis <paul@linuxaudiosystems.com> | 2013-12-09 17:24:34 -0500 |
commit | c4f0063a68d189a59450a5bba658fc3092bc936b (patch) | |
tree | 6cf98672e9897a32d90e921a452d56e5efc49567 /libs/canvas/poly_line.cc | |
parent | 77a63c2bf75d4c8fa6948981a246806453bef95c (diff) |
make PolyLine use distance_to_segment_squared(), and add separate (null, for now) method Curve::covers(Duple) because the math there needs to be different, maybe
Diffstat (limited to 'libs/canvas/poly_line.cc')
-rw-r--r-- | libs/canvas/poly_line.cc | 42 |
1 files changed, 32 insertions, 10 deletions
diff --git a/libs/canvas/poly_line.cc b/libs/canvas/poly_line.cc index 2441e4e3dc..7118e47555 100644 --- a/libs/canvas/poly_line.cc +++ b/libs/canvas/poly_line.cc @@ -17,7 +17,11 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ +#include <algorithm> + #include "canvas/poly_line.h" +#include "canvas/canvas.h" +#include "canvas/utils.h" using namespace ArdourCanvas; @@ -53,21 +57,39 @@ PolyLine::covers (Duple const & point) const Points::size_type j; /* repeat for each line segment */ - + + const Rect visible (_canvas->visible_area()); + static const double threshold = 2.0; + for (i = 1, j = 0; i < npoints; ++i, ++j) { - /* 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. + Duple at; + double t; + Duple a (_points[j]); + Duple b (_points[i]); + + /* + Clamp the line endpoints to the visible area of the canvas. If we do + not do this, we may have a line segment extending to COORD_MAX and our + math goes wrong. */ - - double area = fabs (_points[j].x * (_points[j].y - p.y)) + - (_points[i].x * (p.y - _points[j].y)) + - (p.x * (_points[j].y - _points[i].y)); - if (area < 0.001) { + + a.x = std::min (a.x, visible.x1); + a.y = std::min (a.y, visible.y1); + b.x = std::min (b.x, visible.x1); + b.y = std::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 (d < threshold) { return true; } + } - + return false; } |