diff options
Diffstat (limited to 'src/2geom/sbasis-geometric.cpp')
| -rw-r--r-- | src/2geom/sbasis-geometric.cpp | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/src/2geom/sbasis-geometric.cpp b/src/2geom/sbasis-geometric.cpp index 1c180e143..017b377c9 100644 --- a/src/2geom/sbasis-geometric.cpp +++ b/src/2geom/sbasis-geometric.cpp @@ -4,8 +4,7 @@ //#include <2geom/solver.h> #include <2geom/sbasis-geometric.h> -/* - * Geometric operators on D2<SBasis> (1D->2D). +/** Geometric operators on D2<SBasis> (1D->2D). * Copyright 2007 JF Barraud * Copyright 2007 N Hurst * @@ -746,18 +745,26 @@ Geom::cubics_with_prescribed_curvature(Point const &M0, Point const &M1, } +namespace Geom { /** * \brief returns all the parameter values of A whose tangent passes through P. * \relates D2 */ -std::vector<double> Geom::find_tangents(Point P, D2<SBasis> const &A) { +std::vector<double> find_tangents(Point P, D2<SBasis> const &A) { SBasis crs (cross(A - P, derivative(A))); - crs = shift(crs*Linear(-1, 0)*Linear(-1, 0), -2); // We know that there is a double root at t=0 so we divide out t^2 -// JFB points out that this is equivalent to (t-1)^2 followed by a divide by s^2 (shift) return roots(crs); } +/** +* \brief returns all the parameter values of A whose normal passes through P. +* \relates D2 +*/ +std::vector<double> find_normals(Point P, D2<SBasis> const &A) { + SBasis crs (dot(A - P, derivative(A))); + return roots(crs); +} +} //}; // namespace |