1) Fix bug #178312

2) Fix constrained snapping to objects

(bzr r4314)

4 files changed, 41 insertions, 0 deletions

diff --git a/src/libnr/nr-path.cpp b/src/libnr/nr-path.cpp
index 03882a7fd..a0011c9dc 100644
--- a/src/libnr/nr-path.cpp
+++ b/src/libnr/nr-path.cpp
@@ -503,3 +503,22 @@ nr_path_matrix_bbox_union(NRBPath const *bpath, NR::Matrix const &m,
     }
 }
 
+NArtBpath *nr_path_from_rect(NRRect const &r)
+{
+    NArtBpath *path = g_new (NArtBpath, 6);
+
+    path[0].code = NR_MOVETO;
+    path[0].setC(3, NR::Point(r.x0, r.y0));
+    path[1].code = NR_LINETO;
+    path[1].setC(3, NR::Point(r.x1, r.y0)); 
+    path[2].code = NR_LINETO;
+    path[2].setC(3, NR::Point(r.x1, r.y1)); 
+    path[3].code = NR_LINETO;
+    path[3].setC(3, NR::Point(r.x0, r.y1));
+    path[4].code = NR_LINETO;
+    path[4].setC(3, NR::Point(r.x0, r.y0));    
+    path[5].code = NR_END;
+
+    return path;
+}
+
diff --git a/src/libnr/nr-path.h b/src/libnr/nr-path.h
index 95b4f726b..6fdc85694 100644
--- a/src/libnr/nr-path.h
+++ b/src/libnr/nr-path.h
@@ -46,6 +46,8 @@ void nr_path_matrix_point_bbox_wind_distance (NRBPath *bpath, NR::Matrix const &
 
 void nr_path_matrix_bbox_union(NRBPath const *bpath, NR::Matrix const &m, NRRect *bbox);
 
+NArtBpath *nr_path_from_rect(NRRect const &r);
+
 #endif
 
 /*
diff --git a/src/libnr/nr-point-fns.cpp b/src/libnr/nr-point-fns.cpp
index a18e878b4..4428ed9b3 100644
--- a/src/libnr/nr-point-fns.cpp
+++ b/src/libnr/nr-point-fns.cpp
@@ -103,6 +103,24 @@ get_offset_between_points (NR::Point p, NR::Point begin, NR::Point end)
     return (r / length);
 }
 
+NR::Point
+project_on_linesegment(NR::Point const p, NR::Point const p1, NR::Point const p2) 
+{
+    // p_proj = projection of p on the linesegment running from p1 to p2
+    // p_proj = p1 + u (p2 - p1)
+    // calculate u according to "Minimum Distance between a Point and a Line"
+    // see http://local.wasp.uwa.edu.au/~pbourke/geometry/pointline/        
+    
+    if (p1 == p2) { // to avoid div. by zero below
+        return p;
+    }
+    
+    NR::Point const d1(p-p1); // delta 1
+    NR::Point const d2(p2-p1); // delta 2
+    double const u = (d1[NR::X] * d2[NR::X] + d1[NR::Y] * d2[NR::Y]) / (NR::L2(d2) * NR::L2(d2));
+    
+    return (p1 + u*(p2-p1));
+}
 
 /*
   Local Variables:
diff --git a/src/libnr/nr-point-fns.h b/src/libnr/nr-point-fns.h
index a8c38466f..e927725b4 100644
--- a/src/libnr/nr-point-fns.h
+++ b/src/libnr/nr-point-fns.h
@@ -96,6 +96,8 @@ NR::Point snap_vector_midpoint (NR::Point p, NR::Point begin, NR::Point end, dou
 
 double get_offset_between_points (NR::Point p, NR::Point begin, NR::Point end);
 
+NR::Point project_on_linesegment(NR::Point const p, NR::Point const p1, NR::Point const p2); 
+
 #endif /* !__NR_POINT_OPS_H__ */
 
 /*