X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;ds=inline;f=src%2Fline-snapper.cpp;h=a84a802961fe04ed40a6bd9411bcb9e51bb637d5;hb=baa74b7b366585fca6d90ece888c678f580cb5d9;hp=be35ec2db930b1faaf717ecad13bb2f7d379853e;hpb=bbbe9eebaeb94bab65295acc609a7c98544c4f4c;p=inkscape.git

diff --git a/src/line-snapper.cpp b/src/line-snapper.cpp
index be35ec2db..a84a80296 100644
--- a/src/line-snapper.cpp
+++ b/src/line-snapper.cpp
@@ -1,8 +1,22 @@
+/**
+ * \file line-snapper.cpp
+ * \brief LineSnapper class.
+ *
+ * Authors:
+ *   Diederik van Lierop <mail@diedenrezi.nl>
+ *   And others...
+ * 
+ * Copyright (C) 1999-2007 Authors
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
 #include "libnr/nr-values.h"
 #include "libnr/nr-point-fns.h"
 #include <2geom/geom.h>
 #include "line-snapper.h"
-#include "snapped-line.cpp"
+#include "snapped-line.h"
+#include <gtk/gtk.h>
 
 Inkscape::LineSnapper::LineSnapper(SPNamedView const *nv, NR::Coord const d) : Snapper(nv, d)
 {
@@ -13,14 +27,29 @@ void Inkscape::LineSnapper::_doFreeSnap(SnappedConstraints &sc,
                                                     Inkscape::Snapper::PointType const &t,
                                                     NR::Point const &p,
                                                     bool const &f,
-                                                     std::vector<NR::Point> &points_to_snap,
+                                                    std::vector<NR::Point> &points_to_snap,
                                                     std::list<SPItem const *> const &it) const
 {
-    /* Snap along x (i.e. to vertical lines) */
-    _doConstrainedSnap(sc, t, p, f, points_to_snap, component_vectors[NR::X], it);
-    /* Snap along y (i.e. to horizontal lines) */
-    _doConstrainedSnap(sc, t, p, f, points_to_snap, component_vectors[NR::Y], it);
+    /* Get the lines that we will try to snap to */
+    const LineList lines = _getSnapLines(p);
 
+    // std::cout << "snap point " << p << " to: " << std::endl;
+
+    for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) {
+        NR::Point const p1 = i->second; // point at guide/grid line
+        NR::Point const p2 = p1 + NR::rot90(i->first); // 2nd point at guide/grid line
+        // std::cout << "  line through " << i->second << " with normal " << i->first;
+        g_assert(i->first != NR::Point(0,0)); // we cannot project on an linesegment of zero length
+        
+        NR::Point const p_proj = project_on_linesegment(p, p1, p2);
+        NR::Coord const dist = NR::L2(p_proj - p);
+        //Store any line that's within snapping range
+        if (dist < getSnapperTolerance()) {
+            _addSnappedLine(sc, p_proj, dist, i->first, i->second);
+            // std::cout << " -> distance = " << dist; 
+        }     
+        // std::cout << std::endl;
+    }    
 }
 
 void Inkscape::LineSnapper::_doConstrainedSnap(SnappedConstraints &sc,
@@ -32,33 +61,35 @@ void Inkscape::LineSnapper::_doConstrainedSnap(SnappedConstraints &sc,
                                                std::list<SPItem const *> const &/*it*/) const
 
 {
-    Inkscape::SnappedPoint s = SnappedPoint(p, NR_HUGE);
-
     /* Get the lines that we will try to snap to */
     const LineList lines = _getSnapLines(p);
 
     for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) {
-
-        /* Normal to the line we're trying to snap along */
-        NR::Point const n(NR::rot90(NR::unit_vector(c.getDirection())));
-
-        NR::Point const point_on_line = c.hasPoint() ? c.getPoint() : p;
-
-        /* Constant term of the line we're trying to snap along */
-        NR::Coord const q = dot(n, point_on_line);
-
-        /* Try to intersect this line with the target line */
-        Geom::Point t_2geom(NR_HUGE, NR_HUGE);
-        Geom::IntersectorKind const k = Geom::line_intersection(n.to_2geom(), q, component_vectors[i->first].to_2geom(), i->second, t_2geom);
-        NR::Point t(t_2geom);
-
-        if (k == Geom::intersects) {
-            const NR::Coord dist = L2(t - p);
-            //Store any line that's within snapping range
-            if (dist < getDistance()) {
-				_addSnappedLine(sc, t, dist, c.getDirection(), t);
-                //SnappedLine dummy = SnappedLine(t, dist, c.getDirection(), t);
-                //sc.infinite_lines.push_back(dummy);
+        if (NR::L2(c.getDirection()) > 0) { // Can't do a constrained snap without a constraint
+            /* Normal to the line we're trying to snap along */
+            NR::Point const n(NR::rot90(NR::unit_vector(c.getDirection())));
+    
+            NR::Point const point_on_line = c.hasPoint() ? c.getPoint() : p;
+    
+            /* Constant term of the line we're trying to snap along */
+            NR::Coord const q0 = dot(n, point_on_line);
+            /* Constant term of the grid or guide line */
+            NR::Coord const q1 = dot(i->first, i->second);        
+    
+            /* Try to intersect this line with the target line */
+            Geom::Point t_2geom(NR_HUGE, NR_HUGE);
+            Geom::IntersectorKind const k = Geom::line_intersection(n.to_2geom(), q0, i->first.to_2geom(), q1, t_2geom);
+            NR::Point t(t_2geom);
+    
+            if (k == Geom::intersects) {
+                const NR::Coord dist = L2(t - p);
+                if (dist < getSnapperTolerance()) {
+    				// When doing a constrained snap, we're already at an intersection.
+                    // This snappoint is therefore fully constrained, so there's no need
+                    // to look for additional intersections; just return the snapped point
+                    // and forget about the line
+                    sc.points.push_back(SnappedPoint(t, dist, getSnapperTolerance(), getSnapperAlwaysSnap())); 
+                }
             }
         }
     }