Code

clean up tabs and DOS-ishness
[inkscape.git] / src / line-snapper.cpp
index 383c1fb96725f731c9c62574a00e5422a033d095..219bc7482d7501c54d6259087a488acce0d64d0f 100644 (file)
@@ -1,71 +1,99 @@
+/**
+ * \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 "geom.h"
+#include <2geom/geom.h>
 #include "line-snapper.h"
+#include "snapped-line.h"
+#include <gtk/gtk.h>
 
 Inkscape::LineSnapper::LineSnapper(SPNamedView const *nv, NR::Coord const d) : Snapper(nv, d)
 {
 
 }
 
-Inkscape::SnappedPoint Inkscape::LineSnapper::_doFreeSnap(NR::Point const &p,
-                                                          std::list<SPItem const *> const &it) const
+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::list<SPItem const *> const &it,
+                                                    std::vector<NR::Point> *unselected_nodes) const
 {
-    /* Snap along x (ie to vertical lines) */
-    Inkscape::SnappedPoint const v = _doConstrainedSnap(p, component_vectors[NR::X], it);
-    /* Snap along y (ie to horizontal lines) */
-    Inkscape::SnappedPoint const h = _doConstrainedSnap(p, component_vectors[NR::Y], it);
-
-    /* If we snapped to both, combine the two results.  This is so that, for example,
-    ** we snap nicely to the intersection of two guidelines.
-    */
-    if (v.getDistance() < NR_HUGE && h.getDistance() < NR_HUGE) {
-        return SnappedPoint(NR::Point(v.getPoint()[NR::X], h.getPoint()[NR::Y]), hypot(v.getDistance(), h.getDistance()));
-    }
+    /* Get the lines that we will try to snap to */
+    const LineList lines = _getSnapLines(p);
 
-    /* If we snapped to a vertical line, return that */
-    if (v.getDistance() < NR_HUGE) {
-        return v;
-    }
+    // std::cout << "snap point " << p << " to: " << std::endl;
 
-    /* Otherwise just return any horizontal snap; if we didn't snap to that either
-    ** we haven't snapped to anything.
-    */
-    return h;
+    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;
+    }    
 }
 
-Inkscape::SnappedPoint Inkscape::LineSnapper::_doConstrainedSnap(NR::Point const &p,
-                                                                 NR::Point const &c,
-                                                                 std::list<SPItem const *> const &it) const
-{
-    Inkscape::SnappedPoint s = SnappedPoint(p, NR_HUGE);
-
-    NR::Point const v = NR::unit_vector(c);
+void Inkscape::LineSnapper::_doConstrainedSnap(SnappedConstraints &sc,
+                                               Inkscape::Snapper::PointType const &/*t*/,
+                                               NR::Point const &p,
+                                               bool const &/*f*/,
+                                               std::vector<NR::Point> &/*points_to_snap*/,
+                                               ConstraintLine const &c,
+                                               std::list<SPItem const *> const &/*it*/) const
 
+{
     /* 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(v));
-
-        /* Hence constant term of the line we're trying to snap along */
-        NR::Coord const q = dot(n, p);
-
-        /* Try to intersect this line with the target line */
-        NR::Point t = p;
-        IntersectorKind const k = intersector_line_intersection(n, q, component_vectors[i->first], i->second, t);
-
-        if (k == INTERSECTS) {
-            const NR::Coord dist = L2(t - p);
-            if (dist < getDistance() && dist < s.getDistance() ) {
-                s = SnappedPoint(t, dist);
+        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())); 
+                }
             }
         }
     }
-
-    return s;
 }
 
 /*