diff --git a/src/db/db/dbEdgePairRelations.cc b/src/db/db/dbEdgePairRelations.cc
index cd784e549..cdb1b3ea9 100644
--- a/src/db/db/dbEdgePairRelations.cc
+++ b/src/db/db/dbEdgePairRelations.cc
@@ -54,7 +54,7 @@ db::Edge::distance_type edge_projection (const db::Edge &a, const db::Edge &b)
  *  This function applies Euclidian metrics.
  *  If no such part is found, this function returns false.
  */
-bool euclidian_near_part_of_edge (zero_distance_type zero_distance, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &other, db::Edge *output)
+bool euclidian_near_part_of_edge (collinear_mode_type coll_mode, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &other, db::Edge *output)
 {
   //  Handle the case of point-like basic edge: cannot determine
   //  orientation
@@ -68,8 +68,8 @@ bool euclidian_near_part_of_edge (zero_distance_type zero_distance, db::coord_tr
   int s2 = e.side_of (g.p2 ());
 
   //  "kissing corner" issue: force include zero if the edges are collinear and overlap.
-  bool include_zero = (zero_distance == AlwaysIncludeZeroDistance);
-  if (zero_distance == IncludeZeroDistanceWhenTouch && s1 == 0 && s2 == 0 && e.intersect (g)) {
+  bool include_zero = (coll_mode == AlwaysIncludeCollinear);
+  if (coll_mode == IncludeCollinearWhenTouch && s1 == 0 && s2 == 0 && e.intersect (g)) {
     include_zero = true;
   }
 
@@ -198,7 +198,7 @@ bool euclidian_near_part_of_edge (zero_distance_type zero_distance, db::coord_tr
  *  This function applies Square metrics.
  *  If no such part is found, this function returns false.
  */
-static bool var_near_part_of_edge (zero_distance_type zero_distance, db::coord_traits<db::Coord>::distance_type d, db::coord_traits<db::Coord>::distance_type dd, const db::Edge &e, const db::Edge &other, db::Edge *output)
+static bool var_near_part_of_edge (collinear_mode_type coll_mode, db::coord_traits<db::Coord>::distance_type d, db::coord_traits<db::Coord>::distance_type dd, const db::Edge &e, const db::Edge &other, db::Edge *output)
 {
   //  Handle the case of point-like basic edge: cannot determine
   //  orientation
@@ -212,8 +212,8 @@ static bool var_near_part_of_edge (zero_distance_type zero_distance, db::coord_t
   int s2 = e.side_of (g.p2 ());
 
   //  "kissing corner" issue: force include zero if the edges are collinear and overlap
-  bool include_zero = (zero_distance == AlwaysIncludeZeroDistance);
-  if (zero_distance == IncludeZeroDistanceWhenTouch && s1 == 0 && s2 == 0 && e.intersect (g)) {
+  bool include_zero = (coll_mode == AlwaysIncludeCollinear);
+  if (coll_mode == IncludeCollinearWhenTouch && s1 == 0 && s2 == 0 && e.intersect (g)) {
     include_zero = true;
   }
 
@@ -316,9 +316,9 @@ static bool var_near_part_of_edge (zero_distance_type zero_distance, db::coord_t
  *  This function applies Projected metrics.
  *  If no such part is found, this function returns false.
  */
-bool projected_near_part_of_edge (zero_distance_type zero_distance, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &other, db::Edge *output)
+bool projected_near_part_of_edge (collinear_mode_type coll_mode, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &other, db::Edge *output)
 {
-  return var_near_part_of_edge (zero_distance, d, 0, e, other, output);
+  return var_near_part_of_edge (coll_mode, d, 0, e, other, output);
 }
 
 /**
@@ -327,22 +327,22 @@ bool projected_near_part_of_edge (zero_distance_type zero_distance, db::coord_tr
  *  This function applies Square metrics.
  *  If no such part is found, this function returns false.
  */
-bool square_near_part_of_edge (zero_distance_type zero_distance, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &other, db::Edge *output)
+bool square_near_part_of_edge (collinear_mode_type coll_mode, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &other, db::Edge *output)
 {
-  return var_near_part_of_edge (zero_distance, d, d, e, other, output);
+  return var_near_part_of_edge (coll_mode, d, d, e, other, output);
 }
 
 // ---------------------------------------------------------------------------------
 //  Implementation of EdgeRelationFilter
 
-EdgeRelationFilter::EdgeRelationFilter (edge_relation_type r, distance_type d, metrics_type metrics, double ignore_angle, distance_type min_projection, distance_type max_projection, zero_distance_type include_zero)
-  : m_whole_edges (false), m_include_zero (include_zero), m_r (r), m_d (d), m_metrics (metrics), m_ignore_angle (0), m_min_projection (min_projection), m_max_projection (max_projection)
+EdgeRelationFilter::EdgeRelationFilter (edge_relation_type r, distance_type d, metrics_type metrics, double ignore_angle, distance_type min_projection, distance_type max_projection, collinear_mode_type collinear_mode)
+  : m_whole_edges (false), m_collinear_mode (collinear_mode), m_r (r), m_d (d), m_metrics (metrics), m_ignore_angle (0), m_min_projection (min_projection), m_max_projection (max_projection)
 {
   set_ignore_angle (ignore_angle);
 }
 
 EdgeRelationFilter::EdgeRelationFilter (edge_relation_type r, distance_type d, const EdgesCheckOptions &options)
-  : m_whole_edges (options.whole_edges), m_include_zero (options.include_zero), m_r (r), m_d (d), m_metrics (options.metrics), m_ignore_angle (0), m_min_projection (options.min_projection), m_max_projection (options.max_projection)
+  : m_whole_edges (options.whole_edges), m_collinear_mode (options.collinear_mode), m_r (r), m_d (d), m_metrics (options.metrics), m_ignore_angle (0), m_min_projection (options.min_projection), m_max_projection (options.max_projection)
 {
   set_ignore_angle (options.ignore_angle);
 }
@@ -407,14 +407,14 @@ EdgeRelationFilter::check (const db::Edge &a, const db::Edge &b, db::EdgePair *o
   bool in1, in2;
 
   if (m_metrics == Euclidian) {
-    in2 = euclidian_near_part_of_edge (m_include_zero, m_d, an, bn, ! m_whole_edges && output ? &output->second () : 0);
-    in1 = euclidian_near_part_of_edge (m_include_zero, m_d, bn, an, ! m_whole_edges && output ? &output->first () : 0);
+    in2 = euclidian_near_part_of_edge (m_collinear_mode, m_d, an, bn, ! m_whole_edges && output ? &output->second () : 0);
+    in1 = euclidian_near_part_of_edge (m_collinear_mode, m_d, bn, an, ! m_whole_edges && output ? &output->first () : 0);
   } else if (m_metrics == Square) {
-    in2 = square_near_part_of_edge (m_include_zero, m_d, an, bn, ! m_whole_edges && output ? &output->second () : 0);
-    in1 = square_near_part_of_edge (m_include_zero, m_d, bn, an, ! m_whole_edges && output ? &output->first () : 0);
+    in2 = square_near_part_of_edge (m_collinear_mode, m_d, an, bn, ! m_whole_edges && output ? &output->second () : 0);
+    in1 = square_near_part_of_edge (m_collinear_mode, m_d, bn, an, ! m_whole_edges && output ? &output->first () : 0);
   } else {
-    in2 = projected_near_part_of_edge (m_include_zero, m_d, an, bn, ! m_whole_edges && output ? &output->second () : 0);
-    in1 = projected_near_part_of_edge (m_include_zero, m_d, bn, an, ! m_whole_edges && output ? &output->first () : 0);
+    in2 = projected_near_part_of_edge (m_collinear_mode, m_d, an, bn, ! m_whole_edges && output ? &output->second () : 0);
+    in1 = projected_near_part_of_edge (m_collinear_mode, m_d, bn, an, ! m_whole_edges && output ? &output->first () : 0);
   }
 
   if (in1 && in2) {
diff --git a/src/db/db/dbEdgePairRelations.h b/src/db/db/dbEdgePairRelations.h
index 7dab0c9b9..08d2da83d 100644
--- a/src/db/db/dbEdgePairRelations.h
+++ b/src/db/db/dbEdgePairRelations.h
@@ -99,23 +99,23 @@ enum edge_relation_type
 };
 
 /**
- *  @brief An enum specifying whether the edge relation includes zero distance
+ *  @brief An enum specifying whether how collinear edges are handled
  */
-enum zero_distance_type {
+enum collinear_mode_type {
   /**
-   *  @brief Never include zero distance
+   *  @brief Never include collinear edges
    */
-  NeverIncludeZeroDistance = 0,
+  NeverIncludeCollinear = 0,
 
   /**
-   *  @brief include zero distance when edges touch (e.g. kissing corner case)
+   *  @brief include collinear edges when they touch (e.g. kissing corner case)
    */
-  IncludeZeroDistanceWhenTouch = 1,
+  IncludeCollinearWhenTouch = 1,
 
   /**
-   *  @brief always include zero distance
+   *  @brief always include collinear edges
    */
-  AlwaysIncludeZeroDistance = 2
+  AlwaysIncludeCollinear = 2
 };
 
 /**
@@ -133,13 +133,13 @@ struct DB_PUBLIC EdgesCheckOptions
                       double _ignore_angle = 90,
                       distance_type _min_projection = 0,
                       distance_type _max_projection = std::numeric_limits<distance_type>::max (),
-                      zero_distance_type _include_zero = IncludeZeroDistanceWhenTouch)
+                      collinear_mode_type _collinear_mode = IncludeCollinearWhenTouch)
     : whole_edges (_whole_edges),
       metrics (_metrics),
       ignore_angle (_ignore_angle),
       min_projection (_min_projection),
       max_projection (_max_projection),
-      include_zero (_include_zero)
+      collinear_mode (_collinear_mode)
   { }
 
   /**
@@ -183,13 +183,13 @@ struct DB_PUBLIC EdgesCheckOptions
   distance_type max_projection;
 
   /**
-   *  @brief Specifies zero distance handling
+   *  @brief Specifies collinear edge handling
    *
-   *  This allows implementing the "kissing corners" case. When set to "WhenTouch", kissing corners will
-   *  be reported as errors, when set to "Never", they won't. Note that with merged inputs, edges
+   *  This allows implementing the "kissing corners" case. When set to "IncludeCollinearWhenTouch", kissing corners will
+   *  be reported as errors, when set to "NeverIncludeCollinear", they won't. Note that with merged inputs, edges
    *  will not overlap except at the corners.
    */
-  zero_distance_type include_zero;
+  collinear_mode_type collinear_mode;
 };
 
 /**
@@ -217,7 +217,7 @@ struct DB_PUBLIC EdgeRelationFilter
    *  to each other. If the length of the projection of either edge on the other is >= min_projection
    *  or < max_projection, the edges are considered for the check.
    */
-  EdgeRelationFilter (edge_relation_type r, distance_type d, metrics_type metrics = db::Euclidian, double ignore_angle = 90, distance_type min_projection = 0, distance_type max_projection = std::numeric_limits<distance_type>::max (), zero_distance_type include_zero = AlwaysIncludeZeroDistance);
+  EdgeRelationFilter (edge_relation_type r, distance_type d, metrics_type metrics = db::Euclidian, double ignore_angle = 90, distance_type min_projection = 0, distance_type max_projection = std::numeric_limits<distance_type>::max (), collinear_mode_type include_zero = AlwaysIncludeCollinear);
 
   /**
    *  Constructs an edge relation filter from a CheckOptions structure
@@ -249,19 +249,19 @@ struct DB_PUBLIC EdgeRelationFilter
   }
 
   /**
-   *  @brief Sets a value indicating whether zero distance shall be included in the check
+   *  @brief Sets a value indicating whether collinear edges shall be included in the check
    */
-  void set_include_zero (zero_distance_type f)
+  void set_collinear_mode (collinear_mode_type f)
   {
-    m_include_zero = f;
+    m_collinear_mode = f;
   }
 
   /**
-   *  @brief Gets a value indicating whether zero distance shall be included in the check
+   *  @brief Gets a value indicating whether collinear edges shall be included in the check
    */
-  zero_distance_type include_zero () const
+  collinear_mode_type collinear_mode () const
   {
-    return m_include_zero;
+    return m_collinear_mode;
   }
 
   /**
@@ -361,7 +361,7 @@ struct DB_PUBLIC EdgeRelationFilter
 
 private:
   bool m_whole_edges;
-  zero_distance_type m_include_zero;
+  collinear_mode_type m_collinear_mode;
   edge_relation_type m_r;
   distance_type m_d;
   metrics_type m_metrics;
@@ -372,9 +372,9 @@ private:
 
 //  Internal methods exposed for testing purposes
 
-DB_PUBLIC bool projected_near_part_of_edge (zero_distance_type include_zero, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &g, db::Edge *output);
-DB_PUBLIC bool square_near_part_of_edge (zero_distance_type include_zero, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &g, db::Edge *output);
-DB_PUBLIC bool euclidian_near_part_of_edge (zero_distance_type include_zero, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &g, db::Edge *output);
+DB_PUBLIC bool projected_near_part_of_edge (collinear_mode_type include_zero, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &g, db::Edge *output);
+DB_PUBLIC bool square_near_part_of_edge (collinear_mode_type include_zero, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &g, db::Edge *output);
+DB_PUBLIC bool euclidian_near_part_of_edge (collinear_mode_type include_zero, db::coord_traits<db::Coord>::distance_type d, const db::Edge &e, const db::Edge &g, db::Edge *output);
 DB_PUBLIC db::Edge::distance_type edge_projection (const db::Edge &a, const db::Edge &b);
 
 }
diff --git a/src/db/db/dbRegionLocalOperations.h b/src/db/db/dbRegionLocalOperations.h
index 997ac30ca..bfd95774d 100644
--- a/src/db/db/dbRegionLocalOperations.h
+++ b/src/db/db/dbRegionLocalOperations.h
@@ -130,7 +130,7 @@ struct DB_PUBLIC RegionCheckOptions
                       RectFilter _rect_filter = NoRectFilter,
                       bool _negative = false,
                       PropertyConstraint _prop_constraint = IgnoreProperties,
-                      zero_distance_type _include_zero = IncludeZeroDistanceWhenTouch)
+                      collinear_mode_type _include_zero = IncludeCollinearWhenTouch)
     : EdgesCheckOptions (_whole_edges, _metrics, _ignore_angle, _min_projection, _max_projection, _include_zero),
       shielded (_shielded),
       opposite_filter (_opposite_filter),
diff --git a/src/db/db/gsiDeclDbRegion.cc b/src/db/db/gsiDeclDbRegion.cc
index 43b809553..3de35ff52 100644
--- a/src/db/db/gsiDeclDbRegion.cc
+++ b/src/db/db/gsiDeclDbRegion.cc
@@ -3234,6 +3234,30 @@ gsi::Enum<db::metrics_type> decl_Metrics ("db", "Metrics",
   "This enum has been introduced in version 0.27."
 );
 
+gsi::Enum<db::collinear_mode_type> decl_CollinearMode ("db", "CollinearMode",
+  gsi::enum_const ("NeverIncludeCollinear", db::NeverIncludeCollinear,
+    "@brief Specifies that check functions should never include collinear edges.\n"
+    "With this specification, the check functions will ignore edges which are collinear."
+  ) +
+  gsi::enum_const ("AlwaysIncludeCollinear", db::AlwaysIncludeCollinear,
+    "@brief Specifies that check functions should always include collinear edges\n"
+    "With this specification, the check functions will also check edges which are collinear."
+  ) +
+  gsi::enum_const ("IncludeCollinearWhenTouch", db::IncludeCollinearWhenTouch,
+    "@brief Specifies that check functions should include collinear edges when they touch\n"
+    "With this specification, the check functions will also check edges which are collinear, but only if they touch in at least one point. "
+    "This is the mode that allows checking the 'kissing corner' cases."
+  ),
+  "@brief This class represents the collinear_mode type for \\Region#width and related checks.\n"
+  "This mode determines how collinear edges are treated in the DRC checks. Formally these edges do neither represent "
+  "a space other other relation as they do not face each other. There are three modes available to treat this boundary case: "
+  "Ignore collinear edges (\\NeverIncludeCollinear), always include them (\\AlwaysIncludeCollinear) or only include them "
+  "if they share at least one common point (\\IncludeCollinearWhenTouch). The latter mode allows activating checks for "
+  "the 'kissing corner' case and is the default mode in most checks."
+  "\n"
+  "This enum has been introduced in version 0.29."
+);
+
 //  Inject the Region::Metrics declarations into Region and Edges:
 //  (Edges injection has to be done here because only here defs() is available)
 gsi::ClassExt<db::Region> inject_Metrics_in_Region (decl_Metrics.defs ());
diff --git a/src/db/unit_tests/dbEdgePairRelationsTests.cc b/src/db/unit_tests/dbEdgePairRelationsTests.cc
index f836abec1..305641e4f 100644
--- a/src/db/unit_tests/dbEdgePairRelationsTests.cc
+++ b/src/db/unit_tests/dbEdgePairRelationsTests.cc
@@ -51,139 +51,139 @@ TEST(1)
 TEST(2)
 {
   db::Edge output;
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 10), db::Point (100, 200)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (100, 200)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 50), db::Point (100, 50)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (100, -50)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 10), db::Point (100, 200)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (100, 200)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 50), db::Point (100, 50)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (100, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;100,-50)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;187,-50)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,-50;187,-50)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(-87,-50;187,-50)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (0, -50)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (0, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(-87,-50;0,-50)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -100), db::Point (300, -100)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, 0), db::Point (300, -100)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -100), db::Point (300, -100)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, 0), db::Point (300, -100)), &output), true);
   EXPECT_EQ (output.to_string (), "(-94,-34;164,-77)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 0), db::Point (100, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 0), db::Point (100, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,0;50,-100)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (40, 0), db::Point (140, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (40, 0), db::Point (140, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(40,0;90,-100)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 0), db::Point (200, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 0), db::Point (200, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,0;145,-89)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -200), db::Point (200, -200)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (200, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -200), db::Point (200, -200)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (200, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,0;145,-89)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (120, 200), db::Point (120, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (120, 200), db::Point (120, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(120,0;120,-98)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 200), db::Point (100, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 200), db::Point (100, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,0;100,-100)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 200), db::Point (80, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 200), db::Point (80, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(80,0;80,-100)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-80, 200), db::Point (-80, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-80, 200), db::Point (-80, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(-80,0;-80,-60)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 0), db::Point (-200, -200)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 0), db::Point (-200, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(80,0;-45,-89)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 50), db::Point (100, 50)), &output), false);
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (100, -50)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 50), db::Point (100, 50)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (100, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,-50;100,-50)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (50, -50), db::Point (50, -50)), &output), true);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (50, -50), db::Point (50, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(50,-50;50,-50)");
-  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (190, -50), db::Point (190, -50)), &output), false);
+  EXPECT_EQ (euclidian_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (190, -50), db::Point (190, -50)), &output), false);
 }
 
 TEST(3)
 {
   db::Edge output;
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (100, 200)), &output), false);
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 50), db::Point (100, 50)), &output), false);
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (100, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (100, 200)), &output), false);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 50), db::Point (100, 50)), &output), false);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (100, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;100,-50)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;200,-50)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,-50;200,-50)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(-100,-50;200,-50)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (0, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (0, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(-100,-50;0,-50)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -100), db::Point (300, -100)), &output), false);
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, 0), db::Point (300, -100)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -100), db::Point (300, -100)), &output), false);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, 0), db::Point (300, -100)), &output), true);
   EXPECT_EQ (output.to_string (), "(-100,-33;200,-83)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 0), db::Point (100, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 0), db::Point (100, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,0;50,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (40, 0), db::Point (140, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (40, 0), db::Point (140, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(40,0;90,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 0), db::Point (200, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 0), db::Point (200, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,0;150,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -200), db::Point (200, -200)), &output), false);
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (200, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -200), db::Point (200, -200)), &output), false);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (200, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,0;150,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (120, 200), db::Point (120, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (120, 200), db::Point (120, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(120,0;120,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 200), db::Point (100, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 200), db::Point (100, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,0;100,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 200), db::Point (80, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 200), db::Point (80, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(80,0;80,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-80, 200), db::Point (-80, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-80, 200), db::Point (-80, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(-80,0;-80,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 0), db::Point (-200, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 0), db::Point (-200, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(80,0;-60,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(-100,0;-100,-100)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 50), db::Point (100, 50)), &output), false);
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (100, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 50), db::Point (100, 50)), &output), false);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (100, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,-50;100,-50)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (50, -50), db::Point (50, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (50, -50), db::Point (50, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(50,-50;50,-50)");
-  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (190, -50), db::Point (190, -50)), &output), true);
+  EXPECT_EQ (square_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (190, -50), db::Point (190, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(190,-50;190,-50)");
 }
 
 TEST(4)
 {
   db::Edge output;
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (100, 200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 50), db::Point (100, 50)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (100, -50)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (100, 200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 50), db::Point (100, 50)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (100, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;100,-50)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;100,-50)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (300, -50)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (300, -50)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (300, -50)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (300, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;100,-50)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (0, -50)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -100), db::Point (300, -100)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, 0), db::Point (300, -100)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -50), db::Point (0, -50)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, -100), db::Point (300, -100)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-300, 0), db::Point (300, -100)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,-50;100,-67)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 0), db::Point (100, -200)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 0), db::Point (100, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(0,0;50,-100)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (40, 0), db::Point (140, -200)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (40, 0), db::Point (140, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(40,0;90,-100)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 0), db::Point (200, -200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -200), db::Point (200, -200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (200, -200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (120, 200), db::Point (120, -200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 200), db::Point (100, -200)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 0), db::Point (200, -200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, -200), db::Point (200, -200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (0, 200), db::Point (200, -200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (120, 200), db::Point (120, -200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 200), db::Point (100, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,0;100,-100)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 200), db::Point (80, -200)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 200), db::Point (80, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(80,0;80,-100)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-80, 200), db::Point (-80, -200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 0), db::Point (-200, -200)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-80, 200), db::Point (-80, -200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (80, 0), db::Point (-200, -200)), &output), true);
   EXPECT_EQ (output.to_string (), "(80,0;0,-57)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 50), db::Point (100, 50)), &output), false);
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (100, -50)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (), db::Edge (db::Point (-100, 200), db::Point (-100, -200)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, 50), db::Point (100, 50)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (100, -50), db::Point (100, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(100,-50;100,-50)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (50, -50), db::Point (50, -50)), &output), true);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (50, -50), db::Point (50, -50)), &output), true);
   EXPECT_EQ (output.to_string (), "(50,-50;50,-50)");
-  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeZeroDistance, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (190, -50), db::Point (190, -50)), &output), false);
+  EXPECT_EQ (projected_near_part_of_edge (db::AlwaysIncludeCollinear, 100, db::Edge (db::Point (0, 0), db::Point (100, 0)), db::Edge (db::Point (190, -50), db::Point (190, -50)), &output), false);
 }
 
 TEST(5)
@@ -291,7 +291,7 @@ TEST(7)
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(1,30;1,20)");
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (-1, 30), db::Point (-1, 20)), &output);
   EXPECT_EQ (res, false);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (0, 30), db::Point (0, 20)), &output);
   EXPECT_EQ (res, false);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (1, 30), db::Point (1, 20)), &output);
@@ -300,7 +300,7 @@ TEST(7)
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (-1, 30), db::Point (-1, 20)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::AlwaysIncludeZeroDistance);
+  f.set_collinear_mode (db::AlwaysIncludeCollinear);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (0, 300), db::Point (0, -200)), &output);
   EXPECT_EQ (res, true);
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(0,110;0,-100)");
@@ -309,7 +309,7 @@ TEST(7)
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(1,110;1,-100)");
 
   f.set_metrics (db::Square);
-  f.set_include_zero (db::AlwaysIncludeZeroDistance);
+  f.set_collinear_mode (db::AlwaysIncludeCollinear);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (0, 30), db::Point (0, 20)), &output);
   EXPECT_EQ (res, true);
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(0,30;0,20)");
@@ -318,7 +318,7 @@ TEST(7)
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(1,30;1,20)");
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (-1, 30), db::Point (-1, 20)), &output);
   EXPECT_EQ (res, false);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (0, 30), db::Point (0, 20)), &output);
   EXPECT_EQ (res, false);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (1, 30), db::Point (1, 20)), &output);
@@ -327,7 +327,7 @@ TEST(7)
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (-1, 30), db::Point (-1, 20)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::AlwaysIncludeZeroDistance);
+  f.set_collinear_mode (db::AlwaysIncludeCollinear);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (0, 300), db::Point (0, -200)), &output);
   EXPECT_EQ (res, true);
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(0,110;0,-100)");
@@ -336,7 +336,7 @@ TEST(7)
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(1,110;1,-100)");
 
   f.set_metrics (db::Projection);
-  f.set_include_zero (db::AlwaysIncludeZeroDistance);
+  f.set_collinear_mode (db::AlwaysIncludeCollinear);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (0, 30), db::Point (0, -20)), &output);
   EXPECT_EQ (res, true);
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(0,10;0,0)");
@@ -345,7 +345,7 @@ TEST(7)
   EXPECT_EQ (output.first ().to_string () + ":" + output.second ().to_string (), "(0,0;0,10):(1,10;1,0)");
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (-1, 30), db::Point (-1, -20)), &output);
   EXPECT_EQ (res, false);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (0, 30), db::Point (0, 11)), &output);
   EXPECT_EQ (res, false);
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 10)), db::Edge (db::Point (1, 30), db::Point (1, -20)), &output);
@@ -361,7 +361,7 @@ TEST(8_KissingCornerProblem)
   //  if the projection is >0.
 
   db::EdgeRelationFilter f (db::WidthRelation, 10);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
   db::EdgePair output;
   bool res;
 
@@ -382,7 +382,7 @@ TEST(8_KissingCornerProblem)
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 100)), db::Edge (db::Point (0, -1), db::Point (0, -100)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::NeverIncludeZeroDistance);
+  f.set_collinear_mode (db::NeverIncludeCollinear);
 
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 100)), db::Edge (db::Point (0, 201), db::Point (0, 101)), &output);
   EXPECT_EQ (res, false);
@@ -398,7 +398,7 @@ TEST(8_KissingCornerProblem)
   EXPECT_EQ (res, false);
 
   f = db::EdgeRelationFilter (db::SpaceRelation, 10);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
 
   f.set_metrics (db::Euclidian);
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, 101), db::Point (0, 201)), &output);
@@ -417,7 +417,7 @@ TEST(8_KissingCornerProblem)
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, -100), db::Point (0, -1)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::NeverIncludeZeroDistance);
+  f.set_collinear_mode (db::NeverIncludeCollinear);
 
   f.set_metrics (db::Euclidian);
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, 101), db::Point (0, 201)), &output);
@@ -440,7 +440,7 @@ TEST(9_KissingCornerProblemSquareMetrics)
   //  if the projection is >0.
 
   db::EdgeRelationFilter f (db::WidthRelation, 10);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
   db::EdgePair output;
   bool res;
 
@@ -461,7 +461,7 @@ TEST(9_KissingCornerProblemSquareMetrics)
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 100)), db::Edge (db::Point (0, -1), db::Point (0, -100)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::NeverIncludeZeroDistance);
+  f.set_collinear_mode (db::NeverIncludeCollinear);
 
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 100)), db::Edge (db::Point (0, 201), db::Point (0, 101)), &output);
   EXPECT_EQ (res, false);
@@ -477,7 +477,7 @@ TEST(9_KissingCornerProblemSquareMetrics)
   EXPECT_EQ (res, false);
 
   f = db::EdgeRelationFilter (db::SpaceRelation, 10);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
 
   f.set_metrics (db::Square);
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, 101), db::Point (0, 201)), &output);
@@ -496,7 +496,7 @@ TEST(9_KissingCornerProblemSquareMetrics)
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, -100), db::Point (0, -1)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::NeverIncludeZeroDistance);
+  f.set_collinear_mode (db::NeverIncludeCollinear);
 
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, 101), db::Point (0, 201)), &output);
   EXPECT_EQ (res, false);
@@ -518,7 +518,7 @@ TEST(10_KissingCornerProblemProjectionMetrics)
   //  if the projection is >0. It is not effective in projection metrics as there is no overlap.
 
   db::EdgeRelationFilter f (db::WidthRelation, 10);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
   db::EdgePair output;
   bool res;
 
@@ -537,7 +537,7 @@ TEST(10_KissingCornerProblemProjectionMetrics)
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 100)), db::Edge (db::Point (0, -1), db::Point (0, -100)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::NeverIncludeZeroDistance);
+  f.set_collinear_mode (db::NeverIncludeCollinear);
 
   res = f.check (db::Edge (db::Point (0, 0), db::Point (0, 100)), db::Edge (db::Point (0, 201), db::Point (0, 101)), &output);
   EXPECT_EQ (res, false);
@@ -553,7 +553,7 @@ TEST(10_KissingCornerProblemProjectionMetrics)
   EXPECT_EQ (res, false);
 
   f = db::EdgeRelationFilter (db::SpaceRelation, 10);
-  f.set_include_zero (db::IncludeZeroDistanceWhenTouch);
+  f.set_collinear_mode (db::IncludeCollinearWhenTouch);
 
   f.set_metrics (db::Projection);
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, 101), db::Point (0, 201)), &output);
@@ -570,7 +570,7 @@ TEST(10_KissingCornerProblemProjectionMetrics)
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, -100), db::Point (0, -1)), &output);
   EXPECT_EQ (res, false);
 
-  f.set_include_zero (db::NeverIncludeZeroDistance);
+  f.set_collinear_mode (db::NeverIncludeCollinear);
 
   res = f.check (db::Edge (db::Point (0, 100), db::Point (0, 0)), db::Edge (db::Point (0, 101), db::Point (0, 201)), &output);
   EXPECT_EQ (res, false);