klayout/src/db/unit_tests/dbTriangleTests.cc

/*

  KLayout Layout Viewer
  Copyright (C) 2006-2023 Matthias Koefferlein

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

*/


#include "dbTriangle.h"
#include "tlUnitTest.h"

#include <list>

//  Tests for Vertex class

TEST(Vertex_basic)
{
  db::Vertex v;

  v.set_x (1.5);
  v.set_y (0.5);
  EXPECT_EQ (v.to_string (), "(1.5, 0.5)");
  EXPECT_EQ (v.x (), 1.5);
  EXPECT_EQ (v.y (), 0.5);

  v = db::Vertex (db::DPoint (2, 3));
  EXPECT_EQ (v.to_string (), "(2, 3)");

  v.set_level (42);
  EXPECT_EQ (v.level (), size_t (42));
}

static std::string edges_from_vertex (const db::Vertex &v)
{
  std::string res;
  for (auto e = v.begin_edges (); e != v.end_edges (); ++e) {
    if (! res.empty ()) {
      res += ", ";
    }
    res += e->to_string ();
  }
  return res;
}

static std::string triangles_from_vertex (const db::Vertex &v)
{
  auto tri = v.triangles ();
  std::string res;
  for (auto t = tri.begin (); t != tri.end (); ++t) {
    if (! res.empty ()) {
      res += ", ";
    }
    res += (*t)->to_string ();
  }
  return res;
}

TEST(Vertex_edge_registration)
{
  db::Vertex v1 (0, 0);
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  std::unique_ptr<db::TriangleEdge> e1 (new db::TriangleEdge (&v1, &v2));
  EXPECT_EQ (edges_from_vertex (v1), "((0, 0), (1, 2))");
  EXPECT_EQ (edges_from_vertex (v2), "((0, 0), (1, 2))");
  EXPECT_EQ (edges_from_vertex (v3), "");

  std::unique_ptr<db::TriangleEdge> e2 (new db::TriangleEdge (&v2, &v3));
  EXPECT_EQ (edges_from_vertex (v1), "((0, 0), (1, 2))");
  EXPECT_EQ (edges_from_vertex (v2), "((0, 0), (1, 2)), ((1, 2), (2, 1))");
  EXPECT_EQ (edges_from_vertex (v3), "((1, 2), (2, 1))");

  e2.reset (0);
  EXPECT_EQ (edges_from_vertex (v1), "((0, 0), (1, 2))");
  EXPECT_EQ (edges_from_vertex (v2), "((0, 0), (1, 2))");
  EXPECT_EQ (edges_from_vertex (v3), "");

  e1.reset (0);
  EXPECT_EQ (edges_from_vertex (v1), "");
  EXPECT_EQ (edges_from_vertex (v2), "");
  EXPECT_EQ (edges_from_vertex (v3), "");
}

TEST(Vertex_triangles)
{
  db::Vertex v1 (0, 0);
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);
  db::Vertex v4 (-1, 2);
  EXPECT_EQ (triangles_from_vertex (v1), "");

  std::unique_ptr<db::TriangleEdge> e1 (new db::TriangleEdge (&v1, &v2));
  std::unique_ptr<db::TriangleEdge> e2 (new db::TriangleEdge (&v2, &v3));
  std::unique_ptr<db::TriangleEdge> e3 (new db::TriangleEdge (&v3, &v1));

  std::unique_ptr<db::Triangle> tri (new db::Triangle (e1.get (), e2.get (), e3.get ()));
  EXPECT_EQ (triangles_from_vertex (v1), "((0, 0), (1, 2), (2, 1))");
  EXPECT_EQ (triangles_from_vertex (v2), "((0, 0), (1, 2), (2, 1))");
  EXPECT_EQ (triangles_from_vertex (v3), "((0, 0), (1, 2), (2, 1))");

  std::unique_ptr<db::TriangleEdge> e4 (new db::TriangleEdge (&v1, &v4));
  std::unique_ptr<db::TriangleEdge> e5 (new db::TriangleEdge (&v2, &v4));
  std::unique_ptr<db::Triangle> tri2 (new db::Triangle (e1.get (), e4.get (), e5.get ()));
  EXPECT_EQ (triangles_from_vertex (v1), "((0, 0), (-1, 2), (1, 2)), ((0, 0), (1, 2), (2, 1))");
  EXPECT_EQ (triangles_from_vertex (v2), "((0, 0), (-1, 2), (1, 2)), ((0, 0), (1, 2), (2, 1))");
  EXPECT_EQ (triangles_from_vertex (v3), "((0, 0), (1, 2), (2, 1))");
  EXPECT_EQ (triangles_from_vertex (v4), "((0, 0), (-1, 2), (1, 2))");
}

//  Tests for Triangle class

TEST(Triangle_basic)
{
  db::Vertex v1;
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v2, &v3);
  db::TriangleEdge s3 (&v3, &v1);

  db::Triangle tri (&s1, &s2, &s3);
  EXPECT_EQ (tri.to_string (), "((0, 0), (1, 2), (2, 1))");

  //  ordering
  db::TriangleEdge s11 (&v1, &v2);
  db::TriangleEdge s12 (&v3, &v2);
  db::TriangleEdge s13 (&v1, &v3);

  db::Triangle tri2 (&s11, &s12, &s13);
  EXPECT_EQ (tri2.to_string (), "((0, 0), (1, 2), (2, 1))");

  //  triangle registration
  EXPECT_EQ (s11.right () == &tri2, true);
  EXPECT_EQ (s11.left () == 0, true);
  EXPECT_EQ (s12.left () == &tri2, true);
  EXPECT_EQ (s12.right () == 0, true);
  EXPECT_EQ (s13.left () == &tri2, true);
  EXPECT_EQ (s13.right () == 0, true);
}

TEST(Triangle_find_segment_with)
{
  db::Vertex v1;
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v2, &v3);
  db::TriangleEdge s3 (&v3, &v1);

  db::Triangle tri (&s1, &s2, &s3);

  EXPECT_EQ (tri.find_edge_with (&v1, &v2)->to_string (), "((0, 0), (1, 2))");
  EXPECT_EQ (tri.find_edge_with (&v2, &v1)->to_string (), "((0, 0), (1, 2))");
}

TEST(Triangle_ext_vertex)
{
  db::Vertex v1;
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v2, &v3);
  db::TriangleEdge s3 (&v3, &v1);

  db::Triangle tri (&s1, &s2, &s3);

  EXPECT_EQ (tri.opposite (&s1)->to_string (), "(2, 1)");
  EXPECT_EQ (tri.opposite (&s3)->to_string (), "(1, 2)");
}

TEST(Triangle_opposite_vertex)
{
  db::Vertex v1;
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v2, &v3);
  db::TriangleEdge s3 (&v3, &v1);

  db::Triangle tri (&s1, &s2, &s3);

  EXPECT_EQ (tri.opposite (&s1)->to_string (), "(2, 1)");
  EXPECT_EQ (tri.opposite (&s3)->to_string (), "(1, 2)");
}

TEST(Triangle_opposite_edge)
{
  db::Vertex v1;
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v2, &v3);
  db::TriangleEdge s3 (&v3, &v1);

  db::Triangle tri (&s1, &s2, &s3);

  EXPECT_EQ (tri.opposite (&v1)->to_string (), "((1, 2), (2, 1))");
  EXPECT_EQ (tri.opposite (&v3)->to_string (), "((0, 0), (1, 2))");
}

TEST(Triangle_contains)
{
  db::Vertex v1;
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v2, &v3);
  db::TriangleEdge s3 (&v3, &v1);

  db::Triangle tri (&s1, &s2, &s3);

  EXPECT_EQ (tri.contains (db::DPoint (0, 0)), 0);
  EXPECT_EQ (tri.contains (db::DPoint (-1, -2)), -1);
  EXPECT_EQ (tri.contains (db::DPoint (0.5, 1)), 0);
  EXPECT_EQ (tri.contains (db::DPoint (0.5, 2)), -1);
  EXPECT_EQ (tri.contains (db::DPoint (2.5, 1)), -1);
  EXPECT_EQ (tri.contains (db::DPoint (1, -1)), -1);
  EXPECT_EQ (tri.contains (db::DPoint (1, 1)), 1);

  s1.reverse ();
  s2.reverse ();
  s3.reverse ();

  db::Triangle tri2 (&s3, &s2, &s1);
  EXPECT_EQ (tri2.contains(db::DPoint(0, 0)), 0);
  EXPECT_EQ (tri2.contains(db::DPoint(0.5, 1)), 0);
  EXPECT_EQ (tri2.contains(db::DPoint(0.5, 2)), -1);
  EXPECT_EQ (tri2.contains(db::DPoint(2.5, 1)), -1);
  EXPECT_EQ (tri2.contains(db::DPoint(1, -1)), -1);
  EXPECT_EQ (tri2.contains(db::DPoint(1, 1)), 1);
}

TEST(Triangle_circumcircle)
{
  db::Vertex v1;
  db::Vertex v2 (1, 2);
  db::Vertex v3 (2, 1);

  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v2, &v3);
  db::TriangleEdge s3 (&v3, &v1);

  db::Triangle tri (&s1, &s2, &s3);

  auto cc = tri.circumcircle ();
  auto center = cc.first;
  auto radius = cc.second;

  EXPECT_EQ (tl::to_string (center), "0.833333333333,0.833333333333");
  EXPECT_EQ (tl::to_string (radius), "1.17851130198");

  EXPECT_EQ (db::Vertex::in_circle (center, center, radius), 1);
  EXPECT_EQ (db::Vertex::in_circle (db::DPoint (-1, -1), center, radius), -1);
  EXPECT_EQ (v1.in_circle (center, radius), 0);
  EXPECT_EQ (v2.in_circle (center, radius), 0);
  EXPECT_EQ (v3.in_circle (center, radius), 0);
}

//  Tests for TriangleEdge class

TEST(TriangleEdge_basic)
{
  db::Vertex v1;
  db::Vertex v2 (1, 0.5);

  db::TriangleEdge edge (&v1, &v2);
  EXPECT_EQ (edge.to_string (), "((0, 0), (1, 0.5))");
}

TEST(TriangleEdge_side_of)
{
  db::Vertex v1;
  db::Vertex v2 (1, 0.5);

  db::TriangleEdge edge (&v1, &v2);
  EXPECT_EQ (edge.to_string (), "((0, 0), (1, 0.5))");

  EXPECT_EQ (edge.side_of (db::Vertex (0, 0)), 0)
  EXPECT_EQ (edge.side_of (db::Vertex (0.5, 0.25)), 0)
  EXPECT_EQ (edge.side_of (db::Vertex (0, 1)), -1)
  EXPECT_EQ (edge.side_of (db::Vertex (0, -1)), 1)
  EXPECT_EQ (edge.side_of (db::Vertex (0.5, 0.5)), -1)
  EXPECT_EQ (edge.side_of (db::Vertex (0.5, 0)), 1)

  db::Vertex v3 (1, 0);
  db::Vertex v4 (0, 1);
  db::TriangleEdge edge2 (&v3, &v4);

  EXPECT_EQ (edge2.side_of (db::Vertex(0.2, 0.2)), -1);
}

namespace {
  class VertexHeap
  {
  public:
    db::Vertex *make_vertex (double x, double y)
    {
      m_heap.push_back (db::Vertex (x, y));
      return &m_heap.back ();
    }
  private:
    std::list<db::Vertex> m_heap;
  };
}

TEST(TriangleEdge_crosses)
{
  VertexHeap heap;

  db::TriangleEdge s1 (heap.make_vertex (0, 0), heap.make_vertex (1, 0.5));
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, -0.5), heap.make_vertex(1, -0.5))), false);
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, 0), heap.make_vertex(1, 0))), false);  // only cuts
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, 0.5), heap.make_vertex(1, 0.5))), false);
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, 0.5), heap.make_vertex(2, 0.5))), false);
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, 0.25), heap.make_vertex(2, 0.25))), true);
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, 0.5), heap.make_vertex(-0.1, 0.5))), false);
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, 0.6), heap.make_vertex(0, 0.6))), false);
  EXPECT_EQ (s1.crosses (db::TriangleEdge (heap.make_vertex (-1, 1), heap.make_vertex(1, 1))), false);

  EXPECT_EQ (s1.crosses_including (db::TriangleEdge (heap.make_vertex (-1, -0.5), heap.make_vertex(1, -0.5))), false);
  EXPECT_EQ (s1.crosses_including (db::TriangleEdge (heap.make_vertex (-1, 0), heap.make_vertex(1, 0))), true);  // only cuts
  EXPECT_EQ (s1.crosses_including (db::TriangleEdge (heap.make_vertex (-1, 0.25), heap.make_vertex(2, 0.25))), true);
}

TEST(TriangleEdge_point_on)
{
  VertexHeap heap;

  db::TriangleEdge s1 (heap.make_vertex (0, 0), heap.make_vertex (1, 0.5));
  EXPECT_EQ (s1.point_on (db::DPoint (0, 0)), false); //  endpoints are not "on"
  EXPECT_EQ (s1.point_on (db::DPoint (0, -0.5)), false);
  EXPECT_EQ (s1.point_on (db::DPoint (0.5, 0)), false);
  EXPECT_EQ (s1.point_on (db::DPoint (0.5, 0.25)), true);
  EXPECT_EQ (s1.point_on (db::DPoint (1, 0.5)), false); //  endpoints are not "on"
  EXPECT_EQ (s1.point_on (db::DPoint (1, 1)), false);
  EXPECT_EQ (s1.point_on (db::DPoint (2, 1)), false);
}

TEST(TriangleEdge_intersection_point)
{
  VertexHeap heap;

  db::TriangleEdge s1 (heap.make_vertex (0, 0), heap.make_vertex (1, 0.5));
  EXPECT_EQ (s1.intersection_point (db::TriangleEdge (heap.make_vertex (-1, 0.25), heap.make_vertex (2, 0.25))).to_string (), "0.5,0.25");
}

TEST(TriangleEdge_can_flip)
{
  db::Vertex v1 (2, -1);
  db::Vertex v2 (0, 0);
  db::Vertex v3 (1, 0);
  db::Vertex v4 (0.5, 1);
  db::TriangleEdge s1 (&v1, &v2);
  db::TriangleEdge s2 (&v1, &v3);
  db::TriangleEdge s3 (&v2, &v3);
  db::TriangleEdge s4 (&v2, &v4);
  db::TriangleEdge s5 (&v3, &v4);
  db::Triangle t1 (&s1, &s2, &s3);
  db::Triangle t2 (&s3, &s4, &s5);
  s3.set_left (&t1);
  s3.set_right (&t2);
  EXPECT_EQ (s3.can_flip(), false);
  v1.set_x (0.5);
  EXPECT_EQ (s3.can_flip(), true);
  v1.set_x (-0.25);
  EXPECT_EQ (s3.can_flip(), true);
  v1.set_x (-0.5);
  EXPECT_EQ (s3.can_flip(), false);
  v1.set_x (-1.0);
  EXPECT_EQ (s3.can_flip(), false);
}

TEST(TriangleEdge_distance)
{
  db::Vertex v1 (0, 0);
  db::Vertex v2 (1, 0);

  db::TriangleEdge seg (&v1, &v2);
  EXPECT_EQ (seg.distance (db::DPoint (0, 0)), 0);
  EXPECT_EQ (seg.distance (db::DPoint (0, 1)), 1);
  EXPECT_EQ (seg.distance (db::DPoint (1, 2)), 2);
  EXPECT_EQ (seg.distance (db::DPoint (1, -1)), 1);
  EXPECT_EQ (seg.distance (db::DPoint (2, 0)), 1);
  EXPECT_EQ (seg.distance (db::DPoint (-2, 0)), 2);
  seg.reverse ();
  EXPECT_EQ (seg.distance (db::DPoint (0, 0)), 0);
  EXPECT_EQ (seg.distance (db::DPoint (0, 1)), 1);
  EXPECT_EQ (seg.distance (db::DPoint (1, 2)), 2);
  EXPECT_EQ (seg.distance (db::DPoint (1, -1)), 1);
  EXPECT_EQ (seg.distance (db::DPoint (2, 0)), 1);
  EXPECT_EQ (seg.distance (db::DPoint (-2, 0)), 2);
}