PrusaSlicer-NonPlainar/tests/libslic3r/test_triangulation.cpp
Vojtech Bubnik 59e14cb752 Reworked constrained Delanay triangulation of polygons / expolygons
using CGAL CDT implementation:
Removed all the sets / maps, replaced with vectors and CDT vertex
intrusive indices.
Reworked the outside / inside classification using just the CDT
"constrained edge" attributes and a single queue.

Cherry pick commit 1648ae853d6c69a1118efbc694dadeb9965154ee
2022-03-17 13:09:10 +01:00

137 lines
4.6 KiB
C++

#include <catch2/catch.hpp>
#include <libslic3r/Triangulation.hpp>
#include <libslic3r/SVG.hpp> // only debug visualization
using namespace Slic3r;
namespace Private{
void store_trinagulation(const ExPolygons & shape,
const std::vector<Vec3i> &triangles,
const char* file_name = "Triangulation_visualization.svg",
double scale = 1e5)
{
BoundingBox bb;
for (const auto &expoly : shape) bb.merge(expoly.contour.points);
bb.scale(scale);
SVG svg_vis(file_name, bb);
svg_vis.draw(shape, "gray", .7f);
size_t count = count_points(shape);
Points points;
points.reserve(count);
auto insert_point = [](const Slic3r::Polygon &polygon, Points &points) {
for (const Point &p : polygon.points) points.emplace_back(p);
};
for (const ExPolygon &expolygon : shape) {
insert_point(expolygon.contour, points);
for (const Slic3r::Polygon &hole : expolygon.holes)
insert_point(hole, points);
}
for (const auto &t : triangles) {
Polygon triangle({points[t[0]], points[t[1]], points[t[2]]});
triangle.scale(scale);
svg_vis.draw(triangle, "green");
}
// prevent visualization in test
CHECK(false);
}
} // namespace
TEST_CASE("Triangulate rectangle with restriction on edge", "[Triangulation]")
{
// 0 1 2 3
Points points = {Point(1, 1), Point(2, 1), Point(2, 2), Point(1, 2)};
Triangulation::HalfEdges edges1 = {{1, 3}};
std::vector<Vec3i> indices1 = Triangulation::triangulate(points, edges1);
auto check = [](int i1, int i2, Vec3i t) -> bool {
return true;
return (t[0] == i1 || t[1] == i1 || t[2] == i1) &&
(t[0] == i2 || t[1] == i2 || t[2] == i2);
};
REQUIRE(indices1.size() == 2);
int i1 = edges1.begin()->first, i2 = edges1.begin()->second;
CHECK(check(i1, i2, indices1[0]));
CHECK(check(i1, i2, indices1[1]));
Triangulation::HalfEdges edges2 = {{0, 2}};
std::vector<Vec3i> indices2 = Triangulation::triangulate(points, edges2);
REQUIRE(indices2.size() == 2);
i1 = edges2.begin()->first;
i2 = edges2.begin()->second;
CHECK(check(i1, i2, indices2[0]));
CHECK(check(i1, i2, indices2[1]));
}
TEST_CASE("Triangulation polygon", "[triangulation]")
{
Points points = {Point(416, 346), Point(445, 362), Point(463, 389),
Point(469, 427), Point(445, 491)};
Polygon polygon(points);
Polygons polygons({polygon});
ExPolygon expolygon(points);
ExPolygons expolygons({expolygon});
std::vector<Vec3i> tp = Triangulation::triangulate(polygon);
std::vector<Vec3i> tps = Triangulation::triangulate(polygons);
std::vector<Vec3i> tep = Triangulation::triangulate(expolygon);
std::vector<Vec3i> teps = Triangulation::triangulate(expolygons);
//Private::store_trinagulation(expolygons, teps);
CHECK(tp.size() == tps.size());
CHECK(tep.size() == teps.size());
CHECK(tp.size() == tep.size());
CHECK(tp.size() == 3);
}
TEST_CASE("Triangulation M shape polygon", "[triangulation]")
{
// 0 1 2 3 4
Polygon shape_M = {Point(0, 0), Point(2, 0), Point(2, 2), Point(1, 1), Point(0, 2)};
std::vector<Vec3i> triangles = Triangulation::triangulate(shape_M);
// Check outer triangle is not contain
std::set<int> outer_triangle = {2, 3, 4};
bool is_in = false;
for (const Vec3i &t : triangles) {
for (size_t i = 0; i < 3; i++) {
int index = t[i];
if (outer_triangle.find(index) == outer_triangle.end()) {
is_in = false;
break;
} else {
is_in = true;
}
}
if (is_in) break;
}
//Private::store_trinagulation({ExPolygon(shape_M)}, triangles);
CHECK(triangles.size() == 3);
CHECK(!is_in);
}
// same point in triangulation are not Supported
//TEST_CASE("Triangulation 2 polygons with same point", "[triangulation][not supported]")
//{
// Slic3r::Polygon polygon1 = {
// Point(416, 346), Point(445, 362),
// Point(463, 389), Point(469, 427) /* This point */,
// Point(445, 491)
// };
// Slic3r::Polygon polygon2 = {
// Point(495, 488), Point(469, 427) /* This point */,
// Point(495, 364)
// };
// ExPolygons shape2d = {ExPolygon(polygon1), ExPolygon(polygon2)};
// std::vector<Vec3i> shape_triangles = Triangulation::triangulate(shape2d);
// store_trinagulation(shape2d, shape_triangles);
//}