--- a/src/triangulate.cpp Sun Jul 03 14:35:06 2022 +0300
+++ b/src/triangulate.cpp Sun Jul 03 15:59:22 2022 +0300
@@ -134,28 +134,29 @@
std::vector<glm::vec3>::const_iterator end)
{
std::vector<PlainPolygonElement> result;
- const glm::vec3 xvec = *begin - *(begin + 1);
- const glm::vec3 yvec = *(begin + 2) - *(begin + 1);
- const glm::vec3 zvec = glm::cross(xvec, yvec);
- const glm::mat3 inverseMatrix = glm::inverse(glm::mat3{xvec, yvec, zvec});
- std::vector<std::vector<glm::vec3>> polygons{1};
- std::vector<glm::vec3>& polygon2d = polygons.back();
- polygon2d.reserve(static_cast<std::size_t>(end - begin));
- for (std::vector<glm::vec3>::const_iterator it = begin; it != end; ++it) {
- polygon2d.push_back(inverseMatrix * glm::vec4{*it, 1});
- }
- const std::vector<triangulate::index_t> indices = mapbox::earcut<triangulate::index_t>(polygons);
- triangulate::MergedTriangles mergedTriangles = triangulate::mergeTriangles(indices, begin);
- for (Quadrilateral& quad : mergedTriangles.quadrilaterals) {
- result.push_back(quad);
- }
- for (std::size_t i = 0; i < indices.size(); i += 3) {
- if (not mergedTriangles.cutTriangles.contains({i})) {
- Triangle tri = triangle(
+ // Transform the polygon into XY plane
+ opt<glm::mat3> normal = calculateNormal(begin, end);
+ if (normal.has_value()) {
+ const glm::mat3 normalInverse = glm::inverse(*normal);
+ std::vector<std::vector<glm::vec3>> polygons{1};
+ std::vector<glm::vec3>& polygon2d = polygons.back();
+ polygon2d.reserve(static_cast<std::size_t>(end - begin));
+ for (std::vector<glm::vec3>::const_iterator it = begin; it != end; ++it) {
+ polygon2d.push_back(normalInverse * glm::vec4{*it, 1});
+ }
+ const std::vector<triangulate::index_t> indices = mapbox::earcut<triangulate::index_t>(polygons);
+ triangulate::MergedTriangles mergedTriangles = triangulate::mergeTriangles(indices, begin);
+ for (Quadrilateral& quad : mergedTriangles.quadrilaterals) {
+ result.push_back(quad);
+ }
+ for (std::size_t i = 0; i < indices.size(); i += 3) {
+ if (not mergedTriangles.cutTriangles.contains({i})) {
+ Triangle tri = triangle(
*(begin + indices[i]),
*(begin + indices[i + 1]),
*(begin + indices[i + 2]));
- result.push_back(tri);
+ result.push_back(tri);
+ }
}
}
return result;