Component extract_subset

components/wmtk_components/CMakeLists.txt

@@ -1,5 +1,5 @@
-
 add_subdirectory(input)
 add_subdirectory(isotropic_remeshing)
 add_subdirectory(mesh_info)
-add_subdirectory(output)
+add_subdirectory(output)
+add_subdirectory(extract_subset)

components/wmtk_components/extract_subset/CMakeLists.txt

@@ -0,0 +1,5 @@
+set(SRC_FILES
+    internal/extract_subset_2d.hpp
+    internal/extract_subset_2d.cpp
+    )
+target_sources(wildmeshing_components PRIVATE ${SRC_FILES})

components/wmtk_components/extract_subset/extract_subset.cpp

@@ -0,0 +1,22 @@
+#include "extract_subset.hpp"
+
+
+namespace wmtk{
+namespace components {
+wmtk::TriMesh extract_subset(long dimension, const wmtk::TriMesh& m, std::vector<size_t> tag){
+    switch (dimension){
+        case 2: {
+            // return internal::extrace_subset_2d();
+            std::vector<Tuple> vertices = m.get_all(wmtk::PrimitiveType::Vertex);
+            std::vector<Tuple> triangles = m.get_all(wmtk::PrimitiveType::Face);
+            return internal::extract_subset_2d(vertices, triangles, tag);
+        }
+        case 3: {
+            // to be implemented
+        }
+    }
+
+}
+
+}
+}

components/wmtk_components/extract_subset/extract_subset.hpp

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <vector>
+#include "wmtk/Mesh.hpp"
+#include <wmtk/TriMesh.hpp>
+#include "wmtk/Primitive.hpp"
+#include "internal/extract_subset_2d.hpp"
+
+namespace wmtk::components{
+    wmtk::TriMesh extract_subset(long dimension, const wmtk::TriMesh& m, std::vector<size_t> tag);
+} // namespace wmtk::components

components/wmtk_components/extract_subset/internal/extract_subset_2d.cpp

@@ -0,0 +1,130 @@
+#include "extract_subset_2d.hpp"
+
+wmtk::TriMesh extract_subset_2d(
+    const std::vector<Eigen::Vector2d>& points,
+    Eigen::MatrixXi& triangles, std::vector<size_t> tag){
+
+    int nb_vertex = points.size();
+    int nb_vertex_in = 0;
+    int nb_tri_in = tag.size();
+    // maintain a vector of bool, true if an old vertex is preserved after extraction
+    std::vector<bool> vertices_in_bool(nb_vertex);
+    for (int k = 0; k < nb_vertex; ++k) {vertices_in_bool[k] = false;}
+
+    Eigen::MatrixXi faces_in;
+    faces_in.resize(nb_tri_in, 3);
+
+    //tag the preserved ones and count number of vertex in new extraction
+    for (size_t k = 0; k < nb_tri_in; ++k){
+        for (size_t k2 = 0; k2 < 3; ++k2) {
+            // faces_in(k, k2) = triangles(tag[k], k2);
+            vertices_in_bool[triangles(tag[k], k2)] = true;
+        }
+    }
+    for (bool b: vertices_in_bool) {
+        if (b) nb_vertex_in ++;
+    }
+
+    // construct a map from old vertex id to new new id
+    std::map<int, int> old2new;
+    int j = 0;
+    for (int i = 0; i < nb_vertex; ++i){
+        // ignore the not extracted vertices
+        if (vertices_in_bool[i]){
+            // old vertex id i map to new vertex id j, where j increases by count
+            old2new.insert({i, j});
+            j++;
+        }
+    }
+    assert(j == nb_vertex_in);
+
+    wmtk::TriMesh mesh;
+    wmtk::RowVectors3l tris;
+    tris.resize(nb_tri_in, 3);
+    for (unsigned int i = 0; i < nb_tri_in; ++i){
+        // only put in the extracted ones
+        size_t tri = tag[i];
+        tris.row(i) << old2new[triangles(tri, 0)], old2new[triangles(tri, 1)], old2new[triangles(tri, 2)];
+    }
+    mesh.initialize(tris);
+
+    Eigen::MatrixXd points_in;
+    points_in.resize(nb_vertex_in, 2);
+    for (int i = 0; i < nb_vertex; ++i){
+        if (vertices_in_bool[i]){
+            points_in(old2new[i], 0) = points[i][0];
+            points_in(old2new[i], 1) = points[i][1];
+        }
+    }
+    wmtk::mesh_utils::set_matrix_attribute(points_in, "position", wmtk::PrimitiveType::Vertex, mesh);
+    return mesh;
+}
+
+
+// Note: the above is a draft version of the algo, implemented in bad, drafted data structure
+// The following is new code to be finished
+wmtk::TriMesh extract_subset_2d(std::vector<wmtk::Tuple> vertices, std::vector<wmtk::Tuple> triangles, std::vector<size_t> tag){
+    assert(tag.size() <= triangles.size());
+
+    int nb_vertex = vertices.size();
+    int nb_vertex_in = 0;
+    int nb_tri_in = tag.size();
+    std::vector<bool> vertices_in_bool(nb_vertex);
+    for (int k = 0; k < nb_vertex; ++k) {vertices_in_bool[k] = false;}
+    Eigen::MatrixXi faces_in;
+    faces_in.resize(nb_tri_in, 3);
+
+    //tag the preserved ones and count number of vertex in new extraction
+    for (size_t k = 0; k < nb_tri_in; ++k){
+        // wmtk::attribute::MeshAttributeHandle<long> m_vf_handle;
+        // wmtk::attribute::MeshAttributeHandle<long> m_vf_handle;
+        // wmtk::ConstAccessor<long> vf_accessor = wmtk::Mesh::create_const_accessor<long>(m_vf_handle);
+        // auto f = vf_accessor.index_access().scalar_attribute(k);
+        // wmtk::ConstAccessor<long> fv_accessor = wmtk::Mesh::create_const_accessor<long>(m_fv_handle);
+        // auto fv = fv_accessor.index_access().vector_attribute(f);
+        for (size_t k2 = 0; k2 < 3; ++k2) {
+            // if (fv(k2) == k){
+
+            // }
+
+            // vertices_in_bool[triangles(tag[k], k2)] = true;
+        }
+    }
+//     for (bool b: vertices_in_bool) {
+//         if (b) nb_vertex_in ++;
+//     }
+
+//     // construct a map from old vertex id to new new id
+//     std::map<int, int> old2new;
+//     int j = 0;
+//     for (int i = 0; i < nb_vertex; ++i){
+//         // ignore the not extracted vertices
+//         if (vertices_in_bool[i]){
+//             // old vertex id i map to new vertex id j, where j increases by count
+//             old2new.insert({i, j});
+//             j++;
+//         }
+//     }
+//     assert(j == nb_vertex_in);
+
+    wmtk::TriMesh mesh;
+//     wmtk::RowVectors3l tris;
+//     tris.resize(nb_tri_in, 3);
+//     for (unsigned int i = 0; i < nb_tri_in; ++i){
+//         // only put in the extracted ones
+//         size_t tri = tag[i];
+//         tris.row(i) << old2new[triangles(tri, 0)], old2new[triangles(tri, 1)], old2new[triangles(tri, 2)];
+//     }
+//     mesh.initialize(tris);
+
+//     Eigen::MatrixXd points_in;
+//     points_in.resize(nb_vertex_in, 2);
+//     for (int i = 0; i < nb_vertex; ++i){
+//         if (vertices_in_bool[i]){
+//             points_in(old2new[i], 0) = points[i][0];
+//             points_in(old2new[i], 1) = points[i][1];
+//         }
+//     }
+//     wmtk::mesh_utils::set_matrix_attribute(points_in, "position", wmtk::PrimitiveType::Vertex, mesh);
+    return mesh;
+}

components/wmtk_components/extract_subset/internal/extract_subset_2d.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <vector>
+#include <wmtk/TriMesh.hpp>
+#include <wmtk/utils/mesh_utils.hpp>
+#include <wmtk/Primitive.hpp>
+#include "wmtk/Mesh.hpp"
+#include "wmtk/Tuple.hpp"
+#include <wmtk/Accessor.hpp>
+#include <wmtk/attribute/AttributeHandle.hpp>
+
+namespace wmtk::components::internal {
+wmtk::TriMesh extract_subset_2d(
+    const std::vector<Eigen::Vector2d>& points,
+    Eigen::MatrixXd& vertices,
+    Eigen::MatrixXi& triangles, std::vector<size_t> tag);
+
+wmtk::TriMesh extract_subset_2d(
+    std::vector<Tuple> vertices,
+    std::vector<Tuple> triangles,
+    std::vector<size_t> tag);
+} 
+
+// namespace wmtk::components::internal

tests/components/CMakeLists.txt

@@ -4,6 +4,7 @@ set(TEST_SOURCES
     test_component_mesh_info.cpp
     test_component_output.cpp
 	test_component_isotropic_remeshing.cpp
+    test_component_extract_subset.cpp
 )
 target_sources(wmtk_tests PRIVATE ${TEST_SOURCES})
 

tests/components/test_component_extract_subset.cpp

@@ -0,0 +1,8 @@
+#include <wmtk_components/extract_subset/internal/extract_subset_2d.hpp>
+#include <catch2/catch_test_macros.hpp>
+
+
+TEST_CASE("manual test case", "[components][extract_subset][2D]")
+{
+
+}