Marching: implement algorithm, still untested

MarchingCubes.cpp

@@ -54,7 +54,27 @@ Mesh MarchingCubes::operator()() {
 
                 const std::vector<CubeTri>& cur_triangles =
                     edges_of_intersection[intersections.value()];
-                // TODO
+                for(const CubeTri& cube_tri: cur_triangles) {
+                    Point verts[3] = {
+                        intersect_location(cube_tri.edge[0],
+                                x, y, z),
+                        intersect_location(cube_tri.edge[1],
+                                x, y, z),
+                        intersect_location(cube_tri.edge[2],
+                                x, y, z),
+                    };
+
+                    size_t vert_ids[3];
+                    for(int i=0; i < 3; ++i)
+                        vert_ids[i] = output.add_vertice(verts[i]);
+
+                    for(int i=0; i < 3; ++i) {
+                        output.add_face(
+                                vert_ids[i],
+                                vert_ids[(i+1) % 3],
+                                vert_ids[(i+2) % 3]);
+                    }
+                }
             }
         }
     }

MarchingCubes.hpp

@@ -86,6 +86,12 @@ class MarchingCubes {
             }
             bool x[2], y[2], z[2];
 
+            const bool operator==(const CubeEdge& oth) const {
+                return x[0] == oth.x[0] && x[1] == oth.x[1]
+                    && y[0] == oth.y[0] && y[1] == oth.y[1]
+                    && z[0] == oth.z[0] && z[1] == oth.z[1];
+            }
+
             /** Get the space point at a given position of [0,1] along the edge
              * when the base of the cube (ie. (0, 0, 0)) is given. */
             Point at(double pos,