mesh_misc_functions.cc

// Copyright 2016 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "draco/mesh/mesh_misc_functions.h"

namespace draco {

std::unique_ptr<CornerTable> CreateCornerTableFromPositionAttribute(
    const Mesh *mesh) {
  return CreateCornerTableFromAttribute(mesh, GeometryAttribute::POSITION);
}

std::unique_ptr<CornerTable> CreateCornerTableFromAttribute(
    const Mesh *mesh, GeometryAttribute::Type type) {
  typedef CornerTable::FaceType FaceType;

  const PointAttribute *const att = mesh->GetNamedAttribute(type);
  if (att == nullptr) {
    return nullptr;
  }
  IndexTypeVector<FaceIndex, FaceType> faces(mesh->num_faces());
  FaceType new_face;
  for (FaceIndex i(0); i < mesh->num_faces(); ++i) {
    const Mesh::Face &face = mesh->face(i);
    for (int j = 0; j < 3; ++j) {
      // Map general vertex indices to attribute indices.
      new_face[j] = att->mapped_index(face[j]).value();
    }
    faces[FaceIndex(i)] = new_face;
  }
  // Build the corner table.
  return CornerTable::Create(faces);
}

std::unique_ptr<CornerTable> CreateCornerTableFromAllAttributes(
    const Mesh *mesh) {
  typedef CornerTable::FaceType FaceType;
  IndexTypeVector<FaceIndex, FaceType> faces(mesh->num_faces());
  FaceType new_face;
  for (FaceIndex i(0); i < mesh->num_faces(); ++i) {
    const Mesh::Face &face = mesh->face(i);
    // Each face is identified by point indices that automatically split the
    // mesh along attribute seams.
    for (int j = 0; j < 3; ++j) {
      new_face[j] = face[j].value();
    }
    faces[i] = new_face;
  }
  // Build the corner table.
  return CornerTable::Create(faces);
}
}  // namespace draco