code: /*
   * Copyright (c) 2021 Callum Newlands
   *
   *     This program is free software: you can redistribute it and/or modify
   *     it under the terms of the GNU General Public License as published by
   *     the Free Software Foundation, either version 3 of the License, or
   *     (at your option) any later version.
   *
   *     The additional term of 7.b applies: Requiring preservation of specified
   *     reasonable legal notices or author attributions in that material or in the
   *     Appropriate Legal Notices displayed by works containing it
   *
   *     This program is distributed in the hope that it will be useful,
   *     but WITHOUT ANY WARRANTY; without even the implied warranty of
   *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *     GNU General Public License for more details.
   *
   *     You should have received a copy of the GNU General Public License
   *     along with this program.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  package utils;
  
  import java.util.List;
  import java.util.stream.Collectors;
  import modeldata.meshdata.Mesh;
  import modeldata.meshdata.Vertex;
  import org.joml.Matrix4f;
  import org.joml.Vector3f;
  
  public final class MeshUtils {
  	private MeshUtils() {
  	}
  
  	public static List<Vertex> transform(List<Vertex> vertices, Matrix4f model) {
  		if (vertices.get(0).getTangent() != null) {
  			return vertices.stream()
  					.map(v -> new Vertex(
  							model.transformPosition(new Vector3f(v.getPosition())),
  							model.transformDirection(new Vector3f(v.getNormal())).normalize(),
  							model.transformDirection(new Vector3f(v.getTangent())).normalize(),
  							v.getTexCoord()))
  					.collect(Collectors.toList());
  		}
  		return vertices.stream()
  				.map(v -> new Vertex(
  						model.transformPosition(new Vector3f(v.getPosition())),
  						model.transformDirection(new Vector3f(v.getNormal())).normalize(),
  						v.getTexCoord()))
  				.collect(Collectors.toList());
  	}
  
  	public static Mesh transform(Mesh mesh, Matrix4f model) {
  		List<Vertex> transformedVertices = transform(mesh.getVertices(), model);
  		return new Mesh(mesh, transformedVertices);
  	}
  
  }
  