WoodModel.java

/* Copyright (c) 2012 Jesper Öqvist <jesper@llbit.se>
 *
 * This file is part of Chunky.
 *
 * Chunky 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.
 *
 * Chunky 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 Chunky.  If not, see <http://www.gnu.org/licenses/>.
 */
package se.llbit.chunky.model;

import se.llbit.chunky.resources.Texture;
import se.llbit.math.Quad;
import se.llbit.math.Ray;
import se.llbit.math.Vector3;
import se.llbit.math.Vector4;

/**
 * A block of wood.
 *
 * @author Jesper Öqvist <jesper@llbit.se>
 */
public class WoodModel {
  private static final Quad[] sides = {
      // north
      new Quad(new Vector3(1, 0, 0), new Vector3(0, 0, 0), new Vector3(1, 1, 0),
          new Vector4(1, 0, 0, 1)),

      // south
      new Quad(new Vector3(0, 0, 1), new Vector3(1, 0, 1), new Vector3(0, 1, 1),
          new Vector4(0, 1, 0, 1)),

      // west
      new Quad(new Vector3(0, 0, 0), new Vector3(0, 0, 1), new Vector3(0, 1, 0),
          new Vector4(0, 1, 0, 1)),

      // east
      new Quad(new Vector3(1, 0, 1), new Vector3(1, 0, 0), new Vector3(1, 1, 1),
          new Vector4(1, 0, 0, 1)),

      // top
      new Quad(new Vector3(1, 1, 0), new Vector3(0, 1, 0), new Vector3(1, 1, 1),
          new Vector4(1, 0, 0, 1)),

      // bottom
      new Quad(new Vector3(0, 0, 0), new Vector3(1, 0, 0), new Vector3(0, 0, 1),
          new Vector4(0, 1, 0, 1)),

  };

  private static final int[][] textureIndex =
      {{0, 0, 0, 0, 1, 1}, {0, 0, 1, 1, 0, 0}, {1, 1, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0}};

  private static final int[][] uv =
      {{0, 0, 0, 0, 0, 0}, {1, 1, 0, 0, 1, 1}, {0, 0, 1, 1, 0, 0}, {0, 0, 0, 0, 0, 0},};

  public static boolean intersect(Ray ray, Texture[] texture) {
    boolean hit = false;
    int data = ray.getBlockData();
    int direction = data >> 2;
    ray.t = Double.POSITIVE_INFINITY;
    for (int i = 0; i < sides.length; ++i) {
      Quad side = sides[i];
      if (side.intersect(ray)) {
        double u = ray.u;
        int uv_x = uv[direction][i];
        ray.u = (1 - uv_x) * ray.u + uv_x * ray.v;
        ray.v = uv_x * u + (1 - uv_x) * ray.v;
        texture[textureIndex[direction][i]].getColor(ray);
        ray.n.set(side.n);
        ray.t = ray.tNext;
        hit = true;
      }
    }
    if (hit) {
      ray.color.w = 1;
      ray.distance += ray.t;
      ray.o.scaleAdd(ray.t, ray.d);
    }
    return hit;
  }
}