surface.java

j3me java

/*
 * J3DME Fast 3D software rendering for small devices
 * Copyright (C) 2001 Onno Hommes
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package net.jscience.j3dme;

/**
 * This class implements the explicit geometry Surface.
 * The Surface geometry allows a model to be rendered as a flat surface.
 * The Surface class is extended from the Wireframe and therefor can also be
 rendered
 * as a Wireframe without any changes. The most obvious extensions on top of the
 * Wireframe definitions are the polygon array and the face normal offset.
 * The polygon array is used to set the boundaries of the surfaces of the
 gemoetry and the
 * facen normal offset points to the start of the normals in the coordinate
 stream.
 * Without further explaining it must be obvious that the coordinate stream not
 only contains
 * the vertices for the surface geometry but also the normal vetors of the
 surfaces.
 * All Surface normals must be unit vectors (i.e. vectors of length 1). This
 however must be
 * expressed with 8 bit fixed point integers. E.g. (0,256,0) is a unit vector (8
 bits are
 * fraction).
 * @see Model
 * @see ViewPort
 * @see Wireframe
 */
public class Surface extends Wireframe
{
  protected int normal_offset;
  protected int[] wires;
  protected int[] polygons_from;
  protected int[] polygons_to;


 /** Construct a new Surface Geometry
   * Set each of the surface parameters as provided.
   *
   * @param     w The array representing the wire stream indices for the edges
   * @param     p The array representing the polygon stream indices for the
 bounderies
   * @param     s The array representing the surface stream bounded by the a
 polygon
   * @param     o The array representing the normal index into the coordinate
 stream
   */
 public Surface(int[] x,int[] y,int[] z,
                int[] wf,int[] wt,int[] ws,
		int[] pf,int[] pt,int o){
     super(x,y,z,wf,wt);
     wires = ws;
     polygons_from = pf;
     polygons_to = pt;
     normal_offset = o;
 }

  /**
   * Returns the normal offset<p>
   * This method returns an index of type int into the coordinate stream.
   * The value indicates the place where the face normals start.
   *
   * @return The normal offset of the Surface.
   */
  public int getNormalOffset(){
    return normal_offset;
  }

}