org.simantics.g3d/src/org/simantics/g3d/shape/Sphere.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2013 Association for Decentralized Information Management in
   3  * Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.g3d.shape;
  13
  14 import java.util.ArrayList;
  15 import java.util.List;
  16
  17 import javax.vecmath.AxisAngle4d;
  18 import javax.vecmath.Vector3d;
  19
  20 import org.simantics.g3d.math.MathTools;
  21
  22 public class Sphere {
  23
  24         public static Mesh create(double radius, int s, int p) {
  25                 if (s < 3 || p < 3 || radius < MathTools.NEAR_ZERO)
  26                         throw new IllegalArgumentException();
  27                 List<Vector3d> vertices = new ArrayList<Vector3d>((s-2)*p + 2);
  28                 List<Vector3d> normals = new ArrayList<Vector3d>(vertices.size());
  29                 List<Integer> indices = new ArrayList<Integer>(((s-3)*p*2 + p * 2)*3);
  30                 Vector3d v = new Vector3d(0.0,-radius,0.0);
  31                 Vector3d vp = new Vector3d();
  32                 for (int ip = 0; ip < p; ip++) {
  33                         if (ip == 0) {
  34                                 vertices.add(new Vector3d(0.0,-radius,0.0));
  35                         } else if (ip == p - 1) {
  36                                 vertices.add(new Vector3d(0.0, radius,0.0));
  37                                 int off = 1 + (ip-2)*s;
  38                                 for (int is = 0; is < s; is++) {
  39                                         indices.add(vertices.size() - 1);
  40                                         indices.add(is+off);
  41                                         if (is < s -1)
  42                                                 indices.add(is+off+1);
  43                                         else
  44                                                 indices.add(off);
  45
  46
  47                                 }
  48                         } else {
  49                                 AxisAngle4d aa = new AxisAngle4d(1, 0, 0, ((double)ip/(double)(p-1))*Math.PI);
  50                                 MathTools.rotate(MathTools.getQuat(aa), v, vp);
  51                                 for (int is = 0; is < s; is++) {
  52                                         aa = new AxisAngle4d(0, 1, 0, ((double)is/(double)s)*Math.PI*2);
  53                                         Vector3d vs = new Vector3d();
  54                                         MathTools.rotate(MathTools.getQuat(aa), vp, vs);
  55                                         vertices.add(vs);
  56                                 }
  57                                 if (ip == 1) {
  58                                         for (int is = 0; is < s; is++) {
  59                                                 indices.add(0);
  60                                                 if (is < s -1)
  61                                                         indices.add(is+2);
  62                                                 else
  63                                                         indices.add(1);
  64                                                 indices.add(is+1);
  65                                         }
  66                                 } else {
  67                                         int off = 1 + (ip-1)*s;
  68                                         for (int is = 0; is < s-1; is++) {
  69                                                 indices.add(off + is - s);
  70                                                 indices.add(off + is+1);
  71                                                 indices.add(off + is);
  72
  73
  74                                                 indices.add(off + is - s);
  75                                                 indices.add(off + is + 1 - s);
  76                                                 indices.add(off + is + 1);
  77
  78                                         }
  79                                         indices.add(off - 1);
  80                                         indices.add(off);
  81                                         indices.add(off + s - 1);
  82
  83                                         indices.add(off -1);
  84                                         indices.add(off - s);
  85                                         indices.add(off);
  86
  87                                 }
  88                         }
  89                 }
  90                 for (int i = 0; i < vertices.size(); i++) {
  91                         Vector3d n = new Vector3d(vertices.get(i));
  92                         n.normalize();
  93                         normals.add(n);
  94                 }
  95
  96                 return Mesh.create(vertices,normals,indices);
  97
  98         }
  99
 100         public static void main(String arg[]) {
 101                 Mesh s1 = create(1.0, 3, 3);
 102                 Mesh s2 = create(1.0, 4, 4);
 103                 System.out.println("debug " + s1 + " " + s2);
 104         }
 105 }