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/*
* $RCSfile$
*
* Copyright (c) 2004 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistribution of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any
* kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
* WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
* EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL
* NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF
* USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR
* ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
* CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
* REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
* INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or
* intended for use in the design, construction, operation or
* maintenance of any nuclear facility.
*
* $Revision$
* $Date$
* $State$
*/
import javax.media.j3d.*;
import javax.vecmath.*;
public class Tetrahedron extends Shape3D {
private static final float sqrt3 = (float) Math.sqrt(3.0);
private static final float sqrt3_3 = sqrt3 / 3.0f;
private static final float sqrt24_3 = (float) Math.sqrt(24.0) / 3.0f;
private static final float ycenter = 0.5f * sqrt24_3;
private static final float zcenter = -sqrt3_3;
private static final Point3f p1 = new Point3f(-1.0f, -ycenter, -zcenter);
private static final Point3f p2 = new Point3f(1.0f, -ycenter, -zcenter);
private static final Point3f p3 =
new Point3f(0.0f, -ycenter, -sqrt3 - zcenter);
private static final Point3f p4 =
new Point3f(0.0f, sqrt24_3 - ycenter, 0.0f);
private static final Point3f[] verts = {
p1, p2, p4, // front face
p1, p4, p3, // left, back face
p2, p3, p4, // right, back face
p1, p3, p2, // bottom face
};
private TexCoord2f texCoord[] = {
new TexCoord2f(0.0f, 0.0f),
new TexCoord2f(1.0f, 0.0f),
new TexCoord2f(0.5f, sqrt3 / 2.0f),
};
public Tetrahedron() {
int i;
TriangleArray tetra = new TriangleArray(12, TriangleArray.COORDINATES |
TriangleArray.NORMALS | TriangleArray.TEXTURE_COORDINATE_2);
tetra.setCoordinates(0, verts);
for (i = 0; i < 12; i++) {
tetra.setTextureCoordinate(0, i, texCoord[i%3]);
}
int face;
Vector3f normal = new Vector3f();
Vector3f v1 = new Vector3f();
Vector3f v2 = new Vector3f();
Point3f [] pts = new Point3f[3];
for (i = 0; i < 3; i++) pts[i] = new Point3f();
for (face = 0; face < 4; face++) {
tetra.getCoordinates(face*3, pts);
v1.sub(pts[1], pts[0]);
v2.sub(pts[2], pts[0]);
normal.cross(v1, v2);
normal.normalize();
for (i = 0; i < 3; i++) {
tetra.setNormal((face * 3 + i), normal);
}
}
tetra.setCapability(Geometry.ALLOW_INTERSECT);
this.setGeometry(tetra);
this.setAppearance(new Appearance());
}
}
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