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- /*
- * (c) Copyright 1993, 1994, Silicon Graphics, Inc.
- * ALL RIGHTS RESERVED
- * Permission to use, copy, modify, and distribute this software for
- * any purpose and without fee is hereby granted, provided that the above
- * copyright notice appear in all copies and that both the copyright notice
- * and this permission notice appear in supporting documentation, and that
- * the name of Silicon Graphics, Inc. not be used in advertising
- * or publicity pertaining to distribution of the software without specific,
- * written prior permission.
- *
- * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
- * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
- * FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
- * GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
- * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
- * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
- * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
- * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
- * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
- * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
- * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * US Government Users Restricted Rights
- * Use, duplication, or disclosure by the Government is subject to
- * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
- * (c)(1)(ii) of the Rights in Technical Data and Computer Software
- * clause at DFARS 252.227-7013 and/or in similar or successor
- * clauses in the FAR or the DOD or NASA FAR Supplement.
- * Unpublished-- rights reserved under the copyright laws of the
- * United States. Contractor/manufacturer is Silicon Graphics,
- * Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
- *
- * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
- */
- /*
- * trackball.h
- * A virtual trackball implementation
- * Written by Gavin Bell for Silicon Graphics, November 1988.
- */
-
- /*
- * Pass the x and y coordinates of the last and current positions of
- * the mouse, scaled so they are from (-1.0 ... 1.0).
- *
- * The resulting rotation is returned as a quaternion rotation in the
- * first paramater.
- */
- void
- trackball(float q[4], float p1x, float p1y, float p2x, float p2y);
-
- void
- negate_quat(float *q, float *qn);
-
- /*
- * Given two quaternions, add them together to get a third quaternion.
- * Adding quaternions to get a compound rotation is analagous to adding
- * translations to get a compound translation. When incrementally
- * adding rotations, the first argument here should be the new
- * rotation, the second and third the total rotation (which will be
- * over-written with the resulting new total rotation).
- */
- void
- add_quats(float *q1, float *q2, float *dest);
-
- /*
- * A useful function, builds a rotation matrix in Matrix based on
- * given quaternion.
- */
- void
- build_rotmatrix(float m[4][4], float q[4]);
-
- /*
- * This function computes a quaternion based on an axis (defined by
- * the given vector) and an angle about which to rotate. The angle is
- * expressed in radians. The result is put into the third argument.
- */
- void
- axis_to_quat(float a[3], float phi, float q[4]);
-
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