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