+++ /dev/null
-/*
- * (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- * Unpublished-- rights reserved under the copyright laws of the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 code:
- *
- * Implementation of a virtual trackball.
- * Implemented by Gavin Bell, lots of ideas from Thant Tessman and
- * the August '88 issue of Siggraph's "Computer Graphics," pp. 121-129.
- *
- * Vector manip code:
- *
- * Original code from:
- * David M. Ciemiewicz, Mark Grossman, Henry Moreton, and Paul Haeberli
- *
- * Much mucking with by:
- * Gavin Bell
- */
-#include <math.h>
-#include "trackball.h"
-
-/*
- * This size should really be based on the distance from the center of
- * rotation to the point on the object underneath the mouse. That
- * point would then track the mouse as closely as possible. This is a
- * simple example, though, so that is left as an Exercise for the
- * Programmer.
- */
-#define TRACKBALLSIZE 0.8f
-
-/*
- * Local function prototypes (not defined in trackball.h)
- */
-static float tb_project_to_sphere(float, float, float);
-static void normalize_quat(float[4]);
-
-static void vzero(float *v)
-{
- v[0] = 0.0;
- v[1] = 0.0;
- v[2] = 0.0;
-}
-
-static void vset(float *v, float x, float y, float z)
-{
- v[0] = x;
- v[1] = y;
- v[2] = z;
-}
-
-static void vsub(const float *src1, const float *src2, float *dst)
-{
- dst[0] = src1[0] - src2[0];
- dst[1] = src1[1] - src2[1];
- dst[2] = src1[2] - src2[2];
-}
-
-static void vcopy(const float *v1, float *v2)
-{
- int i;
- for (i = 0; i < 3; i++)
- v2[i] = v1[i];
-}
-
-static void vcross(const float *v1, const float *v2, float *cross)
-{
- float temp[3];
-
- temp[0] = (v1[1] * v2[2]) - (v1[2] * v2[1]);
- temp[1] = (v1[2] * v2[0]) - (v1[0] * v2[2]);
- temp[2] = (v1[0] * v2[1]) - (v1[1] * v2[0]);
- vcopy(temp, cross);
-}
-
-static float vlength(const float *v)
-{
- return sqrtf(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
-}
-
-static void vscale(float *v, float div)
-{
- v[0] *= div;
- v[1] *= div;
- v[2] *= div;
-}
-
-static void vnormal(float *v)
-{
- vscale(v, 1.0f / vlength(v));
-}
-
-static float vdot(const float *v1, const float *v2)
-{
- return v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2];
-}
-
-static void vadd(const float *src1, const float *src2, float *dst)
-{
- dst[0] = src1[0] + src2[0];
- dst[1] = src1[1] + src2[1];
- dst[2] = src1[2] + src2[2];
-}
-
-/*
- * Ok, simulate a track-ball. Project the points onto the virtual
- * trackball, then figure out the axis of rotation, which is the cross
- * product of P1 P2 and O P1 (O is the center of the ball, 0,0,0)
- * Note: This is a deformed trackball-- is a trackball in the center,
- * but is deformed into a hyperbolic sheet of rotation away from the
- * center. This particular function was chosen after trying out
- * several variations.
- *
- * It is assumed that the arguments to this routine are in the range
- * (-1.0 ... 1.0)
- */
-void trackball(float q[4], float p1x, float p1y, float p2x, float p2y)
-{
- float a[3]; /* Axis of rotation */
- float phi; /* how much to rotate about axis */
- float p1[3], p2[3], d[3];
- float t;
-
- if (p1x == p2x && p1y == p2y) {
- /* Zero rotation */
- vzero(q);
- q[3] = 1.0f;
- return;
- }
-
- /*
- * First, figure out z-coordinates for projection of P1 and P2 to
- * deformed sphere
- */
- vset(p1, p1x, p1y, tb_project_to_sphere(TRACKBALLSIZE, p1x, p1y));
- vset(p2, p2x, p2y, tb_project_to_sphere(TRACKBALLSIZE, p2x, p2y));
-
- /*
- * Now, we want the cross product of P1 and P2
- */
- vcross(p2, p1, a);
-
- /*
- * Figure out how much to rotate around that axis.
- */
- vsub(p1, p2, d);
- t = vlength(d) / (2.0f * TRACKBALLSIZE);
-
- /*
- * Avoid problems with out-of-control values...
- */
- t = fminf(t, 1.0f);
- t = fmaxf(t, -1.0f);
- phi = 2.0f * asinf(t);
-
- axis_to_quat(a, phi, q);
-}
-
-/*
- * Given an axis and angle, compute quaternion.
- */
-void axis_to_quat(float a[3], float phi, float q[4])
-{
- vnormal(a);
- vcopy(a, q);
- vscale(q, sinf(phi / 2.0f));
- q[3] = cosf(phi / 2.0f);
-}
-
-/*
- * Project an x,y pair onto a sphere of radius r OR a hyperbolic sheet
- * if we are away from the center of the sphere.
- */
-static float tb_project_to_sphere(float r, float x, float y)
-{
- float d, t, z;
-
- d = hypotf(x, y);
- if (d < r * (1.0f / sqrtf(2.0f))) { /* Inside sphere */
- z = sqrtf(r * r - d * d);
- } else { /* On hyperbola */
- t = r / sqrtf(2.0f);
- z = t * t / d;
- }
- return z;
-}
-
-/*
- * Given two rotations, e1 and e2, expressed as quaternion rotations,
- * figure out the equivalent single rotation and stuff it into dest.
- *
- * This routine also normalizes the result every RENORMCOUNT times it is
- * called, to keep error from creeping in.
- *
- * NOTE: This routine is written so that q1 or q2 may be the same
- * as dest (or each other).
- */
-
-#define RENORMCOUNT 97
-
-void add_quats(float q1[4], float q2[4], float dest[4])
-{
- static int count = 0;
- float t1[4], t2[4], t3[4];
- float tf[4];
-
- vcopy(q1, t1);
- vscale(t1, q2[3]);
-
- vcopy(q2, t2);
- vscale(t2, q1[3]);
-
- vcross(q2, q1, t3);
- vadd(t1, t2, tf);
- vadd(t3, tf, tf);
- tf[3] = q1[3] * q2[3] - vdot(q1, q2);
-
- dest[0] = tf[0];
- dest[1] = tf[1];
- dest[2] = tf[2];
- dest[3] = tf[3];
-
- if (++count > RENORMCOUNT) {
- count = 0;
- normalize_quat(dest);
- }
-}
-
-/*
- * Quaternions always obey: a^2 + b^2 + c^2 + d^2 = 1.0
- * If they don't add up to 1.0, dividing by their magnitued will
- * renormalize them.
- *
- * Note: See the following for more information on quaternions:
- *
- * - Shoemake, K., Animating rotation with quaternion curves, Computer
- * Graphics 19, No 3 (Proc. SIGGRAPH'85), 245-254, 1985.
- * - Pletinckx, D., Quaternion calculus as a basic tool in computer
- * graphics, The Visual Computer 5, 2-13, 1989.
- */
-static void normalize_quat(float q[4])
-{
- int i;
- float mag;
-
- mag = (q[0] * q[0] + q[1] * q[1] + q[2] * q[2] + q[3] * q[3]);
- for (i = 0; i < 4; i++)
- q[i] /= mag;
-}
-
-/*
- * Build a rotation matrix, given a quaternion rotation.
- *
- */
-void build_rotmatrix(float m[4][4], float q[4])
-{
- m[0][0] = 1.0f - 2.0f * (q[1] * q[1] + q[2] * q[2]);
- m[0][1] = 2.0f * (q[0] * q[1] - q[2] * q[3]);
- m[0][2] = 2.0f * (q[2] * q[0] + q[1] * q[3]);
- m[0][3] = 0.0f;
-
- m[1][0] = 2.0f * (q[0] * q[1] + q[2] * q[3]);
- m[1][1] = 1.0f - 2.0f * (q[2] * q[2] + q[0] * q[0]);
- m[1][2] = 2.0f * (q[1] * q[2] - q[0] * q[3]);
- m[1][3] = 0.0f;
-
- m[2][0] = 2.0f * (q[2] * q[0] - q[1] * q[3]);
- m[2][1] = 2.0f * (q[1] * q[2] + q[0] * q[3]);
- m[2][2] = 1.0f - 2.0f * (q[1] * q[1] + q[0] * q[0]);
- m[2][3] = 0.0f;
-
- m[3][0] = 0.0f;
- m[3][1] = 0.0f;
- m[3][2] = 0.0f;
- m[3][3] = 1.0f;
-}
+++ /dev/null
-/*
- * (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);
-
-/*
- * 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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