+++ /dev/null
-#include <stdio.h>
-/*
- * (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- * Unpublished-- rights reserved under the copyright laws of the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
- */
-#if defined(_WIN32)
-#pragma warning (disable:4244) /* disable bogus conversion warnings */
-#endif
-#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[3])
-{
- v[0] = 0.0;
- v[1] = 0.0;
- v[2] = 0.0;
-}
-
-static void
-vset(float v[3], float x, float y, float z)
-{
- v[0] = x;
- v[1] = y;
- v[2] = z;
-}
-
-static void
-vsub(const float src1[3], const float src2[3], float dst[3])
-{
- dst[0] = src1[0] - src2[0];
- dst[1] = src1[1] - src2[1];
- dst[2] = src1[2] - src2[2];
-}
-
-static void
-vcopy(const float v1[3], float v2[3])
-{
- register int i;
- for (i = 0 ; i < 3 ; i++)
- v2[i] = v1[i];
-}
-
-static void
-vcross(const float v1[3], const float v2[3], float cross[3])
-{
- 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[3])
-{
- return sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
-}
-
-static void
-vscale(float v[3], float div)
-{
- v[0] *= div;
- v[1] *= div;
- v[2] *= div;
-}
-
-static void
-vnormal(float v[3])
-{
- vscale(v,1.0/vlength(v));
-}
-
-static float
-vdot(const float v1[3], const float v2[3])
-{
- return v1[0]*v2[0] + v1[1]*v2[1] + v1[2]*v2[2];
-}
-
-static void
-vadd(const float src1[3], const float src2[3], float dst[3])
-{
- 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] = 1.0;
- 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) / (2.0*TRACKBALLSIZE);
-
- /*
- * Avoid problems with out-of-control values...
- */
- if (t > 1.0) t = 1.0;
- if (t < -1.0) t = -1.0;
- phi = 2.0 * asin(t);
-
- axis_to_quat(a,phi,q);
-}
-
-/*
- * Given an axis and angle, compute quaternion.
- */
-void
-axis_to_quat(const float a[3], float phi, float q[4])
-{
- vcopy(a,q);
- vnormal(q);
- vscale(q, sin(phi/2.0));
- q[3] = cos(phi/2.0);
-}
-
-/*
- * 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 = sqrt(x*x + y*y);
- if (d < r * 0.70710678118654752440) { /* Inside sphere */
- z = sqrt(r*r - d*d);
- } else { /* On hyperbola */
- t = r / 1.41421356237309504880;
- 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(const float q1[4], const float q2[4], float dest[4])
-{
- static int count=0;
- float t1[4], t2[4], t3[4];
- float tf[4];
-
-#if 0
-printf("q1 = %f %f %f %f\n", q1[0], q1[1], q1[2], q1[3]);
-printf("q2 = %f %f %f %f\n", q2[0], q2[1], q2[2], q2[3]);
-#endif
-
- 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);
-
-#if 0
-printf("tf = %f %f %f %f\n", tf[0], tf[1], tf[2], tf[3]);
-#endif
-
- 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 = sqrt(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], const float q[4])
-{
- m[0][0] = 1.0 - 2.0 * (q[1] * q[1] + q[2] * q[2]);
- m[0][1] = 2.0 * (q[0] * q[1] - q[2] * q[3]);
- m[0][2] = 2.0 * (q[2] * q[0] + q[1] * q[3]);
- m[0][3] = 0.0;
-
- m[1][0] = 2.0 * (q[0] * q[1] + q[2] * q[3]);
- m[1][1]= 1.0 - 2.0 * (q[2] * q[2] + q[0] * q[0]);
- m[1][2] = 2.0 * (q[1] * q[2] - q[0] * q[3]);
- m[1][3] = 0.0;
-
- m[2][0] = 2.0 * (q[2] * q[0] - q[1] * q[3]);
- m[2][1] = 2.0 * (q[1] * q[2] + q[0] * q[3]);
- m[2][2] = 1.0 - 2.0 * (q[1] * q[1] + q[0] * q[0]);
- m[2][3] = 0.0;
-
- m[3][0] = 0.0;
- m[3][1] = 0.0;
- m[3][2] = 0.0;
- m[3][3] = 1.0;
-}
-
projects / mesa.git / blobdiff