|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* (c) Copyright 1993, 1994, Silicon Graphics, Inc.
|
|
Packit |
328d5c |
* ALL RIGHTS RESERVED
|
|
Packit |
328d5c |
* Permission to use, copy, modify, and distribute this software for
|
|
Packit |
328d5c |
* any purpose and without fee is hereby granted, provided that the above
|
|
Packit |
328d5c |
* copyright notice appear in all copies and that both the copyright notice
|
|
Packit |
328d5c |
* and this permission notice appear in supporting documentation, and that
|
|
Packit |
328d5c |
* the name of Silicon Graphics, Inc. not be used in advertising
|
|
Packit |
328d5c |
* or publicity pertaining to distribution of the software without specific,
|
|
Packit |
328d5c |
* written prior permission.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
|
|
Packit |
328d5c |
* AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
|
|
Packit |
328d5c |
* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
|
|
Packit |
328d5c |
* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
|
|
Packit |
328d5c |
* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
|
|
Packit |
328d5c |
* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
|
|
Packit |
328d5c |
* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
|
|
Packit |
328d5c |
* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
|
|
Packit |
328d5c |
* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
|
|
Packit |
328d5c |
* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
|
|
Packit |
328d5c |
* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
|
|
Packit |
328d5c |
* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* US Government Users Restricted Rights
|
|
Packit |
328d5c |
* Use, duplication, or disclosure by the Government is subject to
|
|
Packit |
328d5c |
* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
|
|
Packit |
328d5c |
* (c)(1)(ii) of the Rights in Technical Data and Computer Software
|
|
Packit |
328d5c |
* clause at DFARS 252.227-7013 and/or in similar or successor
|
|
Packit |
328d5c |
* clauses in the FAR or the DOD or NASA FAR Supplement.
|
|
Packit |
328d5c |
* Unpublished-- rights reserved under the copyright laws of the
|
|
Packit |
328d5c |
* United States. Contractor/manufacturer is Silicon Graphics,
|
|
Packit |
328d5c |
* Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* OpenGL(TM) is a trademark of Silicon Graphics, Inc.
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Trackball code:
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* Implementation of a virtual trackball.
|
|
Packit |
328d5c |
* Implemented by Gavin Bell, lots of ideas from Thant Tessman and
|
|
Packit |
328d5c |
* the August '88 issue of Siggraph's "Computer Graphics," pp. 121-129.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* Vector manip code:
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* Original code from:
|
|
Packit |
328d5c |
* David M. Ciemiewicz, Mark Grossman, Henry Moreton, and Paul Haeberli
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* Much mucking with by:
|
|
Packit |
328d5c |
* Gavin Bell
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
#include <math.h>
|
|
Packit |
328d5c |
#include "trackball.h"
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* This size should really be based on the distance from the center of
|
|
Packit |
328d5c |
* rotation to the point on the object underneath the mouse. That
|
|
Packit |
328d5c |
* point would then track the mouse as closely as possible. This is a
|
|
Packit |
328d5c |
* simple example, though, so that is left as an Exercise for the
|
|
Packit |
328d5c |
* Programmer.
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
#define TRACKBALLSIZE (0.8)
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Local function prototypes (not defined in trackball.h)
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
static float tb_project_to_sphere(float, float, float);
|
|
Packit |
328d5c |
static void normalize_quat(float [4]);
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vzero(float *v)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
v[0] = 0.0;
|
|
Packit |
328d5c |
v[1] = 0.0;
|
|
Packit |
328d5c |
v[2] = 0.0;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vset(float *v, float x, float y, float z)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
v[0] = x;
|
|
Packit |
328d5c |
v[1] = y;
|
|
Packit |
328d5c |
v[2] = z;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vsub(const float *src1, const float *src2, float *dst)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
dst[0] = src1[0] - src2[0];
|
|
Packit |
328d5c |
dst[1] = src1[1] - src2[1];
|
|
Packit |
328d5c |
dst[2] = src1[2] - src2[2];
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vcopy(const float *v1, float *v2)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
int i;
|
|
Packit |
328d5c |
for (i = 0 ; i < 3 ; i++)
|
|
Packit |
328d5c |
v2[i] = v1[i];
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vcross(const float *v1, const float *v2, float *cross)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
float temp[3];
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
temp[0] = (v1[1] * v2[2]) - (v1[2] * v2[1]);
|
|
Packit |
328d5c |
temp[1] = (v1[2] * v2[0]) - (v1[0] * v2[2]);
|
|
Packit |
328d5c |
temp[2] = (v1[0] * v2[1]) - (v1[1] * v2[0]);
|
|
Packit |
328d5c |
vcopy(temp, cross);
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
float
|
|
Packit |
328d5c |
vlength(const float *v)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
return sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vscale(float *v, float div)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
v[0] *= div;
|
|
Packit |
328d5c |
v[1] *= div;
|
|
Packit |
328d5c |
v[2] *= div;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vnormal(float *v)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
vscale(v,1.0/vlength(v));
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
float
|
|
Packit |
328d5c |
vdot(const float *v1, const float *v2)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
return v1[0]*v2[0] + v1[1]*v2[1] + v1[2]*v2[2];
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
vadd(const float *src1, const float *src2, float *dst)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
dst[0] = src1[0] + src2[0];
|
|
Packit |
328d5c |
dst[1] = src1[1] + src2[1];
|
|
Packit |
328d5c |
dst[2] = src1[2] + src2[2];
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Ok, simulate a track-ball. Project the points onto the virtual
|
|
Packit |
328d5c |
* trackball, then figure out the axis of rotation, which is the cross
|
|
Packit |
328d5c |
* product of P1 P2 and O P1 (O is the center of the ball, 0,0,0)
|
|
Packit |
328d5c |
* Note: This is a deformed trackball-- is a trackball in the center,
|
|
Packit |
328d5c |
* but is deformed into a hyperbolic sheet of rotation away from the
|
|
Packit |
328d5c |
* center. This particular function was chosen after trying out
|
|
Packit |
328d5c |
* several variations.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* It is assumed that the arguments to this routine are in the range
|
|
Packit |
328d5c |
* (-1.0 ... 1.0)
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
trackball(float q[4], float p1x, float p1y, float p2x, float p2y)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
float a[3]; /* Axis of rotation */
|
|
Packit |
328d5c |
float phi; /* how much to rotate about axis */
|
|
Packit |
328d5c |
float p1[3], p2[3], d[3];
|
|
Packit |
328d5c |
float t;
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
if (p1x == p2x && p1y == p2y) {
|
|
Packit |
328d5c |
/* Zero rotation */
|
|
Packit |
328d5c |
vzero(q);
|
|
Packit |
328d5c |
q[3] = 1.0;
|
|
Packit |
328d5c |
return;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* First, figure out z-coordinates for projection of P1 and P2 to
|
|
Packit |
328d5c |
* deformed sphere
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
vset(p1,p1x,p1y,tb_project_to_sphere(TRACKBALLSIZE,p1x,p1y));
|
|
Packit |
328d5c |
vset(p2,p2x,p2y,tb_project_to_sphere(TRACKBALLSIZE,p2x,p2y));
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Now, we want the cross product of P1 and P2
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
vcross(p2,p1,a);
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Figure out how much to rotate around that axis.
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
vsub(p1,p2,d);
|
|
Packit |
328d5c |
t = vlength(d) / (2.0*TRACKBALLSIZE);
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Avoid problems with out-of-control values...
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
if (t > 1.0) t = 1.0;
|
|
Packit |
328d5c |
if (t < -1.0) t = -1.0;
|
|
Packit |
328d5c |
phi = 2.0 * asin(t);
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
axis_to_quat(a,phi,q);
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Given an axis and angle, compute quaternion.
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
axis_to_quat(float a[3], float phi, float q[4])
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
vnormal(a);
|
|
Packit |
328d5c |
vcopy(a,q);
|
|
Packit |
328d5c |
vscale(q,sin(phi/2.0));
|
|
Packit |
328d5c |
q[3] = cos(phi/2.0);
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Project an x,y pair onto a sphere of radius r OR a hyperbolic sheet
|
|
Packit |
328d5c |
* if we are away from the center of the sphere.
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
static float
|
|
Packit |
328d5c |
tb_project_to_sphere(float r, float x, float y)
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
float d, t, z;
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
d = sqrt(x*x + y*y);
|
|
Packit |
328d5c |
if (d < r * 0.70710678118654752440) { /* Inside sphere */
|
|
Packit |
328d5c |
z = sqrt(r*r - d*d);
|
|
Packit |
328d5c |
} else { /* On hyperbola */
|
|
Packit |
328d5c |
t = r / 1.41421356237309504880;
|
|
Packit |
328d5c |
z = t*t / d;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
return z;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Given two rotations, e1 and e2, expressed as quaternion rotations,
|
|
Packit |
328d5c |
* figure out the equivalent single rotation and stuff it into dest.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* This routine also normalizes the result every RENORMCOUNT times it is
|
|
Packit |
328d5c |
* called, to keep error from creeping in.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* NOTE: This routine is written so that q1 or q2 may be the same
|
|
Packit |
328d5c |
* as dest (or each other).
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
#define RENORMCOUNT 97
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
add_quats(float q1[4], float q2[4], float dest[4])
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
static int count=0;
|
|
Packit |
328d5c |
float t1[4], t2[4], t3[4];
|
|
Packit |
328d5c |
float tf[4];
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
vcopy(q1,t1);
|
|
Packit |
328d5c |
vscale(t1,q2[3]);
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
vcopy(q2,t2);
|
|
Packit |
328d5c |
vscale(t2,q1[3]);
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
vcross(q2,q1,t3);
|
|
Packit |
328d5c |
vadd(t1,t2,tf);
|
|
Packit |
328d5c |
vadd(t3,tf,tf);
|
|
Packit |
328d5c |
tf[3] = q1[3] * q2[3] - vdot(q1,q2);
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
dest[0] = tf[0];
|
|
Packit |
328d5c |
dest[1] = tf[1];
|
|
Packit |
328d5c |
dest[2] = tf[2];
|
|
Packit |
328d5c |
dest[3] = tf[3];
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
if (++count > RENORMCOUNT) {
|
|
Packit |
328d5c |
count = 0;
|
|
Packit |
328d5c |
normalize_quat(dest);
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Quaternions always obey: a^2 + b^2 + c^2 + d^2 = 1.0
|
|
Packit |
328d5c |
* If they don't add up to 1.0, dividing by their magnitued will
|
|
Packit |
328d5c |
* renormalize them.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* Note: See the following for more information on quaternions:
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
* - Shoemake, K., Animating rotation with quaternion curves, Computer
|
|
Packit |
328d5c |
* Graphics 19, No 3 (Proc. SIGGRAPH'85), 245-254, 1985.
|
|
Packit |
328d5c |
* - Pletinckx, D., Quaternion calculus as a basic tool in computer
|
|
Packit |
328d5c |
* graphics, The Visual Computer 5, 2-13, 1989.
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
static void
|
|
Packit |
328d5c |
normalize_quat(float q[4])
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
int i;
|
|
Packit |
328d5c |
float mag;
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
mag = (q[0]*q[0] + q[1]*q[1] + q[2]*q[2] + q[3]*q[3]);
|
|
Packit |
328d5c |
for (i = 0; i < 4; i++) q[i] /= mag;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
/*
|
|
Packit |
328d5c |
* Build a rotation matrix, given a quaternion rotation.
|
|
Packit |
328d5c |
*
|
|
Packit |
328d5c |
*/
|
|
Packit |
328d5c |
void
|
|
Packit |
328d5c |
build_rotmatrix(float m[4][4], float q[4])
|
|
Packit |
328d5c |
{
|
|
Packit |
328d5c |
m[0][0] = 1.0 - 2.0 * (q[1] * q[1] + q[2] * q[2]);
|
|
Packit |
328d5c |
m[0][1] = 2.0 * (q[0] * q[1] - q[2] * q[3]);
|
|
Packit |
328d5c |
m[0][2] = 2.0 * (q[2] * q[0] + q[1] * q[3]);
|
|
Packit |
328d5c |
m[0][3] = 0.0;
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
m[1][0] = 2.0 * (q[0] * q[1] + q[2] * q[3]);
|
|
Packit |
328d5c |
m[1][1]= 1.0 - 2.0 * (q[2] * q[2] + q[0] * q[0]);
|
|
Packit |
328d5c |
m[1][2] = 2.0 * (q[1] * q[2] - q[0] * q[3]);
|
|
Packit |
328d5c |
m[1][3] = 0.0;
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
m[2][0] = 2.0 * (q[2] * q[0] - q[1] * q[3]);
|
|
Packit |
328d5c |
m[2][1] = 2.0 * (q[1] * q[2] + q[0] * q[3]);
|
|
Packit |
328d5c |
m[2][2] = 1.0 - 2.0 * (q[1] * q[1] + q[0] * q[0]);
|
|
Packit |
328d5c |
m[2][3] = 0.0;
|
|
Packit |
328d5c |
|
|
Packit |
328d5c |
m[3][0] = 0.0;
|
|
Packit |
328d5c |
m[3][1] = 0.0;
|
|
Packit |
328d5c |
m[3][2] = 0.0;
|
|
Packit |
328d5c |
m[3][3] = 1.0;
|
|
Packit |
328d5c |
}
|
|
Packit |
328d5c |
|