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/* $Id:$ */
/*
libg3d - 3D object loading library
Copyright (C) 2005-2009 Markus Dahms <mad@automagically.de>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* some parts based on "trackball.c"
*
* (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.
*/
#include <math.h>
#include <g3d/types.h>
#include <g3d/vector.h>
#include <g3d/matrix.h>
EAPI
gboolean g3d_quat_rotate(G3DQuat *q, G3DVector *axis, G3DFloat angle)
{
gint32 i;
g3d_vector_unify(axis + 0, axis + 1, axis + 2);
for(i = 0; i < 3; i ++)
q[i] = axis[i] * sin(angle / 2.0);
q[3] = cos(angle / 2.0);
return TRUE;
}
EAPI
gboolean g3d_quat_normalize(G3DQuat *q)
{
gint32 i;
G3DDouble div = 0;
for(i = 0; i < 4; i ++)
div += (q[i] * q[i]);
for(i = 0; i < 4; i ++)
q[i] /= div;
return TRUE;
}
EAPI
gboolean g3d_quat_add(G3DQuat *qr, G3DQuat *q1, G3DQuat *q2)
{
gint32 i;
G3DQuat tr[4], t1[4], t2[4], t3[4];
for(i = 0; i < 3; i ++)
t1[i] = q1[i] * q2[3];
for(i = 0; i < 3; i ++)
t2[i] = q2[i] * q1[3];
g3d_vector_normal(q2[0], q2[1], q2[2], q1[0], q1[1], q1[2],
t3, t3 + 1, t3 + 2);
for(i = 0; i < 3; i ++)
tr[i] = t1[i] + t2[i] + t3[i];
tr[3] = q1[3] * q2[3] -
(q1[0] * q2[0] + q1[1] * q2[1] + q1[2] * q2[2]);
for(i = 0; i < 4; i ++)
qr[i] = tr[i];
return TRUE;
}
static inline G3DVector trackball_projection(G3DVector x, G3DVector y,
G3DFloat r)
{
G3DDouble d, t;
d = sqrt(x * x + y * y);
if(d < (r * 0.70710678118654752440))
return sqrt(r * r - d * d);
t = r / 1.41421356237309504880;
return t * t / d;
}
EAPI
gboolean g3d_quat_trackball(G3DQuat *q, G3DFloat x1, G3DFloat y1,
G3DFloat x2, G3DFloat y2, G3DFloat r)
{
G3DVector axis[3], z1, z2, dx, dy, dz;
G3DDouble angle, t;
if((x1 == x2) && (y1 == y2)) {
q[0] = q[1] = q[2] = 0.0;
q[3] = 1.0;
return TRUE;
}
z1 = trackball_projection(x1, y1, r);
z2 = trackball_projection(x2, y2, r);
g3d_vector_normal(x2, y2, z2, x1, y1, z1, axis, axis + 1, axis + 2);
dx = x1 - x2;
dy = y1 - y2;
dz = z1 - z2;
t = sqrt(dx * dx + dy * dy + dz * dz) / (2.0 * r);
t = CLAMP(t, -1.0, 1.0);
angle = 2.0 * asin(t);
return g3d_quat_rotate(q, axis, angle);
}
EAPI
gboolean g3d_quat_to_matrix(G3DQuat *q, G3DMatrix *matrix)
{
g3d_matrix_identity(matrix);
matrix[0 * 4 + 0] = 1.0 - 2.0 * (q[1] * q[1] + q[2] * q[2]);
matrix[0 * 4 + 1] = 2.0 * (q[0] * q[1] - q[2] * q[3]);
matrix[0 * 4 + 2] = 2.0 * (q[2] * q[0] + q[1] * q[3]);
matrix[1 * 4 + 0] = 2.0 * (q[0] * q[1] + q[2] * q[3]);
matrix[1 * 4 + 1] = 1.0 - 2.0 * (q[2] * q[2] + q[0] * q[0]);
matrix[1 * 4 + 2] = 2.0 * (q[1] * q[2] - q[0] * q[3]);
matrix[2 * 4 + 0] = 2.0 * (q[2] * q[0] - q[1] * q[3]);
matrix[2 * 4 + 1] = 2.0 * (q[1] * q[2] + q[0] * q[3]);
matrix[2 * 4 + 2] = 1.0 - 2.0 * (q[1] * q[1] + q[0] * q[0]);
return TRUE;
}
EAPI
gboolean g3d_quat_to_rotation_xyz(G3DQuat *q, G3DFloat *rx, G3DFloat *ry,
G3DFloat *rz)
{
G3DFloat t;
/* rx */
t = 1 - 2 * (q[1] * q[1] + q[2] * q[2]);
if(t != 0)
*rx = atan(2 * (q[0] * q[1] + q[2] * q[3]) / t);
else
*rx = 0.0;
/* ry */
*ry = asin(2 * (q[0] * q[2] - q[1] * q[3]));
/* rz */
t = 1 - 2 * (q[2] * q[2] + q[3] * q[3]);
if(t != 0)
*rz = atan(2 * (q[0] * q[3] + q[1] * q[2]) / t);
else
*rz = 0.0;
return TRUE;
}
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