text: /******************************************************************************
      Copyright (C) 2013 by Hugh Bailey <obs.jim@gmail.com>
  
      This program is free software: you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation, either version 2 of the License, or
      (at your option) any later version.
  
      This program 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 General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
  ******************************************************************************/
  
  #include <string.h>
  #include "matrix3.h"
  #include "matrix4.h"
  #include "plane.h"
  #include "quat.h"
  
  
  void matrix3_from_quat(struct matrix3 *dst, const struct quat *q)
  {
  	float norm = quat_dot(q, q);
  	float s = (norm > 0.0f) ? (2.0f/norm) : 0.0f;
  
  	float xx = q->x * q->x * s;
  	float yy = q->y * q->y * s;
  	float zz = q->z * q->z * s;
  	float xy = q->x * q->y * s;
  	float xz = q->x * q->z * s;
  	float yz = q->y * q->z * s;
  	float wx = q->w * q->x * s;
  	float wy = q->w * q->y * s;
  	float wz = q->w * q->z * s;
  
  	vec3_set(&dst->x, 1.0f - (yy + zz), xy + wz, xz - wy);
  	vec3_set(&dst->y, xy - wz, 1.0f - (xx + zz), yz + wx);
  	vec3_set(&dst->z, xz + wy, yz - wx, 1.0f - (xx + yy));
  	vec3_zero(&dst->t);
  }
  
  void matrix3_from_axisang(struct matrix3 *dst, const struct axisang *aa)
  {
  	struct quat q;
  	quat_from_axisang(&q, aa);
  	matrix3_from_quat(dst, &q);
  }
  
  void matrix3_from_matrix4(struct matrix3 *dst, const struct matrix4 *m)
  {
  	dst->x.m = m->x.m;
  	dst->y.m = m->y.m;
  	dst->z.m = m->z.m;
  	dst->t.m = m->t.m;
  	dst->x.w = 0.0f;
  	dst->y.w = 0.0f;
  	dst->z.w = 0.0f;
  	dst->t.w = 0.0f;
  }
  
  void matrix3_mul(struct matrix3 *dst, const struct matrix3 *m1,
  		const struct matrix3 *m2)
  {
  	if (dst == m2) {
  		struct matrix3 temp;
  		vec3_rotate(&temp.x, &m1->x, m2);
  		vec3_rotate(&temp.y, &m1->y, m2);
  		vec3_rotate(&temp.z, &m1->z, m2);
  		vec3_transform3x4(&temp.t, &m1->t, m2);
  		matrix3_copy(dst, &temp);
  	} else {
  		vec3_rotate(&dst->x, &m1->x, m2);
  		vec3_rotate(&dst->y, &m1->y, m2);
  		vec3_rotate(&dst->z, &m1->z, m2);
  		vec3_transform3x4(&dst->t, &m1->t, m2);
  	}
  }
  
  void matrix3_rotate(struct matrix3 *dst, const struct matrix3 *m,
  		const struct quat *q)
  {
  	struct matrix3 temp;
  	matrix3_from_quat(&temp, q);
  	matrix3_mul(dst, m, &temp);
  }
  
  void matrix3_rotate_aa(struct matrix3 *dst, const struct matrix3 *m,
  		const struct axisang *aa)
  {
  	struct matrix3 temp;
  	matrix3_from_axisang(&temp, aa);
  	matrix3_mul(dst, m, &temp);
  }
  
  void matrix3_scale(struct matrix3 *dst, const struct matrix3 *m,
  		const struct vec3 *v)
  {
  	vec3_mul(&dst->x, &m->x, v);
  	vec3_mul(&dst->y, &m->y, v);
  	vec3_mul(&dst->z, &m->z, v);
  	vec3_mul(&dst->t, &m->t, v);
  }
  
  void matrix3_transpose(struct matrix3 *dst, const struct matrix3 *m)
  {
  	__m128 tmp1, tmp2;
  	vec3_rotate(&dst->t, &m->t, m);
  	vec3_neg(&dst->t, &dst->t);
  
  	tmp1 = _mm_movelh_ps(m->x.m, m->y.m);
  	tmp2 = _mm_movehl_ps(m->y.m, m->x.m);
  	dst->x.m = _mm_shuffle_ps(tmp1, m->z.m, _MM_SHUFFLE(3, 0, 2, 0));
  	dst->y.m = _mm_shuffle_ps(tmp1, m->z.m, _MM_SHUFFLE(3, 1, 3, 1));
  	dst->z.m = _mm_shuffle_ps(tmp2, m->z.m, _MM_SHUFFLE(3, 2, 2, 0));
  }
  
  void matrix3_inv(struct matrix3 *dst, const struct matrix3 *m)
  {
  	struct matrix4 m4;
  	matrix4_from_matrix3(&m4, m);
  	matrix4_inv((struct matrix4*)dst, &m4);
  	dst->t.w = 0.0f;
  }
  
  void matrix3_mirror(struct matrix3 *dst, const struct matrix3 *m,
  	const struct plane *p)
  {
  	vec3_mirrorv(&dst->x, &m->x, &p->dir);
  	vec3_mirrorv(&dst->y, &m->y, &p->dir);
  	vec3_mirrorv(&dst->z, &m->z, &p->dir);
  	vec3_mirror(&dst->t, &m->t, p);
  }
  
  void matrix3_mirrorv(struct matrix3 *dst, const struct matrix3 *m,
         const struct vec3 *v)
  {
  	vec3_mirrorv(&dst->x, &m->x, v);
  	vec3_mirrorv(&dst->y, &m->y, v);
  	vec3_mirrorv(&dst->z, &m->z, v);
  	vec3_mirrorv(&dst->t, &m->t, v);
  }
  