altos: Rename 'core' to 'kernel'

core remains a bad name to use -- dirvish skips files (and
directories, it seems) with that name.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 0 insertions, 249 deletions

diff --git a/src/core/ao_quaternion.h b/src/core/ao_quaternion.h
deleted file mode 100644
index 044f1607..00000000
--- a/src/core/ao_quaternion.h
+++ /dev/null
@@ -1,249 +0,0 @@
-/*
- * Copyright © 2013 Keith Packard <keithp@keithp.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; version 2 of the License.
- *
- * 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, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- */
-
-#ifndef _AO_QUATERNION_H_
-#define _AO_QUATERNION_H_
-
-#include <math.h>
-
-struct ao_quaternion {
-	float	r;		/* real bit */
-	float	x, y, z;	/* imaginary bits */
-};
-
-static inline void ao_quaternion_multiply(struct ao_quaternion *r,
-					  const struct ao_quaternion *a,
-					  const struct ao_quaternion *b)
-{
-	struct ao_quaternion	t;
-#define T(_a,_b)	(((a)->_a) * ((b)->_b))
-
-/*
- * Quaternions
- *
- *	ii = jj = kk = ijk = -1;
- *
- *	kji = 1;
- *
- * 	ij = k;		ji = -k;
- *	kj = -i;	jk = i;
- *	ik = -j;	ki = j;
- *
- * Multiplication p * q:
- *
- *	(pr + ipx + jpy + kpz) (qr + iqx + jqy + kqz) =
- *
- *		( pr * qr +  pr * iqx +  pr * jqy +  pr * kqz) +
- *		(ipx * qr + ipx * iqx + ipx * jqy + ipx * kqz) +
- *		(jpy * qr + jpy * iqx + jpy * jqy + jpy * kqz) +
- *		(kpz * qr + kpz * iqx + kpz * jqy + kpz * kqz) =
- *
- *
- *		 (pr * qr) + i(pr * qx) + j(pr * qy) + k(pr * qz) +
- *		i(px * qr) -  (px * qx) + k(px * qy) - j(px * qz) +
- *		j(py * qr) - k(py * qx) -  (py * qy) + i(py * qz) +
- *		k(pz * qr) + j(pz * qx) - i(pz * qy) -  (pz * qz) =
- *
- *		1 * ( (pr * qr) - (px * qx) - (py * qy) - (pz * qz) ) +
- *		i * ( (pr * qx) + (px * qr) + (py * qz) - (pz * qy) ) +
- *		j * ( (pr * qy) - (px * qz) + (py * qr) + (pz * qx) ) +
- *		k * ( (pr * qz) + (px * qy) - (py * qx) + (pz * qr);
- */
-
-	t.r = T(r,r) - T(x,x) - T(y,y) - T(z,z);
-	t.x = T(r,x) + T(x,r) + T(y,z) - T(z,y);
-	t.y = T(r,y) - T(x,z) + T(y,r) + T(z,x);
-	t.z = T(r,z) + T(x,y) - T(y,x) + T(z,r);
-#undef T
-	*r = t;
-}
-
-static inline void ao_quaternion_conjugate(struct ao_quaternion *r,
-					   const struct ao_quaternion *a)
-{
-	r->r = a->r;
-	r->x = -a->x;
-	r->y = -a->y;
-	r->z = -a->z;
-}
-
-static inline float ao_quaternion_normal(const struct ao_quaternion *a)
-{
-#define S(_a)	(((a)->_a) * ((a)->_a))
-	return S(r) + S(x) + S(y) + S(z);
-#undef S
-}
-
-static inline void ao_quaternion_scale(struct ao_quaternion *r,
-				       const struct ao_quaternion *a,
-				       float b)
-{
-	r->r = a->r * b;
-	r->x = a->x * b;
-	r->y = a->y * b;
-	r->z = a->z * b;
-}
-
-static inline void ao_quaternion_normalize(struct ao_quaternion *r,
-					   const struct ao_quaternion *a)
-{
-	float	n = ao_quaternion_normal(a);
-
-	if (n > 0)
-		ao_quaternion_scale(r, a, 1/sqrtf(n));
-	else
-		*r = *a;
-}
-
-static inline float ao_quaternion_dot(const struct ao_quaternion *a,
-				      const struct ao_quaternion *b)
-{
-#define T(_a)	(((a)->_a) * ((b)->_a))
-	return T(r) + T(x) + T(y) + T(z);
-#undef T
-}
-				     
-
-static inline void ao_quaternion_rotate(struct ao_quaternion *r,
-					const struct ao_quaternion *a,
-					const struct ao_quaternion *b)
-{
-	struct ao_quaternion	c;
-	struct ao_quaternion	t;
-
-	ao_quaternion_multiply(&t, b, a);
-	ao_quaternion_conjugate(&c, b);
-	ao_quaternion_multiply(r, &t, &c);
-}
-
-/*
- * Compute a rotation quaternion between two vectors
- *
- *	cos(θ) + u * sin(θ)
- *
- * where θ is the angle between the two vectors and u
- * is a unit vector axis of rotation
- */
-
-static inline void ao_quaternion_vectors_to_rotation(struct ao_quaternion *r,
-						     const struct ao_quaternion *a,
-						     const struct ao_quaternion *b)
-{
-	/*
-	 * The cross product will point orthogonally to the two
-	 * vectors, forming our rotation axis. The length will be
-	 * sin(θ), so these values are already multiplied by that.
-	 */
-
-	float x = a->y * b->z - a->z * b->y;
-	float y = a->z * b->x - a->x * b->z;
-	float z = a->x * b->y - a->y * b->x;
-
-	float s_2 = x*x + y*y + z*z;
-	float s = sqrtf(s_2);
-
-	/* cos(θ) = a · b / (|a| |b|).
-	 *
-	 * a and b are both unit vectors, so the divisor is one
-	 */
-	float c = a->x*b->x + a->y*b->y + a->z*b->z;
-
-	float c_half = sqrtf ((1 + c) / 2);
-	float s_half = sqrtf ((1 - c) / 2);
-
-	/*
-	 * Divide out the sine factor from the
-	 * cross product, then multiply in the
-	 * half sine factor needed for the quaternion
-	 */
-	float s_scale = s_half / s;
-
-	r->x = x * s_scale;
-	r->y = y * s_scale;
-	r->z = z * s_scale;
-
-	r->r = c_half;
-
-	ao_quaternion_normalize(r, r);
-}
-
-static inline void ao_quaternion_init_vector(struct ao_quaternion *r,
-					     float x, float y, float z)
-{
-	r->r = 0;
-	r->x = x;
-	r->y = y;
-	r->z = z;
-}
-
-static inline void ao_quaternion_init_rotation(struct ao_quaternion *r,
-					       float x, float y, float z,
-					       float s, float c)
-{
-	r->r = c;
-	r->x = s * x;
-	r->y = s * y;
-	r->z = s * z;
-}
-
-static inline void ao_quaternion_init_zero_rotation(struct ao_quaternion *r)
-{
-	r->r = 1;
-	r->x = r->y = r->z = 0;
-}
-
-/*
- * The sincosf from newlib just calls sinf and cosf. This is a bit
- * faster, if slightly less precise
- */
-
-static inline void
-ao_sincosf(float a, float *s, float *c) {
-	float	_s = sinf(a);
-	*s = _s;
-	*c = sqrtf(1 - _s*_s);
-}
-
-/*
- * Initialize a quaternion from 1/2 euler rotation angles (in radians).
- *
- * Yes, it would be nicer if there were a faster way, but because we
- * sample the gyros at only 100Hz, we end up getting angles too large
- * to take advantage of sin(x) ≃ x.
- *
- * We might be able to use just a couple of elements of the sin taylor
- * series though, instead of the whole sin function?
- */
-
-static inline void ao_quaternion_init_half_euler(struct ao_quaternion *r,
-						 float x, float y, float z)
-{
-	float	s_x, c_x;
-	float	s_y, c_y;
-	float	s_z, c_z;
-
-	ao_sincosf(x, &s_x, &c_x);
-	ao_sincosf(y, &s_y, &c_y);
-	ao_sincosf(z, &s_z, &c_z);
-
-	r->r = c_x * c_y * c_z + s_x * s_y * s_z;
-	r->x = s_x * c_y * c_z - c_x * s_y * s_z;
-	r->y = c_x * s_y * c_z + s_x * c_y * s_z;
-	r->z = c_x * c_y * s_z - s_x * s_y * c_z;
-}
-
-#endif /* _AO_QUATERNION_H_ */