/**
* graphene_quaternion_init_from_angles:
* @q: a #graphene_quaternion_t
* @deg_x: rotation angle on the X axis (yaw), in degrees
* @deg_y: rotation angle on the Y axis (pitch), in degrees
* @deg_z: rotation angle on the Z axis (roll), in degrees
*
* Initializes a #graphene_quaternion_t using the values of
* the [Euler angles](http://en.wikipedia.org/wiki/Euler_angles)
* on each axis.
*
* Returns: (transfer none): the initialized quaternion
*
* Since: 1.0
*/
graphene_quaternion_t *
graphene_quaternion_init_from_angles (graphene_quaternion_t *q,
float deg_x,
float deg_y,
float deg_z)
{
float rad_x, rad_y, rad_z;
float sin_x, sin_y, sin_z;
float cos_x, cos_y, cos_z;
rad_x = GRAPHENE_DEG_TO_RAD (deg_x);
rad_y = GRAPHENE_DEG_TO_RAD (deg_y);
rad_z = GRAPHENE_DEG_TO_RAD (deg_z);
sin_x = sinf (rad_x * .5f);
sin_y = sinf (rad_y * .5f);
sin_z = sinf (rad_z * .5f);
cos_x = cosf (rad_x * .5f);
cos_y = cosf (rad_y * .5f);
cos_z = cosf (rad_z * .5f);
q->x = sin_x * cos_y * cos_z + cos_x * sin_y * sin_z;
q->y = cos_x * sin_y * cos_z - sin_x * cos_y * sin_z;
q->z = cos_x * cos_y * sin_z + sin_x * sin_y * cos_z;
q->w = cos_x * cos_y * cos_z - sin_x * sin_y * sin_z;
return q;
}
/**
* graphene_euler_init:
* @e: the #graphene_euler_t to initialize
* @x: rotation angle on the X axis, in degrees
* @y: rotation angle on the Y axis, in degrees
* @z: rotation angle on the Z axis, in degrees
*
* Initializes a #graphene_euler_t using the given angles.
*
* The order of the rotations is %GRAPHENE_EULER_ORDER_DEFAULT.
*
* Returns: (transfer none): the initialized #graphene_euler_t
*
* Since: 1.2
*/
graphene_euler_t *
graphene_euler_init (graphene_euler_t *e,
float x,
float y,
float z)
{
return graphene_euler_init_internal (e,
GRAPHENE_DEG_TO_RAD (x),
GRAPHENE_DEG_TO_RAD (y),
GRAPHENE_DEG_TO_RAD (z),
GRAPHENE_EULER_ORDER_DEFAULT);
}
/**
* graphene_euler_init_with_order:
* @e: the #graphene_euler_t to initialize
* @x: rotation angle on the X axis, in degrees
* @y: rotation angle on the Y axis, in degrees
* @z: rotation angle on the Z axis, in degrees
* @order: the order used to apply the rotations
*
* Initializes a #graphene_euler_t with the given angles and @order.
*
* Returns: (transfer none): the initialized #graphene_euler_t
*
* Since: 1.2
*/
graphene_euler_t *
graphene_euler_init_with_order (graphene_euler_t *e,
float x,
float y,
float z,
graphene_euler_order_t order)
{
return graphene_euler_init_internal (e,
GRAPHENE_DEG_TO_RAD (x),
GRAPHENE_DEG_TO_RAD (y),
GRAPHENE_DEG_TO_RAD (z),
order);
}
/**
* graphene_quaternion_init_from_angle_vec3:
* @q: a #graphene_quaternion_t
* @angle: the rotation on a given axis, in degrees
* @axis: the axis of rotation, expressed as a vector
*
* Initializes a #graphene_quaternion_t using an @angle on a
* specific @axis.
*
* Returns: (transfer none): the initialized quaternion
*
* Since: 1.0
*/
graphene_quaternion_t *
graphene_quaternion_init_from_angle_vec3 (graphene_quaternion_t *q,
float angle,
const graphene_vec3_t *axis)
{
float rad, sin_a, cos_a;
graphene_simd4f_t axis_n;
rad = GRAPHENE_DEG_TO_RAD (angle);
sin_a = sinf (rad / 2.f);
cos_a = cosf (rad / 2.f);
axis_n = graphene_simd4f_mul (graphene_simd4f_normalize3 (axis->value),
graphene_simd4f_splat (sin_a));
q->x = graphene_simd4f_get_x (axis_n);
q->y = graphene_simd4f_get_y (axis_n);
q->z = graphene_simd4f_get_z (axis_n);
q->w = cos_a;
return q;
}
