/**
* graphene_triangle_get_midpoint:
* @t: a #graphene_triangle_t
* @res: (out caller-allocates): return location for the coordinates of
* the midpoint
*
* Computes the coordinates of the midpoint of the given #graphene_triangle_t.
*
* Since: 1.2
*/
void
graphene_triangle_get_midpoint (const graphene_triangle_t *t,
graphene_point3d_t *res)
{
graphene_vec3_t tmp;
graphene_vec3_add (&t->a, &t->b, &tmp);
graphene_vec3_add (&tmp, &t->c, &tmp);
graphene_vec3_scale (&tmp, (1.f / 3.f), &tmp);
graphene_point3d_init_from_vec3 (res, &tmp);
}
/**
* graphene_ray_get_distance_to_point:
* @r: a #graphene_ray_t
* @p: a #graphene_point3d_t
*
* Computes the distance from the origin of the given ray to the given point.
*
* Returns: the distance of the point
*
* Since: 1.4
*/
float
graphene_ray_get_distance_to_point (const graphene_ray_t *r,
const graphene_point3d_t *p)
{
graphene_vec3_t point;
graphene_vec3_t tmp;
float distance;
graphene_point3d_to_vec3 (p, &point);
graphene_vec3_subtract (&point, &r->origin, &tmp);
distance = graphene_vec3_dot (&tmp, &r->direction);
/* the point is behind the ray */
if (distance < 0)
{
graphene_vec3_subtract (&r->origin, &point, &tmp);
return graphene_vec3_length (&tmp);
}
/* get the position on the ray at the given distance */
graphene_vec3_scale (&r->direction, distance, &tmp);
graphene_vec3_add (&tmp, &r->origin, &tmp);
graphene_vec3_subtract (&tmp, &point, &tmp);
return graphene_vec3_length (&tmp);
}
/**
* graphene_ray_get_position_at:
* @r: a #graphene_ray_t
* @t: the distance along the ray
* @position: (out caller-allocates): return location for the position
*
* Retrieves the coordinates of a point at the distance @t along the
* given #graphene_ray_t.
*
* Since: 1.4
*/
void
graphene_ray_get_position_at (const graphene_ray_t *r,
float t,
graphene_point3d_t *position)
{
graphene_vec3_t res;
graphene_vec3_scale (&r->direction, t, &res);
graphene_vec3_add (&res, &r->origin, &res);
graphene_point3d_init_from_vec3 (position, &res);
}
/**
* graphene_ray_get_closest_point_to_point:
* @r: a #graphene_ray_t
* @p: a #graphene_point3d_t
* @res: (out caller-allocates): return location for the closest point3d
*
* Computes the point on the given #graphene_ray_t that is closest to the
* given point @p.
*
* Since: 1.4
*/
void
graphene_ray_get_closest_point_to_point (const graphene_ray_t *r,
const graphene_point3d_t *p,
graphene_point3d_t *res)
{
graphene_vec3_t point, result;
float distance;
graphene_point3d_to_vec3 (p, &point);
graphene_vec3_subtract (&point, &r->origin, &result);
distance = graphene_vec3_dot (&result, &r->direction);
if (distance < 0)
graphene_vec3_init_from_vec3 (&result, &r->origin);
else
{
graphene_vec3_scale (&r->direction, distance, &result);
graphene_vec3_add (&result, &r->origin, &result);
}
graphene_point3d_init_from_vec3 (res, &result);
}
