/**
* graphene_matrix_project_point:
* @m: ...
* @p: ...
* @res: (out caller-allocates): ...
*
* ...
*
* Since: 1.0
*/
void
graphene_matrix_project_point (const graphene_matrix_t *m,
const graphene_point_t *p,
graphene_point_t *res)
{
graphene_vec3_t pa, qa;
graphene_vec3_t pback, qback, uback;
float p_z, u_z, t;
g_return_if_fail (m != NULL);
g_return_if_fail (p != NULL);
g_return_if_fail (res != NULL);
graphene_vec3_init (&pa, p->x, p->y, 0.0f);
graphene_vec3_init (&qa, p->x, p->y, 1.0f);
graphene_matrix_transform_vec3 (m, &pa, &pback);
graphene_matrix_transform_vec3 (m, &qa, &qback);
graphene_vec3_subtract (&qback, &pback, &uback);
p_z = graphene_vec3_get_z (&pback);
u_z = graphene_vec3_get_z (&uback);
t = -p_z / u_z;
graphene_point_init (res,
graphene_vec3_get_x (&pback) + t * graphene_vec3_get_x (&uback),
graphene_vec3_get_y (&pback) + t * graphene_vec3_get_y (&uback));
}
/**
* graphene_rect_get_bottom_left:
* @r: a #graphene_rect_t
* @p: (out caller-allocates): return location for a #graphene_point_t
*
* Retrieves the coordinates of the bottom-left corner of the given rectangle.
*
* Since: 1.0
*/
void
graphene_rect_get_bottom_left (const graphene_rect_t *r,
graphene_point_t *p)
{
graphene_rect_t rr;
rr = *r;
graphene_rect_normalize_in_place (&rr);
graphene_point_init (p, rr.origin.x, rr.origin.y + rr.size.height);
}
/**
* graphene_rect_get_top_right:
* @r: a #graphene_rect_t
* @p: (out caller-allocates): return location for a #graphene_point_t
*
* Retrieves the coordinates of the top-right corner of the given rectangle.
*
* Since: 1.0
*/
void
graphene_rect_get_top_right (const graphene_rect_t *r,
graphene_point_t *p)
{
graphene_rect_t rr;
rr = *r;
graphene_rect_normalize_in_place (&rr);
graphene_point_init (p, rr.origin.x + rr.size.width, rr.origin.y);
}
/**
* graphene_rect_get_center:
* @r: a #graphene_rect_t
* @p: (out caller-allocates): return location for a #graphene_point_t
*
* Retrieves the coordinates of the center of the given rectangle.
*
* Since: 1.0
*/
void
graphene_rect_get_center (const graphene_rect_t *r,
graphene_point_t *p)
{
graphene_rect_t rr;
rr = *r;
graphene_rect_normalize_in_place (&rr);
graphene_point_init (p,
rr.origin.x + (rr.size.width / 2.f),
rr.origin.y + (rr.size.height / 2.f));
}
/**
* graphene_rect_init:
* @r: a #graphene_rect_t
* @x: the X coordinate of the @graphene_rect_t.origin
* @y: the Y coordinate of the @graphene_rect_t.origin
* @width: the width of the @graphene_rect_t.size
* @height: the height of the @graphene_rect_t.size
*
* Initializes the given #graphene_rect_t with the given values.
*
* This function will implicitly normalize the #graphene_rect_t
* before returning.
*
* Returns: (transfer none): the initialized rectangle
*
* Since: 1.0
*/
graphene_rect_t *
graphene_rect_init (graphene_rect_t *r,
float x,
float y,
float width,
float height)
{
graphene_point_init (&r->origin, x, y);
graphene_size_init (&r->size, width, height);
graphene_rect_normalize_in_place (r);
return r;
}
