void
graphene_matrix_project_rect_bounds (const graphene_matrix_t *m,
const graphene_rect_t *r,
graphene_rect_t *res)
{
graphene_point_t points[4];
graphene_point_t ret[4];
float min_x, min_y;
float max_x, max_y;
int i;
graphene_rect_get_top_left (r, &points[0]);
graphene_rect_get_top_right (r, &points[1]);
graphene_rect_get_bottom_left (r, &points[2]);
graphene_rect_get_bottom_right (r, &points[3]);
graphene_matrix_project_point (m, &points[0], &ret[0]);
graphene_matrix_project_point (m, &points[1], &ret[1]);
graphene_matrix_project_point (m, &points[2], &ret[2]);
graphene_matrix_project_point (m, &points[3], &ret[3]);
min_x = max_x = ret[0].x;
min_y = max_y = ret[0].y;
for (i = 1; i < 4; i++)
{
min_x = MIN (ret[i].x, min_x);
min_y = MIN (ret[i].y, min_y);
max_x = MAX (ret[i].x, max_x);
max_y = MAX (ret[i].y, max_y);
}
graphene_rect_init (res, min_x, min_y, max_x - min_x, max_y - min_y);
}
gboolean
graphene_matrix_untransform_point (const graphene_matrix_t *m,
const graphene_point_t *p,
const graphene_rect_t *bounds,
graphene_point_t *res)
{
graphene_matrix_t inverse;
graphene_rect_t bounds_t;
g_return_val_if_fail (m != NULL, FALSE);
g_return_val_if_fail (p != NULL, FALSE);
g_return_val_if_fail (bounds != NULL, FALSE);
g_return_val_if_fail (res != NULL, FALSE);
if (graphene_matrix_is_2d (m))
{
graphene_matrix_inverse (m, &inverse);
graphene_matrix_transform_point (&inverse, p, res);
return TRUE;
}
graphene_matrix_transform_bounds (m, bounds, &bounds_t);
if (!graphene_rect_contains_point (&bounds_t, p))
return FALSE;
graphene_matrix_inverse (m, &inverse);
graphene_matrix_project_point (&inverse, p, res);
return TRUE;
}
/**
* graphene_matrix_untransform_point:
* @m: a #graphene_matrix_t
* @p: a #graphene_point_t
* @bounds: the bounds of the transformation
* @res: (out caller-allocates): return location for the
* untransformed point
*
* Undoes the transformation of a #graphene_point_t using the
* given matrix, within the given rectangular @bounds.
*
* Returns: %true if the point was successfully untransformed
*
* Since: 1.0
*/
bool
graphene_matrix_untransform_point (const graphene_matrix_t *m,
const graphene_point_t *p,
const graphene_rect_t *bounds,
graphene_point_t *res)
{
graphene_matrix_t inverse;
graphene_rect_t bounds_t;
if (graphene_matrix_is_2d (m))
{
graphene_matrix_inverse (m, &inverse);
graphene_matrix_transform_point (&inverse, p, res);
return true;
}
graphene_matrix_transform_bounds (m, bounds, &bounds_t);
if (!graphene_rect_contains_point (&bounds_t, p))
return false;
graphene_matrix_inverse (m, &inverse);
graphene_matrix_project_point (&inverse, p, res);
return true;
}
