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;
}