/*
  stencil.hh -- declare Stencil

  source file of the GNU LilyPond music typesetter

  (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
*/
#ifndef STENCIL_HH
#define STENCIL_HH

#include <cstdlib>		// size_t
using namespace std;

#include "lily-proto.hh"
#include "box.hh"
#include "smobs.hh"

/** a group of individually translated symbols. You can add stencils
    to the top, to the right, etc.

    It is implemented as a "tree" of scheme expressions, as in

    Expr = combine Expr-list
    | translate Offset Expr
    | origin (ORIGIN) Expr
    | no-origin Expr
    | (SCHEME)
    ;

    SCHEME is a Scheme expression that --when eval'd-- produces the
    desired output.

    Notes:

    * Because of the way that Stencil is implemented, it is the most
    efficient to add "fresh" stencils to what you're going to build.

    * Do not create Stencil objects on the heap. That includes passing
    around Stencil* which are produced by unsmob_stencil(). Either
    copy Stencil objects, or use SCM references.

    * Empty stencils have empty dimensions.  If add_at_edge is used to
    init the stencil, we assume that

    DIMENSIONS = (Interval (0, 0), Interval (0, 0)
*/
class Stencil
{
  Box dim_;
  SCM expr_;

  DECLARE_SIMPLE_SMOBS (Stencil);
public:
  Stencil (Box, SCM s);
  Stencil ();

  SCM expr () const;

  /**
     Set dimensions to empty, or to (Interval (0, 0), Interval (0, 0) */
  void set_empty (bool);
  void add_at_edge (Axis a, Direction d, const Stencil &m, Real padding);
  void add_stencil (Stencil const &m);
  void translate (Offset);
  Stencil translated (Offset) const;
  void rotate (Real, Offset);
  void rotate_degrees (Real, Offset);
  void align_to (Axis a, Real x);
  void translate_axis (Real, Axis);

  Interval extent (Axis) const;
  Box extent_box () const;
  bool is_empty () const;
  Stencil in_color (Real r, Real g, Real b) const;
};

DECLARE_UNSMOB (Stencil, stencil);

void interpret_stencil_expression (SCM expr,
				   void (*func) (void *, SCM),
				   void *func_arg,
				   Offset o);
SCM find_expression_fonts (SCM expr);

void register_stencil_head (SCM symbol);
bool is_stencil_head (SCM symbol);
SCM all_stencil_heads ();


#endif /* STENCIL_HH */
