lily/include/stencil.hh

   1 /*
   2   stencil.hh -- declare Stencil
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8 #ifndef STENCIL_HH
   9 #define STENCIL_HH
  10
  11 #include <cstdlib>              // size_t
  12
  13 #include "lily-proto.hh"
  14 #include "box.hh"
  15 #include "smobs.hh"
  16
  17 /** a group of individually translated symbols. You can add stencils
  18     to the top, to the right, etc.
  19
  20     It is implemented as a "tree" of scheme expressions, as in
  21
  22     Expr = combine Expr-list
  23     | translate Offset Expr
  24     | origin (ORIGIN) Expr
  25     | no-origin Expr
  26     | (SCHEME)
  27     ;
  28
  29     SCHEME is a Scheme expression that --when eval'd-- produces the
  30     desired output.
  31
  32     Notes:
  33
  34     * Because of the way that Stencil is implemented, it is the most
  35     efficient to add "fresh" stencils to what you're going to build.
  36
  37     * Do not create Stencil objects on the heap. That includes passing
  38     around Stencil* which are produced by unsmob_stencil(). Either
  39     copy Stencil objects, or use SCM references.
  40
  41     * Empty stencils have empty dimensions.  If add_at_edge is used to
  42     init the stencil, we assume that
  43
  44     DIMENSIONS = (Interval (0, 0), Interval (0, 0)
  45 */
  46 class Stencil
  47 {
  48   friend SCM ly_stencil_set_extent_x (SCM, SCM, SCM);
  49
  50   /*
  51     This provides the reference point of the symbol, for example with
  52     characters, it is on the base line of the character. Usually,
  53     ORIGIN is inside DIM_
  54   */
  55   Offset origin_;
  56   Box dim_;
  57   SCM expr_;
  58
  59   DECLARE_SIMPLE_SMOBS (Stencil,);
  60 public:
  61   Stencil (Box, SCM s);
  62   Stencil ();
  63
  64   Offset origin () const;
  65   SCM expr () const;
  66
  67   /**
  68      Set dimensions to empty, or to (Interval (0, 0), Interval (0, 0) */
  69   void set_empty (bool);
  70   Stencil moved_to_edge (Axis a, Direction d, const Stencil &m, Real padding,
  71                          Real minimum) const;
  72
  73   void add_at_edge (Axis a, Direction d, const Stencil &m, Real padding,
  74                     Real minimum);
  75   void add_stencil (Stencil const &m);
  76   void translate (Offset);
  77   void align_to (Axis a, Real x);
  78   void translate_axis (Real, Axis);
  79
  80   Interval extent (Axis) const;
  81   Box extent_box () const;
  82   bool is_empty () const;
  83   Stencil in_color (Real r, Real g, Real b) const;
  84
  85   static SCM ly_get_stencil_extent (SCM mol, SCM axis);
  86   static SCM ly_set_stencil_extent_x (SCM, SCM, SCM);
  87   static SCM ly_stencil_combined_at_edge (SCM, SCM, SCM, SCM, SCM);
  88 };
  89
  90 DECLARE_UNSMOB (Stencil, stencil);
  91
  92 void interpret_stencil_expression (SCM expr,
  93                                    void (*func) (void *, SCM),
  94                                    void *func_arg,
  95                                    Offset o);
  96 SCM find_expression_fonts (SCM expr);
  97
  98 void register_stencil_head (SCM symbol);
  99 bool is_stencil_head (SCM symbol);
 100 SCM all_stencil_heads ();
 101
 102 #endif /* STENCIL_HH */