lily/include/stencil.hh

   1 /*
   2   stencil.hh -- declare Stencil
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8 #ifndef STENCIL_HH
   9 #define STENCIL_HH
  10
  11 #include <cstdlib>              // size_t
  12 using namespace std;
  13
  14 #include "lily-proto.hh"
  15 #include "box.hh"
  16 #include "smobs.hh"
  17
  18 /** a group of individually translated symbols. You can add stencils
  19     to the top, to the right, etc.
  20
  21     It is implemented as a "tree" of scheme expressions, as in
  22
  23     Expr = combine Expr-list
  24     | translate Offset Expr
  25     | origin (ORIGIN) Expr
  26     | no-origin Expr
  27     | (SCHEME)
  28     ;
  29
  30     SCHEME is a Scheme expression that --when eval'd-- produces the
  31     desired output.
  32
  33     Notes:
  34
  35     * Because of the way that Stencil is implemented, it is the most
  36     efficient to add "fresh" stencils to what you're going to build.
  37
  38     * Do not create Stencil objects on the heap. That includes passing
  39     around Stencil* which are produced by unsmob_stencil(). Either
  40     copy Stencil objects, or use SCM references.
  41
  42     * Empty stencils have empty dimensions.  If add_at_edge is used to
  43     init the stencil, we assume that
  44
  45     DIMENSIONS = (Interval (0, 0), Interval (0, 0)
  46 */
  47 class Stencil
  48 {
  49   Box dim_;
  50   SCM expr_;
  51
  52   DECLARE_SIMPLE_SMOBS (Stencil);
  53 public:
  54   Stencil (Box, SCM s);
  55   Stencil ();
  56
  57   SCM expr () const;
  58
  59   /**
  60      Set dimensions to empty, or to (Interval (0, 0), Interval (0, 0) */
  61   void set_empty (bool);
  62   void add_at_edge (Axis a, Direction d, const Stencil &m, Real padding);
  63   void add_stencil (Stencil const &m);
  64   void translate (Offset);
  65   Stencil translated (Offset) const;
  66   void rotate (Real, Offset);
  67   void rotate_degrees (Real, Offset);
  68   void rotate_degrees_absolute (Real, Offset);
  69   void align_to (Axis a, Real x);
  70   void translate_axis (Real, Axis);
  71
  72   Interval extent (Axis) const;
  73   Box extent_box () const;
  74   bool is_empty () const;
  75   Stencil in_color (Real r, Real g, Real b) const;
  76 };
  77
  78 DECLARE_UNSMOB (Stencil, stencil);
  79
  80 void interpret_stencil_expression (SCM expr,
  81                                    void (*func) (void *, SCM),
  82                                    void *func_arg,
  83                                    Offset o);
  84 SCM find_expression_fonts (SCM expr);
  85
  86 void register_stencil_head (SCM symbol);
  87 bool is_stencil_head (SCM symbol);
  88 SCM all_stencil_heads ();
  89
  90
  91 #endif /* STENCIL_HH */