Stencil::is_empty () const
{
return (expr_ == SCM_EOL
- || dim_[X_AXIS].is_empty ()
- || dim_[Y_AXIS].is_empty ());
+ || dim_.is_empty ());
+}
+
+bool
+Stencil::is_empty (Axis a) const
+{
+ return dim_.is_empty (a);
}
SCM
incr (a);
}
- expr_ = scm_list_n (ly_symbol2scm ("translate-stencil"),
- ly_offset2scm (o),
- expr_, SCM_UNDEFINED);
+ if (!scm_is_null (expr_))
+ expr_ = scm_list_n (ly_symbol2scm ("translate-stencil"),
+ ly_offset2scm (o),
+ expr_, SCM_UNDEFINED);
if (!is_empty ())
dim_.translate (o);
}
void
Stencil::add_stencil (Stencil const &s)
{
- expr_ = scm_list_3 (ly_symbol2scm ("combine-stencil"), s.expr_, expr_);
+ SCM cs = ly_symbol2scm ("combine-stencil");
+ if (scm_is_null (expr_))
+ expr_ = s.expr_;
+ else if (scm_is_null (s.expr_))
+ ;
+ else if (scm_is_pair (expr_)
+ && scm_is_eq (cs, scm_car (expr_)))
+ {
+ if (scm_is_pair (s.expr_)
+ && scm_is_eq (cs, scm_car (s.expr_)))
+ expr_ = scm_append (scm_list_2 (s.expr_, scm_cdr (expr_)));
+ else
+ expr_ = scm_cons2 (cs, s.expr_, scm_cdr (expr_));
+ }
+ else
+ {
+ if (scm_is_pair (s.expr_)
+ && scm_is_eq (cs, scm_car (s.expr_)))
+ expr_ = scm_append (scm_list_2 (s.expr_, scm_list_1 (expr_)));
+ else
+ expr_ = scm_list_3 (cs, s.expr_, expr_);
+ }
dim_.unite (s.dim_);
}
void
Stencil::align_to (Axis a, Real x)
{
- if (is_empty ())
+ if (is_empty (a))
return;
Interval i (extent (a));
}
/* See scheme Function. */
+
+// Any stencil that is empty in the orthogonal axis is spacing.
+// Spacing is not subjected to the max (0) rule and can thus be
+// negative.
+
void
Stencil::add_at_edge (Axis a, Direction d, Stencil const &s, Real padding)
{
- Interval my_extent = dim_[a];
- Interval i (s.extent (a));
- Real his_extent;
- if (i.is_empty ())
+ // Material that is empty in the axis of reference has only limited
+ // usefulness for combining. We still retain as much information as
+ // available since there may be uses like setting page links or
+ // background color or watermarks, and off-axis extents.
+
+ if (is_empty (a))
{
- programming_error ("Stencil::add_at_edge: adding empty stencil.");
- his_extent = 0.0;
+ add_stencil (s);
+ return;
}
- else
- his_extent = i[-d];
- Real offset = (my_extent.is_empty () ? 0.0 : my_extent[d] - his_extent)
- + d * padding;
+ Interval first_extent = extent (a);
+
+ if (s.is_empty (a))
+ {
+ Stencil toadd (s);
+ // translation does not affect axis-empty extent box.
+ toadd.translate_axis (first_extent[d], a);
+ add_stencil (toadd);
+ return;
+ }
+
+ Interval next_extent = s.extent (a);
+
+ bool first_is_spacing = is_empty (other_axis (a));
+ bool next_is_spacing = s.is_empty (other_axis (a));
+
+ Real offset = first_extent[d] - next_extent[-d];
+
+ if (!(first_is_spacing || next_is_spacing))
+ {
+ offset += d * padding;
+ }
Stencil toadd (s);
toadd.translate_axis (offset, a);
add_stencil (toadd);
}
+// Stencil::stack is mainly used for assembling lines or columns
+// of stencils. For the most common case of adding at the right, the
+// reference point of the added stencil is usually placed at the right
+// edge of the current one, unless the added stencil has a negative
+// left extent in which case its left edge is placed at the right edge
+// of the current one.
+//
+// Spacing is special in that it is applied without padding. Spacing
+// at the right edge shifts the right edge accordingly.
+//
+// For spacing at the left edge, there are several approaches. In
+// order to get to predictable behavior, we want to have at least a
+// continuous approach. An obvious idea is to do a "translate" by the
+// appropriate amount. Doing that while retaining the nominal left
+// edge seems like the most straightforward way.
+
+void
+Stencil::stack (Axis a, Direction d, Stencil const &s, Real padding, Real mindist)
+{
+ // Material that is empty in the axis of reference can't be sensibly
+ // stacked. We just revert to add_at_edge behavior then.
+
+ if (is_empty (a))
+ {
+ Stencil toadd (s);
+ toadd.add_stencil (*this);
+ expr_ = toadd.expr ();
+ dim_ = toadd.extent_box ();
+ return;
+ }
+
+ Interval first_extent = extent (a);
+
+ if (s.is_empty (a))
+ {
+ Stencil toadd (s);
+ toadd.translate_axis (first_extent[d], a);
+ toadd.add_stencil (*this);
+ expr_ = toadd.expr ();
+ dim_ = toadd.extent_box ();
+ return;
+ }
+
+ Interval next_extent = s.extent (a);
+
+ // It is somewhat tedious to special-case all spacing, but it turns
+ // out that not doing so makes it astonishingly hard to make the
+ // code do the correct thing.
+
+ // If first is spacing, we translate second accordingly without
+ // letting this affect its backward edge.
+ if (is_empty (other_axis (a)))
+ {
+ Stencil toadd (s);
+ Real offset = d * first_extent.delta ();
+ toadd.translate_axis (offset, a);
+ toadd.add_stencil (*this);
+ expr_ = toadd.expr ();
+ dim_ = toadd.extent_box ();
+ dim_[a][-d] = next_extent[-d];
+ dim_[a][d] = next_extent[d] + offset;
+ return;
+ }
+
+ // If next is spacing, similar action:
+ if (s.is_empty (other_axis (a)))
+ {
+ Stencil toadd (s);
+ Real offset = first_extent [d];
+ toadd.translate_axis (offset, a);
+ toadd.add_stencil (*this);
+ expr_ = toadd.expr ();
+ dim_ = toadd.extent_box ();
+ dim_[a][-d] = first_extent[-d];
+ dim_[a][d] = first_extent[d] + d * next_extent.delta ();
+ return;
+ }
+
+
+ Real offset = first_extent[d];
+
+ // If the added stencil has a backwardly protruding edge, we make
+ // room for it when combining.
+
+ if (d * next_extent [-d] < 0)
+ offset -= next_extent [-d];
+
+ offset += d * padding;
+
+ if (offset * d < mindist)
+ offset = d * mindist;
+
+ Stencil toadd (s);
+ toadd.translate_axis (offset, a);
+ toadd.add_stencil (*this);
+ expr_ = toadd.expr ();
+ dim_ = toadd.extent_box ();
+ dim_[a][-d] = first_extent [-d];
+ dim_[a][d] = next_extent [d] + offset;
+}
+
+
Stencil
Stencil::in_color (Real r, Real g, Real b) const
{
projects / lilypond.git / blobdiff