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-rw-r--r--src/helper/geom-pathstroke.cpp103
-rw-r--r--src/helper/geom-pathstroke.h50
2 files changed, 94 insertions, 59 deletions
diff --git a/src/helper/geom-pathstroke.cpp b/src/helper/geom-pathstroke.cpp
index e1038b03a..e5f207c66 100644
--- a/src/helper/geom-pathstroke.cpp
+++ b/src/helper/geom-pathstroke.cpp
@@ -1,7 +1,8 @@
-/* Author:
+/* Authors:
* Liam P. White
+ * Tavmjong Bah
*
- * Copyright (C) 2014-2015 Author
+ * Copyright (C) 2014-2015 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
@@ -60,14 +61,14 @@ namespace {
// Internal data structure
-struct join_data
-{
+struct join_data {
join_data(Geom::Path &_res, Geom::Path const&_outgoing, Geom::Point _in_tang, Geom::Point _out_tang, double _miter, double _width)
- : res(_res), outgoing(_outgoing), in_tang(_in_tang)
- , out_tang(_out_tang), miter(_miter), width(_width) {}
+ : res(_res), outgoing(_outgoing), in_tang(_in_tang), out_tang(_out_tang), miter(_miter), width(_width) {};
- // I/O
+ // contains the current path that is being built on
Geom::Path &res;
+
+ // contains the next curve to append
Geom::Path const& outgoing;
// input tangents
@@ -382,47 +383,6 @@ void tangents(Geom::Point tang[2], Geom::Curve const& incoming, Geom::Curve cons
tang[0] = tang1, tang[1] = tang2;
}
-void outline_helper(Geom::Path &res, Geom::Path const& temp, Geom::Point in_tang, Geom::Point out_tang, double width, double miter, Inkscape::LineJoinType join)
-{
- if (res.size() == 0 || temp.size() == 0)
- return;
-
- Geom::Curve const& outgoing = temp.front();
- if (Geom::are_near(res.finalPoint(), outgoing.initialPoint())) {
- // if the points are /that/ close, just ignore this one
- res.setFinal(temp.initialPoint());
- res.append(temp);
- return;
- }
-
- join_data jd(res, temp, in_tang, out_tang, miter, width);
-
- bool on_outside = (Geom::cross(in_tang, out_tang) > 0);
-
- if (on_outside) {
- join_func *jf;
- switch (join) {
- case Inkscape::JOIN_BEVEL:
- jf = &bevel_join;
- break;
- case Inkscape::JOIN_ROUND:
- jf = &round_join;
- break;
- case Inkscape::JOIN_EXTRAPOLATE:
- jf = &extrapolate_join;
- break;
- case Inkscape::JOIN_MITER_CLIP:
- jf = &miter_clip_join;
- break;
- default:
- jf = &miter_join;
- }
- jf(jd);
- } else {
- join_inside(jd);
- }
-}
-
// Offsetting a line segment is mathematically stable and quick to do
Geom::LineSegment offset_line(Geom::LineSegment const& l, double width)
{
@@ -696,7 +656,7 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin
res.append(temp);
} else {
tangents(tang, input[u-1], input[u]);
- outline_helper(res, temp, tang[0], tang[1], width, miter, join);
+ outline_join(res, temp, tang[0], tang[1], width, miter, join);
}
// odd number of paths
@@ -704,7 +664,7 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin
temp = Geom::Path();
offset_curve(temp, &input[u+1], width);
tangents(tang, input[u], input[u+1]);
- outline_helper(res, temp, tang[0], tang[1], width, miter, join);
+ outline_join(res, temp, tang[0], tang[1], width, miter, join);
}
}
@@ -716,7 +676,7 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin
Geom::Path temp2;
temp2.append(c2);
tangents(tang, input.back(), input.front());
- outline_helper(temp, temp2, tang[0], tang[1], width, miter, join);
+ outline_join(temp, temp2, tang[0], tang[1], width, miter, join);
res.erase(res.begin());
res.erase_last();
//
@@ -727,6 +687,47 @@ Geom::Path half_outline(Geom::Path const& input, double width, double miter, Lin
return res;
}
+void outline_join(Geom::Path &res, Geom::Path const& temp, Geom::Point in_tang, Geom::Point out_tang, double width, double miter, Inkscape::LineJoinType join)
+{
+ if (res.size() == 0 || temp.size() == 0)
+ return;
+
+ Geom::Curve const& outgoing = temp.front();
+ if (Geom::are_near(res.finalPoint(), outgoing.initialPoint())) {
+ // if the points are /that/ close, just ignore this one
+ res.setFinal(temp.initialPoint());
+ res.append(temp);
+ return;
+ }
+
+ join_data jd(res, temp, in_tang, out_tang, miter, width);
+
+ bool on_outside = (Geom::cross(in_tang, out_tang) > 0);
+
+ if (on_outside) {
+ join_func *jf;
+ switch (join) {
+ case Inkscape::JOIN_BEVEL:
+ jf = &bevel_join;
+ break;
+ case Inkscape::JOIN_ROUND:
+ jf = &round_join;
+ break;
+ case Inkscape::JOIN_EXTRAPOLATE:
+ jf = &extrapolate_join;
+ break;
+ case Inkscape::JOIN_MITER_CLIP:
+ jf = &miter_clip_join;
+ break;
+ default:
+ jf = &miter_join;
+ }
+ jf(jd);
+ } else {
+ join_inside(jd);
+ }
+}
+
} // namespace Inkscape
/*
diff --git a/src/helper/geom-pathstroke.h b/src/helper/geom-pathstroke.h
index 0cfb9f817..6697273cf 100644
--- a/src/helper/geom-pathstroke.h
+++ b/src/helper/geom-pathstroke.h
@@ -1,10 +1,11 @@
#ifndef INKSCAPE_HELPER_PATH_STROKE_H
#define INKSCAPE_HELPER_PATH_STROKE_H
-/* Author:
+/* Authors:
* Liam P. White
+ * Tavmjong Bah
*
- * Copyright (C) 2014-2015 Author
+ * Copyright (C) 2014-2015 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
@@ -26,21 +27,54 @@ enum LineCapType {
BUTT_FLAT,
BUTT_ROUND,
BUTT_SQUARE,
- BUTT_PEAK, // ?
+ BUTT_PEAK, // This is not a line ending supported by the SVG standard.
};
/**
+ * Strokes the path given by @a input.
+ * Joins may behave oddly if the width is negative.
+ *
+ * @param[in] input Input path.
+ * @param[in] width Stroke width.
+ * @param[in] miter Miter limit. Only used when @a join is one of JOIN_MITER, JOIN_MITER_CLIP, and JOIN_EXTRAPOLATE.
+ * @param[in] join Line join type used during offset. Member of LineJoinType enum.
+ * @param[in] cap Line cap type used during stroking. Member of LineCapType enum.
+ *
+ * @return Stroked path.
+ * If the input path is closed, the resultant vector will contain two paths.
+ * Otherwise, there should be only one in the output.
+ */
+Geom::PathVector outline(Geom::Path const& input, double width, double miter, LineJoinType join = JOIN_BEVEL, LineCapType cap = BUTT_FLAT);
+
+/**
* Offset the input path by @a width.
* Joins may behave oddly if the width is negative.
*
- * @param input
- * @param width Amount to offset.
- * @param miter Miter limit. Only used with JOIN_MITER, JOIN_MITER_CLIP, and JOIN_EXTRAPOLATE.
- * @param join
+ * @param[in] input Input path.
+ * @param[in] width Amount to offset.
+ * @param[in] miter Miter limit. Only used when @a join is one of JOIN_MITER, JOIN_MITER_CLIP, and JOIN_EXTRAPOLATE.
+ * @param[in] join Line join type used during offset. Member of LineJoinType enum.
+ *
+ * @return Offsetted output.
*/
Geom::Path half_outline(Geom::Path const& input, double width, double miter, LineJoinType join = JOIN_BEVEL);
-Geom::PathVector outline(Geom::Path const& input, double width, double miter, LineJoinType join = JOIN_BEVEL, LineCapType cap = BUTT_FLAT);
+/**
+ * Builds a join on the provided path.
+ * Joins may behave oddly if the width is negative.
+ *
+ * @param[inout] res The path to build the join on.
+ * The outgoing path (or a portion thereof) will be appended after the join is created.
+ * Previous segments may be modified as an optimization, beware!
+ *
+ * @param[in] outgoing The segment to append on the outgoing portion of the join.
+ * @param[in] in_tang The end tangent to consider on the input path.
+ * @param[in] out_tang The begin tangent to consider on the output path.
+ * @param[in] width
+ * @param[in] miter
+ * @param[in] join
+ */
+void outline_join(Geom::Path &res, Geom::Path const& outgoing, Geom::Point in_tang, Geom::Point out_tang, double width, double miter, LineJoinType join);
} // namespace Inkscape
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-19 01:21:26 +0000