Merge to XFA: Separate agg-authored code from fx-authored code.

Original Review URL: https://codereview.chromium.org/1152743007.
BUG=pdfium:166
R=brucedawson@chromium.org, thestig@chromium.org
TBR=brucedawson@chromium.org, thestig@chromium.org

Review URL: https://codereview.chromium.org/1186423003.

1 files changed, 57 insertions, 0 deletions

diff --git a/third_party/agg23/agg_shorten_path.h b/third_party/agg23/agg_shorten_path.h
new file mode 100644
index 0000000000..d7eb4be018
--- /dev/null
+++ b/third_party/agg23/agg_shorten_path.h
@@ -0,0 +1,57 @@
+
+//----------------------------------------------------------------------------
+// Anti-Grain Geometry - Version 2.3
+// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
+//
+// Permission to copy, use, modify, sell and distribute this software
+// is granted provided this copyright notice appears in all copies.
+// This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+//
+//----------------------------------------------------------------------------
+// Contact: mcseem@antigrain.com
+//          mcseemagg@yahoo.com
+//          http://www.antigrain.com
+//----------------------------------------------------------------------------
+#ifndef AGG_SHORTEN_PATH_INCLUDED
+#define AGG_SHORTEN_PATH_INCLUDED
+#include "agg_basics.h"
+#include "agg_vertex_sequence.h"
+namespace agg
+{
+template<class VertexSequence>
+void shorten_path(VertexSequence& vs, FX_FLOAT s, unsigned closed = 0)
+{
+    typedef typename VertexSequence::value_type vertex_type;
+    if(s > 0 && vs.size() > 1) {
+        FX_FLOAT d;
+        int n = int(vs.size() - 2);
+        while(n) {
+            d = vs[n].dist;
+            if(d > s) {
+                break;
+            }
+            vs.remove_last();
+            s -= d;
+            --n;
+        }
+        if(vs.size() < 2) {
+            vs.remove_all();
+        } else {
+            n = vs.size() - 1;
+            vertex_type& prev = vs[n - 1];
+            vertex_type& last = vs[n];
+            d = (prev.dist - s) / prev.dist;
+            FX_FLOAT x = prev.x + (last.x - prev.x) * d;
+            FX_FLOAT y = prev.y + (last.y - prev.y) * d;
+            last.x = x;
+            last.y = y;
+            if(!prev(last)) {
+                vs.remove_last();
+            }
+            vs.close(closed != 0);
+        }
+    }
+}
+}
+#endif