From 5fdc4cbb36fdae27e0ed1453faad86cbaf44293a Mon Sep 17 00:00:00 2001
From: Duan Yao <duanyao@ustc.edu>
Date: Thu, 19 Jun 2014 11:06:54 +0800
Subject: [PATCH] Improve stroke handling in DrawingTracer by simulating line
 join.

---
 src/DrawingTracer.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/DrawingTracer.cc b/src/DrawingTracer.cc
index c282824..66ebe8c 100644
--- a/src/DrawingTracer.cc
+++ b/src/DrawingTracer.cc
@@ -141,6 +141,10 @@ void DrawingTracer::stroke(GfxState * state)
     // 1. path steps that are not vertical or horizontal lines may still falsely "cover" many chars,
     // can we slice those steps further?
     // 2. if the line width is small, can we just ignore the path?
+    // 3. line join feature can't be retained. We use line-cap-square to minimize the problem that
+    //   some chars actually covered by a line join are missed. However chars covered by a acute angle
+    //   with line-join-miter may be still recognized as not covered.
+    cairo_set_line_cap(cairo, CAIRO_LINE_CAP_SQUARE);
     GfxPath * path = state->getPath();
     for (int i = 0; i < path->getNumSubpaths(); ++i) {
         GfxSubpath * subpath = path->getSubpath(i);