From 67d8f41a1b272518f85cf296a3c8f6bd27149df2 Mon Sep 17 00:00:00 2001
From: Jiri Drbalek <jiri.drbalek@firma.seznam.cz>
Date: Wed, 27 Aug 2014 13:09:20 +0000
Subject: [PATCH] fix angle calculation

Conflicts:
	src/text/vertex_cache.cpp
---
 include/mapnik/text/vertex_cache.hpp |  1 +
 src/text/vertex_cache.cpp            | 31 +++++++++++++++++++---------
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/include/mapnik/text/vertex_cache.hpp b/include/mapnik/text/vertex_cache.hpp
index 6069d03e7..532e74f62 100644
--- a/include/mapnik/text/vertex_cache.hpp
+++ b/include/mapnik/text/vertex_cache.hpp
@@ -138,6 +138,7 @@ private:
     void rewind_subpath();
     bool next_segment();
     bool previous_segment();
+    double current_segment_angle();
     // Position as calculated by last move/forward/next call.
     pixel_position current_position_;
     // First pixel of current segment.
diff --git a/src/text/vertex_cache.cpp b/src/text/vertex_cache.cpp
index 942efd98d..5ccc923cc 100644
--- a/src/text/vertex_cache.cpp
+++ b/src/text/vertex_cache.cpp
@@ -29,29 +29,40 @@
 namespace mapnik
 {
 
+double vertex_cache::current_segment_angle()
+{
+    return std::atan2(-(current_segment_->pos.y - segment_starting_point_.y),
+                   current_segment_->pos.x - segment_starting_point_.x);
+}
+
 double vertex_cache::angle(double width)
 {
- /* IMPORTANT NOTE: See note about coordinate systems in placement_finder::find_point_placement()
-  * for imformation about why the y axis is inverted! */
+    // IMPORTANT NOTE: See note about coordinate systems in placement_finder::find_point_placement()
+    // for imformation about why the y axis is inverted!
     double tmp = width + position_in_segment_;
     if ((tmp <= current_segment_->length) && (tmp >= 0))
     {
         //Only calculate angle on request as it is expensive
         if (!angle_valid_)
         {
-            angle_ = std::atan2(-(current_segment_->pos.y - segment_starting_point_.y),
-                           current_segment_->pos.x - segment_starting_point_.x);
+            angle_ = current_segment_angle();
         }
-        return width >= 0 ? angle_ : angle_ + M_PI;
     } else
     {
         scoped_state s(*this);
-        pixel_position const& old_pos = s.get_state().position();
-        move(width);
-        double angle = std::atan2(-(current_position_.y - old_pos.y),
-                             current_position_.x - old_pos.x);
-        return angle;
+        if (move(width))
+        {
+            pixel_position const& old_pos = s.get_state().position();
+            return std::atan2(-(current_position_.y - old_pos.y),
+                           current_position_.x - old_pos.x);
+        }
+        else
+        {
+            s.restore();
+            angle_ = current_segment_angle();
+        }
     }
+    return width >= 0 ? angle_ : angle_ + M_PI;
 }
 
 bool vertex_cache::next_subpath()