From bfcb154531520d92041a4cad1639d6951c615397 Mon Sep 17 00:00:00 2001
From: vng <viktor.govako@gmail.com>
Date: Sun, 16 Jan 2011 13:35:25 +0200
Subject: [PATCH] Build in stripified triangles in feature structure.

---
 indexer/feature.cpp                     | 28 +++++++++++-
 indexer/indexer_tool/feature_sorter.cpp | 60 +++++++++++++++++++++----
 2 files changed, 78 insertions(+), 10 deletions(-)

diff --git a/indexer/feature.cpp b/indexer/feature.cpp
index 9ddbc87aff..5b3ddbd7fa 100644
--- a/indexer/feature.cpp
+++ b/indexer/feature.cpp
@@ -48,6 +48,13 @@ void FeatureBuilder1::AddPoint(m2::PointD const & p)
 
 void FeatureBuilder1::SetAreaAddHoles(list<vector<m2::PointD> > & holes)
 {
+  // this function is called from InitFeatureBuilder, when no geometry present
+  if (!m_Geometry.empty())
+  {
+    ASSERT ( IsGeometryClosed(), () );
+    m_Geometry.pop_back();
+  }
+
   m_bArea = true;
 
   m_Holes.swap(holes);
@@ -377,7 +384,12 @@ void FeatureBuilder2::Serialize(buffers_holder_t & data)
   PushBackByteSink<buffer_t> sink(data.m_buffer);
 
   uint8_t const ptsCount = static_cast<uint8_t>(data.m_innerPts.size());
-  uint8_t const trgCount = static_cast<uint8_t>(data.m_innerTrg.size() / 3);
+  uint8_t trgCount = static_cast<uint8_t>(data.m_innerTrg.size());
+  if (trgCount > 0)
+  {
+    ASSERT_GREATER ( trgCount, 2, () );
+    trgCount -= 2;
+  }
 
   BitSink< PushBackByteSink<buffer_t> > bitSink(sink);
 
@@ -775,7 +787,19 @@ void FeatureType::ParseHeader2() const
   if (commonH & HEADER_IS_AREA)
   {
     if (trgCount > 0)
-      ReadInnerPoints(src, m_Triangles, 3*trgCount);
+    {
+      trgCount += 2;
+
+      points_t points;
+      ReadInnerPoints(src, points, trgCount);
+
+      for (uint8_t i = 2; i < trgCount; ++i)
+      {
+        m_Triangles.push_back(points[i-2]);
+        m_Triangles.push_back(points[i-1]);
+        m_Triangles.push_back(points[i]);
+      }
+    }
     else
       ReadOffsets(src, trgMask, m_trgOffsets);
   }
diff --git a/indexer/indexer_tool/feature_sorter.cpp b/indexer/indexer_tool/feature_sorter.cpp
index f8492b0be4..04c7fad1de 100644
--- a/indexer/indexer_tool/feature_sorter.cpp
+++ b/indexer/indexer_tool/feature_sorter.cpp
@@ -10,6 +10,7 @@
 
 #include "../../geometry/distance.hpp"
 #include "../../geometry/simplification.hpp"
+#include "../../geometry/polygon.hpp"
 
 #include "../../platform/platform.hpp"
 
@@ -213,6 +214,22 @@ namespace feature
 
       bool m_ptsInner, m_trgInner;
 
+      class strip_emitter
+      {
+        points_t const & m_src;
+        points_t & m_dest;
+      public:
+        strip_emitter(points_t const & src, points_t & dest)
+          : m_src(src), m_dest(dest)
+        {
+          m_dest.reserve(m_src.size());
+        }
+        void operator() (size_t i)
+        {
+          m_dest.push_back(m_src[i]);
+        }
+      };
+
     public:
       GeometryHolder(FeaturesCollector2 & rMain, FeatureBuilder2 & fb)
         : m_rMain(rMain), m_rFB(fb), m_ptsInner(true), m_trgInner(true)
@@ -246,18 +263,41 @@ namespace feature
         return (!m_trgInner || m_buffer.m_innerTrg.empty());
       }
 
-      void AddTriangles(points_t & triangles, int scaleIndex)
+      bool TryToMakeStrip(points_t & points)
       {
-        if (m_trgInner && triangles.size() < 16)
-        {
-          if (m_buffer.m_innerTrg.empty())
-            m_buffer.m_innerTrg.swap(triangles);
-        }
-        else
+        size_t const count = points.size();
+        if (!m_trgInner || count > 15 + 2)
         {
           m_trgInner = false;
-          WriteOuterTriangles(triangles, scaleIndex);
+          return false;
         }
+
+        ASSERT ( m_buffer.m_innerTrg.empty(), () );
+
+        if (!IsPolygonCCW(points.begin(), points.end()))
+          reverse(points.begin(), points.end());
+
+        size_t const index = FindSingleStrip(count,
+          IsDiagonalVisibleFunctor<points_t::const_iterator>(points.begin(), points.end()));
+
+        if (index == count)
+        {
+          m_trgInner = false;
+          return false;
+        }
+
+        MakeSingleStripFromIndex(index, count, strip_emitter(points, m_buffer.m_innerTrg));
+
+        ASSERT_EQUAL ( count, m_buffer.m_innerTrg.size(), () );
+        return true;
+      }
+
+      void AddTriangles(points_t const & triangles, int scaleIndex)
+      {
+        ASSERT ( m_buffer.m_innerTrg.empty(), () );
+        m_trgInner = false;
+
+        WriteOuterTriangles(triangles, scaleIndex);
       }
     };
 
@@ -286,6 +326,10 @@ namespace feature
             // simplify and serialize triangles
 
             list<points_t> const & holes = fb.GetHoles();
+
+            if (holes.empty() && holder.TryToMakeStrip(points))
+              continue;
+
             list<points_t> simpleHoles;
             for (list<points_t>::const_iterator iH = holes.begin(); iH != holes.end(); ++iH)
             {