From cc223b4afcbc5612f931d64023544518155d9a41 Mon Sep 17 00:00:00 2001
From: Yury Melnichek <melnichek@gmail.com>
Date: Mon, 30 May 2011 20:41:46 +0200
Subject: [PATCH] [search] Estimate feature's viewport - first sketch version.

---
 indexer/feature_rect.cpp | 88 +++++++++++++++++++++++++++++++++++++++-
 indexer/mercator.hpp     | 13 ++++++
 2 files changed, 100 insertions(+), 1 deletion(-)

diff --git a/indexer/feature_rect.cpp b/indexer/feature_rect.cpp
index 1f7e04b9ef..7b7a12cb0b 100644
--- a/indexer/feature_rect.cpp
+++ b/indexer/feature_rect.cpp
@@ -1,6 +1,92 @@
 #include "feature_rect.hpp"
+#include "classificator.hpp"
+#include "../geometry/point2d.hpp"
+#include "../base/base.hpp"
+#include "../base/buffer_vector.hpp"
+#include "../base/macros.hpp"
+#include "../base/stl_add.hpp"
+#include "../std/utility.hpp"
+#include "../std/vector.hpp"
+
+namespace
+{
+
+class FeatureViewportEstimator
+{
+public:
+
+  FeatureViewportEstimator()
+  {
+    m_TypeContinent   = GetType("place", "continent");
+    m_TypeCountry     = GetType("place", "country");
+    m_TypeCity        = GetType("place", "city");
+    m_TypeCityCapital = GetType("place", "city", "capital");
+    m_TypeTown        = GetType("place", "town");
+    m_TypeVillage     = GetType("place", "village");
+  }
+
+  m2::RectD GetViewport(FeatureType const & feature) const
+  {
+    m2::RectD limitRect = feature.GetLimitRect(0);
+    if (feature.GetFeatureType() != feature::GEOM_POINT)
+      return limitRect;
+
+    m2::PointD maxSizeMeters(0, 0);
+    typedef buffer_vector<uint32_t, 8> TypeVectorT;
+    TypeVectorT types;
+    BackInsertFunctor<TypeVectorT> backInserter(types);
+    feature.ForEachTypeRef(backInserter);
+    for (size_t i = 0; i < types.size(); ++i)
+    {
+      m2::PointD const sizeMeters = GetSizeForType(types[i], feature);
+      maxSizeMeters.x = max(maxSizeMeters.x, sizeMeters.x);
+      maxSizeMeters.y = max(maxSizeMeters.y, sizeMeters.y);
+    }
+
+    m2::PointD const centerXY = limitRect.Center();
+    return MercatorBounds::RectByCenterXYAndSizeInMeters(centerXY.x, centerXY.y,
+                                                         maxSizeMeters.x, maxSizeMeters.y);
+  }
+
+  // Returns width and height (lon and lat) for a given type.
+  m2::PointD GetSizeForType(uint32_t const type, FeatureType const & feature) const
+  {
+    static double const km = 1000.0;
+    if (type == m_TypeContinent)
+      return m2::PointD(5000*km, 5000*km);
+    if (type == m_TypeCity || type == m_TypeCityCapital)
+    {
+      double const radius = sqrt(feature.GetPopulation() / 3000);
+      return m2::PointD(radius*km, radius*km);
+    }
+    return m2::PointD(0, 0);
+  }
+
+private:
+
+  static uint32_t GetType(string const & s1,
+                          string const & s2 = string(),
+                          string const & s3 = string())
+  {
+    vector<string> path;
+    path.push_back(s1);
+    if (!s2.empty()) path.push_back(s2);
+    if (!s3.empty()) path.push_back(s3);
+    return classif().GetTypeByPath(path);
+  }
+
+  uint32_t m_TypeContinent;
+  uint32_t m_TypeCountry;
+  uint32_t m_TypeCity;
+  uint32_t m_TypeCityCapital;
+  uint32_t m_TypeTown;
+  uint32_t m_TypeVillage;
+};
+
+}  // unnamed namespace
 
 m2::RectD feature::GetFeatureViewport(FeatureType const & feature)
 {
-  return feature.GetLimitRect(-1);
+  static FeatureViewportEstimator const featureViewportEstimator;
+  return featureViewportEstimator.GetViewport(feature);
 }
diff --git a/indexer/mercator.hpp b/indexer/mercator.hpp
index 03807e6aa7..f77e6a5db0 100644
--- a/indexer/mercator.hpp
+++ b/indexer/mercator.hpp
@@ -55,5 +55,18 @@ struct MercatorBounds
                      LatToY(lat + degreeOffset));
   }
 
+  inline static m2::RectD RectByCenterXYAndSizeInMeters(double centerX, double centerY,
+                                                        double sizeX, double sizeY)
+  {
+    ASSERT_GREATER_OR_EQUAL(sizeX, 0, ());
+    ASSERT_GREATER_OR_EQUAL(sizeY, 0, ());
+    double const degreesLon = fabs(sizeX) / 2.0 * degreeInMetres;
+    double const degreesLat = fabs(sizeY) / 2.0 * degreeInMetres;
+    double const lon = XToLon(centerX);
+    double const lat = YToLat(centerY);
+    return m2::RectD(LonToX(lon - degreesLon), LatToY(lat - degreesLat),
+                     LonToX(lon + degreesLon), LatToY(lat + degreesLat));
+  }
+
   static double GetCellID2PointAbsEpsilon() { return 1.0E-4; }
 };