Make HilbertEncoder::sort generic

libgeos · Sep 14, 2022 · 15479c4 · 15479c4
1 parent fbce288
commit 15479c4
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Showing 2 changed files with 38 additions and 30 deletions.
diff --git a/include/geos/shape/fractal/HilbertEncoder.h b/include/geos/shape/fractal/HilbertEncoder.h
@@ -16,15 +16,14 @@
 #pragma once
 
 #include <geos/export.h>
+#include <geos/geom/Geometry.h>
 #include <string>
 #include <vector>
 
 // Forward declarations
 namespace geos {
 namespace geom {
 class Coordinate;
-class Geometry;
-class Envelope;
 }
 }
 
@@ -41,6 +40,28 @@ class GEOS_DLL HilbertEncoder {
     uint32_t encode(const geom::Envelope* env);
     static void sort(std::vector<geom::Geometry*>& geoms);
 
+    template<typename T>
+    static geom::Envelope getEnvelope(T begin, T end) {
+        geom::Envelope extent;
+        for (auto it = begin; it != end; ++it) {
+            const auto* g = *it;
+            if (extent.isNull())
+                extent = *(g->getEnvelopeInternal());
+            else
+                extent.expandToInclude(*(g->getEnvelopeInternal()));
+        }
+
+        return extent;
+    }
+
+    template<typename T>
+    static void sort(T begin, T end) {
+        auto extent = getEnvelope(begin, end);
+        HilbertEncoder encoder(12, extent);
+        HilbertComparator hilbertCompare(encoder);
+        std::sort(begin, end, hilbertCompare);
+    }
+
 private:
 
     uint32_t level;
@@ -49,6 +70,20 @@ class GEOS_DLL HilbertEncoder {
     double strideX;
     double strideY;
 
+    struct HilbertComparator {
+
+        HilbertEncoder& enc;
+
+        HilbertComparator(HilbertEncoder& e)
+            : enc(e) {};
+
+        bool
+        operator()(const geom::Geometry* a, const geom::Geometry* b)
+        {
+            return enc.encode(a->getEnvelopeInternal()) > enc.encode(b->getEnvelopeInternal());
+        }
+    };
+
 };
 
 

diff --git a/src/shape/fractal/HilbertEncoder.cpp b/src/shape/fractal/HilbertEncoder.cpp
@@ -59,34 +59,7 @@ HilbertEncoder::encode(const geom::Envelope* env)
 void
 HilbertEncoder::sort(std::vector<geom::Geometry*>& geoms)
 {
-    struct HilbertComparator {
-
-        HilbertEncoder& enc;
-
-        HilbertComparator(HilbertEncoder& e)
-            : enc(e) {};
-
-        bool
-        operator()(const geom::Geometry* a, const geom::Geometry* b)
-        {
-            return enc.encode(a->getEnvelopeInternal()) > enc.encode(b->getEnvelopeInternal());
-        }
-    };
-
-    geom::Envelope extent;
-    for (const geom::Geometry* geom: geoms)
-    {
-        if (extent.isNull())
-            extent = *(geom->getEnvelopeInternal());
-        else
-            extent.expandToInclude(*(geom->getEnvelopeInternal()));
-    }
-    if (extent.isNull()) return;
-
-    HilbertEncoder encoder(12, extent);
-    HilbertComparator hilbertCompare(encoder);
-    std::sort(geoms.begin(), geoms.end(), hilbertCompare);
-    return;
+    sort(geoms.begin(), geoms.end());
 }