SuperTuxKart 1.5 upstream source (from official release tarball)

lib/irrlicht/include/heapsort.h

@@ -0,0 +1,76 @@
+// Copyright (C) 2002-2012 Nikolaus Gebhardt
+// This file is part of the "Irrlicht Engine".
+// For conditions of distribution and use, see copyright notice in irrlicht.h
+
+#ifndef __IRR_HEAPSORT_H_INCLUDED__
+#define __IRR_HEAPSORT_H_INCLUDED__
+
+#include "irrTypes.h"
+
+namespace irr
+{
+namespace core
+{
+
+//! Function object which can be used for sorting (default)
+template<class T>
+inline bool sortless(const T& a, const T& b)
+{
+	return a < b;
+}
+
+//! Sinks an element into the heap with a custom compare function
+template<class T, class Compare>
+inline void heapsink(T*array, s32 element, s32 max, Compare cmp)
+{
+	while ((element<<1) < max) // there is a left child
+	{
+		s32 j = (element<<1);
+
+		if (j+1 < max && cmp(array[j], array[j+1]))
+			j = j+1; // take right child
+
+		if (cmp(array[element], array[j]))
+		{
+			T t = array[j]; // swap elements
+			array[j] = array[element];
+			array[element] = t;
+			element = j;
+		}
+		else
+			return;
+	}
+}
+
+//! Sorts an array with size 'size' using heapsort with a custom compare function
+template<class T, class Compare>
+inline void heapsort(T* array_, s32 size, Compare cmp)
+{
+	// for heapsink we pretent this is not c++, where
+	// arrays start with index 0. So we decrease the array pointer,
+	// the maximum always +2 and the element always +1
+
+	T* virtualArray = array_ - 1;
+	s32 virtualSize = size + 2;
+	s32 i;
+
+	// build heap
+
+	for (i=((size-1)/2); i>=0; --i)
+		heapsink(virtualArray, i+1, virtualSize-1, cmp);
+
+	// sort array, leave out the last element (0)
+	for (i=size-1; i>0; --i)
+	{
+		T t = array_[0];
+		array_[0] = array_[i];
+		array_[i] = t;
+		heapsink(virtualArray, 1, i + 1, cmp);
+	}
+}
+
+} // end namespace core
+} // end namespace irr
+
+#endif
+