From 7028cbe09c688437910a25623098762bf0fa592d Mon Sep 17 00:00:00 2001 From: David Walter Seikel Date: Mon, 28 Mar 2016 22:28:34 +1000 Subject: Move Irrlicht to src/others. --- src/others/irrlicht-1.8.1/include/heapsort.h | 70 ++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 src/others/irrlicht-1.8.1/include/heapsort.h (limited to 'src/others/irrlicht-1.8.1/include/heapsort.h') diff --git a/src/others/irrlicht-1.8.1/include/heapsort.h b/src/others/irrlicht-1.8.1/include/heapsort.h new file mode 100644 index 0000000..6f87665 --- /dev/null +++ b/src/others/irrlicht-1.8.1/include/heapsort.h @@ -0,0 +1,70 @@ +// 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 +{ + +//! Sinks an element into the heap. +template +inline void heapsink(T*array, s32 element, s32 max) +{ + while ((element<<1) < max) // there is a left child + { + s32 j = (element<<1); + + if (j+1 < max && array[j] < array[j+1]) + j = j+1; // take right child + + if (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. +template +inline void heapsort(T* array_, s32 size) +{ + // 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); + + // 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); + } +} + +} // end namespace core +} // end namespace irr + +#endif + -- cgit v1.1