1
2/*
3 * Copyright 2006 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkTSort_DEFINED
11#define SkTSort_DEFINED
12
13#include "SkTypes.h"
14
15template <typename T>
16void SkTHeapSort_SiftDown(T array[], int root, int bottom) {
17    while (root*2 + 1 <= bottom) {
18        int child = root * 2 + 1;
19        if (child+1 <= bottom && array[child] < array[child+1]) {
20            child += 1;
21        }
22        if (array[root] < array[child]) {
23            SkTSwap<T>(array[root], array[child]);
24            root = child;
25        } else {
26            break;
27        }
28    }
29}
30
31template <typename T> void SkTHeapSort(T array[], int count) {
32    int i;
33    for (i = count/2 - 1; i >= 0; --i) {
34        SkTHeapSort_SiftDown<T>(array, i, count-1);
35    }
36    for (i = count - 1; i > 0; --i) {
37        SkTSwap<T>(array[0], array[i]);
38        SkTHeapSort_SiftDown<T>(array, 0, i-1);
39    }
40}
41
42#endif
43