src/core/SkTSort.h

/* libs/graphics/sgl/SkTSort.h
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License"); 
** you may not use this file except in compliance with the License. 
** You may obtain a copy of the License at 
**
**     http://www.apache.org/licenses/LICENSE-2.0 
**
** Unless required by applicable law or agreed to in writing, software 
** distributed under the License is distributed on an "AS IS" BASIS, 
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
** See the License for the specific language governing permissions and 
** limitations under the License.
*/

#ifndef SkTSort_DEFINED
#define SkTSort_DEFINED

#include "SkTypes.h"

template <typename T>
void SkTHeapSort_SiftDown(T array[], int root, int bottom) {
    while (root*2 + 1 <= bottom) {
        int child = root * 2 + 1;
        if (child+1 <= bottom && array[child] < array[child+1]) {
            child += 1;
        }
        if (array[root] < array[child]) {
            SkTSwap<T>(array[root], array[child]);
            root = child;
        } else {
            break;
        }
    }
}

template <typename T> void SkTHeapSort(T array[], int count) {
    int i;
    for (i = count/2 - 1; i >= 0; --i) {
        SkTHeapSort_SiftDown<T>(array, i, count-1);
    }
    for (i = count - 1; i > 0; --i) {
        SkTSwap<T>(array[0], array[i]);
        SkTHeapSort_SiftDown<T>(array, 0, i-1);
    }
}

#endif