CWE-ou-minkata/Sources/Plasma/PubUtilLib/plMath/hsRadixSort.cpp

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*==LICENSE==*/

#include "hsTypes.h"
#include "hsMemory.h"
#include "hsRadixSort.h"

hsRadixSort::hsRadixSort()
{
    HSMemory::Clear(fHeads, 256*sizeof(Elem*));
    HSMemory::Clear(fTails, 256*sizeof(Elem*));
}

void hsRadixSort::ILink(Elem*& head, Elem*& tail, int i)
{
    if( fHeads[i] )
    {
        if( !head )
            head = fHeads[i];
        else
            tail->fNext = fHeads[i];
        tail = fTails[i];
    }
    fHeads[i] = fTails[i] = nil;
}

void hsRadixSort::ISlot(Elem* in, int i)
{
    if( !fTails[i] )
        fHeads[i] = in;
    else
        fTails[i]->fNext = in;
    in->fNext = nil;
    fTails[i] = in;
}

void hsRadixSort::ICollapse()
{
    Elem* head = nil;
    Elem* tail = nil;

    int i;
    for( i = 0; i < 256; i++ )
        ILink(head, tail, i);

    fList = head;
}

void hsRadixSort::IUnPackSignedInt()
{
    Elem* head = nil;
    Elem* tail = nil;

    int i;
    for( i = 128; i < 256; i++ )
        ILink(head, tail, i);

    for( i = 0; i < 128; i++ )
        ILink(head, tail, i);

    fList = head;
}

void hsRadixSort::IUnPackFloat()
{
    Elem* head = nil;
    Elem* tail = nil;

    int i;
    for( i = 128; i < 256; i++ )
        ILink(head, tail, i);
    fList = head;
    head = tail;
    tail = fList;
    IReverse();

    for( i = 0; i < 128; i++ )
        ILink(head, tail, i);

    fList = head;
}

void hsRadixSort::IReverse()
{
    if( !(fList && fList->fNext) )
        return;

    Elem* p = fList->fNext;
    fList->fNext = nil;
    while( p )
    {
        Elem* n = p->fNext;
        p->fNext = fList;
        fList = p;
        p = n;
    }
}

hsRadixSort::Elem* hsRadixSort::Sort(Elem* inList, UInt32 flags)
{
    if( !(inList && inList->fNext) )
        return inList;

    fList = inList;

    Elem* p;
    Elem* n;

    for( p = fList, n = p->fNext; n; p = n, n = p->fNext )
        ISlot(p, p->fKey.fLong & 0xff);
    ISlot(p, p->fKey.fLong & 0xff);

    ICollapse();

    for( p = fList, n = p->fNext; n; p = n, n = p->fNext )
        ISlot(p, (p->fKey.fLong >> 8) & 0xff);
    ISlot(p, (p->fKey.fLong >> 8) & 0xff);

    ICollapse();

    for( p = fList, n = p->fNext; n; p = n, n = p->fNext )
        ISlot(p, (p->fKey.fLong >> 16) & 0xff);
    ISlot(p, (p->fKey.fLong >> 16) & 0xff);

    ICollapse();

    for( p = fList, n = p->fNext; n; p = n, n = p->fNext )
        ISlot(p, (p->fKey.fLong >> 24) & 0xff);
    ISlot(p, (p->fKey.fLong >> 24) & 0xff);

    if( flags & kSignedInt )
        IUnPackSignedInt();
    else if( flags & kUnsigned )
        ICollapse();
    else
        IUnPackFloat();

    if( flags & kReverse )
        IReverse();

    return fList;
}