/*
 * Copyright 2007, Haiku Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Stephan Aßmus <superstippi@gmx.de>
 */
#include "PolygonQueue.h"

#include <stdio.h>
#include <string.h>

#include "Polygon.h"

// constructor
PolygonQueue::PolygonQueue(Polygon* start, int32 depth)
        : fPolygons(new Polygon*[depth]),
          fDepth(depth)
{
        for (int32 i = 0; i < fDepth; i++)
                fPolygons[i] = NULL;
        fPolygons[fDepth - 1] = start;
}

// destructor
PolygonQueue::~PolygonQueue()
{
        for (int32 i = 0; i < fDepth; i++)
                delete fPolygons[i];
        delete[] fPolygons;
}

// Head
Polygon*
PolygonQueue::Head() const
{
        return fPolygons[fDepth - 1];
}

// Tail
Polygon*
PolygonQueue::Tail() const
{
        return fPolygons[0];
}

// Step
void
PolygonQueue::Step()
{
        if (Polygon* p = Head()) {
                Polygon *np = p->Step();
                // drop tail
                delete Tail();
                // shift
                for (int32 i = 0; i < fDepth - 1; i++)
                        fPolygons[i] = fPolygons[i + 1];
                // and put new head at top
                fPolygons[fDepth - 1] = np;
        }
}