xref: /haiku/src/add-ons/screen_savers/spider/PolygonQueue.cpp (revision 3c5dd345287e30b212cdf2fb92cf8cccc5f2bddd) 
1 /*
2  * Copyright 2007, Haiku Inc. All rights reserved.
3  * Distributed under the terms of the MIT License.
4  *
5  * Authors:
6  *		Stephan Aßmus <superstippi@gmx.de>
7  */
8 #include "PolygonQueue.h"
9 
10 #include <stdio.h>
11 #include <string.h>
12 
13 #include "Polygon.h"
14 
15 // constructor
PolygonQueue(Polygon * start,int32 depth)16 PolygonQueue::PolygonQueue(Polygon* start, int32 depth)
17 	: fPolygons(new Polygon*[depth]),
18 	  fDepth(depth)
19 {
20 	for (int32 i = 0; i < fDepth; i++)
21 		fPolygons[i] = NULL;
22 	fPolygons[fDepth - 1] = start;
23 }
24 
25 // destructor
~PolygonQueue()26 PolygonQueue::~PolygonQueue()
27 {
28 	for (int32 i = 0; i < fDepth; i++)
29 		delete fPolygons[i];
30 	delete[] fPolygons;
31 }
32 
33 // Head
34 Polygon*
Head() const35 PolygonQueue::Head() const
36 {
37 	return fPolygons[fDepth - 1];
38 }
39 
40 // Tail
41 Polygon*
Tail() const42 PolygonQueue::Tail() const
43 {
44 	return fPolygons[0];
45 }
46 
47 // Step
48 void
Step()49 PolygonQueue::Step()
50 {
51 	if (Polygon* p = Head()) {
52 		Polygon *np = p->Step();
53 		// drop tail
54 		delete Tail();
55 		// shift
56 		for (int32 i = 0; i < fDepth - 1; i++)
57 			fPolygons[i] = fPolygons[i + 1];
58 		// and put new head at top
59 		fPolygons[fDepth - 1] = np;
60 	}
61 }
62