The DOOM Classic for iPhone 1.0 source as released on November 3, 2009

code/libtess/priorityq-heap.h

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+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __priorityq_heap_h_
+#define __priorityq_heap_h_
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define PQkey			PQHeapKey
+#define PQhandle		PQHeapHandle
+#define PriorityQ		PriorityQHeap
+
+#define pqNewPriorityQ(leq)	__gl_pqHeapNewPriorityQ(leq)
+#define pqDeletePriorityQ(pq)	__gl_pqHeapDeletePriorityQ(pq)
+
+/* The basic operations are insertion of a new key (pqInsert),
+ * and examination/extraction of a key whose value is minimum
+ * (pqMinimum/pqExtractMin).  Deletion is also allowed (pqDelete);
+ * for this purpose pqInsert returns a "handle" which is supplied
+ * as the argument.
+ *
+ * An initial heap may be created efficiently by calling pqInsert
+ * repeatedly, then calling pqInit.  In any case pqInit must be called
+ * before any operations other than pqInsert are used.
+ *
+ * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
+ * This may also be tested with pqIsEmpty.
+ */
+#define pqInit(pq)		__gl_pqHeapInit(pq)
+#define pqInsert(pq,key)	__gl_pqHeapInsert(pq,key)
+#define pqMinimum(pq)		__gl_pqHeapMinimum(pq)
+#define pqExtractMin(pq)	__gl_pqHeapExtractMin(pq)
+#define pqDelete(pq,handle)	__gl_pqHeapDelete(pq,handle)
+#define pqIsEmpty(pq)		__gl_pqHeapIsEmpty(pq)
+
+
+/* Since we support deletion the data structure is a little more
+ * complicated than an ordinary heap.  "nodes" is the heap itself;
+ * active nodes are stored in the range 1..pq->size.  When the
+ * heap exceeds its allocated size (pq->max), its size doubles.
+ * The children of node i are nodes 2i and 2i+1.
+ *
+ * Each node stores an index into an array "handles".  Each handle
+ * stores a key, plus a pointer back to the node which currently
+ * represents that key (ie. nodes[handles[i].node].handle == i).
+ */
+
+typedef void *PQkey;
+typedef long PQhandle;
+typedef struct PriorityQ PriorityQ;
+
+typedef struct { PQhandle handle; } PQnode;
+typedef struct { PQkey key; PQhandle node; } PQhandleElem;
+
+struct PriorityQ {
+  PQnode	*nodes;
+  PQhandleElem	*handles;
+  long		size, max;
+  PQhandle	freeList;
+  int		initialized;
+  int		(*leq)(PQkey key1, PQkey key2);
+};
+  
+PriorityQ	*pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
+void		pqDeletePriorityQ( PriorityQ *pq );
+
+void		pqInit( PriorityQ *pq );
+PQhandle	pqInsert( PriorityQ *pq, PQkey key );
+PQkey		pqExtractMin( PriorityQ *pq );
+void		pqDelete( PriorityQ *pq, PQhandle handle );
+
+
+#define __gl_pqHeapMinimum(pq)	((pq)->handles[(pq)->nodes[1].handle].key)
+#define __gl_pqHeapIsEmpty(pq)	((pq)->size == 0)
+
+#endif