[11902] Import Recast Navigation

Import Recast Navigation as third party dependency
Credits go to Mikko Mononen memon at inside dot org

dep/recastnavigation/Detour/Source/DetourNode.cpp

@@ -0,0 +1,164 @@
+//
+// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
+//
+// This software is provided 'as-is', without any express or implied
+// warranty.  In no event will the authors be held liable for any damages
+// arising from the use of this software.
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would be
+//    appreciated but is not required.
+// 2. Altered source versions must be plainly marked as such, and must not be
+//    misrepresented as being the original software.
+// 3. This notice may not be removed or altered from any source distribution.
+//
+
+#include "DetourNode.h"
+#include "DetourAlloc.h"
+#include "DetourAssert.h"
+#include "DetourCommon.h"
+#include <string.h>
+
+inline unsigned int dtHashRef(dtPolyRef a)
+{
+    a = (~a) + (a << 18);
+    a = a ^ (a >> 31);
+    a = a * 21;
+    a = a ^ (a >> 11);
+    a = a + (a << 6);
+    a = a ^ (a >> 22);
+    return (unsigned int)a;
+}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+dtNodePool::dtNodePool(int maxNodes, int hashSize) :
+	m_nodes(0),
+	m_first(0),
+	m_next(0),
+	m_maxNodes(maxNodes),
+	m_hashSize(hashSize),
+	m_nodeCount(0)
+{
+	dtAssert(dtNextPow2(m_hashSize) == (unsigned int)m_hashSize);
+	dtAssert(m_maxNodes > 0);
+
+	m_nodes = (dtNode*)dtAlloc(sizeof(dtNode)*m_maxNodes, DT_ALLOC_PERM);
+	m_next = (unsigned short*)dtAlloc(sizeof(unsigned short)*m_maxNodes, DT_ALLOC_PERM);
+	m_first = (unsigned short*)dtAlloc(sizeof(unsigned short)*hashSize, DT_ALLOC_PERM);
+
+	dtAssert(m_nodes);
+	dtAssert(m_next);
+	dtAssert(m_first);
+
+	memset(m_first, 0xff, sizeof(unsigned short)*m_hashSize);
+	memset(m_next, 0xff, sizeof(unsigned short)*m_maxNodes);
+}
+
+dtNodePool::~dtNodePool()
+{
+	dtFree(m_nodes);
+	dtFree(m_next);
+	dtFree(m_first);
+}
+
+void dtNodePool::clear()
+{
+	memset(m_first, 0xff, sizeof(unsigned short)*m_hashSize);
+	m_nodeCount = 0;
+}
+
+dtNode* dtNodePool::findNode(dtPolyRef id)
+{
+	unsigned int bucket = dtHashRef(id) & (m_hashSize-1);
+	unsigned short i = m_first[bucket];
+	while (i != DT_NULL_IDX)
+	{
+		if (m_nodes[i].id == id)
+			return &m_nodes[i];
+		i = m_next[i];
+	}
+	return 0;
+}
+
+dtNode* dtNodePool::getNode(dtPolyRef id)
+{
+	unsigned int bucket = dtHashRef(id) & (m_hashSize-1);
+	unsigned short i = m_first[bucket];
+	dtNode* node = 0;
+	while (i != DT_NULL_IDX)
+	{
+		if (m_nodes[i].id == id)
+			return &m_nodes[i];
+		i = m_next[i];
+	}
+	
+	if (m_nodeCount >= m_maxNodes)
+		return 0;
+	
+	i = (unsigned short)m_nodeCount;
+	m_nodeCount++;
+	
+	// Init node
+	node = &m_nodes[i];
+	node->pidx = 0;
+	node->cost = 0;
+	node->total = 0;
+	node->id = id;
+	node->flags = 0;
+	
+	m_next[i] = m_first[bucket];
+	m_first[bucket] = i;
+	
+	return node;
+}
+
+
+//////////////////////////////////////////////////////////////////////////////////////////
+dtNodeQueue::dtNodeQueue(int n) :
+	m_heap(0),
+	m_capacity(n),
+	m_size(0)
+{
+	dtAssert(m_capacity > 0);
+	
+	m_heap = (dtNode**)dtAlloc(sizeof(dtNode*)*(m_capacity+1), DT_ALLOC_PERM);
+	dtAssert(m_heap);
+}
+
+dtNodeQueue::~dtNodeQueue()
+{
+	dtFree(m_heap);
+}
+
+void dtNodeQueue::bubbleUp(int i, dtNode* node)
+{
+	int parent = (i-1)/2;
+	// note: (index > 0) means there is a parent
+	while ((i > 0) && (m_heap[parent]->total > node->total))
+	{
+		m_heap[i] = m_heap[parent];
+		i = parent;
+		parent = (i-1)/2;
+	}
+	m_heap[i] = node;
+}
+
+void dtNodeQueue::trickleDown(int i, dtNode* node)
+{
+	int child = (i*2)+1;
+	while (child < m_size)
+	{
+		if (((child+1) < m_size) && 
+			(m_heap[child]->total > m_heap[child+1]->total))
+		{
+			child++;
+		}
+		m_heap[i] = m_heap[child];
+		i = child;
+		child = (i*2)+1;
+	}
+	bubbleUp(i, node);
+}