From 39ed87570bdb2f86969d4be821c94b722dc71179 Mon Sep 17 00:00:00 2001
From: Joe Ludwig <joe@valvesoftware.com>
Date: Wed, 26 Jun 2013 15:22:04 -0700
Subject: First version of the SOurce SDK 2013

---
 mp/src/game/server/nav_node.cpp | 488 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 488 insertions(+)
 create mode 100644 mp/src/game/server/nav_node.cpp

(limited to 'mp/src/game/server/nav_node.cpp')

diff --git a/mp/src/game/server/nav_node.cpp b/mp/src/game/server/nav_node.cpp
new file mode 100644
index 00000000..d99ceb79
--- /dev/null
+++ b/mp/src/game/server/nav_node.cpp
@@ -0,0 +1,488 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//
+//=============================================================================//
+// nav_node.cpp
+// AI Navigation Nodes
+// Author: Michael S. Booth (mike@turtlerockstudios.com), January 2003
+
+#include "cbase.h"
+#include "nav_node.h"
+#include "nav_colors.h"
+#include "nav_mesh.h"
+#include "tier1/utlhash.h"
+#include "tier1/generichash.h"
+
+// NOTE: This has to be the last file included!
+#include "tier0/memdbgon.h"
+
+
+NavDirType Opposite[ NUM_DIRECTIONS ] = { SOUTH, WEST, NORTH, EAST };
+
+CNavNode *CNavNode::m_list = NULL;
+unsigned int CNavNode::m_listLength = 0;
+unsigned int CNavNode::m_nextID = 1;
+
+extern Vector NavTraceMins;
+extern Vector NavTraceMaxs;
+
+//--------------------------------------------------------------------------------------------------------------
+// Node hash
+
+class CNodeHashFuncs
+{
+public:
+	CNodeHashFuncs( int ) {}
+
+	bool operator()( const CNavNode *pLhs, const CNavNode *pRhs ) const
+	{
+		return pRhs->GetPosition()->AsVector2D() == pLhs->GetPosition()->AsVector2D();
+	}
+
+	unsigned int operator()( const CNavNode *pItem ) const
+	{
+		return Hash8( &pItem->GetPosition()->AsVector2D() );	
+	}
+};
+
+CUtlHash<CNavNode *, CNodeHashFuncs, CNodeHashFuncs> *g_pNavNodeHash;
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Constructor
+ */
+CNavNode::CNavNode( const Vector &pos, const Vector &normal, CNavNode *parent, bool isOnDisplacement )
+{
+	m_pos = pos;
+	m_normal = normal;
+
+	m_id = m_nextID++;
+
+	int i;
+	for( i=0; i<NUM_DIRECTIONS; ++i )
+	{
+		m_to[ i ] = NULL;
+		m_obstacleHeight[ i ] = 0;
+		m_obstacleStartDist[ i ] = 0;
+		m_obstacleEndDist[ i ] = 0;
+	}
+
+	for ( i=0; i<NUM_CORNERS; ++i )
+	{
+		m_crouch[ i ] = false;
+		m_isBlocked[ i ] = false;
+	}
+
+	m_visited = 0;
+	m_parent = parent;
+
+	m_next = m_list;
+	m_list = this;
+	m_listLength++;
+
+	m_isCovered = false;
+	m_area = NULL;
+
+	m_attributeFlags = 0;
+
+	m_isOnDisplacement = isOnDisplacement;
+
+	if ( !g_pNavNodeHash )
+	{
+		g_pNavNodeHash = new CUtlHash<CNavNode *, CNodeHashFuncs, CNodeHashFuncs>( 16*1024 );
+	}
+
+	bool bDidInsert;
+	UtlHashHandle_t hHash = g_pNavNodeHash->Insert( this, &bDidInsert );
+	if ( !bDidInsert )
+	{
+		CNavNode *pExistingNode = g_pNavNodeHash->Element( hHash );
+		m_nextAtXY = pExistingNode;
+		g_pNavNodeHash->Element( hHash ) = this;
+	}
+	else
+	{
+		m_nextAtXY = NULL;
+	}
+}
+
+CNavNode::~CNavNode()
+{
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavNode::CleanupGeneration()
+{
+	delete g_pNavNodeHash;
+	g_pNavNodeHash = NULL;
+
+	CNavNode *node, *next;
+	for( node = CNavNode::m_list; node; node = next )
+	{
+		next = node->m_next;
+		delete node;
+	}
+	CNavNode::m_list = NULL;
+	CNavNode::m_listLength = 0;
+	CNavNode::m_nextID = 1;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+#if DEBUG_NAV_NODES
+ConVar nav_show_nodes( "nav_show_nodes", "0", FCVAR_CHEAT );
+ConVar nav_show_node_id( "nav_show_node_id", "0", FCVAR_CHEAT );
+ConVar nav_test_node( "nav_test_node", "0", FCVAR_CHEAT );
+ConVar nav_test_node_crouch( "nav_test_node_crouch", "0", FCVAR_CHEAT );
+ConVar nav_test_node_crouch_dir( "nav_test_node_crouch_dir", "4", FCVAR_CHEAT );
+ConVar nav_show_node_grid( "nav_show_node_grid", "0", FCVAR_CHEAT );
+#endif // DEBUG_NAV_NODES
+
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavNode::Draw( void )
+{
+#if DEBUG_NAV_NODES
+
+	if ( !nav_show_nodes.GetBool() )
+		return;
+
+	int r = 0, g = 0, b = 0;
+
+	if ( m_isCovered )
+	{
+		if ( GetAttributes() & NAV_MESH_CROUCH )
+		{
+			b = 255;
+		}
+		else
+		{
+			r = 255;
+		}
+	}
+	else
+	{
+		if ( GetAttributes() & NAV_MESH_CROUCH )
+		{
+			b = 255;
+		}
+		g = 255;
+	}
+
+	NDebugOverlay::Cross3D( m_pos, 2, r, g, b, true, 0.1f );
+
+	if ( (!m_isCovered && nav_show_node_id.GetBool()) || (m_isCovered && nav_show_node_id.GetInt() < 0) )
+	{
+		char text[16];
+		Q_snprintf( text, sizeof( text ), "%d", m_id );
+		NDebugOverlay::Text( m_pos, text, true, 0.1f );
+	}
+
+	if ( (unsigned int)(nav_test_node.GetInt()) == m_id )
+	{
+		TheNavMesh->TestArea( this, 1, 1 );
+		nav_test_node.SetValue( 0 );
+	}
+
+	if ( (unsigned int)(nav_test_node_crouch.GetInt()) == m_id )
+	{
+		CheckCrouch();
+		nav_test_node_crouch.SetValue( 0 );
+	}
+
+	if ( GetAttributes() & NAV_MESH_CROUCH )
+	{
+		int i;
+		for( i=0; i<NUM_CORNERS; i++ )
+		{
+			if ( m_isBlocked[i] || m_crouch[i] )
+			{
+				Vector2D dir;
+				CornerToVector2D( (NavCornerType)i, &dir );
+
+				const float scale = 3.0f;
+				Vector scaled( dir.x * scale, dir.y * scale, 0 );
+
+				if ( m_isBlocked[i] )
+				{
+					NDebugOverlay::HorzArrow( m_pos, m_pos + scaled, 0.5, 255, 0, 0, 255, true, 0.1f );
+				}
+				else
+				{
+					NDebugOverlay::HorzArrow( m_pos, m_pos + scaled, 0.5, 0, 0, 255, 255, true, 0.1f );
+				}
+			}
+		}
+	}
+
+	if ( nav_show_node_grid.GetBool() )
+	{
+		for ( int i = NORTH; i < NUM_DIRECTIONS; i++ )
+		{
+			CNavNode *nodeNext = GetConnectedNode( (NavDirType) i );
+			if ( nodeNext )
+			{
+				NDebugOverlay::Line( *GetPosition(), *nodeNext->GetPosition(), 255, 255, 0, false, 0.1f );
+
+				float obstacleHeight = m_obstacleHeight[i];
+				if ( obstacleHeight > 0 )
+				{
+					float z = GetPosition()->z + obstacleHeight;
+					Vector from = *GetPosition();
+					Vector to = from;
+					AddDirectionVector( &to, (NavDirType) i, m_obstacleStartDist[i] );
+					NDebugOverlay::Line( from, to, 255, 0, 255, false, 0.1f );
+					from = to;
+					to.z = z;
+					NDebugOverlay::Line( from, to, 255, 0, 255, false, 0.1f );
+					from = to;
+					to = *GetPosition();
+					to.z = z;
+					AddDirectionVector( &to, (NavDirType) i, m_obstacleEndDist[i] );
+					NDebugOverlay::Line( from, to, 255, 0, 255, false, 0.1f );
+				}				
+			}
+		}
+	}
+	
+
+#endif // DEBUG_NAV_NODES
+}
+
+
+//--------------------------------------------------------------------------------------------------------
+// return ground height above node in given corner direction (NUM_CORNERS for highest in any direction)
+float CNavNode::GetGroundHeightAboveNode( NavCornerType cornerType ) const
+{
+	if ( cornerType >= 0 && cornerType < NUM_CORNERS )
+		return m_groundHeightAboveNode[ cornerType ];
+
+	float blockedHeight = 0.0f;
+	for ( int i=0; i<NUM_CORNERS; ++i )
+	{
+		blockedHeight = MAX( blockedHeight, m_groundHeightAboveNode[i] );
+	}
+
+	return blockedHeight;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Look up to JumpCrouchHeight in the air to see if we can fit a whole HumanHeight box
+ */
+bool CNavNode::TestForCrouchArea( NavCornerType cornerNum, const Vector& mins, const Vector& maxs, float *groundHeightAboveNode )
+{
+	CTraceFilterWalkableEntities filter( NULL, COLLISION_GROUP_PLAYER_MOVEMENT, WALK_THRU_EVERYTHING );
+	trace_t tr;
+
+	Vector start( m_pos );
+	Vector end( start );
+	end.z += JumpCrouchHeight;
+	UTIL_TraceHull( start, end, NavTraceMins, NavTraceMaxs, MASK_NPCSOLID_BRUSHONLY, &filter, &tr );
+
+	float maxHeight = tr.endpos.z - start.z;
+
+	Vector realMaxs( maxs );
+
+	for ( float height = 0; height <= maxHeight; height += 1.0f )
+	{
+		start = m_pos;
+		start.z += height;
+
+		realMaxs.z = HumanCrouchHeight;
+		UTIL_TraceHull( start, start, mins, realMaxs, MASK_NPCSOLID_BRUSHONLY, &filter, &tr );
+		if ( !tr.startsolid )
+		{
+			*groundHeightAboveNode = start.z - m_pos.z;
+
+			// We found a crouch-sized space.  See if we can stand up.
+			realMaxs.z = HumanHeight;
+			UTIL_TraceHull( start, start, mins, realMaxs, MASK_NPCSOLID_BRUSHONLY, &filter, &tr );
+			if ( !tr.startsolid )
+			{
+				// We found a crouch-sized space.  See if we can stand up.
+#if DEBUG_NAV_NODES
+				if ( (unsigned int)(nav_test_node_crouch.GetInt()) == GetID() )
+				{
+					NDebugOverlay::Box( start, mins, maxs, 0, 255, 255, 100, 100 );
+				}
+#endif // DEBUG_NAV_NODES
+				return true;
+			}
+#if DEBUG_NAV_NODES
+			if ( (unsigned int)(nav_test_node_crouch.GetInt()) == GetID() )
+			{
+				NDebugOverlay::Box( start, mins, maxs, 255, 0, 0, 100, 100 );
+			}
+#endif // DEBUG_NAV_NODES
+
+			return false;
+		}
+	}
+
+	*groundHeightAboveNode = JumpCrouchHeight;
+	m_isBlocked[ cornerNum ] = true;
+	return false;
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+void CNavNode::CheckCrouch( void )
+{
+	// For each direction, trace upwards from our best ground height to VEC_HULL_MAX.z to see if we have standing room.
+	for ( int i=0; i<NUM_CORNERS; ++i )
+	{
+#if DEBUG_NAV_NODES
+		if ( nav_test_node_crouch_dir.GetInt() != NUM_CORNERS && i != nav_test_node_crouch_dir.GetInt() )
+			continue;
+#endif // DEBUG_NAV_NODES
+
+		NavCornerType corner = (NavCornerType)i;
+		Vector2D cornerVec;
+		CornerToVector2D( corner, &cornerVec );
+
+		// Build a mins/maxs pair for the HumanWidth x HalfHumanWidth box facing the appropriate direction
+		Vector mins( 0, 0, 0 );
+		Vector maxs( 0, 0, 0 );
+		if ( cornerVec.x < 0 )
+		{
+			mins.x = -HalfHumanWidth;
+		}
+		else if ( cornerVec.x > 0 )
+		{
+			maxs.x = HalfHumanWidth;
+		}
+		if ( cornerVec.y < 0 )
+		{
+			mins.y = -HalfHumanWidth;
+		}
+		else if ( cornerVec.y > 0 )
+		{
+			maxs.y = HalfHumanWidth;
+		}
+		maxs.z = HumanHeight;
+
+		// now make sure that mins is smaller than maxs
+		for ( int j=0; j<3; ++j )
+		{
+			if ( mins[j] > maxs[j] )
+			{
+				float tmp = mins[j];
+				mins[j] = maxs[j];
+				maxs[j] = tmp;
+			}
+		}
+
+		if ( !TestForCrouchArea( corner, mins, maxs, &m_groundHeightAboveNode[i] ) )
+		{
+			SetAttributes( NAV_MESH_CROUCH );
+			m_crouch[corner] = true;
+		}
+	}
+}
+
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Create a connection FROM this node TO the given node, in the given direction
+ */
+void CNavNode::ConnectTo( CNavNode *node, NavDirType dir, float obstacleHeight, float obstacleStartDist, float obstacleEndDist )
+{
+	Assert( obstacleStartDist >= 0 && obstacleStartDist <= GenerationStepSize );
+	Assert( obstacleEndDist >= 0 && obstacleStartDist <= GenerationStepSize );
+	Assert( obstacleStartDist < obstacleEndDist );
+
+	m_to[ dir ] = node;
+	m_obstacleHeight[ dir ] = obstacleHeight;
+	m_obstacleStartDist[ dir ] = obstacleStartDist;
+	m_obstacleEndDist[ dir ] = obstacleEndDist;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return node at given position.
+ * @todo Need a hash table to make this lookup fast
+ */
+CNavNode *CNavNode::GetNode( const Vector &pos )
+{
+	const float tolerance = 0.45f * GenerationStepSize;			// 1.0f
+	CNavNode *pNode = NULL;
+	if ( g_pNavNodeHash )
+	{
+		static CNavNode lookup;
+		lookup.m_pos = pos;
+		UtlHashHandle_t hNode = g_pNavNodeHash->Find( &lookup );
+
+		if ( hNode != g_pNavNodeHash->InvalidHandle() )
+		{
+			for( pNode = g_pNavNodeHash->Element( hNode ); pNode; pNode = pNode->m_nextAtXY )
+			{
+				float dz = fabs( pNode->m_pos.z - pos.z );
+
+				if (dz < tolerance)
+				{
+					break;
+				}
+			}
+		}
+	}
+
+#ifdef DEBUG_NODE_HASH
+	CNavNode *pTestNode = NULL;
+	for( CNavNode *node = m_list; node; node = node->m_next )
+	{
+		float dx = fabs( node->m_pos.x - pos.x );
+		float dy = fabs( node->m_pos.y - pos.y );
+		float dz = fabs( node->m_pos.z - pos.z );
+
+		if (dx < tolerance && dy < tolerance && dz < tolerance)
+		{
+			pTestNode = node;
+			break;
+		}
+	}
+	AssertFatal( pTestNode == pNode );
+#endif
+
+	return pNode;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if this node is bidirectionally linked to 
+ * another node in the given direction
+ */
+BOOL CNavNode::IsBiLinked( NavDirType dir ) const
+{
+	if (m_to[ dir ] && m_to[ dir ]->m_to[ Opposite[dir] ] == this)
+	{
+		return true;
+	}
+
+	return false;
+}
+
+//--------------------------------------------------------------------------------------------------------------
+/**
+ * Return true if this node is the NW corner of a quad of nodes
+ * that are all bidirectionally linked.
+ */
+BOOL CNavNode::IsClosedCell( void ) const
+{
+	if (IsBiLinked( SOUTH ) &&
+		IsBiLinked( EAST ) &&
+		m_to[ EAST ]->IsBiLinked( SOUTH ) &&
+		m_to[ SOUTH ]->IsBiLinked( EAST ) &&
+		m_to[ EAST ]->m_to[ SOUTH ] == m_to[ SOUTH ]->m_to[ EAST ])
+	{
+		return true;
+	}
+
+	return false;
+}
+
-- 
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