forked from 0ad/0ad
262 lines
7.4 KiB
C++
Executable File
262 lines
7.4 KiB
C++
Executable File
#include "precompiled.h"
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#include "PathfindSparse.h"
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#include "Terrain.h"
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#include "Game.h"
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int SPF_RECURSION_DEPTH = 10;
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sparsePathTree::sparsePathTree( const CVector2D& _from, const CVector2D& _to, HEntity _entity, CBoundingObject* _destinationCollisionObject, int _recursionDepth )
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{
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from = _from; to = _to;
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recursionDepth = _recursionDepth;
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entity = _entity; destinationCollisionObject = _destinationCollisionObject;
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leftPre = NULL; leftPost = NULL;
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rightPre = NULL; rightPost = NULL;
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type = SPF_OPEN_UNVISITED;
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leftImpossible = false; rightImpossible = false;
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nextSubtree = 0;
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}
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sparsePathTree::~sparsePathTree()
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{
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if( leftPre ) delete( leftPre );
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if( leftPost ) delete( leftPost );
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if( rightPre ) delete( rightPre );
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if( rightPost ) delete( rightPost );
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}
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bool sparsePathTree::slice()
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{
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CTerrain *pTerrain = g_Game->GetWorld()->GetTerrain();
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if( type == SPF_OPEN_UNVISITED )
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{
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if( !recursionDepth )
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{
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// Too deep.
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type = SPF_IMPOSSIBLE;
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return( true );
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}
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rayIntersectionResults r;
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CVector2D forward = to - from;
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float len = forward.length();
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if( len == 0.0f )
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{
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// Too weird. (Heavy traffic, obstacles in positions leading to this degenerate state.
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type = SPF_IMPOSSIBLE;
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return( true );
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}
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forward /= len;
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CVector2D v_right = CVector2D( forward.y, -forward.x );
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if( !getRayIntersection( from, forward, v_right, len, entity->m_bounds->m_radius * 1.1f, destinationCollisionObject, &r ) )
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{
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type = SPF_CLOSED_DIRECT;
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return( true );
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}
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float turningRadius = ( entity->m_bounds->m_radius + r.boundingObject->m_radius ) * 1.1f;
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if( entity->m_turningRadius > turningRadius ) turningRadius = entity->m_turningRadius;
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// Too close, an impossible turn
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if( r.distance < turningRadius )
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{
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// Too close to make a proper turn; try dodging immediately a long way to the left or right.
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left = from - v_right * r.boundingObject->m_radius * 2.5f;
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right = from + v_right * r.boundingObject->m_radius * 2.5f;
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}
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else if( r.distance > ( len - turningRadius ) )
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{
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// Again, too close to avoid it properly. Try approaching the goal from the left or right.
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left = to - v_right * r.boundingObject->m_radius * 2.5f;
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right = to + v_right * r.boundingObject->m_radius * 2.5f;
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}
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else
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{
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// Dodge to the left or right of the obstacle.
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// A distance of offsetDistance is sufficient to guarantee we'll make the turn.
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CVector2D delta = r.position - from;
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float length = delta.length();
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float offsetDistance = ( turningRadius * length / sqrt( length * length - turningRadius * turningRadius ) );
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left = r.position - v_right * offsetDistance;
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right = r.position + v_right * offsetDistance;
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}
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favourLeft = false;
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if( r.closestApproach < 0 )
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favourLeft = true;
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// First we path to the left...
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leftPre = new sparsePathTree( from, left, entity, destinationCollisionObject, recursionDepth - 1 );
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leftPost = new sparsePathTree( left, to, entity, destinationCollisionObject, recursionDepth - 1 );
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// Then we path to the right...
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rightPre = new sparsePathTree( from, right, entity, destinationCollisionObject, recursionDepth - 1 );
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rightPost = new sparsePathTree( right, to, entity, destinationCollisionObject, recursionDepth - 1 );
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// If anybody reaches this point and is thinking:
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//
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// "Let's Do The Time-Warp Agaaaain!"
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//
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// Let me know.
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// Check that the subwaypoints are on the map...
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if( !pTerrain->isOnMap( left ) )
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{
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// Shut that path down
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leftPre->type = SPF_IMPOSSIBLE;
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leftPost->type = SPF_IMPOSSIBLE;
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}
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if( !pTerrain->isOnMap( right ) )
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{
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// Shut that path down
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rightPre->type = SPF_IMPOSSIBLE;
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rightPost->type = SPF_IMPOSSIBLE;
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}
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if( ( leftPre->type == SPF_IMPOSSIBLE ) && ( rightPre->type == SPF_IMPOSSIBLE ) )
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{
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// It's unlikely, but I suppose it /might/ happen
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type = SPF_IMPOSSIBLE;
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return( true );
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}
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type = SPF_OPEN_PROCESSING;
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return( true );
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}
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else /* type == SPF_OPEN_PROCESSING */
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{
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bool done = false;
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while( !done )
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{
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if( subtrees[nextSubtree]->type & SPF_OPEN )
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if( subtrees[nextSubtree]->slice() )
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done = true;
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nextSubtree++;
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nextSubtree %= 4;
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}
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if( ( leftPre->type == SPF_IMPOSSIBLE ) || ( leftPost->type == SPF_IMPOSSIBLE ) )
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leftImpossible = true;
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if( ( rightPre->type == SPF_IMPOSSIBLE ) || ( rightPost->type == SPF_IMPOSSIBLE ) )
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rightImpossible = true;
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if( leftImpossible && rightImpossible )
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{
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type = SPF_IMPOSSIBLE;
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return( done );
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}
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if( ( ( leftPre->type & SPF_SOLVED ) && ( leftPost->type & SPF_SOLVED ) ) ||
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( ( rightPre->type & SPF_SOLVED ) && ( rightPost->type & SPF_SOLVED ) ) )
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{
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type = SPF_CLOSED_WAYPOINTED;
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return( done );
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}
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return( done );
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}
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}
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void sparsePathTree::pushResults( std::vector<CVector2D>& nodelist )
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{
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assert( type & SPF_SOLVED );
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if( type == SPF_CLOSED_DIRECT )
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{
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nodelist.push_back( to );
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}
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else /* type == SPF_CLOSED_WAYPOINTED */
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{
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leftImpossible = !( ( leftPre->type & SPF_SOLVED ) && ( leftPost->type & SPF_SOLVED ) );
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rightImpossible = !( ( rightPre->type & SPF_SOLVED ) && ( rightPost->type & SPF_SOLVED ) );
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if( !leftImpossible && ( favourLeft || rightImpossible ) )
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{
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leftPost->pushResults( nodelist );
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leftPre->pushResults( nodelist );
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}
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else
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{
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assert( !rightImpossible );
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rightPost->pushResults( nodelist );
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rightPre->pushResults( nodelist );
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}
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}
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}
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void nodePostProcess( HEntity entity, std::vector<CVector2D>& nodelist )
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{
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std::vector<CVector2D>::iterator it;
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CVector2D next = nodelist.front();
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CEntityOrder node;
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node.m_type = CEntityOrder::ORDER_PATH_END_MARKER;
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entity->m_orderQueue.push_front( node );
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node.m_type = CEntityOrder::ORDER_GOTO_SMOOTHED;
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node.m_data[0].location = next;
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entity->m_orderQueue.push_front( node );
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for( it = nodelist.begin() + 1; it != nodelist.end(); it++ )
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{
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if( ( it + 1 ) == nodelist.end() ) break;
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CVector2D current = *it;
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CVector2D previous = *( it + 1 );
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CVector2D u = current - previous;
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CVector2D v = next - current;
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u = u.normalize();
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v = v.normalize();
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CVector2D ubar = u.beta();
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CVector2D vbar = v.beta();
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float alpha = entity->m_turningRadius * ( ubar - vbar ).length() / ( u + v ).length();
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node.m_data[0].location = current - u * alpha;
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entity->m_orderQueue.push_front( node );
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next = current;
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}
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// If we try to apply turning constraints to getting onto this path, there's a reasonable
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// risk the entity will deviate so far from the first path segment that the path becomes
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// unwalkable for it.
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entity->m_orderQueue.front().m_type = CEntityOrder::ORDER_GOTO_NOPATHING;
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}
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void pathSparse( HEntity entity, CVector2D destination )
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{
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std::vector<CVector2D> pathnodes;
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CVector2D source( entity->m_position.X, entity->m_position.Z );
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// Sanity check:
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if( source.length() < 0.01f ) return;
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sparsePathTree sparseEngine( source, destination, entity, getContainingObject( destination ), SPF_RECURSION_DEPTH );
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while( sparseEngine.type & sparsePathTree::SPF_OPEN ) sparseEngine.slice();
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// assert( sparseEngine.type & sparsePathTree::SPF_SOLVED ); // Shouldn't be any impossible cases yet.
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if( sparseEngine.type & sparsePathTree::SPF_SOLVED )
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{
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sparseEngine.pushResults( pathnodes );
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pathnodes.push_back( source );
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nodePostProcess( entity, pathnodes );
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}
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else
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{
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// Try a straight line. All we can do, really.
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CEntityOrder direct;
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direct.m_type = CEntityOrder::ORDER_GOTO_NOPATHING;
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direct.m_data[0].location = destination;
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entity->m_orderQueue.push_front( direct );
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}
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}
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