kicad/pcbnew/router/pns_walkaround.cpp

/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013  CERN
 * Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
 * 
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.or/licenses/>.
 */

#include <vector>

#include <boost/foreach.hpp>
#include <boost/optional.hpp>

#include <geometry/shape_line_chain.h>

#include "pns_walkaround.h"
#include "pns_optimizer.h"
#include "pns_utils.h"
#include "pns_router.h"

using namespace std;
using boost::optional;

void PNS_WALKAROUND::start( const PNS_LINE& aInitialPath )
{
	m_iteration = 0;
	m_iteration_limit = 50;
}


PNS_NODE::OptObstacle PNS_WALKAROUND::nearestObstacle(const PNS_LINE& aPath)
{
	return m_world->NearestObstacle ( &aPath, m_solids_only ? (PNS_ITEM::SOLID | PNS_ITEM::VIA) : PNS_ITEM::ANY );
}


PNS_WALKAROUND::WalkaroundStatus PNS_WALKAROUND::singleStep(PNS_LINE& aPath, bool aWindingDirection)
{
	optional<PNS_OBSTACLE>& current_obs = aWindingDirection ? m_currentObstacle[0] : m_currentObstacle[1];
	bool& prev_recursive = aWindingDirection ? m_recursiveCollision[0] : m_recursiveCollision[1];
	
	if(!current_obs)
		return DONE;

	SHAPE_LINE_CHAIN path_pre[2], path_walk[2], path_post[2];

	VECTOR2I last = aPath.GetCLine().CPoint(-1);

	if((current_obs->hull).PointInside(last))
	{
		m_recursiveBlockageCount ++;

		if(m_recursiveBlockageCount < 3)
			aPath.GetLine().Append( current_obs->hull.NearestPoint(last) );
		else {
			aPath = aPath.ClipToNearestObstacle(m_world);
			return STUCK;
		}
	}

	aPath.NewWalkaround(current_obs->hull, path_pre[0], path_walk[0], path_post[0], aWindingDirection);
	aPath.NewWalkaround(current_obs->hull, path_pre[1], path_walk[1], path_post[1], !aWindingDirection);


	int len_pre = path_walk[0].Length();
	int len_alt = path_walk[1].Length();
		
	PNS_LINE walk_path (aPath, path_walk[1]);
		
	bool alt_collides = m_world->CheckColliding(&walk_path, m_solids_only ? PNS_ITEM::SOLID : PNS_ITEM::ANY);

	SHAPE_LINE_CHAIN pnew;

	if(!m_forceSingleDirection && len_alt < len_pre && !alt_collides && !prev_recursive)
	{
		pnew = path_pre[1];
		pnew.Append(path_walk[1]);
		pnew.Append(path_post[1]);
		
		current_obs = nearestObstacle(PNS_LINE(aPath, path_post[1]));
		prev_recursive = false;
	} else {
		pnew = path_pre[0];
		pnew.Append(path_walk[0]);
		pnew.Append(path_post[0]);
	
		current_obs = nearestObstacle(PNS_LINE(aPath, path_walk[0]));

		if(!current_obs)
		{
			prev_recursive = false;
			current_obs = nearestObstacle(PNS_LINE(aPath, path_post[0]));
		} else
			prev_recursive = true;
	}

		
	pnew.Simplify();
	aPath.SetShape(pnew);

	return IN_PROGRESS;
}

PNS_WALKAROUND::WalkaroundStatus PNS_WALKAROUND::Route( const PNS_LINE& aInitialPath, PNS_LINE& aWalkPath, bool aOptimize )
{
	PNS_LINE path_cw(aInitialPath), path_ccw(aInitialPath);
	WalkaroundStatus s_cw = IN_PROGRESS, s_ccw = IN_PROGRESS;
	SHAPE_LINE_CHAIN best_path;

	start(aInitialPath);

	m_currentObstacle[0] = m_currentObstacle[1] = nearestObstacle(aInitialPath);
	m_recursiveBlockageCount = 0;

	aWalkPath = aInitialPath;

	while(m_iteration < m_iteration_limit)
	{
		if(s_cw != STUCK)
			s_cw = singleStep(path_cw, true);
			
		if(s_ccw != STUCK)
			s_ccw = singleStep(path_ccw, false);

		if((s_cw == DONE && s_ccw == DONE) || (s_cw == STUCK && s_ccw == STUCK))
		{
			int len_cw = path_cw.GetCLine().Length();
			int len_ccw = path_ccw.GetCLine().Length();


			if(m_forceLongerPath)
				aWalkPath = (len_cw > len_ccw ? path_cw : path_ccw);
			else
				aWalkPath = (len_cw < len_ccw ? path_cw : path_ccw);

			break;
		} else if(s_cw == DONE && !m_forceLongerPath) {
			aWalkPath = path_cw;
			break;
		} else if (s_ccw == DONE && !m_forceLongerPath) {
			aWalkPath = path_ccw;
			break;
		}


		m_iteration++;
	}

	if(m_iteration == m_iteration_limit)
	{
		int len_cw = path_cw.GetCLine().Length();
		int len_ccw = path_ccw.GetCLine().Length();


		if(m_forceLongerPath)
			aWalkPath = (len_cw > len_ccw ? path_cw : path_ccw);
		else
			aWalkPath = (len_cw < len_ccw ? path_cw : path_ccw);

	}

	if(m_cursorApproachMode)
	{
		//int len_cw = path_cw.GetCLine().Length();
		//int len_ccw = path_ccw.GetCLine().Length();
		bool found = false;

		SHAPE_LINE_CHAIN l = aWalkPath.GetCLine();

			
			for(int i = 0; i < l.SegmentCount(); i++)
			{
				const SEG s = l.Segment(i);

				VECTOR2I nearest = s.NearestPoint(m_cursorPos);
				VECTOR2I::extended_type dist_a = (s.a - m_cursorPos).SquaredEuclideanNorm();
				VECTOR2I::extended_type dist_b = (s.b - m_cursorPos).SquaredEuclideanNorm();
				VECTOR2I::extended_type dist_n = (nearest - m_cursorPos).SquaredEuclideanNorm();


			
				if(dist_n <= dist_a && dist_n < dist_b)
				{
					//PNSDisplayDebugLine(l, 3);
					l.Remove(i + 1, -1);
					l.Append( nearest );
					l.Simplify();
					found = true;
					break;
				}
			}
			if(found)
			{
				aWalkPath =  aInitialPath;
				aWalkPath.SetShape(l);
			}
		}


	aWalkPath.SetWorld(m_world);
	aWalkPath.GetLine().Simplify();

	WalkaroundStatus st = s_ccw == DONE || s_cw == DONE ? DONE : STUCK;

	if(aOptimize && st == DONE)
		PNS_OPTIMIZER::Optimize(&aWalkPath, PNS_OPTIMIZER::MERGE_OBTUSE, m_world);

	return st;
}