ObjectPosSelector.h

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/*
 * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
 * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
 *
 * 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 2 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.org/licenses/>.
 */

#ifndef _OBJECT_POS_SELECTOR_H
#define _OBJECT_POS_SELECTOR_H

#include<Common.h>

#include<map>

enum UsedPosType { USED_POS_PLUS, USED_POS_MINUS };

inline UsedPosType operator ~(UsedPosType uptype)
{
 return uptype==USED_POS_PLUS ? USED_POS_MINUS : USED_POS_PLUS;
}

struct TC_GAME_API ObjectPosSelector
{
 struct UsedPos
 {
 UsedPos(float sign_, float size_, float dist_) : sign(sign_), size(size_), dist(dist_) { }

 float sign;

 float size; // size of point
 float dist; // dist to central point (including central point size)
 };

 typedef std::multimap<float, UsedPos> UsedPosList; // abs(angle)->Node

 ObjectPosSelector(float x, float y, float size, float dist);

 void AddUsedPos(float size, float angle, float dist);
 void InitializeAngle();

 bool FirstAngle(float& angle);
 bool NextAngle(float& angle);
 bool NextUsedAngle(float& angle);

 bool NextPosibleAngle(float& angle);

 bool CheckAngle(UsedPosList::value_type const& nextUsedPos, float sign, float angle ) const
 {
 float angle_step2 = GetAngle(nextUsedPos.second);

 float next_angle = nextUsedPos.first;
 if (nextUsedPos.second.sign * sign < 0) // last node from diff. list (-pi+alpha)
 next_angle = 2 * float(M_PI) - next_angle; // move to positive

 return std::fabs(angle) + angle_step2 <= next_angle;
 }

 bool CheckOriginal() const
 {
 return (m_UsedPosLists[USED_POS_PLUS].empty() || CheckAngle(*m_UsedPosLists[USED_POS_PLUS].begin(), 1.0f, 0)) &&
 (m_UsedPosLists[USED_POS_MINUS].empty() || CheckAngle(*m_UsedPosLists[USED_POS_MINUS].begin(), -1.0f, 0));
 }

 bool IsNonBalanced() const { return m_UsedPosLists[USED_POS_PLUS].empty() != m_UsedPosLists[USED_POS_MINUS].empty(); }

 bool NextAngleFor(UsedPosList::value_type const& usedPos, float sign, UsedPosType uptype, float &angle)
 {
 float angle_step = GetAngle(usedPos.second);

 // next possible angle
 angle = usedPos.first * usedPos.second.sign + angle_step * sign;

 UsedPosList::value_type const* nextNode = nextUsedPos(uptype);
 if (nextNode)
 {
 // if next node permit use selected angle, then do it
 if (!CheckAngle(*nextNode, sign, angle))
 {
 m_smallStepOk[uptype] = false;
 return false;
 }
 }

 // possible more points
 m_smallStepOk[uptype] = true;
 m_smallStepAngle[uptype] = angle;
 m_smallStepNextUsedPos[uptype] = nextNode;

 return true;
 }

 bool NextSmallStepAngle(float sign, UsedPosType uptype, float &angle)
 {
 // next possible angle
 angle = m_smallStepAngle[uptype] + m_anglestep * sign;

 if (std::fabs(angle) > float(M_PI))
 {
 m_smallStepOk[uptype] = false;
 return false;
 }

 if (m_smallStepNextUsedPos[uptype])
 {
 if (std::fabs(angle) >= m_smallStepNextUsedPos[uptype]->first)
 {
 m_smallStepOk[uptype] = false;
 return false;
 }

 // if next node permit use selected angle, then do it
 if (!CheckAngle(*m_smallStepNextUsedPos[uptype], sign, angle))
 {
 m_smallStepOk[uptype] = false;
 return false;
 }
 }

 // possible more points
 m_smallStepAngle[uptype] = angle;
 return true;
 }

 // next used post for m_nextUsedPos[uptype]
 UsedPosList::value_type const* nextUsedPos(UsedPosType uptype);

 // angle from used pos to next possible free pos
 float GetAngle(UsedPos const& usedPos) const { return std::acos(m_dist/(usedPos.dist+usedPos.size+m_size)); }

 float m_center_x;
 float m_center_y;
 float m_size; // size of object in center
 float m_dist; // distance for searching pos (including central object size)
 float m_anglestep;

 UsedPosList m_UsedPosLists[2];
 UsedPosList::const_iterator m_nextUsedPos[2];

 // field for small step from first after next used pos until next pos
 float m_smallStepAngle[2];
 bool m_smallStepOk[2];
 UsedPosList::value_type const* m_smallStepNextUsedPos[2];
};
#endif