Warning, file /games/killbots/src/engine.cpp was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

 /*
     This file is part of Killbots.
 
     SPDX-FileCopyrightText: 2006-2009 Parker Coates <coates@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "engine.h"
 
 #include "coordinator.h"
 #include "settings.h"
 #include "sprite.h"
 
 #include "killbots_debug.h"
 
 #include <QRandomGenerator>
 
 #include <array>
 
 uint qHash(const QPoint &point)
 {
     return qHash(point.x() * 1000 + point.y());
 }
 
 inline int sign(int num)
 {
     return (num > 0) ? 1 : (num == 0) ? 0 : -1;
 }
 
 Killbots::Engine::Engine(Killbots::Coordinator *scene, QObject *parent)
     : QObject(parent),
       m_coordinator(scene),
       m_hero(nullptr),
       m_rules(nullptr),
       m_round(0),
       m_score(0),
       m_energy(0),
       m_maxEnergy(0.0),
       m_robotCount(0.0),
       m_fastbotCount(0.0),
       m_junkheapCount(0.0),
       m_heroIsDead(false),
       m_waitingOutRound(false),
       m_spriteMap()
 {
 }
 
 Killbots::Engine::~Engine()
 {
     delete m_rules;
 }
 
 void Killbots::Engine::setRuleset(const Ruleset *ruleset)
 {
     if (ruleset && ruleset != m_rules) {
         delete m_rules;
         m_rules = ruleset;
     }
 }
 
 const Killbots::Ruleset *Killbots::Engine::ruleset() const
 {
     return m_rules;
 }
 
 bool Killbots::Engine::gameHasStarted() const
 {
     return m_hero && m_score > 0;
 }
 
 bool Killbots::Engine::isRoundComplete() const
 {
     return m_bots.isEmpty();
 }
 
 bool Killbots::Engine::isHeroDead() const
 {
     return m_heroIsDead;
 }
 
 bool Killbots::Engine::isBoardFull() const
 {
     return m_robotCount + m_fastbotCount + m_junkheapCount
            > m_rules->rows() * m_rules->columns() / 2;
 }
 
 bool Killbots::Engine::canSafeTeleport() const
 {
     return m_rules->safeTeleportEnabled()
            && m_energy >= m_rules->costOfSafeTeleport();
 }
 
 bool Killbots::Engine::canUseVaporizer() const
 {
     return m_rules->vaporizerEnabled()
            && m_energy >= m_rules->costOfVaporizer();
 }
 
 void Killbots::Engine::startNewGame()
 {
     Q_ASSERT(m_rules != nullptr);
 
     // Don't show the new game message on first start.
     if (m_round != 0) {
         Q_EMIT showNewGameMessage();
     }
 
     m_heroIsDead = false;
 
     m_round = 1;
     m_score = 0;
     m_maxEnergy = m_rules->energyEnabled() ? m_rules->maxEnergyAtGameStart() : 0;
     m_energy = m_rules->energyEnabled() ? m_rules->energyAtGameStart() : 0;
     m_robotCount = m_rules->enemiesAtGameStart();
     m_fastbotCount = m_rules->fastEnemiesAtGameStart();
     m_junkheapCount = m_rules->junkheapsAtGameStart();
 
     Q_EMIT teleportAllowed(true);
     Q_EMIT waitOutRoundAllowed(true);
     Q_EMIT teleportSafelyAllowed(canSafeTeleport());
     Q_EMIT vaporizerAllowed(canUseVaporizer());
 
     // Code used to generate theme previews
     //newRound( "  r\nhjf", false );
 
     startNewRound(false);
 }
 
 void Killbots::Engine::startNewRound(bool incrementRound, const QString &layout)
 {
     cleanUpRound();
 
     m_waitingOutRound = false;
 
     m_coordinator->beginNewAnimationStage();
 
     if (incrementRound) {
         ++m_round;
 
         if (m_rules->energyEnabled()) {
             m_maxEnergy += m_rules->maxEnergyAddedEachRound();
             updateEnergy(m_rules->energyAddedEachRound());
         }
         m_robotCount += m_rules->enemiesAddedEachRound();
         m_fastbotCount += m_rules->fastEnemiesAddedEachRound();
         m_junkheapCount += m_rules->junkheapsAddedEachRound();
     }
 
     if (layout.isEmpty()) {
         // Place the hero in the centre of the board.
         const QPoint centre = QPoint(qRound((float)(m_rules->columns() / 2)), qRound((float)(m_rules->rows() / 2)));
         m_hero = m_coordinator->createSprite(Hero, centre);
 
         // Create and randomly place junkheaps.
         for (int i = m_junkheapCount; i > 0 ; --i) {
             const QPoint point = randomEmptyCell();
             m_junkheaps << m_coordinator->createSprite(Junkheap, point);
             m_spriteMap.insert(point, m_junkheaps.last());
         }
 
         // Create and randomly place robots.
         for (int i = m_robotCount; i > 0; --i) {
             const QPoint point = randomEmptyCell();
             m_bots << m_coordinator->createSprite(Robot, point);
             m_spriteMap.insert(point, m_bots.last());
         }
 
         // Create and randomly place fastbots.
         for (int i = m_fastbotCount; i > 0; --i) {
             const QPoint point = randomEmptyCell();
             m_bots << m_coordinator->createSprite(Fastbot, point);
             m_spriteMap.insert(point, m_bots.last());
         }
     } else {
         const QStringList rows = layout.split(QLatin1Char('\n'));
         for (int r = 0; r < rows.size(); ++r) {
             for (int c = 0; c < rows.at(r).size(); ++c) {
                 const QChar ch = rows.at(r).at(c);
                 const QPoint point(c, r);
 
                 if (ch == QLatin1Char('h') && m_hero == nullptr) {
                     m_hero = m_coordinator->createSprite(Hero, point);
         } else if (ch == QLatin1Char('r')) {
                     m_bots << m_coordinator->createSprite(Robot, point);
         } else if (ch == QLatin1Char('f')) {
                     m_bots << m_coordinator->createSprite(Fastbot, point);
         } else if (ch == QLatin1Char('j')) {
                     m_junkheaps << m_coordinator->createSprite(Junkheap, point);
                 }
             }
         }
     }
 
     Q_EMIT roundChanged(m_round);
     Q_EMIT scoreChanged(m_score);
     Q_EMIT enemyCountChanged(m_bots.size());
     Q_EMIT energyChanged(m_energy);
 
     refreshSpriteMap();
 }
 
 // Returns true if the move was performed, returns false otherwise.
 bool Killbots::Engine::moveHero(Killbots::HeroAction direction)
 {
     refreshSpriteMap();
     const QPoint newCell = m_hero->gridPos() + offsetFromDirection(direction);
     const bool preventUnsafeMoves = Settings::preventUnsafeMoves() || direction < 0;
 
     if (moveIsValid(newCell, direction) && (moveIsSafe(newCell, direction) || !preventUnsafeMoves)) {
         if (direction != Hold) {
             m_coordinator->beginNewAnimationStage();
 
             if (spriteTypeAt(newCell) == Junkheap) {
                 pushJunkheap(m_spriteMap.value(newCell), direction);
             }
 
             m_coordinator->slideSprite(m_hero, newCell);
         }
         return true;
     } else {
         return false;
     }
 }
 
 // Always returns true as teleports always succeed.
 bool Killbots::Engine::teleportHero()
 {
     refreshSpriteMap();
     const QPoint point = randomEmptyCell();
     m_coordinator->beginNewAnimationStage();
     m_coordinator->teleportSprite(m_hero, point);
     return true;
 }
 
 // Returns true if a safe cell was found. If no safe cell was found than
 // the board must be full.
 bool Killbots::Engine::teleportHeroSafely()
 {
     refreshSpriteMap();
 
     // Choose a random cell...
     const QPoint startPoint = QPoint(QRandomGenerator::global()->bounded(m_rules->columns()),
                                      QRandomGenerator::global()->bounded(m_rules->rows()));
     QPoint point = startPoint;
 
     // ...and step through all the cells on the board looking for a safe cell.
     do {
         if (point.x() < m_rules->columns() - 1) {
             point.rx()++;
         } else {
             point.rx() = 0;
             if (point.y() < m_rules->rows() - 1) {
                 point.ry()++;
             } else {
                 point.ry() = 0;
             }
         }
 
         // Looking for an empty and safe cell.
         if (spriteTypeAt(point) == NoSprite && point != m_hero->gridPos() && moveIsSafe(point, Teleport)) {
             break;
         }
     } while (point != startPoint);
 
     // If we stepped through every cell and found none that were safe, reset the robot counts.
     if (point == startPoint) {
         return false;
     } else {
         m_coordinator->beginNewAnimationStage();
         updateEnergy(-m_rules->costOfSafeTeleport());
         m_coordinator->teleportSprite(m_hero, point);
 
         return true;
     }
 }
 
 // Returns true if any enemies were within range.
 bool Killbots::Engine::useVaporizer()
 {
     refreshSpriteMap();
     QList<Sprite *> neighbors;
     for (int i = Right; i <= DownRight; ++i) {
         const QPoint neighbor = m_hero->gridPos() + offsetFromDirection(i);
         if (cellIsValid(neighbor) && (spriteTypeAt(neighbor) == Robot || spriteTypeAt(neighbor) == Fastbot)) {
             neighbors << m_spriteMap.value(neighbor);
         }
     }
 
     if (!neighbors.isEmpty()) {
         m_coordinator->beginNewAnimationStage();
         for (Sprite *sprite : std::as_const(neighbors)) {
             destroySprite(sprite);
         }
         updateEnergy(-m_rules->costOfVaporizer());
         return true;
     } else {
         return false;
     }
 }
 
 bool Killbots::Engine::waitOutRound()
 {
     m_waitingOutRound = true;
     return true;
 }
 
 void Killbots::Engine::moveRobots(bool justFastbots)
 {
     m_coordinator->beginNewAnimationStage();
 
     if (justFastbots) {
         refreshSpriteMap();
         for (Sprite *bot : std::as_const(m_bots)) {
             if (bot->spriteType() == Fastbot) {
                 const QPoint offset(sign(m_hero->gridPos().x() - bot->gridPos().x()), sign(m_hero->gridPos().y() - bot->gridPos().y()));
                 const QPoint target = bot->gridPos() + offset;
                 if (spriteTypeAt(target) != Robot || !m_rules->fastEnemiesArePatient()) {
                     m_coordinator->slideSprite(bot, target);
                 }
             }
         }
     } else {
         for (Sprite *bot : std::as_const(m_bots)) {
             const QPoint offset(sign(m_hero->gridPos().x() - bot->gridPos().x()), sign(m_hero->gridPos().y() - bot->gridPos().y()));
             m_coordinator->slideSprite(bot, bot->gridPos() + offset);
         }
     }
 }
 
 void Killbots::Engine::assessDamage()
 {
     refreshSpriteMap();
 
     m_coordinator->beginNewAnimationStage();
 
     if (m_spriteMap.count(m_hero->gridPos()) > 0) {
         m_heroIsDead = true;
     }
 
     // Check junkheaps for dead robots
     const auto junkheaps = m_junkheaps;
     for (Sprite *junkheap : junkheaps) {
         destroyAllCollidingBots(junkheap, !m_heroIsDead);
     }
 
     // Check for robot-on-robot violence
     int i = 0;
     while (i < m_bots.size()) {
         Sprite *bot = m_bots[i];
         if (bot->gridPos() != m_hero->gridPos() && destroyAllCollidingBots(bot, !m_heroIsDead)) {
             m_junkheaps << m_coordinator->createSprite(Junkheap, bot->gridPos());
             destroySprite(bot, !m_heroIsDead);
         } else {
             i++;
         }
     }
 
     if (isRoundComplete()) {
         m_coordinator->beginNewAnimationStage();
         Q_EMIT showRoundCompleteMessage();
     }
 }
 
 void Killbots::Engine::resetBotCounts()
 {
     m_coordinator->beginNewAnimationStage();
     Q_EMIT showBoardFullMessage();
 
     m_maxEnergy = m_rules->maxEnergyAtGameStart();
     m_robotCount = m_rules->enemiesAtGameStart();
     m_fastbotCount = m_rules->fastEnemiesAtGameStart();
     m_junkheapCount = m_rules->junkheapsAtGameStart();
 
     m_coordinator->beginNewAnimationStage();
     startNewRound(false);
 }
 
 void Killbots::Engine::endGame()
 {
     Q_EMIT showGameOverMessage();
     Q_EMIT teleportAllowed(false);
     Q_EMIT waitOutRoundAllowed(false);
     Q_EMIT teleportSafelyAllowed(false);
     Q_EMIT vaporizerAllowed(false);
     Q_EMIT gameOver(m_score, m_round);
 }
 
 // The hero action functions and the assessDamage functions must know the
 // contents of each cell. This function updates the hash that maps cells to
 // their contents.
 void Killbots::Engine::refreshSpriteMap()
 {
     m_spriteMap.clear();
     for (Sprite *bot : std::as_const(m_bots)) {
         m_spriteMap.insert(bot->gridPos(), bot);
     }
     for (Sprite *junkheap : std::as_const(m_junkheaps)) {
         m_spriteMap.insert(junkheap->gridPos(), junkheap);
     }
 }
 
 // A convenience function to query the type of a sprite any the given cell.
 int Killbots::Engine::spriteTypeAt(const QPoint &cell) const
 {
     if (m_spriteMap.contains(cell)) {
         return m_spriteMap.value(cell)->spriteType();
     } else {
         return NoSprite;
     }
 }
 
 QPoint Killbots::Engine::offsetFromDirection(int direction) const
 {
     if (direction < 0) {
         direction = -direction - 1;
     }
 
     switch (direction) {
     case Right:
         return QPoint(1,  0);
     case UpRight:
         return QPoint(1, -1);
     case Up:
         return QPoint(0, -1);
     case UpLeft:
         return QPoint(-1, -1);
     case Left:
         return QPoint(-1,  0);
     case DownLeft:
         return QPoint(-1,  1);
     case Down:
         return QPoint(0,  1);
     case DownRight:
         return QPoint(1,  1);
     default:
         return QPoint(0,  0);
     };
 }
 
 // Returns a random empty cell on the grid. Depends on a fresh spritemap.
 QPoint Killbots::Engine::randomEmptyCell() const
 {
     QPoint point;
     do {
         point = QPoint(QRandomGenerator::global()->bounded(m_rules->columns()),
                        QRandomGenerator::global()->bounded(m_rules->rows()));
     } while (spriteTypeAt(point) != NoSprite || point == m_hero->gridPos());
     return point;
 }
 
 // Returns true if the given cell lies inside the game grid.
 bool Killbots::Engine::cellIsValid(const QPoint &cell) const
 {
     return (0 <= cell.x()
             && cell.x() < m_rules->columns()
             && 0 <= cell.y()
             && cell.y() < m_rules->rows()
            );
 }
 
 bool Killbots::Engine::moveIsValid(const QPoint &cell, HeroAction direction) const
 {
     // The short version
     return (cellIsValid(cell)
             && (spriteTypeAt(cell) == NoSprite
                 || (spriteTypeAt(cell) == Junkheap
                     && canPushJunkheap(m_spriteMap.value(cell), direction)
                    )
                )
            );
 
     /*  // The debuggable version
         bool result = true;
 
         if ( cellIsValid( cell ) )
         {
             if ( spriteTypeAt( cell ) != NoSprite )
             {
                 if ( spriteTypeAt( cell ) == Junkheap )
                 {
                     if ( !canPushJunkheap( m_spriteMap.value( cell ), direction ) )
                     {
                         result = false;
                         //qCDebug(KILLBOTS_LOG) << "Move is invalid. Cannot push junkheap.";
                     }
                 }
                 else
                 {
                     result = false;
                     //qCDebug(KILLBOTS_LOG) << "Move is invalid. Cell is occupied by an unpushable object.";
                 }
             }
         }
         else
         {
             result = false;
             //qCDebug(KILLBOTS_LOG) << "Move is invalid. Cell is lies outside grid.";
         }
 
         return result;
     */
 }
 
 bool Killbots::Engine::moveIsSafe(const QPoint &cell, HeroAction direction) const
 {
     /*
     Warning: This algorithm might break your head. The following diagrams and descriptions try to help.
 
     Note: This algorithm assumes that the proposed move has already been checked for validity.
 
     Legend
     H = The position of the hero after the proposed move (the cell who's safeness we're trying to determine).
     J = The position of a junkheap after the proposed move, whether moved by the hero or sitting there already.
     R = The position of a robot.
     F = The position of a fastbot.
     * = A cell that we don't particularly care about in this diagram.
 
     +---+---+---+---+---+
     | * | * | * | * | * |
     +---+---+---+---+---+
     | * |   |   | F | * |
     +---+---+---+---+---+
     | * |   | H |   | * |    If any of the neighbouring cells contain a robot or fastbot, the move is unsafe.
     +---+---+---+---+---+
     | * |   | R |   | * |
     +---+---+---+---+---+
     | * | * | * | * | * |
     +---+---+---+---+---+
 
     +---+---+---+---+---+
     |   |   |   |   |   |
     +---+---+---+---+---+
     |   |   |   |   |   |
     +---+---+---+---+---+
     |   | *<==J<==H |   |    If the proposed move involved pushing a junkheap, we can ignore the cell that the junkheap
     +---+---+---+---+---+    will end up in, because if there were an enemy there, it would be crushed.
     |   |   |   |   |   |
     +---+---+---+---+---+
     |   |   |   |   |   |
     +---+---+---+---+---+
 
     +---+---+---+---+---+
     |C01|   |   |   |   |
     +---+---+---+---+---+    Fastbots can attack from two cells away, making it trickier to determine whether they
     |   |N01|   |   |E01|    pose a threat. First we have to understand the attack vector of a fastbot. A fastbot
     +---+---+---+---+---+    attacking from a "corner" cell such as C01 will pass through a diagonal neighbour like
     |   |   | H |N02|E02|    like N01. Any fastbot attacking from an "edge" cell like E01, E02 or E03 will have to
     +---+---+---+---+---+    pass through a horizontal or vertical neighbour like N02. This mean that when checking
     |   |   |   |   |E03|    a diagonal neighbour we only need to check the one cell "behind" it for fastbots, but
     +---+---+---+---+---+    when checking a horizontal or vertical neighbour we need to check the three cells
     |   |   |   |   |   |    "behind" it for fastbots.
     +---+---+---+---+---+
 
     +---+---+---+---+---+
     |   |   |   |   | * |
     +---+---+---+---+---+
     | * |   |   | J |   |
     +---+---+---+---+---+    Back to junkheaps. If a neighbouring cell contains a junkheap, we don't need to check
     | * | J | H |   |   |    the cells behind it for fastbots because if there were any there, they'd just collide
     +---+---+---+---+---+    with the junkheap anyway.
     | * |   |   |   |   |
     +---+---+---+---+---+
     |   |   |   |   |   |
     +---+---+---+---+---+
 
     +---+---+---+---+---+
     | * | * | * | * | F |
     +---+---+---+---+---+
     | * | * | * |   | * |
     +---+---+---+---+---+
     | * | * | H | * | * |    "Corner" fastbot threats are easy enough to detect. If a diagonal neighbour is empty
     +---+---+---+---+---+    and the cell behind it contains a fastbot, the move is unsafe.
     | * | * | * | * | * |
     +---+---+---+---+---+
     | * | * | * | * | * |
     +---+---+---+---+---+
 
     +---+---+---+---+---+
     | * | * | * | * | * |
     +---+---+---+---+---+
     | R | * | * | * | * |
     +---+---+---+---+---+    "Edge" fastbots threats are much harder to detect because any fastbots on an edge might
     | F |   | H | * | * |    collide with robots or other fastbots on their way to the neighbouring cell. For example,
     +---+---+---+---+---+    the hero in this diagram is perfectly safe because all the fastbots will be destroyed
     |   | * |   | * | * |    before they can become dangerous.
     +---+---+---+---+---+
     | * | F |   | F | * |
     +---+---+---+---+---+
 
     +---+---+---+---+---+
     | * | F |   |   | * |
     +---+---+---+---+---+
     | * | * |   | * |   |
     +---+---+---+---+---+    With a bit of thought, it's easy to see that an "edge" fastbot is only a threat if there
     | * | * | H |   |   |    is exactly one fastbot and zero robots on that edge.
     +---+---+---+---+---+
     | * | * |   | * | F |    When you put all of the above facts together you (hopefully) get the following algorithm.
     +---+---+---+---+---+
     | * |   | F |   | * |
     +---+---+---+---+---+
     */
 
     // The move is assumed safe until proven unsafe.
     bool result = true;
 
     // If we're pushing a junkheap, store the cell that the junkheap will end up in. Otherwise store an invalid cell.
     const QPoint cellBehindJunkheap = (spriteTypeAt(cell) != Junkheap)
                                       ? QPoint(-1, -1)
                                       : cell + offsetFromDirection(direction);
 
     // We check the each of the target cells neighbours.
     for (int i = Right; i <= DownRight && result; ++i) {
         const QPoint neighbor = cell + offsetFromDirection(i);
 
         // If the neighbour is invalid or the cell behind the junkheap, continue to the next neighbour.
         if (!cellIsValid(neighbor) || spriteTypeAt(neighbor) == Junkheap || neighbor == cellBehindJunkheap) {
             continue;
         }
 
         // If the neighbour contains an enemy, the move is unsafe.
         if (spriteTypeAt(neighbor) == Robot || spriteTypeAt(neighbor) == Fastbot) {
             result = false;
         } else {
             // neighboursNeighbour is the cell behind the neighbour, with respect to the target cell.
             const QPoint neighborsNeighbor = neighbor + offsetFromDirection(i);
 
             // If we're examining a diagonal neighbour (an odd direction)...
             if (i % 2 == 1) {
                 // ...and neighboursNeighbour is a fastbot then the move is unsafe.
                 if (spriteTypeAt(neighborsNeighbor) == Fastbot) {
                     result = false;
                 }
             }
             // If we're examining an vertical or horizontal neighbour, things are more complicated...
             else {
                 // Assemble a list of the cells behind the neighbour.
                 const std::array<QPoint, 3> cellsBehindNeighbor {
             neighborsNeighbor,
                 // Add neighboursNeighbour's anticlockwise neighbour.
                 // ( i + 2 ) % 8 is the direction a quarter turn anticlockwise from i.
             neighborsNeighbor + offsetFromDirection((i + 2) % 8),
                 // Add neighboursNeighbour's clockwise neighbour.
                 // ( i + 6 ) % 8 is the direction a quarter turn clockwise from i.
             neighborsNeighbor + offsetFromDirection((i + 6) % 8),
         };
 
                 // Then we just count the number of fastbots and robots in the list of cells.
                 int fastbotsFound = 0;
                 int robotsFound = 0;
                 for (const QPoint &cell : cellsBehindNeighbor) {
                     if (spriteTypeAt(cell) == Fastbot) {
                         ++fastbotsFound;
                     } else if (spriteTypeAt(cell) == Robot) {
                         ++robotsFound;
                     }
                 }
 
                 // If there is exactly one fastbots and zero robots, the move is unsafe.
                 if (fastbotsFound == 1 && robotsFound == 0) {
                     result = false;
                 }
             }
         }
     }
 
     return result;
 }
 
 bool Killbots::Engine::canPushJunkheap(const Sprite *junkheap, HeroAction direction) const
 {
     Q_ASSERT(junkheap->spriteType() == Junkheap);
 
     const QPoint nextCell = junkheap->gridPos() + offsetFromDirection(direction);
 
     if (m_rules->pushableJunkheaps() != Ruleset::None && cellIsValid(nextCell)) {
         if (spriteTypeAt(nextCell) == NoSprite) {
             return true;
         } else if (spriteTypeAt(nextCell) == Junkheap) {
             return m_rules->pushableJunkheaps() == Ruleset::Many && canPushJunkheap(m_spriteMap.value(nextCell), direction);
         } else {
             return m_rules->squaskKillsEnabled();
         }
     } else {
         return false;
     }
 }
 
 void Killbots::Engine::pushJunkheap(Sprite *junkheap, HeroAction direction)
 {
     const QPoint nextCell = junkheap->gridPos() + offsetFromDirection(direction);
     Sprite *currentOccupant = m_spriteMap.value(nextCell);
     if (currentOccupant) {
         if (currentOccupant->spriteType() == Junkheap) {
             pushJunkheap(currentOccupant, direction);
         } else {
             destroySprite(currentOccupant);
             updateScore(m_rules->squashKillPointBonus());
             updateEnergy(m_rules->squashKillEnergyBonus());
         }
     }
 
     m_coordinator->slideSprite(junkheap, nextCell);
 }
 
 void Killbots::Engine::cleanUpRound()
 {
     m_coordinator->beginNewAnimationStage();
 
     if (m_hero) {
         destroySprite(m_hero);
     }
     m_hero = nullptr;
 
     const auto bots = m_bots;
     for (Sprite *bot : bots) {
         destroySprite(bot, false);
     }
     Q_ASSERT(m_bots.isEmpty());
     m_bots.clear();
 
     const auto junkheaps = m_junkheaps;
     for (Sprite *junkheap : junkheaps) {
         destroySprite(junkheap);
     }
     Q_ASSERT(m_junkheaps.isEmpty());
     m_junkheaps.clear();
 
     m_spriteMap.clear();
 }
 
 void Killbots::Engine::destroySprite(Sprite *sprite, bool calculatePoints)
 {
     const SpriteType type = sprite->spriteType();
 
     if (type == Robot || type == Fastbot) {
         if (calculatePoints) {
             if (type == Robot) {
                 updateScore(m_rules->pointsPerEnemyKilled());
             } else {
                 updateScore(m_rules->pointsPerFastEnemyKilled());
             }
 
             if (m_waitingOutRound) {
                 updateScore(m_rules->waitKillPointBonus());
                 updateEnergy(m_rules->waitKillEnergyBonus());
             }
         }
         m_bots.removeOne(sprite);
         Q_EMIT enemyCountChanged(m_bots.size());
     } else if (type == Junkheap) {
         m_junkheaps.removeOne(sprite);
     }
 
     m_coordinator->destroySprite(sprite);
 }
 
 bool Killbots::Engine::destroyAllCollidingBots(const Sprite *sprite, bool calculatePoints)
 {
     bool result = false;
 
     const auto robotsAtPos = m_spriteMap.values(sprite->gridPos());
     for (Sprite *robot : robotsAtPos) {
         if (robot != sprite && (robot->spriteType() == Robot || robot->spriteType() == Fastbot)) {
             destroySprite(robot, calculatePoints);
             result = true;
         }
     }
 
     return result;
 }
 
 void Killbots::Engine::updateScore(int changeInScore)
 {
     if (changeInScore != 0) {
         m_score = m_score + changeInScore;
         Q_EMIT scoreChanged(m_score);
     }
 }
 
 void Killbots::Engine::updateEnergy(int changeInEnergy)
 {
     if (m_rules->energyEnabled() && changeInEnergy != 0) {
         if (changeInEnergy > 0 && m_energy > int(m_maxEnergy)) {
             m_score += changeInEnergy * m_rules->pointsPerEnergyAboveMax();
         } else if (changeInEnergy > 0 && m_energy + changeInEnergy > int(m_maxEnergy)) {
             m_score += (m_energy + changeInEnergy - int(m_maxEnergy)) * m_rules->pointsPerEnergyAboveMax();
             m_energy = int(m_maxEnergy);
         } else {
             m_energy = m_energy + changeInEnergy;
         }
 
         Q_EMIT energyChanged(m_energy);
         Q_EMIT teleportSafelyAllowed(canSafeTeleport());
         Q_EMIT vaporizerAllowed(canUseVaporizer());
     }
 }
 
 QString Killbots::Engine::gridToString() const
 {
     QString string;
     for (int r = 0; r < m_rules->rows(); ++r) {
         for (int c = 0; c < m_rules->columns(); ++c) {
             switch (spriteTypeAt(QPoint(c, r))) {
             case Robot:
                 string += QLatin1Char('r');
                 break;
             case Fastbot:
                 string += QLatin1Char('f');
                 break;
             case Junkheap:
         string += QLatin1Char('j');
                 break;
             default:
         string += QLatin1Char(' ');
                 break;
             }
         }
                 string += QLatin1Char('\n');
     }
     return string;
 }