pacman/lib/PacManAI.cpp
2021-10-05 13:43:08 +02:00

82 lines
2.3 KiB
C++

#include "PacManAI.hpp"
#include "Board.hpp"
#include <fmt/format.h>
namespace pacman {
void PacManAI::reset() {
pos = {};
direction = Direction::RIGHT;
}
Direction PacManAI::suggestedDirection() const {
return direction;
}
GridPosition PacManAI::pelletClosestToPacman(GridPosition pacmanGridPosition,
std::vector<GridPosition> & pellets) {
auto pelletSort = [&pacmanGridPosition](GridPosition pelletA, GridPosition pelletB) {
double distanceA = positionDistance(pacmanGridPosition, pelletA);
double distanceB = positionDistance(pacmanGridPosition, pelletB);
return distanceA < distanceB;
};
std::sort(pellets.begin(), pellets.end(), pelletSort);
return pellets[0];
}
bool PacManAI::isValidMove(const Move & move) {
const bool isOpposite = (move.direction == oppositeDirection(direction));
if (isOpposite) {
return false;
}
const bool canWalk = isWalkableForPacMan(move.position);
if (!canWalk) {
return false;
}
return true;
}
Direction PacManAI::optimalDirection(const std::array<Move, 4> & moves) {
const auto optimalMove = std::min_element(moves.begin(), moves.end(), [](const auto & a, const auto & b) {
return a.distanceToTarget < b.distanceToTarget;
});
const auto & move = *optimalMove;
return move.direction;
}
void PacManAI::update(const PacMan & pacMan, const Pellets & pellets) {
const GridPosition pacManGridPos = pacMan.positionInGrid();
const GridPosition currentGridPos = positionToGridPosition(pos);
if (!isIntersection(pacManGridPos) || currentGridPos == pacManGridPos) {
return;
}
auto pelletPositions = pellets.allPellets();
if (pelletPositions.empty()) {
return;
}
const GridPosition targetPos = pelletClosestToPacman(pacManGridPos, pelletPositions);
const GridPosition currentPosition = pacMan.positionInGrid();
const auto [x, y] = currentPosition;
std::array<Move, 4> possibleMoves = {
Move{ Direction::UP, { x, y - 1 } },
Move{ Direction::LEFT, { x - 1, y } },
Move{ Direction::DOWN, { x, y + 1 } },
Move{ Direction::RIGHT, { x + 1, y } }
};
for (auto & move : possibleMoves) {
if (!isValidMove(move))
continue;
move.distanceToTarget = positionDistance(move.position, targetPos);
}
direction = optimalDirection(possibleMoves);
}
} // namespace pacman