raycaster/maze.cpp

#include <fmt/core.h>
#include <string>
#include "rand.hpp"
#include "constants.hpp"
#include "maze.hpp"

using std::string;
using matrix::Matrix;

inline size_t rand(size_t i, size_t j) {
  if(i < j) {
    return Random::uniform(i, j);
  } else if(j < i) {
    return Random::uniform(j, i);
  } else {
    return i;
  }
}


inline bool split_dir(size_t iDim, size_t jDim) {
  if(iDim < jDim) {
    return false;
  } else if(jDim < iDim) {
    return true;
  } else {
    return Random::uniform(0, 1);
  }
}

inline bool good_hole(Matrix &map, size_t split, size_t hole, bool horiz) {
  if(hole % 2 == 0) return false;

  size_t j = horiz ? split : hole;
  size_t i = horiz ? hole : split;
  if(map[j][i] == WALL_PATH_LIMIT) return false;

  return true;
}

void divide(Matrix& map, std::vector<Room> &rooms,
    Point iCoords, Point jCoords, bool horizontal) {
  int iDim = iCoords.y - iCoords.x;
  int jDim = jCoords.y - jCoords.x;
  bool punch_room = false;

  if(iDim <= 0 || jDim <= 0) {
    return;
  } else if(iDim <= 2 && jDim <= 2) {
    fmt::println("MADE ROOM! {},{}; {},{}",
        iCoords.x, iCoords.y, jCoords.x, jCoords.y);
    punch_room = true;
  }

  if(horizontal) {
    size_t split = 0;
    do {
      split = rand(iCoords.x, iCoords.x + iDim + 1);
    } while(split % 2);

    size_t hole = 0;
    do {
      hole = rand(jCoords.x, jCoords.x + jDim +1);
    } while(good_hole(map, split, hole, horizontal));

    for(size_t j = jCoords.x; j <= jCoords.y; j++) {
      if(j != hole) {
        map[split][j] = WALL_PATH_LIMIT;
      }
    }

    divide(map, rooms,
        {iCoords.x, size_t(split - 1)},
        jCoords,
        split_dir(split - iCoords.x - 1, jDim));

    divide(map, rooms,
        {size_t(split + 1), iCoords.y},
        jCoords,
        split_dir(iCoords.x - split - 1, jDim));
  } else {
    size_t split = 0;
    do {
      split = rand(jCoords.x, jCoords.x + jDim + 1);
    } while(split % 2);

    size_t hole = 0;
    do {
      hole = rand(iCoords.x, iCoords.x + iDim + 1);
    } while(good_hole(map, split, hole, horizontal));

    for(size_t i = iCoords.x; i <= iCoords.y; i++) {
      if(i != hole) {
        map[i][split] = WALL_PATH_LIMIT;
      }
    }

    divide(map, rooms,
        iCoords,
        {jCoords.x, size_t(split - 1)},
        split_dir(iDim, split - jCoords.x - 1));

    divide(map, rooms,
        iCoords,
        {size_t(split + 1), jCoords.y},
        Random::uniform(0, 1));
  }

  if(punch_room) {
    // for(size_t j = jCoords.x; j <= jCoords.y; j++) {
    //   for(size_t i = iCoords.x; i <= iCoords.y; i++) {
    //     map[j][i] = 0;
    //   }
    // }

    Room room{iCoords.x, jCoords.x, iCoords.y - iCoords.x + 1, jCoords.y - jCoords.x + 1};

    for(auto r : rooms) {
      if(r.x == room.x && r.y == room.y) {
        return;
      }
    }

    rooms.push_back(room);
  }
}


void maze::recursive_div(Matrix& map, std::vector<Room>& rooms) {
  size_t width = matrix::width(map);
  size_t height = matrix::height(map);

  for(size_t i = 0; i < height; i++) {
    for(size_t j = 0; j < width; j++) {
      int val = (i == 0 ||
          j == 0 ||
          i == height - 1 ||
          j == width - 1);

      map[i][j] = val == 1 ? WALL_PATH_LIMIT : 0;
    }
  }

  divide(map, rooms, {1, height - 2}, {1, width - 2}, split_dir(1, 1));
}


bool complete(Matrix& maze) {
  size_t width = matrix::width(maze);
  size_t height = matrix::height(maze);

  for(size_t row = 1; row < height; row += 2) {
    for(size_t col = 1; col < width; col += 2) {
      if(maze[row][col] != 0) return false;
    }
  }

  // dbc::sentinel("LOL it's complete eh?");
  return true;
}

std::vector<Point> neighborsAB(Matrix& maze, Point on) {
  std::vector<Point> result;

  std::array<Point, 4> points{{
    {on.x, on.y - 2},
    {on.x, on.y + 2},
    {on.x - 2, on.y},
    {on.x + 2, on.y}
  }};

  for(auto point : points) {
    if(matrix::inbounds(maze, point.x, point.y)) {
      result.push_back(point);
    }
  }

  return result;
}

std::vector<Point> neighbors(Matrix& maze, Point on) {
  std::vector<Point> result;

  std::array<Point, 4> points{{
    {on.x, on.y - 2},
    {on.x, on.y + 2},
    {on.x - 2, on.y},
    {on.x + 2, on.y}
  }};

  for(auto point : points) {
    if(matrix::inbounds(maze, point.x, point.y)) {
      if(maze[point.y][point.x] == WALL_PATH_LIMIT) {
        result.push_back(point);
      }
    }
  }

  return result;
}

std::pair<Point, Point> findCoord(Matrix& maze) {
  size_t width = matrix::width(maze);
  size_t height = matrix::height(maze);

  for(size_t y = 1; y < height; y += 2) {
    for(size_t x = 1; x < width; x += 2) {
      if(maze[y][x] == WALL_PATH_LIMIT) {
        auto found = neighborsAB(maze, {x, y});

        for(auto point : found) {
          if(maze[point.y][point.x] == 0) {
            return {{x, y}, point};
          }
        }
      }
    }
  }

  matrix::dump("BAD MAZE", maze);
  dbc::sentinel("failed to find coord?");
}

void maze::hunt_and_kill(Matrix& maze, std::vector<Room>& rooms) {
  size_t width = matrix::width(maze);
  size_t height = matrix::height(maze);
  matrix::assign(maze, WALL_PATH_LIMIT);

  Room start{2, 2, 3, 3};
  rooms.push_back(start);
  Room goal{width-4, height-4, 3, 3};
  rooms.push_back(goal);

  for(auto& room : rooms) {
    for(matrix::box it{maze, room.x, room.y, 1}; it.next();) {
      maze[it.y][it.x] = 0;
    }
  }

  Point on{1,1};
  while(!complete(maze)) {
    auto n = neighbors(maze, on);
    if(n.size() == 0) {
      auto t = findCoord(maze);
      on = t.first;
      maze[on.y][on.x] = 0;
      size_t row = (on.y + t.second.y) / 2;
      size_t col = (on.x + t.second.x) / 2;
      maze[row][col] = 0;
    } else {
      auto nb = n[Random::uniform(size_t(0), n.size() - 1)];
      maze[nb.y][nb.x] = 0;

      size_t row = (nb.y + on.y) / 2;
      size_t col = (nb.x + on.x) / 2;
      maze[row][col] = 0;
      on = nb;
    }
  }
}