tsnake.cpp

#include <algorithm>
#include <cstdlib>
#include <deque>
#include <ncurses.h>
#include <random>
#include <string>
#include <unistd.h>

#include "tsnake.hpp"

#define height 25
#define width (height * 2)

int main(int argc, char *argv[]) {
  std::random_device rd;
  std::uniform_int_distribution<int> randX(1, width - 3);
  std::uniform_int_distribution<int> randY(1, height - 3);

  initscr();
  curs_set(0); // hide terminal cursor
  cbreak();    // read individual keY hits rather than complete lines of text
  noecho();    // stop echoing keYboard inputs
  refresh();   // refresh stdscr

  WINDOW *board = createWin();

  int input;
  int highscore = 0;

  do {
    int X = width / 2, Y = height / 2;
    int tailY = Y, tailX = X;
    int appleX = randX(rd), appleY = randY(rd);
    int score = 0;
    int nextdireciton = -1, direction = KEY_UP;
    char body = 'o', apple = 'A';

    std::vector<char> snake(10, 'X');
    std::deque<int> moves;
    std::vector<std::pair<int, int>> positons;

    printHomeScreen(board, highscore);

    wgetch(board);

    redraw(board);

    printScore(board, score);

    // print snake
    for (char c : snake) {
      mvwaddch(board, tailY++, tailX, body);
      positons.push_back(std::make_pair(tailX, tailY));
    }
    wrefresh(board);

    // print the first apple
    mvwaddch(board, appleY, appleX, apple);

    for (int i = 0; i < snake.size(); i++)
      moves.push_back(KEY_UP); // record initial moves for tail end

    auto pos = std::find(positons.begin(), positons.end(),
                         std::make_pair(tailX, tailY));
    auto it = std::find(positons.begin(), positons.end(),
                        std::make_pair(appleX, appleY));
    mvwaddch(board, tailY, tailX, ' ');

    while (Y < height - 1 && Y > 0 && X < width - 1 && X > 0) // main game loop
    {
      // print new head positon
      mvwaddch(board, Y, X, body);
      positons.push_back(std::make_pair(X, Y));
      wrefresh(board);

      // wait and take input
      do {
        wtimeout(board, 200);
        nextdireciton = wgetch(board);
      } while (nextdireciton != KEY_UP && nextdireciton != KEY_DOWN &&
               nextdireciton != KEY_LEFT && nextdireciton != KEY_RIGHT &&
               nextdireciton != -1);

      // if there is change in direction
      if (nextdireciton != -1) {
        if ((direction == KEY_RIGHT && nextdireciton != KEY_LEFT) ||
            (direction == KEY_LEFT && nextdireciton != KEY_RIGHT) ||
            (direction == KEY_DOWN && nextdireciton != KEY_UP) ||
            (direction == KEY_UP && nextdireciton != KEY_DOWN))
          direction = nextdireciton;
      }

      // updtae next head direction from input
      if (direction == KEY_UP)
        --Y;
      else if (direction == KEY_DOWN)
        ++Y;
      else if (direction == KEY_LEFT)
        --X;
      else if (direction == KEY_RIGHT)
        ++X;

      // if the snake eat the apple
      if (Y == appleY && X == appleX) {
        // increase score bY 5 and print it
        score += 5;
        printScore(board, score);

        // print new apple in another random location
        do {
          appleY = randY(rd);
          appleX = randX(rd);
          mvwaddch(board, appleY, appleX, apple);
          auto it = std::find(positons.begin(), positons.end(),
                              std::make_pair(appleX, appleY));
        } while (it == positons.end()); // new apple location must note be
                                        // inside the snake body

        moves.push_back(direction); // record the next move
      } else {
        moves.push_back(direction); // record the next move

        // update tail end
        if (moves.front() == KEY_UP)
          --tailY;
        else if (moves.front() == KEY_DOWN)
          ++tailY;
        else if (moves.front() == KEY_LEFT)
          --tailX;
        else if (moves.front() == KEY_RIGHT)
          ++tailX;

        // remove the current tail end piece
        moves.pop_front();
        positons.erase(positons.begin());
        mvwaddch(board, tailY, tailX, ' ');
      }

      // check if the snake bite itself
      auto pos =
          std::find(positons.begin(), positons.end(), std::make_pair(X, Y));
      if (pos != positons.end())
        break;
    }

    if (highscore < score)
      highscore = score;
    printEndScreen(board, highscore, score);

    // take input
    do {
      wtimeout(board, -1);
      input = wgetch(board);
    } while (input != 10 &&
             input != 113); // input must be either 'ENTER' or 'Q';

  } while (input == 10);

  destroy_win(board);

  endwin();
  return 0;
}