minicrossterm/examples/program_examples/snake/src/map.rs

use super::variables::{Position, Size, Direction };
use super::snake::Snake;

use crossterm::{Crossterm, Screen};
use crossterm::cursor::from_screen;
use crossterm::style::{ObjectStyle, StyledObject, Color, style};

use rand::distributions::{IndependentSample, Range};

use std::hash::Hash;
use std::collections::HashMap;
use std::fmt::Display;
use std::ops::Index;

use rand;

pub struct Map
{
    pub size: Size,
    pub foot_pos: Position,
}

impl Map
{
   pub fn new(size: Size) -> Self
   {
       Map { size: size, foot_pos: Position::new(0,0) }
   }

    // render the map on the screen.
    pub fn render_map(&mut self, screen: &Screen, free_positions: &mut HashMap<String, Position>)
    {
        let crossterm = Crossterm::from_screen(screen);
        let mut cursor = crossterm.cursor();
        let mut terminal = crossterm.terminal();

        for y in 0..self.size.height
        {
            for x in 0..self.size.height
            {
                if (y == 0 || y == self.size.height - 1) || (x == 0 || x == self.size.width - 1)
                {
                    cursor.goto(x as u16, y as u16);
                    terminal.write("█")
                }else {
                    free_positions.insert(format!("{},{}",x,y), Position::new(x,y));
                }
            }
        }
    }

    pub fn is_out_of_bounds(&self, new_pos: Position) -> bool
    {
        if (new_pos.x == 0 || new_pos.x == self.size.width) || (new_pos.y == 0 || new_pos.y == self.size.height)
        {
            return true;
        }

        return false;
    }

    pub fn is_food_eaten(&self, snake_head: Position) -> bool
    {
        snake_head.x == self.foot_pos.x && snake_head.y == self.foot_pos.y
    }

    pub fn spawn_food(&mut self, free_positions: &HashMap<String, Position>, screen: &Screen)
    {
        let index = Range::new(0, free_positions.len()).ind_sample(&mut rand::thread_rng());
        self.foot_pos = free_positions.values().skip(index).next().unwrap().clone();
        self.draw_food(screen);
    }

    fn draw_food(&self, screen: &Screen)
    {
        from_screen(screen).goto(self.foot_pos.x as u16, self.foot_pos.y as u16);
        style("$").with(Color::Green).paint(screen);
        screen.stdout.flush();
    }
}