Fixed marking cells with bombs for example mines (#792)

* Implemented gaming part of example `mines`. Not implemented: reveal nearby unmarket cells by middle mouse click and count scores.

* Disable game board after end of game

* small refactoring

* refactoring: rearrange code in files

* Fixed feature marking cells where assumed bomb.
All state moved to model (flag marks) therefore `border::view::Overlay` became meaningless type and was removed.
Now method `BoardView::draw()` using data about cells from model.

* unify Rect use

Co-authored-by: Alexandre Bury <[email protected]>

* simplified pub

Co-authored-by: Alexandre Bury <[email protected]>

* simplified pub

Co-authored-by: Alexandre Bury <[email protected]>

* simplified pub

Co-authored-by: Alexandre Bury <[email protected]>

* removed redundant code

Co-authored-by: Alexandre Bury <[email protected]>

* simplified pub

Co-authored-by: Alexandre Bury <[email protected]>

* simplified pub

Co-authored-by: Alexandre Bury <[email protected]>

* removed redundant allocation of new Vec<Cell>

Co-authored-by: Alexandre Bury <[email protected]>

* Removed redundant space

---------

Co-authored-by: Alexandre Bury <[email protected]>

cursive/examples/mines/board/mod.rs

@@ -0,0 +1,2 @@
+pub mod view;
+pub mod model;

cursive/examples/mines/board/model.rs

@@ -0,0 +1,279 @@
+use rand::seq::SliceRandom;
+use std::ops::{Index, IndexMut};
+use std::slice::Iter;
+use ahash::AHashSet;
+use cursive::{Rect, Vec2};
+use crate::board::model::CellState::*;
+
+#[derive(Clone, Copy)]
+pub struct Options {
+    pub size: Vec2,
+    pub mines: usize,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum CellContent {
+    Bomb,
+    // numer of near bombs
+    Free(usize),
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub enum CellState {
+    Closed,
+    // Marked by user, that this cell contains bomb
+    Marked,
+    Opened,
+}
+
+#[derive(Copy, Clone)]
+pub struct Cell {
+    pub state: CellState,
+
+    pub content: CellContent,
+}
+
+impl Cell {
+    pub fn new(content: CellContent) -> Self {
+        Self {
+            state: Closed,
+            content,
+        }
+    }
+}
+
+pub struct Field {
+    size: Vec2,
+    cells: Vec<Cell>,
+}
+
+impl Field {
+    fn new(size: Vec2) -> Self {
+        Self {
+            size,
+            // init stub for cells, see method `Field::place_bombs()` details
+            cells: vec![Cell::new(CellContent::Free(0)); size.x * size.y],
+        }
+    }
+
+    fn pos_to_cell_idx(&self, pos: Vec2) -> usize {
+        pos.x + pos.y * self.size.x
+    }
+
+    fn place_bombs(&mut self, click_pos: Vec2, bombs_count: usize) {
+        // For avoiding losing on first player's move we should place bombs excluding
+        // position where player clicked and it's neighbours
+
+        // calculation cells from starting rect
+        let rect = self.neighbours_rect(click_pos);
+        let exclusion_cells: Vec<_> = (rect.top()..rect.bottom())
+            .flat_map(|y| (rect.left()..rect.right()).map(move |x| Vec2::new(x, y)))
+            .collect();
+
+        // init bombs on board
+        let n_cells = self.cells.len();
+        self.cells.clear();
+        self.cells.resize(bombs_count, Cell:: new(CellContent::Bomb));
+        self.cells.resize(n_cells - exclusion_cells.len(), Cell:: new(CellContent::Free(0)));
+        let mut rng = rand::thread_rng();
+        self.cells.shuffle(&mut rng);
+
+        // push empty cells near of cursor to avoid bombs in this positions
+        for pos in exclusion_cells {
+            self.cells.insert(self.pos_to_cell_idx(pos), Cell::new(CellContent::Free(0)));
+        }
+
+        // recalculate near bombs
+        for pos in self.all_cell_pos_iter() {
+            if let CellContent::Free(_) = self[pos].content {
+                self[pos].content = CellContent::Free(self.calc_neighbors_bomb_count(pos));
+            }
+        }
+    }
+
+    pub fn all_cell_pos_iter(&self) -> impl Iterator<Item=Vec2> {
+        let size = self.size;
+        (0..size.y).flat_map(move |x| (0..size.x).map(move |y| Vec2::new(y, x)))
+    }
+
+    fn neighbours_rect(&self, pos: Vec2) -> Rect {
+        let pos_min = pos.saturating_sub((1, 1));
+        let pos_max = (pos + (2, 2)).or_min(self.size);
+
+        Rect::from_corners(pos_min, pos_max)
+    }
+
+    fn neighbours(&self, pos: Vec2) -> impl Iterator<Item=Vec2> {
+        let pos_min = pos.saturating_sub((1, 1));
+        let pos_max = (pos + (2, 2)).or_min(self.size);
+
+        (pos_min.y..pos_max.y)
+            .flat_map(move |x| (pos_min.x..pos_max.x).map(move |y| Vec2::new(y, x)))
+            .filter(move |&p| p != pos)
+    }
+
+    fn calc_neighbors_bomb_count(&self, cell_pos: Vec2) -> usize {
+        let mut bombs_count = 0;
+        for near_pos in self.neighbours(cell_pos) {
+            if self[near_pos].content == CellContent::Bomb {
+                bombs_count += 1;
+            }
+        }
+
+        bombs_count
+    }
+}
+
+impl Index<Vec2> for Field {
+    type Output = Cell;
+
+    fn index(&self, pos: Vec2) -> &Self::Output {
+        &self.cells[self.pos_to_cell_idx(pos)]
+    }
+}
+
+impl IndexMut<Vec2> for Field {
+    fn index_mut(&mut self, pos: Vec2) -> &mut Self::Output {
+        let idx = self.pos_to_cell_idx(pos);
+        &mut self.cells[idx]
+    }
+}
+
+
+pub struct Board {
+    pub size: Vec2,
+    pub bombs_count: usize,
+    pub field: Field,
+    is_bomb_placed: bool,
+    pub is_ended: bool,
+}
+
+impl Board {
+    pub fn new(options: Options) -> Self {
+        let n_cells = options.size.x * options.size.y;
+        if options.mines > n_cells {
+            // Something is wrong here...
+            // Use different options instead.
+            return Board::new(Options {
+                size: options.size,
+                mines: n_cells,
+            });
+        }
+
+        Board {
+            size: options.size,
+            bombs_count: options.mines,
+            is_bomb_placed: false,
+            field: Field::new(options.size),
+            is_ended: false,
+        }
+    }
+
+    pub fn iter(&self) -> Iter<'_, Cell>
+    {
+        self.field.cells.iter()
+    }
+
+    fn place_bombs_if_needed(&mut self, pos: Vec2) {
+        if !self.is_bomb_placed {
+            self.field.place_bombs(pos, self.bombs_count);
+
+            self.is_bomb_placed = true;
+        }
+    }
+
+    pub fn reveal(&mut self, pos: Vec2) -> RevealResult {
+        self.place_bombs_if_needed(pos);
+
+        let cell = &mut self.field[pos];
+        match cell.content {
+            CellContent::Bomb => {
+                self.is_ended = true;
+
+                RevealResult::Loss
+            }
+            CellContent::Free(_) => {
+                cell.state = Opened;
+
+                self.auto_reveal(pos)
+            }
+        }
+    }
+
+    pub(crate) fn auto_reveal(&mut self, pos: Vec2) -> RevealResult {
+        self.place_bombs_if_needed(pos);
+
+
+        let mut opened = AHashSet::new();
+        if let CellContent::Free(n) = self.field[pos].content {
+            let market_cells = self.field.neighbours(pos).filter(|pos| self.field[*pos].state == Marked).count();
+            if market_cells == n {
+                for near_pos in self.field.neighbours(pos) {
+                    if !self.check_neighbours_for_auto_reveal(near_pos, &mut opened) {
+                        return RevealResult::Loss;
+                    }
+                }
+            }
+        }
+
+        match self.check_victory() {
+            true => {
+                self.is_ended = true;
+                RevealResult::Victory
+            }
+            false => RevealResult::Revealed
+        }
+    }
+
+    pub(crate) fn toggle_flag(&mut self, pos: Vec2) {
+        self.place_bombs_if_needed(pos);
+
+        let cell = &mut self.field[pos];
+        cell.state = match cell.state {
+            Closed => Marked,
+            Marked => Closed,
+            Opened => Opened,
+        }
+    }
+
+    // NOTE: Returned when was bomb
+    fn check_neighbours_for_auto_reveal(&mut self, pos: Vec2, opened: &mut AHashSet<Vec2>) -> bool {
+        if self.field[pos].state == Opened || opened.contains(&pos) {
+            return true;
+        }
+
+        self.field[pos].state = Opened;
+        opened.insert(pos);
+
+        match self.field[pos].content {
+            CellContent::Bomb => false,
+            CellContent::Free(0) => {
+                for pos in self.field.neighbours(pos) {
+                    if !self.check_neighbours_for_auto_reveal(pos, opened) {
+                        return false;
+                    }
+                }
+                true
+            }
+            _ => true,
+        }
+    }
+
+    fn check_victory(&self) -> bool {
+        self.field.cells.iter().filter(|x| matches!(x.content, CellContent::Free(_))).all(|x| x.state == Opened)
+    }
+}
+
+impl Index<Vec2> for Board {
+    type Output = Cell;
+
+    fn index(&self, pos: Vec2) -> &Self::Output {
+        &self.field[pos]
+    }
+}
+
+pub enum RevealResult {
+    Revealed,
+    Loss,
+    Victory,
+}