ngx-chess-board/src/lib/models/pieces/knight.ts

Chess game component

import { PieceConstant } from '../../utils/unicode-constants';
import { Board } from '../board';
import { Color } from './color';
import { Piece } from './piece';
import { Point } from './point';

export class Knight extends Piece {
    isMovedAlready = false;

    constructor(
        point: Point,
        color: Color,
        constant: PieceConstant,
        board: Board
    ) {
        super(point, color, constant, 3, board);
    }

    getPossibleMoves(): Point[] {
        const possiblePoints = [];

        const row = this.point.row;
        const col = this.point.col;

        // gora -> lewo
        if (this.board.isFieldEmpty(row - 2, col - 1)) {
            possiblePoints.push(new Point(row - 2, col - 1));
        }

        // gora -> prawo
        if (this.board.isFieldEmpty(row - 2, col + 1)) {
            possiblePoints.push(new Point(row - 2, col + 1));
        }

        // lewo -> gora
        if (this.board.isFieldEmpty(row - 1, col - 2)) {
            possiblePoints.push(new Point(row - 1, col - 2));
        }

        // prawo -> gora
        if (this.board.isFieldEmpty(row - 1, col + 2)) {
            possiblePoints.push(new Point(row - 1, col + 2));
        }

        // lewo -> dol
        if (this.board.isFieldEmpty(row + 1, col - 2)) {
            possiblePoints.push(new Point(row + 1, col - 2));
        }

        // prawo -> dol
        if (this.board.isFieldEmpty(row + 1, col + 2)) {
            possiblePoints.push(new Point(row + 1, col + 2));
        }

        // dol -> lewo
        if (this.board.isFieldEmpty(row + 2, col - 1)) {
            possiblePoints.push(new Point(row + 2, col - 1));
        }

        // dol -> prawo
        if (this.board.isFieldEmpty(row + 2, col + 1)) {
            possiblePoints.push(new Point(row + 2, col + 1));
        }

        return possiblePoints;
    }

    getPossibleCaptures(): Point[] {
        const possiblePoints = [];

        const row = this.point.row;
        const col = this.point.col;

        // gora -> lewo
        if (
            this.board.isFieldTakenByEnemy(
                row - 2,
                col - 1,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row - 2, col - 1));
        }

        // gora -> prawo
        if (
            this.board.isFieldTakenByEnemy(
                row - 2,
                col + 1,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row - 2, col + 1));
        }

        // lewo -> gora
        if (
            this.board.isFieldTakenByEnemy(
                row - 1,
                col - 2,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row - 1, col - 2));
        }

        // prawo -> gora
        if (
            this.board.isFieldTakenByEnemy(
                row - 1,
                col + 2,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row - 1, col + 2));
        }

        // lewo -> dol
        if (
            this.board.isFieldTakenByEnemy(
                row + 1,
                col - 2,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row + 1, col - 2));
        }

        // prawo -> dol
        if (
            this.board.isFieldTakenByEnemy(
                row + 1,
                col + 2,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row + 1, col + 2));
        }

        // dol -> lewo
        if (
            this.board.isFieldTakenByEnemy(
                row + 2,
                col - 1,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row + 2, col - 1));
        }

        // dol -> prawo
        if (
            this.board.isFieldTakenByEnemy(
                row + 2,
                col + 1,
                this.color === Color.WHITE ? Color.BLACK : Color.WHITE
            )
        ) {
            possiblePoints.push(new Point(row + 2, col + 1));
        }

        return possiblePoints;
    }

    getCoveredFields(): Point[] {
        const possiblePoints = [];

        const row = this.point.row;
        const col = this.point.col;

        // gora -> lewo
        possiblePoints.push(new Point(row - 2, col - 1));

        // gora -> prawo
        possiblePoints.push(new Point(row - 2, col + 1));

        // lewo -> gora
        possiblePoints.push(new Point(row - 1, col - 2));

        // prawo -> gora
        possiblePoints.push(new Point(row - 1, col + 2));

        // lewo -> dol
        possiblePoints.push(new Point(row + 1, col - 2));

        // prawo -> dol
        possiblePoints.push(new Point(row + 1, col + 2));

        // dol -> lewo
        possiblePoints.push(new Point(row + 2, col - 1));

        // dol -> prawo
        possiblePoints.push(new Point(row + 2, col + 1));

        return possiblePoints;
    }
}