tetris.js

var math = require('mathjs');
var mechanics = require('./modules/mechanics')
var pieces = require('./modules/pieces')

const readline = require('readline');

readline.emitKeypressEvents(process.stdin);
process.stdin.setRawMode(true);
process.stdin.on('keypress', (str, key) => {
    if (key.ctrl && key.name === 'c') {
        process.exit();
    }
    else {
        switch (key.name) {
            case 'up':
                if (piece.id != 4) {
                    if (!mechanics.detectSpinCollision(piece, board)) {
                        piece = mechanics.spin(piece);
                        displayPieceOnBoard(board);
                    }
                }
                break;
            case 'down':
                step();
                break;
            case 'left':
                if (!mechanics.detectCollision(piece, board, 'left')) {
                    piece.left -= 1;
                    displayPieceOnBoard(board);
                }
                break;
            case 'right':
                if (!mechanics.detectCollision(piece, board, 'right')) {
                    piece.left += 1;
                    displayPieceOnBoard(board);
                }
                break;
            case "space":
                while (piece.top > 0) {
                    dropPiece();
                }
        }
    }
});

function setBoard() {
    var board = math.zeros(28, 16);

    //set up the board with a solid perimeter
    board.forEach(function(value, index, matrix) {
        if (index[1] == 0 || index[1] == 1 || index[1] == 2 || index[1] == 13 || index[1] == 14 || index[1] == 15) {
            board._data[index[0]][index[1]] = 1;
        }
        if (index[0] > 23) {
            board._data[index[0]][index[1]] = 1;
        }
    });

    return board;
}

// displays the current board
function showBoard(theBoard) {
    process.stdout.write('\033c');
    for (var i = 0; i < theBoard._size[0]; i++) {
        if (i > 2 && i < 25) {
            console.log(theBoard._data[i].toString()
                .replace(/,/g, " ")
                .replace(/0/g, " ")
                .replace(/2\s/g, "██")
                .replace(/1\s?/g, "██")
                .replace(/3\s/g, "\x1b[33m██\x1b[0m")
                .replace(/4\s/g, "\x1b[34m██\x1b[0m")
                .replace(/5\s/g, "\x1b[35m██\x1b[0m")
                .replace(/6\s/g, "\x1b[36m██\x1b[0m")
                .replace(/7\s/g, "\x1b[32m██\x1b[0m")
                .replace(/8\s/g, "\x1b[31m██\x1b[0m")
            );
        }
    }

}

// See if we can drop the piece, and return true if we did. 
// Return false if the piece cannot go any lower. 
function dropPiece() {

    var hitSomething = mechanics.detectCollision(piece, board, 'down');

    if (hitSomething == true) {
        if (piece.top < 2) {
            clearInterval(looper);
            lockPiece();
            showBoard(board);
            console.log("GAME OVER, LOSER!");
        }
        else {
            lockPiece();
            checkLines();
            spawnPiece();
        }
    }
    else {
        // Did not hit any other piece, or the bottom, so let's drop down
        piece.top += 1;
    }
    return !hitSomething;
}

// Lock the piece in place on the main board 
function lockPiece() {
    piece.matrix.forEach(function(value, index, matrix) {
        //  console.log('value:', value, 'index:', index);
        if (value == piece.id)
            board = board.subset(math.index(index[0] + piece.top, index[1] + piece.left), piece.id);
    });
}

function spawnPiece() {
    piece = pieces.getNewPiece();
}

function checkLines() {
    let lines = 0;
    for (let i = piece.top; i < piece.top + 5; i++) {
        if (i > 23) break;
        if (board._data[i].indexOf(0) === -1) {
            clearLine(board, i);
            lines++;
        }
    }
    calcPoints(lines);
}

function calcPoints(lines) {
    if (lines === 1) {
        gameScore += 100;
    }
    else {
        gameScore += (lines * 200);
    }
}

function clearLine(board, row) {
    var temp = math.subset(board, math.index(math.range(0, row), math.range(3, 13)));
    board.subset(math.index(math.range(1, row + 1), math.range(3, 13)), temp);
}

function displayPieceOnBoard() {
    var tempBoard = board.clone();
    // Copies a piece onto the board
    piece.matrix.forEach(function(value, index, matrix) {
        //  console.log('value:', value, 'index:', index);
        if (index[0] + piece.top >= 0 && value == piece.id) {
            tempBoard.subset(math.index(index[0] + piece.top, index[1] + piece.left), piece.id);
        }
    });
    showBoard(tempBoard);
    console.log("score: ", gameScore);
    console.log("level: ", level);
    // console.log("interval: ", interval);
}

function step() {
    if (dropPiece()) {
        displayPieceOnBoard();
        if (gameScore > (level * 1000)) {
            interval /= 2;
            looper = setInterval(step, interval)
            level++;
        }
    }
}

// set the initial board
var board = setBoard();

var piece = pieces.getNewPiece();

var next = pieces.getNewPiece();

displayPieceOnBoard();

// This calls the step() function [to drop the current piece] each <interval> seconds
var interval = 600;
var looper = setInterval(step, interval);
var looping = true;
var gameScore = 0;
var level = 1;