react-native/Examples/2048/GameBoard.js

202 lines
5.8 KiB
JavaScript

/**
* The examples provided by Facebook are for non-commercial testing and
* evaluation purposes only.
*
* Facebook reserves all rights not expressly granted.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL
* FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* @providesModule GameBoard
* @flow
*/
'use strict';
// NB: Taken straight from: https://github.com/IvanVergiliev/2048-react/blob/master/src/board.js
// with no modification except to format it for CommonJS and fix lint/flow errors
var rotateLeft = function (matrix) {
var rows = matrix.length;
var columns = matrix[0].length;
var res = [];
for (var row = 0; row < rows; ++row) {
res.push([]);
for (var column = 0; column < columns; ++column) {
res[row][column] = matrix[column][columns - row - 1];
}
}
return res;
};
var Tile = function (value?: number, row?: number, column?: number) {
this.value = value || 0;
this.row = row || -1;
this.column = column || -1;
this.oldRow = -1;
this.oldColumn = -1;
this.markForDeletion = false;
this.mergedInto = null;
this.id = Tile.id++;
};
Tile.id = 0;
Tile.prototype.moveTo = function (row, column) {
this.oldRow = this.row;
this.oldColumn = this.column;
this.row = row;
this.column = column;
};
Tile.prototype.isNew = function () {
return this.oldRow === -1 && !this.mergedInto;
};
Tile.prototype.hasMoved = function () {
return (this.fromRow() !== -1 && (this.fromRow() !== this.toRow() || this.fromColumn() !== this.toColumn())) ||
this.mergedInto;
};
Tile.prototype.fromRow = function () {
return this.mergedInto ? this.row : this.oldRow;
};
Tile.prototype.fromColumn = function () {
return this.mergedInto ? this.column : this.oldColumn;
};
Tile.prototype.toRow = function () {
return this.mergedInto ? this.mergedInto.row : this.row;
};
Tile.prototype.toColumn = function () {
return this.mergedInto ? this.mergedInto.column : this.column;
};
var Board = function () {
this.tiles = [];
this.cells = [];
for (var i = 0; i < Board.size; ++i) {
this.cells[i] = [this.addTile(), this.addTile(), this.addTile(), this.addTile()];
}
this.addRandomTile();
this.setPositions();
this.won = false;
};
Board.prototype.addTile = function () {
var res = new Tile();
Tile.apply(res, arguments);
this.tiles.push(res);
return res;
};
Board.size = 4;
Board.prototype.moveLeft = function () {
var hasChanged = false;
for (var row = 0; row < Board.size; ++row) {
var currentRow = this.cells[row].filter(function (tile) { return tile.value !== 0; });
var resultRow = [];
for (var target = 0; target < Board.size; ++target) {
var targetTile = currentRow.length ? currentRow.shift() : this.addTile();
if (currentRow.length > 0 && currentRow[0].value === targetTile.value) {
var tile1 = targetTile;
targetTile = this.addTile(targetTile.value);
tile1.mergedInto = targetTile;
var tile2 = currentRow.shift();
tile2.mergedInto = targetTile;
targetTile.value += tile2.value;
}
resultRow[target] = targetTile;
this.won = this.won || (targetTile.value === 2048);
hasChanged = hasChanged || (targetTile.value !== this.cells[row][target].value);
}
this.cells[row] = resultRow;
}
return hasChanged;
};
Board.prototype.setPositions = function () {
this.cells.forEach(function (row, rowIndex) {
row.forEach(function (tile, columnIndex) {
tile.oldRow = tile.row;
tile.oldColumn = tile.column;
tile.row = rowIndex;
tile.column = columnIndex;
tile.markForDeletion = false;
});
});
};
Board.fourProbability = 0.1;
Board.prototype.addRandomTile = function () {
var emptyCells = [];
for (var r = 0; r < Board.size; ++r) {
for (var c = 0; c < Board.size; ++c) {
if (this.cells[r][c].value === 0) {
emptyCells.push({r: r, c: c});
}
}
}
var index = Math.floor(Math.random() * emptyCells.length);
var cell = emptyCells[index];
var newValue = Math.random() < Board.fourProbability ? 4 : 2;
this.cells[cell.r][cell.c] = this.addTile(newValue);
};
Board.prototype.move = function (direction) {
// 0 -> left, 1 -> up, 2 -> right, 3 -> down
this.clearOldTiles();
for (var i = 0; i < direction; ++i) {
this.cells = rotateLeft(this.cells);
}
var hasChanged = this.moveLeft();
for (var i = direction; i < 4; ++i) {
this.cells = rotateLeft(this.cells);
}
if (hasChanged) {
this.addRandomTile();
}
this.setPositions();
return this;
};
Board.prototype.clearOldTiles = function () {
this.tiles = this.tiles.filter(function (tile) { return tile.markForDeletion === false; });
this.tiles.forEach(function (tile) { tile.markForDeletion = true; });
};
Board.prototype.hasWon = function () {
return this.won;
};
Board.deltaX = [-1, 0, 1, 0];
Board.deltaY = [0, -1, 0, 1];
Board.prototype.hasLost = function () {
var canMove = false;
for (var row = 0; row < Board.size; ++row) {
for (var column = 0; column < Board.size; ++column) {
canMove = canMove || (this.cells[row][column].value === 0);
for (var dir = 0; dir < 4; ++dir) {
var newRow = row + Board.deltaX[dir];
var newColumn = column + Board.deltaY[dir];
if (newRow < 0 || newRow >= Board.size || newColumn < 0 || newColumn >= Board.size) {
continue;
}
canMove = canMove || (this.cells[row][column].value === this.cells[newRow][newColumn].value);
}
}
}
return !canMove;
};
module.exports = Board;