samegame.js Example File

demos/declarative/samegame/qml/samegame/SamegameCore/samegame.js
 /* This script file handles the game logic */

 var maxColumn = 10;
 var maxRow = 15;
 var maxIndex = maxColumn*maxRow;
 var board = new Array(maxIndex);
 var blockSrc = "SamegameCore/BoomBlock.qml";
 var scoresURL = "";
 var gameDuration;
 var component = Qt.createComponent(blockSrc);
 var highScoreBar = 0;

 // Index function used instead of a 2D array
 function index(column, row)
 {
     return column + row * maxColumn;
 }

 function timeStr(msecs)
 {
     var secs = Math.floor(msecs/1000);
     var m = Math.floor(secs/60);
     var ret = "" + m + "m " + (secs%60) + "s";
     return ret;
 }

 function startNewGame()
 {
     // Delete blocks from previous game
     for (var i = 0; i < maxIndex; i++) {
         if (board[i] != null)
             board[i].destroy();
     }

     // Calculate board size
     maxColumn = Math.floor(gameCanvas.width/gameCanvas.blockSize);
     maxRow = Math.floor(gameCanvas.height/gameCanvas.blockSize);
     maxIndex = maxRow * maxColumn;

     // Close dialogs
     nameInputDialog.forceClose();
     dialog.forceClose();

     // Initialize Board
     board = new Array(maxIndex);
     gameCanvas.score = 0;
     for (var column = 0; column < maxColumn; column++) {
         for (var row = 0; row < maxRow; row++) {
             board[index(column, row)] = null;
             createBlock(column, row);
         }
     }
     gameDuration = new Date();
 }

 var fillFound;  // Set after a floodFill call to the number of blocks found
 var floodBoard; // Set to 1 if the floodFill reaches off that node

 // NOTE: Be careful with vars named x,y, as the calling object's x,y are still in scope
 function handleClick(x,y)
 {
     var column = Math.floor(x/gameCanvas.blockSize);
     var row = Math.floor(y/gameCanvas.blockSize);
     if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)
         return;
     if (board[index(column, row)] == null)
         return;
     // If it's a valid block, remove it and all connected (does nothing if it's not connected)
     floodFill(column,row, -1);
     if (fillFound <= 0)
         return;
     gameCanvas.score += (fillFound - 1) * (fillFound - 1);
     shuffleDown();
     victoryCheck();
 }

 function floodFill(column,row,type)
 {
     if (board[index(column, row)] == null)
         return;
     var first = false;
     if (type == -1) {
         first = true;
         type = board[index(column,row)].type;

         // Flood fill initialization
         fillFound = 0;
         floodBoard = new Array(maxIndex);
     }
     if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)
         return;
     if (floodBoard[index(column, row)] == 1 || (!first && type != board[index(column, row)].type))
         return;
     floodBoard[index(column, row)] = 1;
     floodFill(column + 1, row, type);
     floodFill(column - 1, row, type);
     floodFill(column, row + 1, type);
     floodFill(column, row - 1, type);
     if (first == true && fillFound == 0)
         return; // Can't remove single blocks
     board[index(column, row)].dying = true;
     board[index(column, row)] = null;
     fillFound += 1;
 }

 function shuffleDown()
 {
     // Fall down
     for (var column = 0; column < maxColumn; column++) {
         var fallDist = 0;
         for (var row = maxRow - 1; row >= 0; row--) {
             if (board[index(column,row)] == null) {
                 fallDist += 1;
             } else {
                 if (fallDist > 0) {
                     var obj = board[index(column, row)];
                     obj.y = (row + fallDist) * gameCanvas.blockSize;
                     board[index(column, row + fallDist)] = obj;
                     board[index(column, row)] = null;
                 }
             }
         }
     }
     // Fall to the left
     fallDist = 0;
     for (column = 0; column < maxColumn; column++) {
         if (board[index(column, maxRow - 1)] == null) {
             fallDist += 1;
         } else {
             if (fallDist > 0) {
                 for (row = 0; row < maxRow; row++) {
                     obj = board[index(column, row)];
                     if (obj == null)
                         continue;
                     obj.x = (column - fallDist) * gameCanvas.blockSize;
                     board[index(column - fallDist,row)] = obj;
                     board[index(column, row)] = null;
                 }
             }
         }
     }
 }

 function victoryCheck()
 {
     // Awards bonuses for no blocks left
     var deservesBonus = true;
     for (var column = maxColumn - 1; column >= 0; column--)
         if (board[index(column, maxRow - 1)] != null)
             deservesBonus = false;
     if (deservesBonus)
         gameCanvas.score += 500;
     // Checks for game over
     if (deservesBonus || !(floodMoveCheck(0, maxRow - 1, -1))) {
         gameDuration = new Date() - gameDuration;
         if(gameCanvas.score > highScoreBar){
             nameInputDialog.show("You won! Please enter your name:                 ");
             nameInputDialog.initialWidth = nameInputDialog.text.width + 20;
             if (nameInputDialog.name == "")
                 nameInputDialog.width = nameInputDialog.initialWidth;
             nameInputDialog.text.opacity = 0; // Just a spacer
         }else{
             dialog.show("You won!");
         }
     }
 }

 // Only floods up and right, to see if it can find adjacent same-typed blocks
 function floodMoveCheck(column, row, type)
 {
     if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)
         return false;
     if (board[index(column, row)] == null)
         return false;
     var myType = board[index(column, row)].type;
     if (type == myType)
         return true;
     return floodMoveCheck(column + 1, row, myType) ||
            floodMoveCheck(column, row - 1, board[index(column, row)].type);
 }

 function createBlock(column,row)
 {
     // Note that we don't wait for the component to become ready. This will
     // only work if the block QML is a local file. Otherwise the component will
     // not be ready immediately. There is a statusChanged signal on the
     // component you could use if you want to wait to load remote files.
     if(component.status == Component.Ready){
         var dynamicObject = component.createObject(gameCanvas,
                 {"type": Math.floor(Math.random() * 3),
                 "x": column*gameCanvas.blockSize,
                 "width": gameCanvas.blockSize,
                 "height": gameCanvas.blockSize});
         if(dynamicObject == null){
             console.log("error creating block");
             console.log(component.errorString());
             return false;
         }
         dynamicObject.y = row*gameCanvas.blockSize;
         dynamicObject.spawned = true;

         board[index(column,row)] = dynamicObject;
     }else{
         console.log("error loading block component");
         console.log(component.errorString());
         return false;
     }
     return true;
 }

 function initHighScoreBar()
 {
     if(scoresURL != "")
         return true;//don't query remote scores
     var db = openDatabaseSync(
         "SameGameScores",
         "1.0",
         "Local SameGame High Scores",
         100
     );
     db.transaction(
         function(tx) {
             tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(name TEXT, score NUMBER, gridSize TEXT, time NUMBER)');
             // Only show results for the current grid size
             var rs = tx.executeSql('SELECT * FROM Scores WHERE gridSize = "'
                 + maxColumn + "x" + maxRow + '" ORDER BY score desc LIMIT 10');
             if(rs.rows.length < 10)
                 highScoreBar = 0;
             else
                 highScoreBar = rs.rows.item(rs.rows.length - 1).score;
         }
     );
 }

 function saveHighScore(name)
 {
     if (scoresURL != "")
         sendHighScore(name);
     // Offline storage
     var db = openDatabaseSync(
         "SameGameScores",
         "1.0",
         "Local SameGame High Scores",
         100
     );
     var dataStr = "INSERT INTO Scores VALUES(?, ?, ?, ?)";
     var data = [
         name,
         gameCanvas.score,
         maxColumn + "x" + maxRow,
         Math.floor(gameDuration / 1000)
     ];
     db.transaction(
         function(tx) {
             tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(name TEXT, score NUMBER, gridSize TEXT, time NUMBER)');
             tx.executeSql(dataStr, data);

             // Only show results for the current grid size
             var rs = tx.executeSql('SELECT * FROM Scores WHERE gridSize = "'
                 + maxColumn + "x" + maxRow + '" ORDER BY score desc LIMIT 10');
             var r = "\nHIGH SCORES for this grid size\n\n"
             for (var i = 0; i < rs.rows.length; i++) {
                 r += (i+1) + ". " + rs.rows.item(i).name + ' got '
                     + rs.rows.item(i).score + ' points in '
                     + rs.rows.item(i).time + ' seconds.\n';
             }
             if(rs.rows.length == 10)
                 highScoreBar = rs.rows.item(9).score;
             dialog.show(r);
         }
     );
 }

 function sendHighScore(name)
 {
     var postman = new XMLHttpRequest()
     var postData = "name=" + name + "&score=" + gameCanvas.score
         + "&gridSize=" + maxColumn + "x" + maxRow
         + "&time=" + Math.floor(gameDuration / 1000);
     postman.open("POST", scoresURL, true);
     postman.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
     postman.onreadystatechange = function() {
         if (postman.readyState == postman.DONE) {
             dialog.show("Your score has been uploaded.");
         }
     }
     postman.send(postData);
 }