- Qt 5.15
- Qt Quick Demo - Same Game
- Qt 5.15.19 Reference Documentation

# Qt Quick Demo - Same Game

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     /* This script file handles the game logic */
     .pragma library
     .import QtQuick.LocalStorage 2.0 as Sql

     var maxColumn = 10;
     var maxRow = 13;
     var types = 3;
     var maxIndex = maxColumn*maxRow;
     var board = new Array(maxIndex);
     var blockSrc = "Block.qml";
     var gameDuration;
     var component = Qt.createComponent(blockSrc);
     var gameCanvas;
     var betweenTurns = false;

     var puzzleLevel = null;
     var puzzlePath = "";

     var gameMode = "arcade"; //Set in new game, then tweaks behaviour of other functions
     var gameOver = false;

     function changeBlock(src)
     {
         blockSrc = src;
         component = Qt.createComponent(blockSrc);
     }

     // 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 cleanUp()
     {
         if (gameCanvas == undefined)
             return;
         // Delete blocks from previous game
         for (var i = 0; i < maxIndex; i++) {
             if (board[i] != null)
                 board[i].destroy();
             board[i] = null;
         }
         if (puzzleLevel != null){
             puzzleLevel.destroy();
             puzzleLevel = null;
         }
         gameCanvas.mode = ""
     }

     function startNewGame(gc, mode, map)
     {
         gameCanvas = gc;
         if (mode == undefined)
             gameMode = "arcade";
         else
             gameMode = mode;
         gameOver = false;

         cleanUp();

         gc.gameOver = false;
         gc.mode = gameMode;
         // Calculate board size
         maxColumn = Math.floor(gameCanvas.width/gameCanvas.blockSize);
         maxRow = Math.floor(gameCanvas.height/gameCanvas.blockSize);
         maxIndex = maxRow * maxColumn;
         if (gameMode == "arcade") //Needs to be after board sizing
             getHighScore();

         // Initialize Board
         board = new Array(maxIndex);
         gameCanvas.score = 0;
         gameCanvas.score2 = 0;
         gameCanvas.moves = 0;
         gameCanvas.curTurn = 1;
         if (gameMode == "puzzle")
             loadMap(map);
         else//Note that we load them in reverse order for correct visual stacking
             for (var column = maxColumn - 1; column >= 0; column--)
                 for (var row = maxRow - 1; row >= 0; row--)
                     createBlock(column, row);
         if (gameMode == "puzzle")
             getLevelHistory();//Needs to be after map load
         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)
     {
         if (betweenTurns || gameOver || gameCanvas == undefined)
             return;
         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;
         if (gameMode == "multiplayer" && gameCanvas.curTurn == 2)
             gameCanvas.score2 += (fillFound - 1) * (fillFound - 1);
         else
             gameCanvas.score += (fillFound - 1) * (fillFound - 1);
         if (gameMode == "multiplayer" && gameCanvas.curTurn == 2)
             shuffleUp();
         else
             shuffleDown();
         gameCanvas.moves += 1;
         if (gameMode == "endless")
             refill();
         else if (gameMode != "multiplayer")
             victoryCheck();
         if (gameMode == "multiplayer" && !gc.gameOver){
             betweenTurns = true;
             gameCanvas.swapPlayers();//signal, animate and call turnChange() when ready
         }
     }

     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 shuffleUp()
     {
         // Fall up
         for (var column = 0; column < maxColumn; column++) {
             var fallDist = 0;
             for (var row = 0; row < maxRow; 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 (or should it be right, so as to be left for P2?)
         fallDist = 0;
         for (column = 0; column < maxColumn; column++) {
             if (board[index(column, 0)] == 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 turnChange()//called by ui outside
     {
         betweenTurns = false;
         if (gameCanvas.curTurn == 1){
             shuffleUp();
             gameCanvas.curTurn = 2;
             victoryCheck();
         }else{
             shuffleDown();
             gameCanvas.curTurn = 1;
             victoryCheck();
         }
     }

     function refill()
     {
         for (var column = 0; column < maxColumn; column++) {
             for (var row = 0; row < maxRow; row++) {
                 if (board[index(column, row)] == null)
                     createBlock(column, row);
             }
         }
     }

     function victoryCheck()
     {
         // Awards bonuses for no blocks left
         var deservesBonus = true;
         if (board[index(0,maxRow - 1)] != null || board[index(0,0)] != null)
             deservesBonus = false;
         // Checks for game over
         if (deservesBonus){
             if (gameCanvas.curTurn = 1)
                 gameCanvas.score += 1000;
             else
                 gameCanvas.score2 += 1000;
         }
         gameOver = deservesBonus;
         if (gameCanvas.curTurn == 1){
             if (!(floodMoveCheck(0, maxRow - 1, -1)))
                 gameOver = true;
         }else{
             if (!(floodMoveCheck(0, 0, -1, true)))
                 gameOver = true;
         }
         if (gameMode == "puzzle"){
             puzzleVictoryCheck(deservesBonus);//Takes it from here
             return;
         }
         if (gameOver) {
             var winnerScore = Math.max(gameCanvas.score, gameCanvas.score2);
             if (gameMode == "multiplayer"){
                 gameCanvas.score = winnerScore;
                 saveHighScore(gameCanvas.score2);
             }
             saveHighScore(gameCanvas.score);
             gameDuration = new Date() - gameDuration;
             gameCanvas.gameOver = true;
         }
     }

     // Only floods up and right, to see if it can find adjacent same-typed blocks
     function floodMoveCheck(column, row, type, goDownInstead)
     {
         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;
         if (goDownInstead)
             return floodMoveCheck(column + 1, row, myType, goDownInstead) ||
                    floodMoveCheck(column, row + 1, myType, goDownInstead);
         else
             return floodMoveCheck(column + 1, row, myType) ||
                    floodMoveCheck(column, row - 1, myType);
     }

     function createBlock(column,row,type)
     {
         // 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 == 1){
             if (type == undefined)
                 type = Math.floor(Math.random() * types);
             if (type < 0 || type > 4) {
                 console.log("Invalid type requested");//TODO: Is this triggered by custom levels much?
                 return;
             }
             var dynamicObject = component.createObject(gameCanvas,
                     {"type": type,
                     "x": column*gameCanvas.blockSize,
                     "y": -1*gameCanvas.blockSize,
                     "width": gameCanvas.blockSize,
                     "height": gameCanvas.blockSize,
                     "particleSystem": gameCanvas.ps});
             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 showPuzzleError(str)
     {
         //TODO: Nice user visible UI?
         console.log(str);
     }

     function loadMap(map)
     {
         puzzlePath = map;
         var levelComp = Qt.createComponent(puzzlePath);
         if (levelComp.status != 1){
             console.log("Error loading level");
             showPuzzleError(levelComp.errorString());
             return;
         }
         puzzleLevel = levelComp.createObject();
         if (puzzleLevel == null || !puzzleLevel.startingGrid instanceof Array) {
             showPuzzleError("Bugger!");
             return;
         }
         gameCanvas.showPuzzleGoal(puzzleLevel.goalText);
         //showPuzzleGoal should call finishLoadingMap as the next thing it does, before handling more events
     }

     function finishLoadingMap()
     {
         for (var i in puzzleLevel.startingGrid)
             if (! (puzzleLevel.startingGrid[i] >= 0 && puzzleLevel.startingGrid[i] <= 9) )
                 puzzleLevel.startingGrid[i] = 0;
         //TODO: Don't allow loading larger levels, leads to cheating
         while (puzzleLevel.startingGrid.length > maxIndex) puzzleLevel.startingGrid.shift();
         while (puzzleLevel.startingGrid.length < maxIndex) puzzleLevel.startingGrid.unshift(0);
         for (var i in puzzleLevel.startingGrid)
             if (puzzleLevel.startingGrid[i] > 0)
                 createBlock(i % maxColumn, Math.floor(i / maxColumn), puzzleLevel.startingGrid[i] - 1);

         //### Experimental feature - allow levels to contain arbitrary QML scenes as well!
         //while (puzzleLevel.children.length)
         //    puzzleLevel.children[0].parent = gameCanvas;
         gameDuration = new Date(); //Don't start until we finish loading
     }

     function puzzleVictoryCheck(clearedAll)//gameOver has also been set if no more moves
     {
         var won = true;
         var soFar = new Date() - gameDuration;
         if (puzzleLevel.scoreTarget != -1 && gameCanvas.score < puzzleLevel.scoreTarget){
             won = false;
         } if (puzzleLevel.scoreTarget != -1 && gameCanvas.score >= puzzleLevel.scoreTarget && !puzzleLevel.mustClear){
             gameOver = true;
         } if (puzzleLevel.timeTarget != -1 && soFar/1000.0 > puzzleLevel.timeTarget){
             gameOver = true;
         } if (puzzleLevel.moveTarget != -1 && gameCanvas.moves >= puzzleLevel.moveTarget){
             gameOver = true;
         } if (puzzleLevel.mustClear && gameOver && !clearedAll) {
             won = false;
         }

         if (gameOver) {
             gameCanvas.gameOver = true;
             gameCanvas.showPuzzleEnd(won);

             if (won) {
                 // Store progress
                 saveLevelHistory();
             }
         }
     }

     function getHighScore()
     {
         var db = Sql.LocalStorage.openDatabaseSync(
             "SameGame",
             "2.0",
             "SameGame Local Data",
             100
         );
         db.transaction(
             function(tx) {
                 tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(game 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 + '" AND game = "' + gameMode + '" ORDER BY score desc');
                 if (rs.rows.length > 0)
                     gameCanvas.highScore = rs.rows.item(0).score;
                 else
                     gameCanvas.highScore = 0;
             }
         );
     }

     function saveHighScore(score)
     {
         // Offline storage
         var db = Sql.LocalStorage.openDatabaseSync(
             "SameGame",
             "2.0",
             "SameGame Local Data",
             100
         );
         var dataStr = "INSERT INTO Scores VALUES(?, ?, ?, ?)";
         var data = [
             gameMode,
             score,
             maxColumn + "x" + maxRow,
             Math.floor(gameDuration / 1000)
         ];
         if (score >= gameCanvas.highScore)//Update UI field
             gameCanvas.highScore = score;

         db.transaction(
             function(tx) {
                 tx.executeSql('CREATE TABLE IF NOT EXISTS Scores(game TEXT, score NUMBER, gridSize TEXT, time NUMBER)');
                 tx.executeSql(dataStr, data);
             }
         );
     }

     function getLevelHistory()
     {
         var db = Sql.LocalStorage.openDatabaseSync(
             "SameGame",
             "2.0",
             "SameGame Local Data",
             100
         );
         db.transaction(
             function(tx) {
                 tx.executeSql('CREATE TABLE IF NOT EXISTS Puzzle(level TEXT, score NUMBER, moves NUMBER, time NUMBER)');
                 var rs = tx.executeSql('SELECT * FROM Puzzle WHERE level = "' + puzzlePath + '" ORDER BY score desc');
                 if (rs.rows.length > 0) {
                     gameCanvas.puzzleWon = true;
                     gameCanvas.highScore = rs.rows.item(0).score;
                 } else {
                     gameCanvas.puzzleWon = false;
                     gameCanvas.highScore = 0;
                 }
             }
         );
     }

     function saveLevelHistory()
     {
         var db = Sql.LocalStorage.openDatabaseSync(
             "SameGame",
             "2.0",
             "SameGame Local Data",
             100
         );
         var dataStr = "INSERT INTO Puzzle VALUES(?, ?, ?, ?)";
         var data = [
             puzzlePath,
             gameCanvas.score,
             gameCanvas.moves,
             Math.floor(gameDuration / 1000)
         ];
         gameCanvas.puzzleWon = true;

         db.transaction(
             function(tx) {
                 tx.executeSql('CREATE TABLE IF NOT EXISTS Puzzle(level TEXT, score NUMBER, moves NUMBER, time NUMBER)');
                 tx.executeSql(dataStr, data);
             }
         );
     }

     function nuke() //For "Debug mode"
     {
         for (var row = 1; row <= 5; row++) {
             for (var col = 0; col < 5; col++) {
                 if (board[index(col, maxRow - row)] != null) {
                     board[index(col, maxRow - row)].dying = true;
                     board[index(col, maxRow - row)] = null;
                 }
             }
         }
         if (gameMode == "multiplayer" && gameCanvas.curTurn == 2)
             shuffleUp();
         else
             shuffleDown();
         if (gameMode == "endless")
             refill();
         else
             victoryCheck();
     }