Qt 4.8: samegame.js Example File (declarative/tutorials/samegame/samegame3/samegame.js)

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# samegame.js Example File

declarative/tutorials/samegame/samegame3/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 component;

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

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

         //Close dialogs
         dialog.hide();

         //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);
             }
         }
     }

     function createBlock(column, row) {
         if (component == null)
             component = Qt.createComponent("Block.qml");

         // Note that if Block.qml was not a local file, component.status would be
         // Loading and we should wait for the component's statusChanged() signal to
         // know when the file is downloaded and ready before calling createObject().
         if (component.status == Component.Ready) {
             var dynamicObject = component.createObject(gameCanvas);
             if (dynamicObject == null) {
                 console.log("error creating block");
                 console.log(component.errorString());
                 return false;
             }
             dynamicObject.type = Math.floor(Math.random() * 3);
             dynamicObject.x = column * gameCanvas.blockSize;
             dynamicObject.y = row * gameCanvas.blockSize;
             dynamicObject.width = gameCanvas.blockSize;
             dynamicObject.height = gameCanvas.blockSize;
             board[index(column, row)] = dynamicObject;
         } else {
             console.log("error loading block component");
             console.log(component.errorString());
             return false;
         }
         return true;
     }

     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

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

     function victoryCheck() {
         //Award bonus points if 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;

         //Check whether game has finished
         if (deservesBonus || !(floodMoveCheck(0, maxRow - 1, -1)))
             dialog.show("Game Over. Your score is " + gameCanvas.score);
     }

     //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);
     }