samegame.js Example File

  /* 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);
  }