Qt Quick Demo - Maroon in Trouble

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 .pragma library // Shared game state
 .import QtQuick 2.0 as QQ

 // Game Stuff
 var gameState // Local reference
 function getGameState() { return gameState; }

 var towerData = [ // Name and cost, stats are in the delegate per instance
     { "name": "Melee", "cost": 20 },
     { "name": "Ranged", "cost": 50 },
     { "name": "Bomb", "cost": 75 },
     { "name": "Factory", "cost": 25 }
 ]

 var waveBaseData = [300, 290, 280, 270, 220, 180, 160, 80, 80, 80, 30, 30, 30, 30];
 var waveData = [];

 var towerComponents = new Array(towerData.length);
 var mobComponent = Qt.createComponent("mobs/MobBase.qml");

 function endGame()
 {
     gameState.gameRunning = false;
     gameState.gameOver = true;
     for (var i = 0; i < gameState.cols; i++) {
         for (var j = 0; j < gameState.rows; j++) {
             if (gameState.towers[towerIdx(i, j)]) {
                 gameState.towers[towerIdx(i, j)].destroy();
                 gameState.towers[towerIdx(i, j)] = null;
             }
         }
         for (var j in gameState.mobs[i])
             gameState.mobs[i][j].destroy();
         gameState.mobs[i].splice(0,gameState.mobs[i].length); //Leaves queue reusable
     }
 }

 function startGame(gameCanvas)
 {
     waveData = new Array();
     for (var i in waveBaseData)
         waveData[i] = waveBaseData[i];
     gameState.freshState();
     for (var i = 0; i < gameCanvas.cols; i++) {
         for (var j = 0; j < gameCanvas.rows; j++)
             gameState.towers[towerIdx(i, j)] = null;
         gameState.mobs[i] = new Array();
     }
     gameState.towers[towerIdx(0, 0)] = newTower(3, 0, 0);//Start with a starfish in the corner
     gameState.gameRunning = true;
     gameState.gameOver = false;
 }

 function newGameState(gameCanvas)
 {
     for (var i = 0; i < towerComponents.length; i++) {
         towerComponents[i] = Qt.createComponent("towers/" + towerData[i].name + ".qml");
         if (towerComponents[i].status == QQ.Component.Error) {
             gameCanvas.errored = true;
             gameCanvas.errorString += "Loading Tower " + towerData[i].name + "\n" + (towerComponents[i].errorString());
             console.log(towerComponents[i].errorString());
         }
     }
     gameState = gameCanvas;
     gameState.freshState();
     gameState.towers = new Array(gameCanvas.rows * gameCanvas.cols);
     gameState.mobs = new Array(gameCanvas.cols);
     return gameState;
 }

 function row(y)
 {
     return Math.floor(y / gameState.squareSize);
 }

 function col(x)
 {
     return Math.floor(x / gameState.squareSize);
 }

 function towerIdx(x, y)
 {
     return y + (x * gameState.rows);
 }

 function newMob(col)
 {
     var ret = mobComponent.createObject(gameState.canvas,
         { "col" : col,
           "speed" : (Math.min(2.0, 0.10 * (gameState.waveNumber + 1))),
           "y" : gameState.canvas.height });
     gameState.mobs[col].push(ret);
     return ret;
 }

 function newTower(type, row, col)
 {
     var ret = towerComponents[type].createObject(gameState.canvas);
     ret.row = row;
     ret.col = col;
     ret.fireCounter = ret.rof;
     ret.spawn();
     return ret;
 }

 function buildTower(type, x, y)
 {
     if (gameState.towers[towerIdx(x,y)] != null) {
         if (type <= 0) {
             gameState.towers[towerIdx(x,y)].sell();
             gameState.towers[towerIdx(x,y)] = null;
         }
     } else {
         if (gameState.coins < towerData[type - 1].cost)
             return;
         gameState.towers[towerIdx(x, y)] = newTower(type - 1, y, x);
         gameState.coins -= towerData[type - 1].cost;
     }
 }

 function killMob(col, mob)
 {
     if (!mob)
         return;
     var idx = gameState.mobs[col].indexOf(mob);
     if (idx == -1 || !mob.hp)
         return;
     mob.hp = 0;
     mob.die();
     gameState.mobs[col].splice(idx,1);
 }

 function killTower(row, col)
 {
     var tower = gameState.towers[towerIdx(col, row)];
     if (!tower)
         return;
     tower.hp = 0;
     tower.die();
     gameState.towers[towerIdx(col, row)] = null;
 }

 function tick()
 {
     if (!gameState.gameRunning)
         return;

     // Spawn
     gameState.waveProgress += 1;
     var i = gameState.waveProgress;
     var j = 0;
     while (i > 0 && j < waveData.length)
         i -= waveData[j++];
     if ( i == 0 ) // Spawn a mob
         newMob(Math.floor(Math.random() * gameState.cols));
     if ( j == waveData.length ) { // Next Wave
         gameState.waveNumber += 1;
         gameState.waveProgress = 0;
         var waveModifier = 10; // Constant governing how much faster the next wave is to spawn (not fish speed)
         for (var k in waveData ) // Slightly faster
             if (waveData[k] > waveModifier)
                 waveData[k] -= waveModifier;
     }

     // Towers Attack
     for (var j in gameState.towers) {
         var tower = gameState.towers[j];
         if (tower == null)
             continue;
         if (tower.fireCounter > 0) {
             tower.fireCounter -= 1;
             continue;
         }
         var column = tower.col;
         for (var k in gameState.mobs[column]) {
             var conflict = gameState.mobs[column][k];
             if (conflict.y <= gameState.canvas.height && conflict.y + conflict.height > tower.y
                 && conflict.y - ((tower.row + 1) * gameState.squareSize) < gameState.squareSize * tower.range) { // In Range
                 tower.fire();
                 tower.fireCounter = tower.rof;
                 conflict.hit(tower.damage);
             }
         }

         // Income
         if (tower.income) {
             gameState.coins += tower.income;
             tower.fire();
             tower.fireCounter = tower.rof;
         }
     }

     // Mobs move
     for (var i = 0; i < gameState.cols; i++) {
         for (var j = 0; j < gameState.mobs[i].length; j++) {
             var mob = gameState.mobs[i][j];
             var newPos = gameState.mobs[i][j].y - gameState.mobs[i][j].speed;
             if (newPos < 0) {
                 gameState.lives -= 1;
                 killMob(i, mob);
                 if (gameState.lives <= 0)
                     endGame();
                 continue;
             }
             var conflict = gameState.towers[towerIdx(i, row(newPos))];
             if (conflict != null) {
                 if (mob.y < conflict.y + gameState.squareSize)
                     gameState.mobs[i][j].y += gameState.mobs[i][j].speed * 10; // Moved inside tower, now hurry back out
                 if (mob.fireCounter > 0) {
                     mob.fireCounter--;
                 } else {
                     gameState.mobs[i][j].fire();
                     conflict.hp -= mob.damage;
                     if (conflict.hp <= 0)
                         killTower(conflict.row, conflict.col);
                     mob.fireCounter = mob.rof;
                 }
             } else {
                 gameState.mobs[i][j].y = newPos;
             }
         }
     }

 }