//The number of rows that fit onscreen at one time.//We add one, because we might have half a tile showing at the top, and half at the bottom.numberOfRows = (myScreenHeight/MyTileHeight) + 1 //The current row at the top of the screen. (Where we start drawing from)startingRow = cameraY//Loop through each row onscreen.for(int row = startingRow; row < (startingRow + numberOfRows); row++){    //Loop around, if needed, by ensuring 'row' stays between 0 and the max number of rows we have in a map.    if(row >= maxNumberOfRowsInAMap)        row -= maxNumberOfRowsInAMap;    //You only need this one, if you can scroll down also.    if(row < 0)        row += maxNumberOfRowsInAMap;        //Draw each tile on this row. (I assume you can't scroll horizontally, since you implied that, but this can easily be made to scroll horizontally as well as vertically)    for(int col = 0; col < numberOfCols; col++}        drawTile(col * MyTileWidth, row * MyTileHeight, myArrayOfTheMapsTiles[col][row].image) //drawTile(pixelLocationX, pixelLocationY, imageToDraw)}