Level complete detection

It's all well and good having three levels, but without a mechanism to move between them they are useless. We are going to add a check to see if the player has finished a level, if they have then increment the level counter and load the next level in the array. We only need to do the check at the end of every move; to do so every frame would be redundant.

We'll write the following method first and then explain it:

// If this method returns true then we have finished the level
boolhaveFinishedLevel () {
  // Initialise the counter for how many crates are on goal 
  // tiles
  int cratesOnGoalTiles = 0;
  // Loop through all the rows in the current level
  for (int i = 0; i< levels[currentLevel].Length; i++) {
    // Get the tile ID for the column and pass it the switch 
    // statement
    for (int j = 0; j < levels[currentLevel][i].Length; j++) {
      switch (levels[currentLevel][i][j]) {
        case 5:
        // Do we have a match for a crate on goal 
 ...