QT_CORE Implementation

• This is the Core implementation process of my project.

Learning process for QT_Core part

• Before I developed the algorithm in C++, I played the game several times in order to encounter all the possible cases that I need to consider for my algorithm, including ways to determine win and loss.
• Then I planned out the whole structure for my program
  • A class Matrix with 2D vector as its underlying structure
  • Have member functions to move(left, right, up, and down), determine win and lose, and generate numbers on random blocks.
• When implementing:
  • Start from the LEFT and RIGHT function
    • Confused at first, because when thinking deep about the algorithm there are actually a lot of cases to consider and check.

    Look online: https://www.codeproject.com/Articles/1173541/A-Walkthrough-to-Implement-Game.

    • From this, I learned to split the left function into two parts: add and move. Because considered separately, each of them can be implemented easily.
  • Got the first attempt, and it seemed to work
  • However, when I tested the algorithm, it was not the case. :-(
  • Debugging steps: continue commenting out unchecked codes from top to the bottom to check which steps cause errors. Also, I learned to print out every step
  • Three issues were found:
    • I kept change the index(terminating) value inside the for loop, which is not a standard way to use the “for” loop. => use while loop inside
    • In the second step: moving, I used lots of nested loops to determine which block should I move my cell to, which confused me a lot and therefore caused errors. => use function instead to reduce the number of nested loops.
    • Actually, the fatal issue is that I define every row in the matrix as a new variable line, but forgot to update after the actual values were changed due to the move steps.
  • Try the UP and DOWN function
    • First thought to implement from scratch, but it’s hard to manipulate a 2d vector across rows

    Look online: https://www.leaseweb.com/labs/2014/03/text-mode-2048-game-c-algorithm-explained/

    • The above online enabled me to think out of box that the UP and DOWN functions could be implemented by first do rotations on the original matrixes and then use LEFT and RIGHT functions to perform the moves.
  • Generate “random” numbers on “random” positions
    • First learn about the randomness rule about 2048 that 90% is 2 and 10% is 4

    https://gaming.stackexchange.com/questions/170665/what-is-the-probability-of-4

    • Then learn about how to generate actually random numbers instead of the pseudo ones.

    http://www.math.uaa.alaska.edu/~afkjm/csce211/fall2018/handouts/RandomFunctions.pdf