How to implement multiple walls that detect intersection in Java GUI

Question

I have a GUI Maze game that I am creating and I am having trouble implementing walls that prevent the player from moving. The walls are rectangles but the player is a circle so I had to create a collision detection method between a rectangle and a circle. The problem I am having is that my collidesWith() method is in the player class and it takes a single wall as a parameter and returns a string that tells you which side of the wall is the player intersecting with. This means I can only check if the player is colliding with one wall at a time. Here is the code for the collidesWith() method. x and y are the x and y coordinates of the player since this method is in the player class:

I should mention that the code above doesn't exactly work how I wanted it to since it only works when the player is coming from the sides. If the player is coming from the top or bottom, the player just goes through the wall.

The reason I need this method to return a string to tell me where the player is coming from is so that I can explicitly restrict the movement of the player when the up, down, left, right keys are pressed. This is in another class where all the GUI components are. Here is the code for that. I have created a wall object on top so that it can be passed as a parameter here when checking for intersection:

score 0 · Answer 1 · answered Apr 22 '22 at 20:16

In my view, it is better to avoid to iterate through the whole array of wallsArraylist. If I understood correctly, it is necessary to explore neighbour cells, if yes, then you can explore neighbours in a two-dimensional array using this approach:

(pseudo-code)

row_limit = count(array);
if(row_limit > 0){
  column_limit = count(array[0]);
  for(x = max(0, i-1); x <= min(i+1, row_limit); x++){
    for(y = max(0, j-1); y <= min(j+1, column_limit); y++){
      if(x != i || y != j){
        print array[x][y];
      }
    }
  }
}

In addition, try to avoid magic strings. Replace "comingFromRight" and etc to constant string:

public static final String COMING_FROM_RIGHT = "comingFromRight";

How to implement multiple walls that detect intersection in Java GUI

1 Answers1