Question

public void checkForCollision () {
          
  int headX = cells[0].x; 
  int headY = cells[0].y;
  int noOfParts = nPoints;
  
  for(int i = 1; i <noOfParts;i++)
  {
     int tempX = cells[i].x;
     int tempY = cells[i].y;
     
     
      if(tempX == headX && tempY == headY){
          JOptionPane.showMessageDialog(null,"Head hit body");
          //EndGameCollectScore etc.
        }
  }
       
} 

EDIT: ‘Cells[]’ is an array of type Point AND noOfParts is just how many segments the snake has

main Question

With the above code I’m trying to compare tempX to headX but i would like to have a sort of margin for error e.g. +-5 but am unsure how to accomplish this, my reasoning behind this is i’m thinking maybe the x and Y variables might be a few digits apart so if i have the radius of one of the segment of the snake (explanation of ‘snake’ in Alternate below) then if i’m right and the values are a tiny bit off it should still come back positive.

OR

Alternative

if anyone can suggest a better way for doing this? Basically it’s for a Snake game and headX and headY is the head of the snake and the remaining X and Y variables in Cells is the body, and I’m attempting to compare if the head hits the body.

I tested it and it seemed to work but after i tested it again it seems it will only pick up the collision if i make the snake double back on itself for a few squares. e.g. IF i cross the body perpendicular it will not detect the collision.

Also i am fairly certain that this method is called after each block the snake moves.

Cheers,
Shane.

P.S Running of very little sleep and way too much sugar in my blood, If you need further clarification because the above doesn’t make alot of sense let me know.

Answer 1

int eps = 5;
if (Math.abs(tempX - headX) <= eps && Math.abs(tempY - headY) <= eps) { 
    // ...
}