C# How to get all the tile in a straight path in a grid based game?

Question

Hi,

So I want to do a function that return a list of tile from a grid in a straight path (and each tile shall touch each other) from two coordinate in a grid, the start and the end tile.

I've seen a the Bresenham's Line Algorithm but I just can't understand it since all the video that I see are not explaining that well or I'm dumb.

I could do it with the A* algorithm that I already implemented, but I feel like it would not make perfect line since he just need to find the fastest path and it might be to only go on x until its at the good coordinate and the go on y. (My A* don t work with the diagonal neighbour because I don't want the caracter to go diagonaly(I could make it diagonaly but that would not really solve my problem since I want to get all the tile in a straight and the tile shall touch each other))

the only solutions I thought could go well would be to do a ray cast all and I transform all there position into there tile linked to it, but I feel like it would use a lot of performance compare to the a simple mathmatical formula.

Thanks for the help! alt text

Answer 1

Ok so I tried to make it that they all touch but it's kinda complicated to accomplish but I still got this code that work perfectly :

 List<Cell> validCells = new List<Cell>();
 
         Vector2Int currentPosition = startCell.Position;
         Vector2Int endPosition = endCell.Position;
 
         Vector2Int startDifference = new Vector2Int(Mathf.Abs(endPosition.x - currentPosition.x), Mathf.Abs(endPosition.y - currentPosition.y));
 
         int error = 0;
 
         Vector2Int difference = startDifference * 2;
 
         Vector2Int addition = new Vector2Int(1, 1);
 
         if (currentPosition.x > endPosition.x) addition.x = -1;
         if (currentPosition.y > endPosition.y) addition.y = -1;
 
         if (startDifference.x > startDifference.y)
         {
             error = startDifference.x;
             for (int i = 0; i <= startDifference.x; i++)
             {
                 validCells.Add(_mapManager.GetCell(currentPosition));
                 currentPosition.x += addition.x;
                 error -= difference.y;
                 if (error <= 0)
                 {
                     currentPosition.y += addition.y;
                     error += difference.x;
                 }
             }
         }
         else
         {
             error = startDifference.y;
             for (int i = 0; i <= startDifference.y; i++)
             {
                 validCells.Add(_mapManager.GetCell(currentPosition));
                 currentPosition.y += addition.y;
                 error -= difference.x;
                 if (error <= 0)
                 {
                     currentPosition.x += addition.x;
                     error += difference.y;
                 }
             }
         }

C# How to get all the tile in a straight path in a grid based game?

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