using UnityEngine;
using UnityEngine.UI;

public class ZigzagGridLayout : GridLayoutGroup
{
    public override void SetLayoutHorizontal()
    {
        base.SetLayoutHorizontal();
        LayoutChildren();
    }

    public override void SetLayoutVertical()
    {
        base.SetLayoutVertical();
        LayoutChildren();
    }

    private void LayoutChildren()
    {
        int cols = Mathf.FloorToInt((rectTransform.rect.width - padding.left - padding.right + spacing.x) / (cellSize.x + spacing.x));

        for (int i = 0; i < rectChildren.Count; i++)
        {
            var child = rectChildren[i];

            int row = i / cols;
            int col = i % cols;

            // 홀수 줄이면 col 순서를 반대로
            if (row % 2 == 1)
                col = cols - 1 - col;

            float x = padding.left + col * (cellSize.x + spacing.x);
            float y = padding.top + row * (cellSize.y + spacing.y);

            SetChildAlongAxis(child, 0, x, cellSize.x);
            SetChildAlongAxis(child, 1, y, cellSize.y);
        }
    }
}