【Unity】RectTransform の端の位置を返す拡張メソッド

概要

using UnityEngine;

/// <summary>
/// RectTransform 型の拡張メソッドを管理するクラス
/// </summary>
internal static class RectTransformExt
{
    /// <summary>
    /// 左端の位置を返します
    /// </summary>
    public static float GetAnchoredPositionLeft( this RectTransform self )
    {
        return self.anchoredPosition.x - self.sizeDelta.x * self.pivot.x * self.localScale.x;
    }

    /// <summary>
    /// 右端の位置を返します
    /// </summary>
    public static float GetAnchoredPositionRight( this RectTransform self )
    {
        return self.anchoredPosition.x + self.sizeDelta.x * ( 1 - self.pivot.x ) * self.localScale.x;
    }

    /// <summary>
    /// 下端の位置を返します
    /// </summary>
    public static float GetAnchoredPositionBottom( this RectTransform self )
    {
        return self.anchoredPosition.y - self.sizeDelta.y * self.pivot.y * self.localScale.y;
    }

    /// <summary>
    /// 上端の位置を返します
    /// </summary>
    public static float GetAnchoredPositionTop( this RectTransform self )
    {
        return self.anchoredPosition.y + self.sizeDelta.y * ( 1 - self.pivot.y ) * self.localScale.y;
    }

    /// <summary>
    /// 端を表す矩形を返します
    /// </summary>
    public static Rect GetAnchoredEdge( this RectTransform self )
    {
        var rect = new Rect
        {
            xMin = self.GetAnchoredPositionLeft(),
            xMax = self.GetAnchoredPositionRight(),
            yMin = self.GetAnchoredPositionBottom(),
            yMax = self.GetAnchoredPositionTop(),
        };

        return rect;
    }
}