using System;

using System.Collections.Generic;

namespace UnityEngine.UI

{

public static class Clipping

{

public static Rect FindCullAndClipWorldRect(List<RectMask2D> rectMaskParents, out bool validRect)

{

Rect result;

if (rectMaskParents.Count == 0)

{

validRect = false;

result = default(Rect);

}

else

{

Rect a = rectMaskParents[0].canvasRect;

for (int i = 0; i < rectMaskParents.Count; i++)

{

a = Clipping.RectIntersect(a, rectMaskParents[i].canvasRect);

}

bool flag = a.width <= 0f || a.height <= 0f;

if (flag)

{

validRect = false;

result = default(Rect);

}

else

{

Vector3 vector = new Vector3(a.x, a.y, 0f);

Vector3 vector2 = new Vector3(a.x + a.width, a.y + a.height, 0f);

validRect = true;

result = new Rect(vector.x, vector.y, vector2.x - vector.x, vector2.y - vector.y);

}

}

return result;

}

private static Rect RectIntersect(Rect a, Rect b)

{

float num = Mathf.Max(a.x, b.x);

float num2 = Mathf.Min(a.x + a.width, b.x + b.width);

float num3 = Mathf.Max(a.y, b.y);

float num4 = Mathf.Min(a.y + a.height, b.y + b.height);

Rect result;

if (num2 >= num && num4 >= num3)

{

result = new Rect(num, num3, num2 - num, num4 - num3);

}

else

{

result = new Rect(0f, 0f, 0f, 0f);

}

return result;

}

}

}