using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public enum CollisionType
{
	BallvsBall = 1, 
	BallvsBox, 
	BoxvsBox
}


/// <summary>
/// 碰撞的信息
/// </summary>
public struct PhysicsCollisionInfo
{
	public CollisionType type;
	public PhysicsPrimitive prim1;
	public PhysicsPrimitive prim2;
	public Vector3 contact;
    public Vector3 size;
}

public sealed class PhysicsHelper
{

    public static bool BallContains(PhysicsBall ball, Vector3 point)
    {
        return false;
    }

    public static bool BallContains(PhysicsBall ball, Vector2 point)
    {
        return false;
    }

    public static bool BoxContains(PhysicsBox box, Vector3 point)
    {
        return false;
    }

    public static bool BoxContains(PhysicsBox box, Vector2 point)
    {
        return false;
    }

    public static bool BallvsBall2D(PhysicsBall ball1, PhysicsBall ball2, ref PhysicsCollisionInfo info)
    {

        return true;
    }

    public static bool BoxvsBox2D(PhysicsBox box1, PhysicsBox box2, ref PhysicsCollisionInfo info)
    {
		if(box1.Left < box2.Right && box1.Right > box2.Left && box1.Bottom < box2.Top && box1.Top > box2.Bottom)
		{
			info.type = CollisionType.BoxvsBox;
			info.prim1 = box1;
			info.prim2 = box2;

			float left = Mathf.Max(box1.Left, box2.Left);
			float right = Mathf.Min(box1.Right, box2.Right);
			float top = Mathf.Min(box1.Top, box2.Top);
			float bottom = Mathf.Max(box1.Bottom, box2.Bottom);
			info.contact = new Vector3((left + right )/2f, (top + bottom)/2f, 0 );
            info.size = new Vector3(right - left, top - bottom, 1);

			return true;
		}
		return false;
    }

    public static bool BallvsBox2D(PhysicsBall ball, PhysicsBox box, ref PhysicsCollisionInfo info)
    {
        return true;
    }

	public static bool BallvsRay(PhysicsBall ball, Vector3 ray)
	{
		return false;
	}

	public static bool BoxvsRay(PhysicsBox box, Vector3 ray)
	{
		return false;
	}

	public static bool RayvsRay(Vector3 ray1, Vector3 ray2)
	{
		return false;
	}

	public static bool PrimvsPrim(PhysicsPrimitive prim1, PhysicsPrimitive prim2, ref PhysicsCollisionInfo info)
	{
		if(prim1.Type == PrimitiveType.Ball)
		{
			if (prim2.Type == PrimitiveType.Ball)
				return BallvsBall2D(prim1 as PhysicsBall, prim2 as PhysicsBall, ref info);
			else
				return BallvsBox2D(prim1 as PhysicsBall, prim2 as PhysicsBox, ref info);
		}
		else
		{
			if (prim2.Type == PrimitiveType.Ball)
				return BallvsBox2D(prim2 as PhysicsBall, prim1 as PhysicsBox, ref info);
			else
				return BoxvsBox2D(prim1 as PhysicsBox, prim2 as PhysicsBox, ref info);
		}
	}

}