using UnityEngine;

/// <summary>
/// 绘制多边形
/// TODO: 存在两点重合时绘制有问题
/// </summary>
public class PolygonDrawer : MonoBehaviour
{
	public Material material;
	public Transform[] vertices;
	private MeshRenderer mRenderer;
	private MeshFilter mFilter;

	void Start()
	{
		Draw();
	}

	void Update()
	{
		Draw();
	}

	[ContextMenu("Draw")]
	public void Draw()
	{
		Vector2[] vertices2D = new Vector2[vertices.Length];
		Vector3[] vertices3D = new Vector3[vertices.Length];
		for (int i = 0; i < vertices.Length; i++)
		{
			Vector3 vertice = vertices[i].localPosition;
			vertices2D[i] = new Vector2(vertice.x, vertice.y);
			vertices3D[i] = vertice;
		}

		Triangulator tr = new Triangulator(vertices2D);
		int[] triangles = tr.Triangulate();

		Mesh mesh = new Mesh();
		mesh.vertices = vertices3D;
		mesh.triangles = triangles;

		if (mRenderer == null)
		{
			mRenderer = gameObject.GetOrAddComponent<MeshRenderer>();
		}
		mRenderer.material = material;
		if (mFilter == null)
		{
			mFilter = gameObject.GetOrAddComponent<MeshFilter>();
		}
		mFilter.mesh = mesh;
		
	}
}