using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class draw001 : MonoBehaviour {
public Material material;
private List<Vector3> lineInfo;
public Transform CUBE;
private Vector3 _vec3TargetScreenSpace;
Vector3 coords;
// Use this for initialization
void Start () {
//初始化鼠标线段链表
lineInfo=new List<Vector3>();
}
// Update is called once per frame
void Update () {
//coords = CUBE.position;
if (CUBE.position!=coords) {
//每次鼠标改变的位置存储进链表
//lineInfo.Add (Input.mousePosition);
_vec3TargetScreenSpace = Camera.main.WorldToScreenPoint(CUBE.position);
lineInfo.Add (_vec3TargetScreenSpace);
}
coords = CUBE.position;
if (Input.GetMouseButtonUp (1)) {
//每次鼠标改变的位置存储进链表
lineInfo.Clear ();
}
}
void OnGUI(){
GUILayout.Label ("当前鼠标x轴的位置:" + _vec3TargetScreenSpace.x);
GUILayout.Label ("当前鼠标y轴的位置:" + _vec3TargetScreenSpace.y);
}
//此绘制方法由系统调用
void OnPostRender(){
if (!material) {
Debug.LogError ("请给材质资源赋值");
return;
}
//设置该材质的通道，0位默认值
material.SetPass(0);
//设置绘制2D图像
GL.LoadOrtho ();
//表示开始绘制，绘制类型为线段
GL.Begin (GL.LINES);
//得到鼠标点信息的总数量
int size = lineInfo.Count;
//遍历鼠标点的链表
for (int i = 0; i < size - 1; i++) {
Vector3 start = lineInfo [i];
Vector3 end = lineInfo [i + 1];
//绘制线段
DrawLine (start.x, start.y, end.x, end.y);
}
//结束绘制
GL.End ();
}
void DrawLine(float x1,float y1,float x2,float y2){
//绘制线段，某个点的像素坐标除以屏幕宽或者高
GL.Vertex(new Vector3(x1/Screen.width,y1/Screen.height,0));
GL.Vertex(new Vector3(x2/Screen.width,y2/Screen.height,0));
}
}
