1 Introduction
Paper implements a dynamic line drawing functions by GL class, that is, every mouse click, a line will be drawn, and a dynamic line will appear.
2. Code
Since the screen by the input pixel value acquired based mouse coordinates, the coordinates of the line are also pixel coordinates, so it is to draw the screen space.
using System.Collections;
using System.Collections.Generic; using UnityEngine; public class Graphics04GLDrawLineDynamic : MonoBehaviour { private Material glMat; private List<Vector3> points = new List<Vector3>(); private void SetMaterialPass() { if (glMat == null) { glMat = new Material(Shader.Find("Hidden/Internal-Colored")); } glMat.SetPass(0); } private void OnRenderObject() { if (points.Count != 0) { SetMaterialPass(); DrawLines(); } } private void DrawLines() { GL.PushMatrix(); GL.LoadPixelMatrix(); GL.Begin(GL.LINES); GL.Color(Color.red); for (int i = 0; i < points.Count - 1; i++) { GL.Vertex(points[i]); GL.Vertex(points[i + 1]); } GL.Vertex(points[points.Count - 1]); GL.Vertex(Input.mousePosition); GL.End(); GL.PopMatrix(); } private void Update() { if (Input.GetMouseButtonDown(0)) { points.Add(Input.mousePosition); } } }