Unity3D笔记十八 GL图像库

作者：PEPE
出处：http://pepe.cnblogs.com/

1、绘制2D图像的时需要使用GL.LoadOrtho()方法来将图形映射到平面中。

　　2、所有绘制相关的内容都要写在OnPostRender()方法中。

　　3、有关GL图像库的脚本需要绑定到Hierarchy视图中Camera上，否则无法显示绘制的图像。

　　4、在GL图像库的平面坐标系中，每个点的横坐标和纵坐标都应当是0与1之间的浮点数，而真实的像素坐标需要根据这个浮点数来计算

一、绘制线

　　别忘了添加物理材质public Material material;

using UnityEngine;
using System.Collections;/// <summary>
/// GL 图像库
/// 1、GL图像库是底层的图像库，主要功能是使用程序来绘制常见的2D与3D几何图形。这些图形
/// 具有一定的特殊性，它们不属于3D网格图形，只会以面的形式渲染
/// 
/// 2、绘制2D图像时，需要使用GL.LoadOrtho()方法来将图形映射在平面中，绘制的是3D图形，就无须使用此方法
/// 
/// 3、使用GL图像库时，需要将所有绘制相关的内容写在OnPostRender()方法中
/// </summary>
public class _7_5 : MonoBehaviour
{/// <summary>/// 绘制线段的材质/// </summary>public Material material;private void OnPostRender(){if (!material){Debug.Log("请给材质资源赋值");return;}material.SetPass(0);//设置该材质通道，0为默认值GL.LoadOrtho();//设置绘制2D图像GL.Begin(GL.LINES);//表示开始绘制，绘制类型为线段DrawLine(0, 0, 200, 100);//绘制线段0DrawLine(0, 50, 200, 150);//绘制线段1DrawLine(0, 100, 200, 200);//绘制线段2GL.End();//结束绘制
    }private void DrawLine(float x1, float y1, float x2, float y2){//绘制线段，需要将屏幕中某个点的像素坐标除以屏幕宽或高GL.Vertex(new Vector3(x1 / Screen.width, y1 / Screen.height, 0));// ['vɜ:teks] n. 最高点；顶点；<数>（三角形、圆锥体等与底相对的）顶；GL.Vertex(new Vector3(x2 / Screen.width, y2 / Screen.height, 0));}// Use this for initializationvoid Start(){}// Update is called once per framevoid Update(){}
}

二、绘制曲线

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
/// <summary>
/// 绘制曲线
/// </summary>
public class _7_5_1 : MonoBehaviour
{/// <summary>/// 绘制线段材质/// </summary>public Material material;private List<Vector3> lineInfo;// Use this for initializationvoid Start(){//初始化鼠标线段链表lineInfo = new List<Vector3>();}// Update is called once per framevoid Update(){//将每次鼠标改变的位置存储进链表
        lineInfo.Add(Input.mousePosition);}private void OnGUI(){GUILayout.Label("当前鼠标x轴位置" + Input.mousePosition.x);GUILayout.Label("当前鼠标y轴位置" + Input.mousePosition.y);}private void OnPostRender(){if (!material){Debug.LogError("请给材质资源赋值");return;}material.SetPass(0);//设置该材质通道，0为默认值GL.LoadOrtho();//设置绘制2D图像GL.Begin(GL.LINES);//表示开始绘制，绘制类型为线段 for (int i = 0; i < lineInfo.Count - 1; i++){Vector3 start = lineInfo[i];Vector3 end = lineInfo[i + 1];//绘制线段
            DrawLine(start.x, start.y, end.x, end.y);}GL.End();}/// <summary>/// 绘制线段/// </summary>/// <param name="x1"></param>/// <param name="y1"></param>/// <param name="x2"></param>/// <param name="y2"></param>private void DrawLine(float x1, float y1, float x2, float y2){//绘制线段，需要将屏幕中某个点的像素坐标点除以屏幕宽或高GL.Vertex(new Vector3(x1 / Screen.width, y1 / Screen.height, 0));// [ˈvɜ:ˌteks] 最高点；顶点GL.Vertex(new Vector3(x2 / Screen.width, y2 / Screen.height, 0));}
}

三、绘制四边形

　　绘制四边形，需要使用GL.Begin(GL.QUADS)方法

using UnityEngine;
using System.Collections;public class _7_5_3 : MonoBehaviour
{/// <summary>/// 可用材质0/// </summary>public Material material0;/// <summary>/// 可用材质1/// </summary>public Material material1;/// <summary>/// 可用材质2/// </summary>public Material material2;private void OnPostRender(){//绘制正四边形DrawRect(100, 100, 100, 100, material0);DrawRect(250, 100, 100, 100, material1);//绘制无规则四边形DrawQuads(15, 5, 10, 115, 95, 110, 90, 10, material2);}/// <summary>/// 绘制正四边形/// </summary>/// <param name="x">x轴起始坐标</param>/// <param name="y">y轴起始坐标</param>/// <param name="width">正四边形的宽</param>/// <param name="height">正四边形的高</param>/// <param name="material"></param>private void DrawRect(float x, float y, float width, float height, Material material){GL.PushMatrix();   // [ˈmeɪtrɪks]n. <数>矩阵；模型；基质；母体，子宫material.SetPass(0);GL.LoadOrtho();GL.Begin(GL.QUADS);//绘制类型为四边形GL.Vertex3(x / Screen.width, y / Screen.height, 0);//['vɜ:teks] n. 最高点；顶点GL.Vertex3(x / Screen.width, (y + height) / Screen.height, 0);GL.Vertex3((x + width) / Screen.width, (y + height) / Screen.height, 0);GL.Vertex3((x + width) / Screen.width, y / Screen.height, 0);GL.End();GL.PopMatrix();}/// <summary>/// 绘制无规则的四边形/// </summary>/// <param name="x1">起始点1的横坐标</param>/// <param name="y1">起始点1的纵坐标</param>/// <param name="x2">起始点2的横坐标</param>/// <param name="y2">起始点2的纵坐标</param>/// <param name="x3">起始点3的横坐标</param>/// <param name="y3">起始点3的纵坐标</param>/// <param name="x3">起始点4的横坐标</param>/// <param name="y3">起始点4的纵坐标</param>/// <param name="material">material</param>private void DrawQuads(float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4, Material material){GL.PushMatrix();material.SetPass(0);GL.LoadOrtho();GL.Begin(GL.QUADS);//绘制类型为四边形GL.Vertex3(x1 / Screen.width, y1 / Screen.height, 0);GL.Vertex3(x2 / Screen.width, y2 / Screen.height, 0);GL.Vertex3(x3 / Screen.width, y3 / Screen.height, 0);GL.Vertex3(x4 / Screen.width, y4 / Screen.height, 0);GL.End();GL.PopMatrix();}// Use this for initializationvoid Start(){}// Update is called once per framevoid Update(){}
}

四、绘制三角形

　　使用GL.Begin(GL.TRIANGLE)方法,参数为三角形的类型。['traɪæŋɡl]n. 三角形；三人一组；三角铁；三角板

using UnityEngine;
using System.Collections;
/// <summary>
/// 绘制三角形
/// 使用GL.Vertex3()方法确定三角形三个顶点的位置，并将绘制三角形
///的所有方法封装在DrawTriangle()方法中，最后使用GL.End()方法将三角形显示在屏幕中。
///需要说明的是，在调用DrawTriangle()方法时，需要将三个点的坐标与材质传入该方法。
/// </summary>
public class _7_5_4 : MonoBehaviour
{/// <summary>/// 材质/// </summary>public Material material;private void OnPostRender(){//绘制三角形DrawTriangle(100, 0, 100, 200, 200, 100, material);}/// <summary>///绘制三角形///Triangle n. 三角形；三人一组['traɪæŋɡl]/// </summary>private void DrawTriangle(float x1, float y1, float x2, float y2, float x3, float y3, Material material){material.SetPass(0);GL.LoadOrtho();GL.Begin(GL.TRIANGLES);//绘制三角形GL.Vertex3(x1 / Screen.width, y1 / Screen.height, 0);GL.Vertex3(x2 / Screen.width, y2 / Screen.height, 0);GL.Vertex3(x3 / Screen.width, y3 / Screen.height, 0);GL.End();}// Use this for initializationvoid Start(){}// Update is called once per framevoid Update(){}
}

五、绘制3D几何图形

using UnityEngine;
using System.Collections;/// <summary>
/// 绘制 3D几何图形
/// </summary>
public class _7_5_5 : MonoBehaviour
{#region 材质public Material material0;public Material material1;public Material material2;#endregionprivate void OnPostRender(){//绘制正四边形DrawRect(100, 100, 100, 100, material0);DrawRect(250, 100, 100, 100, material1);//绘制无规则四边形DrawQuads(15, 5, 10, 115, 95, 110, 90, 10, material2);}/// <summary>/// 绘制正四边形/// </summary>/// <param name="x">x轴起始坐标</param>/// <param name="y">y轴起始坐标</param>/// <param name="width">正四边形的宽</param>/// <param name="height">正四边形的高</param>/// <param name="material">material</param>private void DrawRect(float x, float y, float width, float height, Material material){GL.PushMatrix();material.SetPass(0);GL.Begin(GL.QUADS);//四边形GL.Vertex3(x / Screen.width, y / Screen.height, 0);GL.Vertex3(x / Screen.width, (y + height) / Screen.height, 0);GL.Vertex3((x + width) / Screen.width, (y + height) / Screen.height, 0);GL.Vertex3(x / Screen.width, (y + height) / Screen.height, 0);GL.End();GL.PopMatrix();}/// <summary>/// 绘制无规则四边形/// </summary>/// <param name="x1">起始点1的横坐标</param>/// <param name="y1">起始点1的纵坐标</param>/// <param name="x2">起始点2的横坐标</param>/// <param name="y2">起始点2的纵坐标</param>/// <param name="x3">起始点3的横坐标</param>/// <param name="y3">起始点3的纵坐标</param>/// <param name="x4">起始点4的横坐标</param>/// <param name="y4">起始点4的纵坐标</param>/// <param name="material">material</param>private void DrawQuads(float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4,Material material){GL.PushMatrix();//[ˈmeɪtrɪks] n. <数>矩阵；模型；基质；母体，子宫material.SetPass(0);GL.Begin(GL.QUADS);GL.Vertex3(x1 / Screen.width, y1 / Screen.height, 0);GL.Vertex3(x2 / Screen.width, y2 / Screen.height, 0);GL.Vertex3(x3 / Screen.width, y3 / Screen.height, 0);GL.Vertex3(x4 / Screen.width, y4 / Screen.height, 0);GL.End();GL.PopMatrix();}// Use this for initializationvoid Start(){}// Update is called once per framevoid Update(){}
}

六、绘制线

　　任何一个模型都由若干网格面组成，而每一个面又由若干个三角形组成，也就是说，模型是由若干个三角形面组成的

using UnityEngine;
using System.Collections;public class _7_5_7 : MonoBehaviour
{#region 构成三角形1的三个顶点位置Vector3 v0 = new Vector3(5, 0, 0);Vector3 v1 = new Vector3(0, 5, 0);Vector3 v2 = new Vector3(0, 0, 5);#endregion//构成三角形2的三个顶点位置Vector3 v3 = new Vector3(-5, 0, 0);Vector3 v4 = new Vector3(0, -5, 0);Vector3 v5 = new Vector3(0, 0, -5);//构成三角形1的贴图比例Vector2 u0 = new Vector2(0, 0);Vector2 u1 = new Vector2(0, 5);Vector2 u2 = new Vector2(5, 5);//构成三角形2的贴图比例Vector2 u3 = new Vector2(0, 0);Vector2 u4 = new Vector2(0, 1);Vector2 u5 = new Vector2(1, 1);// Use this for initializationvoid Start(){//得到网格渲染器对象MeshFilter meshFilter = (MeshFilter)GameObject.Find("face").GetComponent(typeof(MeshFilter));Mesh mesh = meshFilter.mesh; //通过渲染器对象得到网格对象mesh.vertices = new Vector3[] { v0, v1, v2, v3, v4, v5 };// n. 至高点，头顶；最高点( vertex的名词复数 )；[ˈvə:tisi:z] mesh.uv = new Vector2[] { v0, v1, v2, v3, v4, v5 };//设置三角形面上的贴图比例mesh.triangles = new int[] { 0, 1, 2, 3, 4, 5 };//[t'raɪæŋɡlz] n. 三角形( triangle的名词复数 )；
    }// Update is called once per framevoid Update(){}
}