为所有纹理单位均设置当前纹理坐标 (x,y,z)。
在 OpenGL 中，当未提供多纹理处理时，其与所有纹理单位的 glMultiTexCoord 或
glTexCoord 相匹配。在其他图形 API 中，对应的
功能是模拟实现的。
The Z component is used only when:
1. You access a cubemap (which you access with a vector coordinate, hence x,y & z).
2. You do "projective texturing", where the X & Y coordinates are divided by Z to get the final coordinate. This would be mostly useful for water reflections and similar things.
此函数只能在 GL.Begin 与 GL.End 函数之间加以调用。
using UnityEngine;
using System.Collections;
public class ExampleClass : MonoBehaviour {
public Material mat;
void OnPostRender() {
if (!mat) {
Debug.LogError("Please Assign a material on the inspector");
return;
}
GL.PushMatrix();
mat.SetPass(1);
GL.LoadOrtho();
GL.Begin(GL.QUADS);
GL.TexCoord3(0, 0, 0);
GL.Vertex3(0.25F, 0.25F, 0);
GL.TexCoord3(0, 1, 0);
GL.Vertex3(0.25F, 0.75F, 0);
GL.TexCoord3(1, 1, 0);
GL.Vertex3(0.75F, 0.75F, 0);
GL.TexCoord3(1, 0, 0);
GL.Vertex3(0.75F, 0.25F, 0);
GL.End();
GL.PopMatrix();
}
}