Opengl GLGS：我该怎么做；“连接”；纹理的采样器？

我试图从几何体着色器中的3D纹理中读取：

#version 150

layout(points) in; // origo of cell
layout(points, max_vertices = 1) out;

uniform sampler3D text;

void main (void) 
{   
    for(int i = 0; i < gl_in.length(); ++i)
    {
        // texture coordinates:
        float u, v, w;

        // set u, v, and w somehow
        ...

        float value = texture(text, vec3(u, v, w)).r;

        bool show;

        // set show based on value somehow:
        ...

        if(show) {      
            gl_Position = gl_in[i].gl_Position;
            EmitVertex();
            EndPrimitive();  
        }  
    }
}

但是如何将几何体着色器中的采样器“文本”与我的纹理相关联？

到目前为止，我还没有告诉OpenGL有一个名为“文本”的采样器，它将对纹理进行采样

编辑：我尝试了以下方法：

GLint textLoc = glGetUniformLocation(program, "text");
glUniform1i(textLoc, 0); // sends 0 to "text" in shader
// why do I not just hardcode 0 inside the geometry shader instead ? 
glBindTexture(GL_TEXTURE_3D , texture); 
glActiveTexture(GL_TEXTURE0); // same as 0 ?
GLuint sampler_state = 0;
glGenSamplers(1, &sampler_state);
glBindSampler(0, sampler_state); // what does this do?

---

这里出了什么问题？

My compiler（VS2008）给了我：错误C3861:“glBindSampler”：找不到标识符。我包括“GLee.h”和“glut.h”。我在哪个.h文件中找到glBindSampler？解决了它。包括glew.h而不是GLee.h（并链接到glew32.lib）。看起来glew和GLee是相互排斥的，并且做着同样的事情，但是glew更符合时代？

GLint textLoc = glGetUniformLocation(program, "text");
glUniform1i(textLoc, 0); // sends 0 to "text" in shader
// why do I not just hardcode 0 inside the geometry shader instead ? 
glBindTexture(GL_TEXTURE_3D , texture); 
glActiveTexture(GL_TEXTURE0); // same as 0 ?
GLuint sampler_state = 0;
glGenSamplers(1, &sampler_state);
glBindSampler(0, sampler_state); // what does this do?