OpenGL 在glUseProgram后报错 GL_INVALID_OPERATION

the_mercury

请大家帮忙看一下我下面的这个代码错在哪里:

程序中使用了OpenGL Shader

1. // vertex shader
   
2. #version 130
   
3. in vec4 osg_Vertex;
   
4. in vec4 osg_Color;
   
5. out vec4 color;
   
6. uniform mat4 osg_ModelViewProjectionMatrix;
   
7. uniform float pointSize;
   
8. void main(void)
   
9. {
   
10.     color = osg_Color;
    
11.     gl_PointSize = pointSize;
    
12.     gl_Position = osg_ModelViewProjectionMatrix * osg_Vertex;
    
13. }
    
14. 
    
15. // fragment shader
    
16. #version 130
    
17. in vec4 color;
    
18. out vec4 fragColor;
    
19. void main(void)
    
20. {
    
21.     fragColor = color;
    
22. }

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下面是osg的Ｃ++代码

1. osg::ref_ptr<osg::Shader> vertexShader = new osg::Shader(osg::Shader::VERTEX, vertex_shader_code);
   
2. osg::ref_ptr<osg::Shader> fragmentShader = new osg::Shader(osg::Shader::FRAGMENT, fragment_shader_code);
   
3. osg::ref_ptr<osg::Program> program = new osg::Program();
   
4. program->addShader(vertexShader);
   
5. program->addShader(fragmentShader);
   
6. program->addBindFragDataLocation("fragColor", 0);
   
7. stateSet->setAttributeAndModes(program, osg::StateAttribute::ON);
   
8. stateSet->setMode(GL_PROGRAM_POINT_SIZE_EXT, osg::StateAttribute::ON);
   
9. osg::ref_ptr<osg::Uniform> pointSize = new osg::Uniform("pointSize", 5.0);
   
10. stateSet->addUniform(pointSize);
    

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这个时候osg在执行到glUseProgram的时候报错GL_INVALID_OPERATION,当程序作改动之后，程序就正常了

改动后的Shader如下

1. // vertex shader
   
2. #version 130
   
3. in vec4 osg_Vertex;
   
4. in vec4 osg_Color;
   
5. out vec4 color;
   
6. uniform mat4 osg_ModelViewProjectionMatrix;
   
7. void main(void)
   
8. {
   
9.     color = osg_Color;
   
10.     gl_Position = osg_ModelViewProjectionMatrix * osg_Vertex;
    
11. }
    
12. 
    
13. // fragment shader
    
14. #version 130
    
15. in vec4 color;
    
16. out vec4 fragColor;
    
17. void main(void)
    
18. {
    
19.     fragColor = color;
    
20. }

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并且在程序中去掉以下行：

1. stateSet->setMode(GL_PROGRAM_POINT_SIZE_EXT, osg::StateAttribute::ON);
   
2. osg::ref_ptr<osg::Uniform> pointSizeUniform = new osg::Uniform("pointSize", 5.0);
   
3. stateSet->addUniform(pointSizeUniform);

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显卡型号为NVIDIA GeForce GT720/PCIe/SSE2 OpenGL和GLSL版本分别为４.5


请问如何在程序中设置gl_PointSize内置变量啊，为什么我的就是不对呢