OpenGL glGetError 1281值不好

Question

我正在使用带有顶点和着色器的OpenGL,我的屏幕上没有显示任何内容,因此我使用glGetError进行调试:我的一个名为color_array_buffer的缓冲区出现错误1281(错误值),这是我正在讨论的部分:

    GLenum error =  glGetError();
if(error) {
    cout << error << endl; 
    return ;
} else {
    cout << "no error yet" << endl;
}
//no error


// Get a handle for our "myTextureSampler" uniform
    GLuint TextureID  = glGetUniformLocation(shaderProgram, "myTextureSampler");
    if(!TextureID)
        cout << "TextureID not found ..." << endl;

// Bind our texture in Texture Unit 0
    glActiveTexture(GL_TEXTURE0);
    sf::Texture::bind(texture);
// Set our "myTextureSampler" sampler to user Texture Unit 0
    glUniform1i(TextureID, 0);
// 2nd attribute buffer : UVs
    GLuint vertexUVID = glGetAttribLocation(shaderProgram, "color");
    if(!vertexUVID)
        cout << "vertexUVID not found ..." << endl;
    glEnableVertexAttribArray(vertexUVID);
    glBindBuffer(GL_ARRAY_BUFFER, color_array_buffer);
    glVertexAttribPointer(vertexUVID, 2, GL_FLOAT, GL_FALSE, 0, 0);

error =  glGetError();
if(error) {
    cout << error << endl; 
    return ;
}
//error 1281

这里是我将缓冲区链接到数组的代码:

    if (textured) {
        texture = new sf::Texture();
    if(!texture->loadFromFile("textures/simple.jpeg"/*,sf::IntRect(0, 0, 128, 128)*/))
        std::cout << "Error loading texture !!" << std::endl;
        glGenBuffers(1, &color_array_buffer);
        glBindBuffer(GL_ARRAY_BUFFER, color_array_buffer);
        glBufferData(GL_ARRAY_BUFFER, uvs.size() * sizeof(glm::vec3), &uvs[0], GL_STATIC_DRAW);
    }

和我的uvs值:

uvs [0]:0.748573-0.750412

uvs [1]:0.749279-0.501284

uvs [2]:0.99911-0.501077

uvs [3]:0.999455-0.75038

uvs [4]:0.250471-0.500702

uvs [5]:0.249682-0.749677

uvs [6]:0.001085-0.75038

uvs [7]:0.001517-0.499994

uvs [8]:0.499422-0.500239

uvs [9]:0.500149-0.750166

uvs [10]:0.748355-0.99823

uvs [11]:0.500193-0.998728

uvs [12]:0.498993-0.250415

uvs [13]:0.748953-0.25092

我做错了什么,如果有人可以帮助我那会很棒.

Answer 1

您检查glGetAttribLocation()无法找到该属性是不正确的:

GLuint vertexUVID = glGetAttribLocation(shaderProgram, "color");
if(!vertexUVID)
    cout << "vertexUVID not found ..." << endl;

glGetAttribLocation()返回a GLint(not GLuint),结果是-1在程序中找不到具有给定名称的属性.由于您将值分配给无符号变量,因此它最终将成为最大的无符号变量,如果将其传递给glEnableVertexAttribArray()之后,则该变量将成为无效参数.

你的代码应该是这样的:

GLint vertexUVID = glGetAttribLocation(shaderProgram, "color");
if(vertexUVID < 0)
    cout << "vertexUVID not found ..." << endl;

请注意,这0是一个完全有效的属性位置.