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的缓冲区出现了错误1281(错误值),这里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);
error = glGetError();
if(error) {
cout << error << endl;
return ;
}
//error 1281
if (textured) {
texture = new sf::Texture();
if(!texture->loadFromFile("textures/simple.jpeg"/*,sf::IntRect(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.
解决方法
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GLint(不是GLuint),如果在程序中找不到具有给定名称的属性,则结果为-1.由于您将值赋值给无符号变量,因此它最终将成为最大的无符号变量,如果您之后将其传递给glEnableVertexAttribArray(),那么这将是无效参数.
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,0是完全有效的属性位置.
