c++openglglbinding

glBinding/GLFW "Error after macro substitution"

I am trying to learn OpenGL with GLFW/glBinding and I if i want to create and use a vertexbuffer, I get the Compilingerror

error: cannot convert ‘int’ to ‘gl::GLenum’ for argument ‘1’ to ‘void gl::glBindBuffer(gl::GLenum, gl::GLuint)’
 gl::glBindBuffer(GL_ARRAY_BUFFER, VBO);

My IDE (Clion) tells me, that there is a param mismatch (obviously) after a Macro substitution. So my Question is: what did I wrong? Because if it was the macros fault, there would be more hits on google for this topic :)

Code:

GLuint VBO;
gl::glGenBuffers(1, &VBO);
gl::glBindBuffer(GL_ARRAY_BUFFER, VBO);

My Tutorial is this and it it says not to use the namespace gl:: but if I don't I can't access the functions, so i guess this is not the problem.

thanks

Solution

  • First step: according to glBinding's documentation, the argument should be something like gl::GL_ARRAY_BUFFER. Still, this won't solve the whole problem.

    This is because your OpenGL implementation used #define's to expose constants such as GL_ARRAY_BUFFER, in the following manner:

    #define GL_ARRAY_BUFFER 1

    This means that your code is actually preprocessed to:

    gl::glBindBuffer(1, VBO);

    And that, before the compiler has had a chance to see your code and use glBinding's GL_ARRAY_BUFFER. Hence the error.

    The solution is, as stated in the documentation, to remove and replace the standard GL.h include with the include from glBinding.