OSX OpenGL 4.1 glEnableVertexAttribArray glDrawArrays GL_INVALID_OPERATION

Question

I programmed an OpenGL application with an SDL window. Core Profile running OpenGL 4.1 on a Mac OSX 10.9. The command glClearColor works great and I get the right color on screen. But inside my renderer I got the GL_INVALID_OPERATION error everytime I execute the commands glEnableVertexAttribArray and glDrawArrays .

That is the code:

Vertex Shader:

#version 410

in vec4 position;

void main(void)
{
    gl_Position = position;
}

Fragment Shader:

#version 410

out vec4 out_Color;

void main(void)
{
    out_Color = vec4(0.0, 1.0, 0.0, 1.0);
}

All shader compile and linked to an program. No linking error!

Creating buffer with data:

static const float VertexBufferData[] = {
            0.75f, 0.75f, 0.0f, 1.0f,
            0.75f, -0.75f, 0.0f, 1.0f,
            -0.75f, -0.75f, 0.0f, 1.0f,
 };

 glGenBuffers(1, &m_VertexBuffer);
 glBindBuffer(GL_ARRAY_BUFFER, m_VertexBuffer);
 glBufferData(GL_ARRAY_BUFFER, sizeof(VertexBufferData), VertexBufferData, GL_STATIC_DRAW);
 glBindBuffer(GL_ARRAY_BUFFER, 0);

Render:

glUseProgram(m_ShaderProgram);

glBindBuffer(GL_ARRAY_BUFFER, m_VertexBuffer);

glEnableVertexAttribArray(0);

glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);

glDrawArrays(GL_TRIANGLES, 0, 3);

// glDrawElements( GL_TRIANGLES, 3, GL_UNSIGNED_INT, nullptr);

glDisableVertexAttribArray(0);

glBindBuffer(GL_ARRAY_BUFFER, 0);

glUseProgram(0);

Output:

Answer 1

AS BDL already said: The solution is to create a VAO. As a short description: A VAO (Vertex Array Object) is a collection of VBOs, which describes the vertex layout and the vertices for the shader.

More informations here:

• OpenGL VAO best practices
• http://www.swiftless.com/tutorials/opengl4/4-opengl-4-vao.html

So I have changed the following code blocks:

Buffer:

    static const float VertexBufferData[] = {
            0.75f, 0.75f, 0.0f, 1.0f,
            0.75f, -0.75f, 0.0f, 1.0f,
            -0.75f, -0.75f, 0.0f, 1.0f,
        };

    glGenVertexArrays(1, &m_VertexBufferArray);
    glBindVertexArray(m_VertexBufferArray);

    glGenBuffers(1, &m_VertexBuffer);
    glBindBuffer(GL_ARRAY_BUFFER, m_VertexBuffer);
    glBufferData(GL_ARRAY_BUFFER, sizeof(VertexBufferData), VertexBufferData, GL_STATIC_DRAW);

    glEnableVertexAttribArray(0);

    glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);

    glBindVertexArray(0);

Render:

    glUseProgram(m_ShaderProgram);

    glBindVertexArray(m_VertexBufferArray);

    glDrawArrays(GL_TRIANGLES, 0, 3);

    glBindVertexArray(0);

    glUseProgram(0);

Result: