Enable a vertex attribute array. Attributes will be used for use by
subsequent draw operations. Be sure to call disableVertexAttribArray()
on the same attribute to prevent currently enabled attributes from affecting
later rendering.
index (int) – Index of the attribute to enable. If legacy=True, this value should be a GLenum type corresponding to the capability to bind the buffer to, such as GL_VERTEX_ARRAY, GL_TEXTURE_COORD_ARRAY, GL_NORMAL_ARRAY, etc.
legacy (bool, optional) – Use legacy vertex attributes (ie. GL_VERTEX_ARRAY, GL_TEXTURE_COORD_ARRAY, etc.) for backwards compatibility.