Function primitive_new 

pub unsafe fn primitive_new(
    operation: c_int,
    convexity: u32,
    callback: RenderFn,
    user_data: *mut c_void,
) -> *mut OcsgPrimitive

Create a new OpenCSG primitive.

Safety

callback will be invoked by OpenCSG during rendering passes. user_data must remain valid for the lifetime of the primitive.