Game: spot the error

tutorials
1

I spent about 1/2 an hour trying to work out why the run function wasn't visible. Can you spot why?

#![cfg(not(any(feature = "vulkan", feature = "dx12", feature = "metal")))]
compile_error!("must enable a backend feature");

#[cfg(feature = "dx12")]
use gfx_backend_dx12 as back;
#[cfg(feature = "metal")]
use gfx_backend_metal as back;
#[cfg(feature = "vulkan")]
use gfx_backend_vulkan as back;
use gfx_hal as hal;

pub mod path;

const DIMS: Extent2D = Extent2D {
    width: 1024,
    height: 768,
};
const ENTRY_NAME: &str = "main";

#[derive(Debug, Clone, Copy)]
#[allow(non_snake_case)]
struct Vertex {
    a_Pos: [f32; 2],
}

#[cfg_attr(rustfmt, rustfmt_skip)]
const QUAD: [Vertex; 3] = [
    Vertex { a_Pos: [-0.5,-1.0 ] },
    Vertex { a_Pos: [ 1.0, 0.0 ] },
    Vertex { a_Pos: [ 0.5,-1.0 ] },
];

pub fn run() -> Result<(), failure::Error> {
    env_logger::init();

    // winit
    let mut events_loop = winit::EventsLoop::new();
    let wb = winit::WindowBuilder::new()
        .with_dimensions(winit::dpi::LogicalSize::new(
            DIMS.width as _,
            DIMS.height as _,
        ))
        .with_title("quad".to_string());
    let window = wb.build(&events_loop).context("creating window")?;

    // instance
    let instance = back::Instance::create("gfx-rs quad", 1);
    let surface = instance.create_surface(&window);
    let adapter = instance.enumerate_adapters();
}

Hopefully you won't have to sit for quite as long if you make the same mistake :smiley:

EDIT oops had the corrected version of the code. (un)fixed to the broken version now.

2

What a shebang!

1 Like
3

Is it pub? Yes. Ok, is it wrapped in any macros or attributes? No. So it's an issue with the visibility path; where are the intermediate modules? There aren't any. So it should be visible, but isn't. Must be something in the context, not the function itself.

*scrolls to the top*

A cfg attribute; that would hide it if it was... *look at start of line* yup.

1 Like