Problem initializing glium and glutin window.

init_glium.rs

//Hello rusters, I'm writing a rust graphics environment with a custom scripting language using glium.
//As example program, I'm writing a tic-tac-toe game which needs to be able to capture location of mouse clicks.
//I want to find mouse location on screen, and glutin event returns location in pixels.
//But I need location as a ratio of OpenGL display size.
//It appears I can use glium::glutin::Window.get_inner_size_pixels(&self).
//But to initialize glium, it captures WindowBuilder,
// preventing me from building the window.

use glium::glutin::WindowBuilder;

let win_builder = WindowBuilder::new();

let display = win_builder.build_glium().unwrap();
let window = win_builder.build().unwrap(); //causes problem
//...somewhere in the main loop...
let mut mouse_x = 0.0, mouse_y = 0.0;

let polled_events = display.poll_events();
for ev in polled_events {
  if let Event::MouseMoved(x, y) = ev {
     self.mouse_pos.0 = x as f32;
     self.mouse_pos.1 = y as f32;
  }
}
                  
let pos_x = mouse_x / window.get_inner_size_pixels().unwrap().0;
let pos_y = mouse_y / window.get_inner_size_pixels().unwrap().1;

//The actual code where I ran into the problem is here:
//https://github.com/KostyaKow/skomakare/blob/master/src/game.rs#L27
//This file is a part of a small graphics environment aimed at teaching Lisp to kids.
//I'm using my own lisp interpreter (https://github.com/KostyaKow/LambdaOxide)
//and it's still in early stages of development but the minimum functionality already works.
//I would love feedback on my coding style, since it's my first rust project.

//Here's an example to draw circle:
//https://github.com/KostyaKow/skomakare/blob/master/circle.lo
//And this is example I started for tictactoe:
//https://github.com/KostyaKow/skomakare/blob/master/tictactoe.lo

Solved by using GlutinFacade::get_framebuffer_dimensions()