在 glium 中设置帧重绘率？

Question

I am trying to make a game loop using glium in rust. My goal is to get the screen to redraw 60 times per second. With the current event loop code I have, the frame only gets redrawn when the window size changes. I read in the glutin docs, that I need to call request_redraw somewhere, but I'm not sure how/where. This is my code so far:

event_loop.run(move |event, _target, control_flow| match event {
    Event::LoopDestroyed => return,
    Event::WindowEvent {
        window_id: _window_id,
        event: winevent,
    } => match winevent {
        WindowEvent::Resized(physical_size) => display.gl_window().resize(physical_size),
        WindowEvent::CloseRequested => {
            *control_flow = ControlFlow::Exit;
        }
        _ => {}
    },
    Event::RedrawRequested(_window_id) => {
        let mut target = display.draw();
        target.clear_color_srgb(rng.gen(), rng.gen(), rng.gen(), 1.0);
        target.finish().unwrap();
    }
    _ => {}
});

Answer 1

I haven't used glium before (I've been making some graphics applications directly off of Vulkano for a while). However, perusing the API, it seems you can get your Window handle from winit by going through a series of apis. I outlined them in the below code. Something like the below should work for you. The key is getting access to the Window handle from winit . Scrolling through the Window API you should see this: request_redraw . You can then insert game-loop logic around your event handler like this:

use std::time::Instant;
use glium::Display;
use winit::event_loop::{EventLoop, ControlFlow};
use winit::event::{Event, WindowEvent};
use winit::window::Window;

const TARGET_FPS: u64 = 60;

/* ... some function for main loop ... */

let display: Display = ... /* glium Display instance */

event_loop.run(move |event, _target, control_flow| {
    let start_time = Instant::now();
    match event {
        Event::WindowEvent { event: WindowEvent::CloseRequested, .. } => {
            *control_flow = ControlFlow::Exit;
        },
        ...
    /*
     * Process events here
     */
    }
    match *control_flow {
        ControlFlow::Exit => (),
        _ => {
            /*
             * Grab window handle from the display (untested - based on API)
             */
            display.gl_window().window().request_redraw();
            /*
             * Below logic to attempt hitting TARGET_FPS.
             * Basically, sleep for the rest of our milliseconds
             */
            let elapsed_time = Instant::now().duration_since(start_time).as_millis() as u64;

            let wait_millis = match 1000 / TARGET_FPS >= elapsed_time {
                true => 1000 / TARGET_FPS - elapsed_time,
                false => 0
            };
            let new_inst = start_time + std::time::Duration::from_millis(wait_millis);
            *control_flow = ControlFlow::WaitUntil(new_inst);
        }
    }
});