demo.rs

use {egui_miniquad as egui_mq, miniquad as mq};

struct Stage {
    egui_mq: egui_mq::EguiMq,
    show_egui_demo_windows: bool,
    egui_demo_windows: egui_demo_lib::DemoWindows,
    color_test: egui_demo_lib::ColorTest,
    prev_egui_zoom_factor: f32,
    zoom_factor: f32,
    mq_ctx: Box<dyn mq::RenderingBackend>,
}

impl Stage {
    fn new() -> Self {
        let mut mq_ctx = mq::window::new_rendering_backend();

        Self {
            egui_mq: egui_mq::EguiMq::new(&mut *mq_ctx),
            show_egui_demo_windows: true,
            egui_demo_windows: Default::default(),
            color_test: Default::default(),
            prev_egui_zoom_factor: 1.0,
            zoom_factor: 1.0,
            mq_ctx,
        }
    }
}

impl mq::EventHandler for Stage {
    fn update(&mut self) {}

    fn draw(&mut self) {
        self.mq_ctx.clear(Some((1., 1., 1., 1.)), None, None);
        self.mq_ctx
            .begin_default_pass(mq::PassAction::clear_color(0.0, 0.0, 0.0, 1.0));
        self.mq_ctx.end_render_pass();

        let dpi_scale = mq::window::dpi_scale();

        // Run the UI code:
        self.egui_mq.run(&mut *self.mq_ctx, |_mq_ctx, egui_ctx| {
            if self.show_egui_demo_windows {
                self.egui_demo_windows.ui(egui_ctx);
            }

            // zoom factor could have been changed by the user in egui using Ctrl/Cmd and -/+/0,
            // but it could also be in the middle of being changed by us using the slider. So we
            // only allow egui's zoom to override our zoom if the egui zoom is different from what
            // we saw last time (meaning the user has changed it).
            let curr_egui_zoom = egui_ctx.zoom_factor();
            if self.prev_egui_zoom_factor != curr_egui_zoom {
                self.zoom_factor = curr_egui_zoom;
            }
            self.prev_egui_zoom_factor = curr_egui_zoom;

            egui::Window::new("egui ❤ miniquad").show(egui_ctx, |ui| {
                egui::widgets::global_dark_light_mode_buttons(ui);
                ui.checkbox(&mut self.show_egui_demo_windows, "Show egui demo windows");

                ui.group(|ui| {
                    ui.label("Physical pixels per each logical 'point':");
                    ui.label(format!("native: {:.2}", dpi_scale));
                    ui.label(format!("egui:   {:.2}", ui.ctx().pixels_per_point()));
                    ui.label("Current zoom factor:");
                    ui.add(
                        egui::Slider::new(&mut self.zoom_factor, 0.75..=3.0).logarithmic(true),
                    )
                    .on_hover_text("Override egui zoom factor manually (changes effective pixels per point)");
                    if ui.button("Reset").clicked() {
                        self.zoom_factor = 1.0;
                    }

                    ui.label("By default, egui allows zooming with\nCtrl/Cmd and +/-/0");
                    // Creating a checkbox that directly mutates the egui context's options causes a
                    // freeze so we copy the state out, possibly mutate it with the checkbox, and
                    // then copy it back in.
                    let mut zoom_with_keyboard = egui_ctx.options(|o| o.zoom_with_keyboard);
                    ui.checkbox(&mut zoom_with_keyboard, "Allow egui zoom with keyboard");
                    egui_ctx.options_mut(|o|
                        o.zoom_with_keyboard = zoom_with_keyboard
                    );
                });

                #[cfg(not(target_arch = "wasm32"))]
                {
                    if ui.button("Quit").clicked() {
                        std::process::exit(0);
                    }
                }
            });

            // Don't change zoom while dragging the slider
            if !egui_ctx.is_using_pointer() {
                egui_ctx.set_zoom_factor(self.zoom_factor);
            }

            egui::Window::new("Color Test").show(egui_ctx, |ui| {
                egui::ScrollArea::both()
                    .auto_shrink([false; 2])
                    .show(ui, |ui| {
                        self.color_test.ui(ui);
                    });
            });
        });

        // Draw things behind egui here

        self.egui_mq.draw(&mut *self.mq_ctx);

        // Draw things in front of egui here

        self.mq_ctx.commit_frame();
    }

    fn mouse_motion_event(&mut self, x: f32, y: f32) {
        self.egui_mq.mouse_motion_event(x, y);
    }

    fn mouse_wheel_event(&mut self, dx: f32, dy: f32) {
        self.egui_mq.mouse_wheel_event(dx, dy);
    }

    fn mouse_button_down_event(&mut self, mb: mq::MouseButton, x: f32, y: f32) {
        self.egui_mq.mouse_button_down_event(mb, x, y);
    }

    fn mouse_button_up_event(&mut self, mb: mq::MouseButton, x: f32, y: f32) {
        self.egui_mq.mouse_button_up_event(mb, x, y);
    }

    fn char_event(&mut self, character: char, _keymods: mq::KeyMods, _repeat: bool) {
        self.egui_mq.char_event(character);
    }

    fn key_down_event(&mut self, keycode: mq::KeyCode, keymods: mq::KeyMods, _repeat: bool) {
        self.egui_mq.key_down_event(keycode, keymods);
    }

    fn key_up_event(&mut self, keycode: mq::KeyCode, keymods: mq::KeyMods) {
        self.egui_mq.key_up_event(keycode, keymods);
    }
}

fn main() {
    #[cfg(not(target_arch = "wasm32"))]
    {
        // Log to stdout (if you run with `RUST_LOG=debug`).
        tracing_subscriber::fmt::init();
    }

    let conf = mq::conf::Conf {
        high_dpi: true,
        window_width: 1200,
        window_height: 1024,
        ..Default::default()
    };
    mq::start(conf, || Box::new(Stage::new()));
}