Question mark.

src/slide/s8_mosaic.rs

@@ -3,13 +3,13 @@ use crate::component::arrow::Arrow;
 use crate::component::grid::Grid;
 use crate::component::image::Image;
 use crate::component::triangle::Triangle;
-use crate::egui::{Color32, Context, TextureHandle, Ui, Vec2};
+use crate::egui::{Align2, Color32, Context, TextureHandle, Ui, Vec2};
 use crate::fade_in::{fade_in, fade_in_manual, fade_out_manual};
 use crate::img;
 use crate::slide::Slide;
 use crate::window::WindowPosition;
 use eframe::egui::style::Margin;
-use eframe::egui::{ColorImage, Frame, Pos2, Shape, Stroke};
+use eframe::egui::{ColorImage, FontFamily, FontId, Frame, Pos2, Shape, Stroke};
 use eframe::emath::Rot2;
 use eframe::epaint::CircleShape;
 use imageproc::drawing::draw_filled_polygon_mut;
@@ -282,6 +282,16 @@ impl Slide for Mosaic {
             ui.ctx().request_repaint();
 
             match &mut self.state {
+                MosaicState::Before => {
+                    // Question mark.
+                    ui.painter().text(
+                        to_screen * Pos2::new(0.5, 0.5),
+                        Align2::CENTER_CENTER,
+                        "?",
+                        FontId::new(100.0, FontFamily::Proportional),
+                        ui.style().visuals.text_color(),
+                    );
+                }
                 &mut MosaicState::Point { fade_start } => {
                     fade_in_manual(ui, fade_start, |ui, alpha| {
                         let center = to_screen * Self::RANDOM_POINT;