extract ui to module

src/main.rs

@@ -1,224 +1,18 @@
-use std::ops::{Deref, DerefMut};
+use bevy_ecs::prelude::*;
-
+use eframe::egui;
-use bevy_ecs::{
-    prelude::*,
-    query::WorldQuery,
-    system::{Commands, IntoSystem, Query, ReadOnlySystem, Res, ResMut, System},
-};
-use eframe::{
-    egui::{self, CursorIcon, Painter, Response, Sense},
-    emath::{Pos2, Rect, RectTransform, Vec2},
-    epaint::{Color32, Hsva, Stroke},
-};
-use geometry::{Line, LineBundle, Point, PointId, PointPos, PointPosQueryMut};
 
 mod geometry;
 pub mod optimization;
 mod relations;
 #[cfg(feature = "trace")]
 mod tracing;
+mod ui;
 
 fn init(mut commands: Commands) {
     let p1 = geometry::insert_point_at(&mut commands, (10., 30.));
     let p2 = geometry::insert_point_at(&mut commands, (-20., 15.));
     geometry::insert_point_at(&mut commands, (0., -10.));
-    commands.spawn(LineBundle::new(p1, p2));
+    commands.spawn(geometry::LineBundle::new(p1, p2));
-}
-
-#[derive(Resource)]
-struct ContextRes(egui::Context);
-
-impl Deref for ContextRes {
-    type Target = egui::Context;
-
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-fn prepare(ctx: Res<ContextRes>) {
-    ctx.request_repaint();
-    ctx.set_visuals(egui::Visuals::dark());
-}
-
-fn toolbar(
-    ctx: Res<ContextRes>,
-    selected: Query<Entity, With<Selected>>,
-    mut commands: Commands,
-    mut tool: ResMut<Tool>,
-) {
-    egui::TopBottomPanel::top("top_panel").show(&ctx, |ui| {
-        // ui.heading("sketchrs");
-        let mut selected_tool = *tool;
-        ui.horizontal(|ui| {
-            ui.radio_value(&mut selected_tool, Tool::Select, "Select");
-            ui.radio_value(&mut selected_tool, Tool::Move, "Move");
-            ui.radio_value(&mut selected_tool, Tool::AddPoint, "Add Point");
-            ui.radio_value(&mut selected_tool, Tool::AddLine, "Add Line");
-        });
-        if selected_tool != *tool {
-            *tool = selected_tool;
-
-            for selected in selected.iter() {
-                commands.entity(selected).remove::<Selected>();
-            }
-        }
-    });
-}
-
-struct ShowEntitiesSchedule(Schedule);
-
-#[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
-#[system_set(base)]
-pub enum ShowEntitiesStage {
-    Update,
-    Input,
-    Tools,
-    PostTools,
-    Paint,
-}
-
-impl Default for ShowEntitiesSchedule {
-    fn default() -> Self {
-        let mut schedule = Schedule::new();
-        schedule.configure_sets(
-            (
-                ShowEntitiesStage::Update,
-                ShowEntitiesStage::Input,
-                ShowEntitiesStage::Tools,
-                ShowEntitiesStage::PostTools,
-                ShowEntitiesStage::Paint,
-            )
-                .chain(),
-        );
-        schedule.add_systems(
-            (geometry::update_point_pos, geometry::update_line_pos)
-                .in_base_set(ShowEntitiesStage::Update),
-        );
-        schedule.add_systems(
-            (update_hover_point, update_hover_line).in_base_set(ShowEntitiesStage::Input),
-        );
-        schedule.add_systems(
-            (
-                select_tool.run_if(is_tool_active(Tool::Select)),
-                move_tool.run_if(is_tool_active(Tool::Move)),
-                add_point_tool.run_if(is_tool_active(Tool::AddPoint)),
-                add_line_tool.run_if(is_tool_active(Tool::AddLine)),
-                add_relation_tool.run_if(is_tool_active(Tool::AddRelation)),
-            )
-                .distributive_run_if(is_hovered)
-                .in_base_set(ShowEntitiesStage::Tools),
-        );
-        schedule
-            .add_system(geometry::remove_dangling_lines.in_base_set(ShowEntitiesStage::PostTools));
-        schedule.add_systems(
-            (paint_lines, paint_points)
-                .chain()
-                .in_base_set(ShowEntitiesStage::Paint),
-        );
-        Self(schedule)
-    }
-}
-
-fn central_panel(world: &mut World, mut schedule: Local<ShowEntitiesSchedule>) {
-    let ctx = world.get_resource::<ContextRes>().unwrap().0.clone();
-    egui::CentralPanel::default()
-        .frame(egui::Frame::none())
-        .show(&ctx, |ui| {
-            let sense = match *world.resource::<Tool>() {
-                Tool::Move => Sense::drag(),
-                Tool::Select | Tool::AddPoint | Tool::AddLine | Tool::AddRelation => Sense::click(),
-            };
-
-            let (response, painter) = ui.allocate_painter(ui.available_size(), sense);
-            let to_screen = RectTransform::from_to(
-                Rect::from_center_size(Pos2::ZERO, response.rect.size() / 2.0),
-                response.rect,
-            );
-            world.insert_resource(ToScreen(to_screen));
-            world.insert_resource(ResponseRes(response));
-            world.insert_resource(PainterRes(painter));
-
-            schedule.0.run(world);
-
-            world.remove_resource::<PainterRes>();
-            world.remove_resource::<ResponseRes>();
-            world.remove_resource::<ToScreen>();
-        });
-}
-
-#[derive(WorldQuery)]
-struct SelectableEntity<'a> {
-    id: Entity,
-    point: Option<&'a Point>,
-    line: Option<&'a Line>,
-}
-
-fn side_panel_ui(
-    ui: &mut egui::Ui,
-    selected: Query<SelectableEntity, With<Selected>>,
-    tool: Res<Tool>,
-) {
-    let tool = *tool;
-    ui.vertical(|ui| match tool {
-        Tool::Select => {
-            let mut count = 0;
-            selected.for_each(|sel| {
-                count += 1;
-                if sel.point.is_some() {
-                    ui.label(format!("Selected point {}", sel.id.index()));
-                } else if sel.line.is_some() {
-                    ui.label(format!("Selected line {}", sel.id.index()));
-                }
-            });
-            if count == 0 {
-                ui.label("Nothing selected");
-            }
-        }
-        Tool::Move => {
-            let mut count = 0;
-            selected.for_each(|sel| {
-                count += 1;
-                if sel.point.is_some() {
-                    ui.label(format!("Selected point {}", sel.id.index()));
-                } else if sel.line.is_some() {
-                    ui.label(format!("Selected line {}", sel.id.index()));
-                }
-            });
-            if count == 0 {
-                ui.label("Nothing selected");
-            }
-        }
-        Tool::AddPoint => {
-            ui.label("Click to add a point");
-        }
-        Tool::AddLine => {
-            ui.label("Click to add a line");
-        }
-        Tool::AddRelation => {
-            ui.label("Click to add a relation");
-        }
-    });
-}
-
-fn side_panel(
-    ctx: Res<ContextRes>,
-    selected: Query<SelectableEntity, With<Selected>>,
-    tool: Res<Tool>,
-) {
-    egui::SidePanel::right("side_panel")
-        .resizable(true)
-        .default_width(150.0)
-        .width_range(80.0..=200.0)
-        .show(&ctx, |ui| side_panel_ui(ui, selected, tool));
-}
-
-fn bottom_panel(ctx: Res<ContextRes>) {
-    egui::TopBottomPanel::bottom("bottom_panel").show(&ctx, |ui| {
-        ui.horizontal(|ui| {
-            ui.label("Status:");
-        });
-    });
 }
 
 struct MyApp {
@@ -231,6 +25,7 @@ impl Default for MyApp {
         Self::new()
     }
 }
+
 impl MyApp {
     fn new() -> Self {
         let mut world = World::default();
@@ -238,27 +33,29 @@ impl MyApp {
         #[cfg(feature = "trace")]
         tracing::setup(&mut world);
 
+        world.init_resource::<ui::Tool>();
+
         let mut init_sched = Schedule::new();
         init_sched.add_system(init);
         init_sched.run(&mut world);
 
-        let mut update = Schedule::default();
+        let mut update_schedule = Schedule::default();
-        update.add_systems((prepare, toolbar, side_panel, bottom_panel, central_panel).chain());
+        ui::add_to_schedule(&mut update_schedule);
 
         Self {
             world,
-            update_schedule: update,
+            update_schedule,
         }
     }
 }
 
 impl eframe::App for MyApp {
     fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
-        self.world.insert_resource(ContextRes(ctx.clone()));
+        self.world.insert_resource(ui::ContextRes(ctx.clone()));
 
         self.update_schedule.run(&mut self.world);
 
-        self.world.remove_resource::<ContextRes>();
+        self.world.remove_resource::<ui::ContextRes>();
     }
 }
 

src/ui.rs

@@ -0,0 +1,570 @@
+use std::ops::Deref;
+
+use bevy_ecs::{prelude::*, query::WorldQuery, system::ReadOnlySystem};
+use eframe::{
+    egui::{self, CursorIcon, Painter, Response, Sense},
+    emath::RectTransform,
+    epaint::{Color32, Hsva, Pos2, Rect, Stroke, Vec2},
+};
+
+use crate::geometry::{self};
+
+#[derive(Clone, Copy, PartialEq, Resource)]
+pub enum Tool {
+    Select,
+    Move,
+    AddPoint,
+    AddLine,
+    AddRelation,
+}
+
+#[allow(clippy::derivable_impls)]
+impl Default for Tool {
+    fn default() -> Self {
+        Tool::Select
+    }
+}
+
+#[derive(Resource)]
+struct UiRes {
+    response: Response,
+    painter: Painter,
+    to_screen: ToScreen,
+}
+struct ToScreen(RectTransform);
+
+impl ToScreen {
+    fn transform_pos(&self, pos: &geometry::PointPos) -> Pos2 {
+        self.0 * Pos2::new(pos.x as f32, pos.y as f32)
+    }
+
+    fn inverse_transform(&self, pos: Pos2) -> Pos2 {
+        self.0.inverse() * pos
+    }
+
+    fn inverse_transform_to_point(&self, pos: Pos2) -> geometry::PointPos {
+        let pos = self.inverse_transform(pos);
+        geometry::PointPos::new(pos.x as f64, pos.y as f64)
+    }
+}
+
+#[derive(Component)]
+struct Hovered;
+
+#[derive(Component)]
+struct Selected;
+
+fn color_for_var_status(status: geometry::VarStatus) -> Hsva {
+    use geometry::VarStatus::*;
+    match status {
+        Free => Hsva::new(200. / 360., 0.90, 0.80, 1.0),
+        Dependent => todo!(),
+        Unique => todo!(),
+        Overconstrained => todo!(),
+    }
+}
+
+const POINT_RADIUS: f32 = 3.0;
+
+fn update_hover_point(
+    ui: Res<UiRes>,
+    points: Query<(geometry::PointId, &geometry::ComputedPointPos)>,
+    mut commands: Commands,
+) {
+    points.for_each(|(id, pos)| {
+        let hovered = if let Some(hover_pos) = ui.response.hover_pos() {
+            let center = ui.to_screen.transform_pos(pos);
+
+            (hover_pos - center).length() < (POINT_RADIUS * 3.)
+        } else {
+            false
+        };
+
+        if hovered {
+            commands.entity(id).insert(Hovered);
+        } else {
+            commands.entity(id).remove::<Hovered>();
+        }
+    });
+}
+
+fn update_hover_line(
+    ui: Res<UiRes>,
+    lines: Query<(Entity, &geometry::ComputedLinePos)>,
+    mut commands: Commands,
+) {
+    lines.for_each(|(id, pos)| {
+        let hovered = if let Some(hover_pos) = ui.response.hover_pos() {
+            let points = [
+                ui.to_screen.transform_pos(&pos.start),
+                ui.to_screen.transform_pos(&pos.end),
+            ];
+
+            let b = points[1] - points[0];
+            let a = hover_pos - points[0];
+            let p = a.dot(b) / b.dot(b);
+            let perp = a - (p * b);
+            ((0.)..=1.).contains(&p) && perp.length() < 5.0
+        } else {
+            false
+        };
+
+        if hovered {
+            commands.entity(id).insert(Hovered);
+        } else {
+            commands.entity(id).remove::<Hovered>();
+        }
+    });
+}
+
+fn select_tool(
+    ui: Res<UiRes>,
+    hovered: Query<Entity, With<Hovered>>,
+    selected: Query<Entity, With<Selected>>,
+    mut commands: Commands,
+) {
+    ui.response.ctx.output_mut(|output| {
+        output.cursor_icon = if !hovered.is_empty() {
+            CursorIcon::PointingHand
+        } else {
+            CursorIcon::Default
+        }
+    });
+
+    if ui.response.clicked() {
+        if !ui.response.ctx.input(|input| input.modifiers.shift) {
+            selected.for_each(|selected| {
+                commands.entity(selected).remove::<Selected>();
+            });
+        }
+        // TODO: choose which to select
+        if let Some(hovered) = hovered.iter().next() {
+            commands.entity(hovered).insert(Selected);
+        }
+    }
+
+    if ui
+        .response
+        .ctx
+        .input(|input| input.key_pressed(egui::Key::Escape))
+    {
+        selected.for_each(|selected| {
+            commands.entity(selected).remove::<Selected>();
+        });
+    } else if ui
+        .response
+        .ctx
+        .input(|input| input.key_pressed(egui::Key::Delete))
+    {
+        selected.for_each(|selected| {
+            commands.entity(selected).despawn();
+        });
+    }
+}
+
+#[derive(Default)]
+struct DragDelta(Vec2);
+
+// TODO: move other entities
+fn move_tool(
+    ui: Res<UiRes>,
+    mut drag_delta: Local<DragDelta>,
+    mut point_pos: geometry::PointPosQueryMut,
+    hovered: Query<(Entity, &geometry::Point), With<Hovered>>,
+    selected: Query<(Entity, &geometry::Point), With<Selected>>,
+    mut commands: Commands,
+) {
+    let response = &ui.response;
+    let to_screen = &ui.to_screen;
+    let hover_pos = response.hover_pos().unwrap();
+
+    response.ctx.output_mut(|o| {
+        o.cursor_icon = if !selected.is_empty() {
+            CursorIcon::Grabbing
+        } else if !hovered.is_empty() {
+            CursorIcon::Grab
+        } else {
+            CursorIcon::Move
+        }
+    });
+
+    let selected = if response.drag_started() {
+        // TODO: choose which to select
+        let to_select = hovered.iter().next();
+        if let Some(hovered) = to_select {
+            commands.entity(hovered.0).insert(Selected);
+        }
+        to_select
+    } else if response.drag_released() {
+        selected.for_each(|selected| {
+            commands.entity(selected.0).remove::<Selected>();
+        });
+        drag_delta.0 = Vec2::ZERO;
+        None
+    } else {
+        selected.iter().next()
+    };
+
+    if let Some((_, point)) = selected {
+        if response.drag_started() {
+            let drag_point_pos = point_pos.get(point).unwrap();
+            drag_delta.0 = hover_pos - to_screen.transform_pos(&drag_point_pos);
+        }
+        let move_to = to_screen.inverse_transform_to_point(hover_pos - drag_delta.0);
+        point_pos.set(point, move_to).unwrap();
+    }
+}
+
+fn add_point(commands: &mut Commands, pos: Pos2, to_screen: &ToScreen) -> geometry::PointId {
+    let point_pos = to_screen.inverse_transform(pos);
+    let point_pos = (point_pos.x as f64, point_pos.y as f64);
+    geometry::insert_point_at(commands, point_pos)
+}
+
+fn add_point_tool(ui: Res<UiRes>, mut commands: Commands) {
+    let hover_pos = ui.response.hover_pos().unwrap();
+    if ui.response.clicked() {
+        add_point(&mut commands, hover_pos, &ui.to_screen);
+    } else {
+        ui.painter
+            .circle_filled(hover_pos, POINT_RADIUS, Color32::WHITE);
+    }
+}
+
+fn add_line_tool(
+    ui: Res<UiRes>,
+    hovered: Query<Entity, (With<Hovered>, With<geometry::Point>)>,
+    selected: Query<(Entity, &geometry::ComputedPointPos), With<Selected>>,
+    mut commands: Commands,
+) {
+    let UiRes {
+        response,
+        painter,
+        to_screen,
+    } = &*ui;
+    let hover_pos = response.hover_pos().unwrap();
+
+    match (selected.iter().next(), response.clicked()) {
+        (None, false) => {
+            painter.circle_filled(hover_pos, POINT_RADIUS, Color32::DARK_GRAY);
+        }
+        (None, true) => {
+            let point_id = match hovered.iter().next() {
+                Some(hovered) => hovered,
+                None => add_point(&mut commands, hover_pos, &to_screen),
+            };
+            commands.entity(point_id).insert(Selected);
+        }
+        (Some((_, start_point_pos)), false) => {
+            let points = [to_screen.transform_pos(start_point_pos), hover_pos];
+
+            let stroke = Stroke::new(2.0, Color32::DARK_GRAY);
+
+            painter.line_segment(points, stroke);
+
+            painter.circle_filled(hover_pos, POINT_RADIUS, Color32::DARK_GRAY);
+        }
+        (Some((start_point_id, _)), true) => {
+            // TODO: add point if no hover point
+            let end_point = hovered
+                .iter()
+                .next()
+                .unwrap_or_else(|| add_point(&mut commands, hover_pos, &to_screen));
+
+            let line = geometry::LineBundle::new(start_point_id, end_point);
+            commands.spawn(line);
+
+            selected.for_each(|(selected_id, _)| {
+                commands.entity(selected_id).remove::<Selected>();
+            });
+        }
+    }
+}
+
+fn add_relation_tool(
+    ui: Res<UiRes>,
+    hovered: Query<Entity, With<Hovered>>,
+    selected: Query<Entity, With<Selected>>,
+    mut commands: Commands,
+) {
+    let response = &ui.response;
+    response.ctx.output_mut(|o| {
+        o.cursor_icon = if !hovered.is_empty() {
+            CursorIcon::PointingHand
+        } else {
+            CursorIcon::Default
+        }
+    });
+
+    if response.clicked() {
+        // TODO: choose which to select
+        if let Some(hovered) = hovered.iter().next() {
+            commands.entity(hovered).insert(Selected);
+        } else {
+            selected.for_each(|selected| {
+                commands.entity(selected).remove::<Selected>();
+            });
+        }
+    }
+}
+
+fn is_hovered(ui: Res<UiRes>) -> bool {
+    ui.response.hover_pos().is_some()
+}
+
+fn is_tool_active(tool: Tool) -> impl System<In = (), Out = bool> + ReadOnlySystem {
+    IntoSystem::into_system(move |active_tool: Res<Tool>| *active_tool == tool)
+}
+
+fn paint_lines(
+    ui: Res<UiRes>,
+    lines: Query<(Entity, &geometry::ComputedLinePos)>,
+    hovered: Query<(), With<Hovered>>,
+    selected: Query<(), With<Selected>>,
+) {
+    lines.for_each(|(id, pos)| {
+        let points = [
+            ui.to_screen.transform_pos(&pos.start),
+            ui.to_screen.transform_pos(&pos.end),
+        ];
+
+        let mut color = color_for_var_status(pos.status);
+        color.v -= 0.6;
+        if hovered.contains(id) || selected.contains(id) {
+            color.s -= 0.8;
+        }
+
+        let stroke = Stroke::new(2.0, color);
+
+        ui.painter.line_segment(points, stroke);
+    });
+}
+
+fn paint_points(
+    ui: Res<UiRes>,
+    points: Query<(Entity, &geometry::ComputedPointPos)>,
+    hovered: Query<(), With<Hovered>>,
+    selected: Query<(), With<Selected>>,
+) {
+    points.for_each(|(id, pos)| {
+        let center = ui.to_screen.transform_pos(pos);
+
+        let color = color_for_var_status(pos.status);
+        let stroke = if selected.contains(id) || hovered.contains(id) {
+            // color.s -= 0.8;
+            Stroke::new(1.0, Color32::WHITE)
+        } else {
+            Stroke::default()
+        };
+        ui.painter.circle(center, POINT_RADIUS, color, stroke);
+    });
+}
+
+#[derive(Resource)]
+pub struct ContextRes(pub egui::Context);
+
+impl Deref for ContextRes {
+    type Target = egui::Context;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+fn prepare(ctx: Res<ContextRes>) {
+    // ctx.request_repaint();
+    ctx.set_visuals(egui::Visuals::dark());
+}
+
+fn toolbar(
+    ctx: Res<ContextRes>,
+    selected: Query<Entity, With<Selected>>,
+    mut commands: Commands,
+    mut tool: ResMut<Tool>,
+) {
+    egui::TopBottomPanel::top("top_panel").show(&ctx, |ui| {
+        // ui.heading("sketchrs");
+        let mut selected_tool = *tool;
+        ui.horizontal(|ui| {
+            ui.radio_value(&mut selected_tool, Tool::Select, "Select");
+            ui.radio_value(&mut selected_tool, Tool::Move, "Move");
+            ui.radio_value(&mut selected_tool, Tool::AddPoint, "Add Point");
+            ui.radio_value(&mut selected_tool, Tool::AddLine, "Add Line");
+        });
+        if selected_tool != *tool {
+            *tool = selected_tool;
+
+            for selected in selected.iter() {
+                commands.entity(selected).remove::<Selected>();
+            }
+        }
+    });
+}
+
+struct ShowEntitiesSchedule(Schedule);
+
+#[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+#[system_set(base)]
+pub enum ShowEntitiesStage {
+    Update,
+    UpdateFlush,
+    Input,
+    InputFlush,
+    Tools,
+    PostTools,
+    ToolsFlush,
+    Paint,
+}
+
+impl Default for ShowEntitiesSchedule {
+    fn default() -> Self {
+        let mut schedule = Schedule::new();
+        schedule
+            .configure_sets(
+                (
+                    ShowEntitiesStage::Update,
+                    ShowEntitiesStage::UpdateFlush,
+                    ShowEntitiesStage::Input,
+                    ShowEntitiesStage::InputFlush,
+                    ShowEntitiesStage::Tools,
+                    ShowEntitiesStage::ToolsFlush,
+                    ShowEntitiesStage::PostTools,
+                    ShowEntitiesStage::Paint,
+                )
+                    .chain(),
+            )
+            .add_systems(
+                (geometry::update_point_pos, geometry::update_line_pos)
+                    .in_base_set(ShowEntitiesStage::Update),
+            )
+            .add_system(apply_system_buffers.in_base_set(ShowEntitiesStage::UpdateFlush))
+            .add_systems(
+                (update_hover_point, update_hover_line).in_base_set(ShowEntitiesStage::Input),
+            )
+            .add_system(apply_system_buffers.in_base_set(ShowEntitiesStage::InputFlush))
+            .add_systems(
+                (
+                    select_tool.run_if(is_tool_active(Tool::Select)),
+                    move_tool.run_if(is_tool_active(Tool::Move)),
+                    add_point_tool.run_if(is_tool_active(Tool::AddPoint)),
+                    add_line_tool.run_if(is_tool_active(Tool::AddLine)),
+                    add_relation_tool.run_if(is_tool_active(Tool::AddRelation)),
+                )
+                    .distributive_run_if(is_hovered)
+                    .in_base_set(ShowEntitiesStage::Tools),
+            )
+            .add_system(geometry::remove_dangling_lines.in_base_set(ShowEntitiesStage::PostTools))
+            .add_system(apply_system_buffers.in_base_set(ShowEntitiesStage::ToolsFlush))
+            .add_systems(
+                (paint_lines, paint_points)
+                    .chain()
+                    .in_base_set(ShowEntitiesStage::Paint),
+            );
+        Self(schedule)
+    }
+}
+
+fn central_panel(world: &mut World, mut schedule: Local<ShowEntitiesSchedule>) {
+    let ctx = world.get_resource::<ContextRes>().unwrap().0.clone();
+    egui::CentralPanel::default()
+        .frame(egui::Frame::none())
+        .show(&ctx, |ui| {
+            let sense = match *world.resource::<Tool>() {
+                Tool::Move => Sense::drag(),
+                Tool::Select | Tool::AddPoint | Tool::AddLine | Tool::AddRelation => Sense::click(),
+            };
+
+            let (response, painter) = ui.allocate_painter(ui.available_size(), sense);
+            let to_screen = ToScreen(RectTransform::from_to(
+                Rect::from_center_size(Pos2::ZERO, response.rect.size() / 2.0),
+                response.rect,
+            ));
+            world.insert_resource(UiRes {
+                response,
+                painter,
+                to_screen,
+            });
+
+            schedule.0.run(world);
+
+            world.remove_resource::<UiRes>();
+        });
+}
+
+#[derive(WorldQuery)]
+struct SelectableEntity<'a> {
+    id: Entity,
+    point: Option<&'a geometry::Point>,
+    line: Option<&'a geometry::Line>,
+}
+
+fn side_panel_ui(
+    ui: &mut egui::Ui,
+    selected: Query<SelectableEntity, With<Selected>>,
+    tool: Res<Tool>,
+) {
+    let tool = *tool;
+    ui.vertical(|ui| match tool {
+        Tool::Select => {
+            let mut count = 0;
+            selected.for_each(|sel| {
+                count += 1;
+                if sel.point.is_some() {
+                    ui.label(format!("Selected point {}", sel.id.index()));
+                } else if sel.line.is_some() {
+                    ui.label(format!("Selected line {}", sel.id.index()));
+                }
+            });
+            if count == 0 {
+                ui.label("Nothing selected");
+            }
+        }
+        Tool::Move => {
+            let mut count = 0;
+            selected.for_each(|sel| {
+                count += 1;
+                if sel.point.is_some() {
+                    ui.label(format!("Selected point {}", sel.id.index()));
+                } else if sel.line.is_some() {
+                    ui.label(format!("Selected line {}", sel.id.index()));
+                }
+            });
+            if count == 0 {
+                ui.label("Nothing selected");
+            }
+        }
+        Tool::AddPoint => {
+            ui.label("Click to add a point");
+        }
+        Tool::AddLine => {
+            ui.label("Click to add a line");
+        }
+        Tool::AddRelation => {
+            ui.label("Click to add a relation");
+        }
+    });
+}
+
+fn side_panel(
+    ctx: Res<ContextRes>,
+    selected: Query<SelectableEntity, With<Selected>>,
+    tool: Res<Tool>,
+) {
+    egui::SidePanel::right("side_panel")
+        .resizable(true)
+        .default_width(150.0)
+        .width_range(80.0..=200.0)
+        .show(&ctx, |ui| side_panel_ui(ui, selected, tool));
+}
+
+fn bottom_panel(ctx: Res<ContextRes>) {
+    egui::TopBottomPanel::bottom("bottom_panel").show(&ctx, |ui| {
+        ui.horizontal(|ui| {
+            ui.label("Status:");
+        });
+    });
+}
+
+pub fn add_to_schedule(schedule: &mut Schedule) {
+    schedule.add_systems((prepare, toolbar, side_panel, bottom_panel, central_panel).chain());
+}