docs/knowledgebase/feature-inventory.md

@@ -34,7 +34,7 @@ Notes:
 | Script language parser | MakePath guide and VistaPro manual describe scripts and “Run Script” workflows. | Partial | `src/script.rs` parser, tests in `src/script.rs`, `README.md` script section. | Parser exists, but script execution is intentionally deferred. |
 | Script execution and animation frames | MakePath guide says scripts should render full animations and VistaPro can run scripts from the Script menu. | Planned | No script runner or frame-sequencing engine exists yet. | Add execution semantics once the command model is stable. |
 | MakePath-style path generation and motion models | MakePath guide describes spline nodes, previewing a path, and vehicle models (jet, glider, dune buggy, motorcycle, helicopter, cruise missile, custom). | Planned | No path generator or motion-model layer exists yet. | This is a separate planner/animation feature, not just a script parser. |
-| UI shell, menus, dialogs, and numeric gadgets | VistaPro screenshots/manuals show dense menus, dialogs, map tools, and numeric gadgets. | Partial | `src/app.rs`, `src/app_state.rs`, `src/bin/openvistapro_app.rs`. | Current UI is an egui CPU-preview shell with a small control set, not the legacy menu hierarchy. |
+| UI shell, menus, dialogs, and numeric gadgets | VistaPro screenshots/manuals show dense menus, dialogs, map tools, and numeric gadgets. | Partial | `src/app.rs`, `src/app_state.rs`, `src/ui_shell.rs`, `src/bin/openvistapro_app.rs`. | OpenVistaPro now has a durable docked egui shell with stable navigation, sidebar, viewport, inspector, and status chrome; menus/dialogs/numeric gadgets still remain to be filled in. |
 | Legacy image / landscape export formats | VistaPro manuals mention saving rendered images and landscapes in formats like IFF/IFF24/RGB and DEM/binary landscape files. | Planned | Current output is PNG plus project-owned `.ovp.toml` scenes. | Add separate compatibility/export work only after the clean internal pipeline is stable. |
 
 ## Current reconciliation summary

src/app.rs

@@ -3,12 +3,17 @@ use image::RgbImage;
 
 use crate::app_state::{AppAction, AppData, RendererMode, TerrainPreset};
 use crate::scene::Vec3;
+use crate::ui_shell::{ShellSection, UiShellState};
 
 pub const WINDOW_TITLE: &str = "OpenVistaPro";
 
+/// Top-level egui application. Owns the renderable scene state ([`AppData`])
+/// and the navigation state ([`UiShellState`]); the `update` body is a thin
+/// view that renders durable panels around those two state objects.
 #[derive(Default)]
 pub struct OpenVistaProApp {
     data: AppData,
+    shell: UiShellState,
     texture: Option<egui::TextureHandle>,
 }
 
@@ -33,82 +38,164 @@ impl OpenVistaProApp {
             }
         }
     }
-}
 
-impl eframe::App for OpenVistaProApp {
-    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
-        let mut changed = false;
-
-        egui::SidePanel::left("scene_controls").show(ctx, |ui| {
-            ui.heading("OpenVistaPro");
-            ui.label("CPU preview shell");
-
-            ui.separator();
-            ui.label("Terrain");
-            let mut preset = self.data.terrain_preset;
-            changed |= ui
-                .radio_value(&mut preset, TerrainPreset::RadialHill, "Radial hill")
-                .changed();
-            changed |= ui
-                .radio_value(&mut preset, TerrainPreset::Plane, "Plane")
-                .changed();
-            if preset != self.data.terrain_preset {
-                self.data.apply(AppAction::SetTerrainPreset(preset));
-            }
-
-            ui.separator();
-            ui.label("Renderer");
-            let mut renderer_mode = self.data.renderer_mode;
-            changed |= ui
-                .radio_value(&mut renderer_mode, RendererMode::TopDown, "Top-down")
-                .changed();
-            changed |= ui
-                .radio_value(&mut renderer_mode, RendererMode::Perspective, "Perspective")
-                .changed();
-            if renderer_mode != self.data.renderer_mode {
-                self.data.apply(AppAction::SetRendererMode(renderer_mode));
-            }
-
-            ui.separator();
-            ui.label("Scene bands");
-            let mut water = self.data.scene.water_level;
-            let mut trees = self.data.scene.tree_line;
-            let mut snow = self.data.scene.snow_line;
-            let mut haze = self.data.scene.haze;
-            changed |= ui
-                .add(egui::Slider::new(&mut water, -5.0..=10.0).text("Water"))
-                .changed();
-            changed |= ui
-                .add(egui::Slider::new(&mut trees, -5.0..=12.0).text("Trees"))
-                .changed();
-            changed |= ui
-                .add(egui::Slider::new(&mut snow, -5.0..=15.0).text("Snow"))
-                .changed();
-            changed |= ui
-                .add(egui::Slider::new(&mut haze, 0.0..=1.0).text("Haze"))
-                .changed();
-            self.data.apply(AppAction::SetWaterLevel(water));
-            self.data.apply(AppAction::SetTreeLine(trees));
-            self.data.apply(AppAction::SetSnowLine(snow));
-            self.data.apply(AppAction::SetHaze(haze));
-
-            ui.separator();
-            ui.label("Camera");
-            let mut camera_position = self.data.scene.camera.position;
-            let mut camera_target = self.data.scene.camera.target;
-            changed |= vec3_controls(ui, "Position", &mut camera_position);
-            changed |= vec3_controls(ui, "Target", &mut camera_target);
-            self.data
-                .apply(AppAction::SetCameraPosition(camera_position));
-            self.data.apply(AppAction::SetCameraTarget(camera_target));
+    /// Top command/navigation bar. Every section is always present so
+    /// navigation stays stable even where the surface is only a placeholder.
+    fn command_bar(&mut self, ctx: &egui::Context) {
+        egui::TopBottomPanel::top("command_bar").show(ctx, |ui| {
+            ui.horizontal_wrapped(|ui| {
+                ui.strong(WINDOW_TITLE);
+                ui.separator();
+                for &section in self.shell.sections() {
+                    let active = self.shell.is_active(section);
+                    if ui.selectable_label(active, section.title()).clicked() {
+                        self.shell.activate(section);
+                    }
+                }
+            });
         });
+    }
 
-        if changed || self.texture.is_none() {
-            self.rebuild_texture(ctx);
+    /// Left panel: controls contextual to the active section. Sections without
+    /// an implemented surface still show their labelled placeholder.
+    ///
+    /// Returns `true` when an edit changed something the preview depends on.
+    fn controls_panel(&mut self, ctx: &egui::Context) -> bool {
+        let mut changed = false;
+        egui::SidePanel::left("controls_panel")
+            .resizable(true)
+            .default_width(240.0)
+            .show(ctx, |ui| {
+                ui.heading(self.shell.section_title());
+                ui.label(self.shell.section_summary());
+                ui.separator();
+                match self.shell.active_section {
+                    ShellSection::Terrain => changed |= self.terrain_controls(ui),
+                    ShellSection::Scene => changed |= self.scene_controls(ui),
+                    ShellSection::Render => changed |= self.render_controls(ui),
+                    ShellSection::Import
+                    | ShellSection::Script
+                    | ShellSection::Path
+                    | ShellSection::Project => {
+                        ui.label(self.shell.placeholder_label());
+                    }
+                }
+            });
+        changed
+    }
+
+    fn terrain_controls(&mut self, ui: &mut egui::Ui) -> bool {
+        let mut changed = false;
+        let mut preset = self.data.terrain_preset;
+        changed |= ui
+            .radio_value(&mut preset, TerrainPreset::RadialHill, "Radial hill")
+            .changed();
+        changed |= ui
+            .radio_value(&mut preset, TerrainPreset::Plane, "Plane")
+            .changed();
+        if preset != self.data.terrain_preset {
+            self.data.apply(AppAction::SetTerrainPreset(preset));
         }
+        changed
+    }
 
+    fn render_controls(&mut self, ui: &mut egui::Ui) -> bool {
+        let mut changed = false;
+        let mut renderer_mode = self.data.renderer_mode;
+        changed |= ui
+            .radio_value(&mut renderer_mode, RendererMode::TopDown, "Top-down")
+            .changed();
+        changed |= ui
+            .radio_value(&mut renderer_mode, RendererMode::Perspective, "Perspective")
+            .changed();
+        if renderer_mode != self.data.renderer_mode {
+            self.data.apply(AppAction::SetRendererMode(renderer_mode));
+        }
+        changed
+    }
+
+    fn scene_controls(&mut self, ui: &mut egui::Ui) -> bool {
+        let mut changed = false;
+        ui.label("Scene bands");
+        let mut water = self.data.scene.water_level;
+        let mut trees = self.data.scene.tree_line;
+        let mut snow = self.data.scene.snow_line;
+        let mut haze = self.data.scene.haze;
+        changed |= ui
+            .add(egui::Slider::new(&mut water, -5.0..=10.0).text("Water"))
+            .changed();
+        changed |= ui
+            .add(egui::Slider::new(&mut trees, -5.0..=12.0).text("Trees"))
+            .changed();
+        changed |= ui
+            .add(egui::Slider::new(&mut snow, -5.0..=15.0).text("Snow"))
+            .changed();
+        changed |= ui
+            .add(egui::Slider::new(&mut haze, 0.0..=1.0).text("Haze"))
+            .changed();
+        self.data.apply(AppAction::SetWaterLevel(water));
+        self.data.apply(AppAction::SetTreeLine(trees));
+        self.data.apply(AppAction::SetSnowLine(snow));
+        self.data.apply(AppAction::SetHaze(haze));
+
+        ui.separator();
+        ui.label("Camera");
+        let mut camera_position = self.data.scene.camera.position;
+        let mut camera_target = self.data.scene.camera.target;
+        changed |= vec3_controls(ui, "Position", &mut camera_position);
+        changed |= vec3_controls(ui, "Target", &mut camera_target);
+        self.data
+            .apply(AppAction::SetCameraPosition(camera_position));
+        self.data.apply(AppAction::SetCameraTarget(camera_target));
+        changed
+    }
+
+    /// Right panel: durable inspector summarising current scene state.
+    fn inspector_panel(&self, ctx: &egui::Context) {
+        egui::SidePanel::right("inspector_panel")
+            .resizable(true)
+            .default_width(220.0)
+            .show(ctx, |ui| {
+                ui.heading("Inspector");
+                ui.separator();
+                let info = self.shell.active_info();
+                ui.label(format!("Section: {}", info.title));
+                ui.label(info.summary);
+                ui.separator();
+                ui.label(format!("Terrain: {:?}", self.data.terrain_preset));
+                ui.label(format!("Renderer: {:?}", self.data.renderer_mode));
+                let (width, height) = self.data.preview_size;
+                ui.label(format!("Preview: {width} x {height}"));
+                ui.label(format!("Water level: {:.2}", self.data.scene.water_level));
+            });
+    }
+
+    /// Bottom panel: durable status bar.
+    fn status_panel(&self, ctx: &egui::Context) {
+        egui::TopBottomPanel::bottom("status_panel").show(ctx, |ui| {
+            ui.horizontal(|ui| {
+                ui.label("Ready");
+                ui.separator();
+                ui.label(format!("Active: {}", self.shell.section_title()));
+                ui.separator();
+                let scene_label = match &self.data.loaded_scene_path {
+                    Some(path) => format!("Scene: {path}"),
+                    None => "Scene: unsaved".to_owned(),
+                };
+                ui.label(scene_label);
+            });
+        });
+    }
+
+    /// Central viewport: shows the CPU preview, with a placeholder banner for
+    /// sections whose dedicated surface is not built yet.
+    fn viewport_panel(&self, ctx: &egui::Context) {
         egui::CentralPanel::default().show(ctx, |ui| {
-            ui.heading("Preview");
+            ui.heading(format!("{} viewport", self.shell.section_title()));
+            if section_is_placeholder(self.shell.active_section) {
+                ui.label(self.shell.placeholder_label());
+                ui.separator();
+            }
             if let Some(texture) = &self.texture {
                 ui.image((texture.id(), texture.size_vec2()));
             } else {
@@ -118,6 +205,30 @@ impl eframe::App for OpenVistaProApp {
     }
 }
 
+impl eframe::App for OpenVistaProApp {
+    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
+        self.command_bar(ctx);
+        let changed = self.controls_panel(ctx);
+        self.inspector_panel(ctx);
+        self.status_panel(ctx);
+
+        if changed || self.texture.is_none() {
+            self.rebuild_texture(ctx);
+        }
+
+        self.viewport_panel(ctx);
+    }
+}
+
+/// Sections whose dedicated workspace is not built yet — they render a
+/// placeholder banner over the shared preview rather than being hidden.
+fn section_is_placeholder(section: ShellSection) -> bool {
+    matches!(
+        section,
+        ShellSection::Import | ShellSection::Script | ShellSection::Path | ShellSection::Project
+    )
+}
+
 fn vec3_controls(ui: &mut egui::Ui, label: &str, value: &mut Vec3) -> bool {
     let mut changed = false;
     ui.label(label);

src/lib.rs

@@ -11,3 +11,4 @@ pub mod scene_file;
 pub mod script;
 pub mod script_exec;
 pub mod terrain;
+pub mod ui_shell;

src/ui_shell.rs

@@ -0,0 +1,224 @@
+//! Pure state model for the OpenVistaPro UI shell.
+//!
+//! This module owns the navigation model — which feature family is currently
+//! active — plus the static metadata describing every section. It deliberately
+//! contains no egui types so the shell can be exercised by unit tests without a
+//! windowing backend, and so the rendering code in `app.rs` stays a thin view
+//! over this state.
+
+/// One feature family surfaced by the shell's command/navigation bar.
+///
+/// The ordering of these variants is the canonical tab order used throughout
+/// the UI; see [`UiShellState::sections`].
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub enum ShellSection {
+    #[default]
+    Terrain,
+    Scene,
+    Render,
+    Import,
+    Script,
+    Path,
+    Project,
+}
+
+/// Stable, ordered list of every section the shell exposes.
+///
+/// Navigation is intentionally static: unimplemented surfaces stay visible as
+/// placeholders rather than being hidden, so this list never changes at
+/// runtime.
+const SECTIONS: [ShellSection; 7] = [
+    ShellSection::Terrain,
+    ShellSection::Scene,
+    ShellSection::Render,
+    ShellSection::Import,
+    ShellSection::Script,
+    ShellSection::Path,
+    ShellSection::Project,
+];
+
+/// Static description of a single section, used to render its nav entry and
+/// its placeholder surface.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct SectionInfo {
+    /// The section this metadata describes.
+    pub section: ShellSection,
+    /// Short human-readable label shown in the nav bar and panel headings.
+    pub title: &'static str,
+    /// One-line description of what the section is for.
+    pub summary: &'static str,
+    /// Label shown on the central viewport when the section has no
+    /// implemented surface yet.
+    pub placeholder: &'static str,
+}
+
+impl ShellSection {
+    /// Returns the static metadata for this section.
+    pub fn info(self) -> SectionInfo {
+        match self {
+            ShellSection::Terrain => SectionInfo {
+                section: self,
+                title: "Terrain",
+                summary: "Generate and sculpt terrain height fields.",
+                placeholder: "Terrain workspace coming soon",
+            },
+            ShellSection::Scene => SectionInfo {
+                section: self,
+                title: "Scene",
+                summary: "Tune scene bands, lighting, and camera framing.",
+                placeholder: "Scene workspace coming soon",
+            },
+            ShellSection::Render => SectionInfo {
+                section: self,
+                title: "Render",
+                summary: "Configure renderer mode and preview output.",
+                placeholder: "Render workspace coming soon",
+            },
+            ShellSection::Import => SectionInfo {
+                section: self,
+                title: "Import",
+                summary: "Bring in external height data and imagery.",
+                placeholder: "Import workspace coming soon",
+            },
+            ShellSection::Script => SectionInfo {
+                section: self,
+                title: "Script",
+                summary: "Automate scene setup with scripted commands.",
+                placeholder: "Script workspace coming soon",
+            },
+            ShellSection::Path => SectionInfo {
+                section: self,
+                title: "Path",
+                summary: "Lay out camera paths and animation keyframes.",
+                placeholder: "Path workspace coming soon",
+            },
+            ShellSection::Project => SectionInfo {
+                section: self,
+                title: "Project",
+                summary: "Manage project files, scenes, and settings.",
+                placeholder: "Project workspace coming soon",
+            },
+        }
+    }
+
+    /// Short label for the nav bar and panel headings.
+    pub fn title(self) -> &'static str {
+        self.info().title
+    }
+
+    /// One-line description of the section.
+    pub fn summary(self) -> &'static str {
+        self.info().summary
+    }
+
+    /// Placeholder label for the section's not-yet-built surface.
+    pub fn placeholder(self) -> &'static str {
+        self.info().placeholder
+    }
+}
+
+/// Navigation state for the shell: the single source of truth for which
+/// section the UI is currently showing.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub struct UiShellState {
+    pub active_section: ShellSection,
+}
+
+impl UiShellState {
+    /// Creates a shell at its default section ([`ShellSection::Terrain`]).
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Returns the canonical, ordered list of all sections.
+    pub fn sections(&self) -> &'static [ShellSection] {
+        &SECTIONS
+    }
+
+    /// Switches the active section. Navigation never fails — every section is
+    /// always reachable, even if its surface is only a placeholder.
+    pub fn activate(&mut self, section: ShellSection) {
+        self.active_section = section;
+    }
+
+    /// Returns `true` if `section` is the one currently shown.
+    pub fn is_active(&self, section: ShellSection) -> bool {
+        self.active_section == section
+    }
+
+    /// Metadata for the currently active section.
+    pub fn active_info(&self) -> SectionInfo {
+        self.active_section.info()
+    }
+
+    /// Title of the active section.
+    pub fn section_title(&self) -> &'static str {
+        self.active_section.title()
+    }
+
+    /// One-line summary of the active section.
+    pub fn section_summary(&self) -> &'static str {
+        self.active_section.summary()
+    }
+
+    /// Placeholder label for the active section's surface.
+    pub fn placeholder_label(&self) -> &'static str {
+        self.active_section.placeholder()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ui_shell_sections_cover_the_major_feature_families() {
+        let shell = UiShellState::new();
+
+        assert_eq!(
+            shell.sections(),
+            &[
+                ShellSection::Terrain,
+                ShellSection::Scene,
+                ShellSection::Render,
+                ShellSection::Import,
+                ShellSection::Script,
+                ShellSection::Path,
+                ShellSection::Project,
+            ]
+        );
+    }
+
+    #[test]
+    fn ui_shell_active_section_has_a_named_placeholder() {
+        let shell = UiShellState::new();
+
+        assert_eq!(shell.section_title(), "Terrain");
+        assert!(shell.section_summary().contains("terrain"));
+        assert!(shell.placeholder_label().contains("coming soon"));
+    }
+
+    #[test]
+    fn ui_shell_starts_on_terrain_and_navigates_between_sections() {
+        let mut shell = UiShellState::new();
+        assert!(shell.is_active(ShellSection::Terrain));
+
+        shell.activate(ShellSection::Render);
+        assert!(shell.is_active(ShellSection::Render));
+        assert!(!shell.is_active(ShellSection::Terrain));
+        assert_eq!(shell.section_title(), "Render");
+    }
+
+    #[test]
+    fn every_section_has_non_empty_metadata() {
+        let shell = UiShellState::new();
+
+        for &section in shell.sections() {
+            let info = section.info();
+            assert_eq!(info.section, section);
+            assert!(!info.title.is_empty());
+            assert!(!info.summary.is_empty());
+            assert!(info.placeholder.contains("coming soon"));
+        }
+    }
+}