basic drawing

kiln-core/src/board.rs

@@ -329,6 +329,50 @@ impl Board {
         self.objects.insert(id, object);
         id
     }
+
+    /// Editor primitive: stamps `arch` (with visual `glyph`) into the cell at
+    /// `(x, y)`, applying the editor's placement/removal rules.
+    ///
+    /// Two cases, keyed only on the archetype (the floor is **never** touched — the
+    /// drawing tools cannot place, remove, or alter a floor):
+    ///
+    /// - **Terrain** (`arch != Empty`, always solid today): removes any solid object
+    ///   already in the cell, then writes `(glyph, arch)` into the cell's terrain.
+    /// - **Erase** (`arch == Empty`): removes the cell's terrain *and* every object in
+    ///   it, leaving the floor (a visible `Empty` cell on a lower layer) in place.
+    ///
+    /// Terrain is written to the cell's existing terrain layer (the single non-`Empty`
+    /// archetype across layers, if any) or else the top layer; a vacated terrain cell
+    /// becomes a transparent `Empty` so a lower floor shows through. Panics if `(x, y)`
+    /// is out of bounds.
+    pub fn place_archetype(&mut self, x: usize, y: usize, arch: Archetype, glyph: Glyph) {
+        if arch == Archetype::Empty {
+            // Erase: drop every object in the cell and clear its terrain (keep floor).
+            for id in self.object_ids_at(x, y) {
+                self.objects.remove(&id);
+            }
+            if let Some(z) = self.terrain_layer_at(x, y) {
+                *self.get_mut(z, x, y) = (Glyph::transparent(), Archetype::Empty);
+            }
+            return;
+        }
+
+        // Placing solid terrain: a solid object can't share the cell, so drop it.
+        if let Some(id) = self.solid_object_id_at(x, y) {
+            self.objects.remove(&id);
+        }
+        // Reuse the existing terrain layer if the cell already has terrain, else the
+        // top layer (so the new wall draws above any floor on a lower layer).
+        let z = self.terrain_layer_at(x, y).unwrap_or(self.layers.len() - 1);
+        *self.get_mut(z, x, y) = (glyph, arch);
+    }
+
+    /// Returns the index of the layer whose terrain cell at `(x, y)` is non-`Empty`
+    /// (the cell's single terrain archetype, if any). By the one-solid-per-cell
+    /// invariant there is at most one such layer.
+    fn terrain_layer_at(&self, x: usize, y: usize) -> Option<usize> {
+        (0..self.layers.len()).find(|&z| self.get(z, x, y).1 != Archetype::Empty)
+    }
 }
 
 #[cfg(test)]
@@ -559,6 +603,62 @@ pub(crate) mod tests {
         assert_eq!(board.glyph_at(0, 0).tile, '*' as u32);
     }
 
+    #[test]
+    fn place_wall_keeps_floor_and_removes_solid_object() {
+        // Floor on layer 0, terrain layer on top; a solid object sits at (1,0).
+        let mut board = open_board(3, 1, (2, 0), vec![ObjectDef::new(1, 0)]);
+        let floor = Glyph {
+            tile: '.' as u32,
+            ..Glyph::transparent()
+        };
+        add_floor(&mut board, floor);
+
+        let wall = Archetype::Wall.default_glyph();
+        board.place_archetype(1, 0, Archetype::Wall, wall);
+
+        // The wall landed on the terrain (top) layer; the floor below is untouched.
+        assert_eq!(board.get(1, 1, 0), &(wall, Archetype::Wall));
+        assert_eq!(board.get(0, 1, 0).0, floor);
+        // The solid object that was there is gone.
+        assert!(board.object_ids_at(1, 0).is_empty());
+        assert_eq!(board.glyph_at(1, 0), wall);
+    }
+
+    #[test]
+    fn place_wall_overwrites_existing_terrain_in_place() {
+        // A crate already occupies the top layer at (1,0).
+        let mut board = open_board(3, 1, (2, 0), vec![]);
+        crate_at(&mut board, 1, 0);
+        let wall = Archetype::Wall.default_glyph();
+        board.place_archetype(1, 0, Archetype::Wall, wall);
+        assert_eq!(board.get(0, 1, 0), &(wall, Archetype::Wall));
+    }
+
+    #[test]
+    fn erase_removes_terrain_and_objects_but_keeps_floor() {
+        // Floor, a wall on the terrain layer, and a (non-solid) object all at (1,0).
+        let mut obj = ObjectDef::new(1, 0);
+        obj.solid = false;
+        let mut board = open_board(3, 1, (2, 0), vec![obj]);
+        let floor = Glyph {
+            tile: '.' as u32,
+            ..Glyph::transparent()
+        };
+        add_floor(&mut board, floor);
+        wall_at(&mut board, 1, 0);
+
+        board.place_archetype(1, 0, Archetype::Empty, Glyph::transparent());
+
+        // Terrain cleared to transparent Empty; object removed; floor still there.
+        assert_eq!(
+            board.get(1, 1, 0),
+            &(Glyph::transparent(), Archetype::Empty)
+        );
+        assert!(board.object_ids_at(1, 0).is_empty());
+        assert_eq!(board.get(0, 1, 0).0, floor);
+        assert_eq!(board.glyph_at(1, 0), floor);
+    }
+
     #[test]
     fn fresh_board_is_valid_and_reports_errors() {
         let mut board = open_board(1, 1, (0, 0), vec![]);

kiln-core/src/lib.rs

@@ -2,10 +2,10 @@ mod action;
 mod archetype;
 mod board;
 mod builtin_scripts;
-/// CP437 tile-index → character mapping ([`cp437::tile_to_char`]) for the default font.
-pub mod cp437;
 /// The 16 EGA/VGA named colors ([`colors::NAMED_COLORS`]), shared by scripts and the editor.
 pub mod colors;
+/// CP437 tile-index → character mapping ([`cp437::tile_to_char`]) for the default font.
+pub mod cp437;
 /// Procedural floor generators ([`floor::FloorGenerator`]).
 pub mod floor;
 /// Core game types: [`board::Board`], [`glyph::Glyph`], [`archetype::Archetype`], etc.
@@ -23,6 +23,7 @@ mod utils;
 /// World type: a named collection of boards in a single `.toml` file ([`world::World`], [`world::load`]).
 pub mod world;
 
+pub use archetype::Archetype;
 pub use board::Board;
 pub use utils::Direction;
 

kiln-tui/src/editor.rs

@@ -8,15 +8,20 @@
 //! sub-menus. `Esc` walks back up the tree, opening the overlay
 //! [editor menu](editor_menu::editor_menu_items) at the root.
 
+use crate::editor_menu;
+use crate::editor_menu::{MenuEntry, MenuLevel};
+use crate::log::{LogWidget, log_preview_line};
+use crate::render::{BoardWidget, board_to_screen, screen_to_board};
+use crate::ui::Ui;
+use crate::utils::rgba8_to_color;
+use kiln_core::cp437::tile_to_char;
+use kiln_core::glyph::Glyph;
+use kiln_core::log::LogLine;
+use kiln_core::world::World;
+use kiln_core::{Archetype, Board};
 use kiln_ui::code_editor::{CodeEditor, CodeEditorOutcome};
 use kiln_ui::dialog::{Dialog, DialogResult, ListDialogResponse};
 use kiln_ui::glyph_dialog::GlyphDialog;
-use crate::log::{log_preview_line, LogWidget};
-use crate::render::{board_to_screen, screen_to_board, BoardWidget};
-use crate::ui::Ui;
-use kiln_core::Board;
-use kiln_core::log::LogLine;
-use kiln_core::world::World;
 use ratatui::Frame;
 use ratatui::crossterm::event::Event;
 use ratatui::layout::{Constraint, Layout, Rect, Spacing};
@@ -24,9 +29,7 @@ use ratatui::style::{Color, Style};
 use ratatui::symbols::merge::MergeStrategy;
 use ratatui::text::{Line, Span};
 use ratatui::widgets::{Block, Paragraph};
-use std::cell::Ref;
-use crate::editor_menu;
-use crate::editor_menu::{MenuEntry, MenuLevel};
+use std::cell::{Ref, RefMut};
 
 /// How long each half of the cursor blink lasts, in seconds.
 const BLINK_SECS: f32 = 0.5;
@@ -36,6 +39,8 @@ const DEFAULT_SIDEBAR_WIDTH: u16 = 24;
 const MIN_PANEL_WIDTH: u16 = 8;
 /// The cursor glyph: a solid full block (CP437 219) drawn in light gray.
 const CURSOR_CHAR: char = '█';
+/// Height (in rows) of the drawing-controls footer pinned to the sidebar bottom.
+const DRAW_FOOTER_HEIGHT: u16 = 5;
 
 /// All state for an active editing session.
 ///
@@ -61,6 +66,15 @@ pub(crate) struct EditorState {
     pub(crate) glyph_dialog: Option<GlyphDialog<EditorState>>,
     /// Cursor position in board cells, clamped to the board bounds.
     cursor: (i32, i32),
+    /// The archetype the drawing tools stamp on [`place_current`](EditorState::place_current).
+    /// Defaults to [`Archetype::Wall`]; the UI to change it comes later.
+    current_archetype: Archetype,
+    /// The glyph the drawing tools stamp. Starts as the current archetype's default
+    /// glyph and is edited via the glyph picker (`g`).
+    current_glyph: Glyph,
+    /// Whether draw mode is on: when set, moving the cursor stamps the current thing
+    /// into each newly-entered cell (as if `space` were pressed after the move).
+    draw_mode: bool,
     /// Width of the right-hand sidebar in terminal columns (mouse-resizable).
     sidebar_width: u16,
     /// Whether the blinking cursor is currently in its visible phase.
@@ -87,6 +101,9 @@ impl EditorState {
             code_editor: None,
             glyph_dialog: None,
             cursor: (0, 0),
+            current_archetype: Archetype::Wall,
+            current_glyph: Archetype::Wall.default_glyph(),
+            draw_mode: false,
             sidebar_width: DEFAULT_SIDEBAR_WIDTH,
             blink_on: true,
             blink_timer: 0.0,
@@ -128,11 +145,15 @@ impl EditorState {
     /// Opens a text dialog to rename the world; OK writes [`World::name`].
     pub(crate) fn open_name_dialog(&mut self) {
         let current = self.world.name.clone();
-        self.dialog = Some(Dialog::text("World Name", current, |opt, ed: &mut EditorState| {
+        self.dialog = Some(Dialog::text(
+            "World Name",
+            current,
+            |opt, ed: &mut EditorState| {
                 if let Some(s) = opt {
                     ed.world.name = s;
                 }
-        }));
+            },
+        ));
     }
 
     /// Opens a list dialog to choose the entry board; selecting one writes [`World::start`].
@@ -155,22 +176,27 @@ impl EditorState {
     pub(crate) fn open_scripts_dialog(&mut self) {
         let mut names: Vec<String> = self.world.scripts.keys().cloned().collect();
         names.sort();
-        self.dialog = Some(Dialog::list("Scripts", names, true, |resp, ed: &mut EditorState| {
-            match resp {
+        self.dialog = Some(Dialog::list(
+            "Scripts",
+            names,
+            true,
+            |resp, ed: &mut EditorState| match resp {
                 ListDialogResponse::Select(name) | ListDialogResponse::Create(name) => {
                     let source = ed.world.scripts.get(&name).cloned().unwrap_or_default();
                     ed.code_editor = Some(CodeEditor::new(&name, &source));
                 }
                 ListDialogResponse::Cancel => {}
-            }
-        }));
+            },
+        ));
     }
 
     /// Closes the code editor, saving its text back into the in-memory script pool
     /// (mirrors how the Name/Entry-board dialogs mutate the loaded `World`).
     pub(crate) fn close_script_editor(&mut self) {
         if let Some(editor) = self.code_editor.take() {
-            self.world.scripts.insert(editor.name().to_string(), editor.text());
+            self.world
+                .scripts
+                .insert(editor.name().to_string(), editor.text());
         }
     }
 
@@ -178,35 +204,54 @@ impl EditorState {
     pub(crate) fn open_boards_dialog(&mut self) {
         let mut names: Vec<String> = self.world.boards.keys().cloned().collect();
         names.sort();
-        self.dialog = Some(Dialog::list("Boards", names, false, |_resp, _ed: &mut EditorState| {}));
+        self.dialog = Some(Dialog::list(
+            "Boards",
+            names,
+            false,
+            |_resp, _ed: &mut EditorState| {},
+        ));
     }
 
-    /// Opens the glyph picker seeded from the glyph currently under the cursor.
-    /// On OK the chosen glyph is logged (there is no paint tool yet).
+    /// Opens the glyph picker seeded from the current drawing glyph. On OK the chosen
+    /// glyph becomes the new drawing glyph (used by subsequent placements).
     pub(crate) fn open_glyph_picker(&mut self) {
-        let glyph = {
-            let board = self.board();
-            board.glyph_at(self.cursor.0 as usize, self.cursor.1 as usize)
-        };
         self.glyph_dialog = Some(GlyphDialog::new(
             "Glyph",
-            glyph,
+            self.current_glyph,
             |chosen, ed: &mut EditorState| {
                 if let Some(g) = chosen {
-                    ed.log.push(LogLine::raw(format!(
-                        "glyph tile={} fg=#{:02X}{:02X}{:02X} bg=#{:02X}{:02X}{:02X}",
-                        g.tile, g.fg.r, g.fg.g, g.fg.b, g.bg.r, g.bg.g, g.bg.b
-                    )));
+                    ed.current_glyph = g;
                 }
             },
         ));
     }
 
+    /// Stamps the current drawing thing (archetype + glyph) into the cell under the
+    /// cursor, applying the placement rules (see [`Board::place_archetype`]).
+    pub(crate) fn place_current(&mut self) {
+        let (x, y) = (self.cursor.0 as usize, self.cursor.1 as usize);
+        let (arch, glyph) = (self.current_archetype, self.current_glyph);
+        self.board_mut().place_archetype(x, y, arch, glyph);
+    }
+
+    /// Toggles draw mode (whether cursor movement auto-stamps the current thing).
+    pub(crate) fn toggle_draw_mode(&mut self) {
+        self.draw_mode = !self.draw_mode;
+        if self.draw_mode {
+            self.place_current()
+        }
+    }
+
     /// Borrows the board currently being edited.
     pub(crate) fn board(&self) -> Ref<'_, Board> {
         self.world.boards[&self.board_name].borrow()
     }
 
+    /// Mutably borrows the board currently being edited.
+    pub(crate) fn board_mut(&self) -> RefMut<'_, Board> {
+        self.world.boards[&self.board_name].borrow_mut()
+    }
+
     /// Advances the cursor blink by `dt` seconds (the editor's only animation).
     pub(crate) fn tick(&mut self, dt: f32) {
         self.blink_timer += dt;
@@ -216,22 +261,33 @@ impl EditorState {
         }
     }
 
-    /// Moves the cursor by `(dx, dy)`, clamped to the board bounds.
+    /// Moves the cursor by `(dx, dy)`, clamped to the board bounds. When draw mode is
+    /// on and the cursor lands on a new cell, stamps the current thing there.
     pub(crate) fn move_cursor(&mut self, dx: i32, dy: i32) {
         let (w, h) = {
             let b = self.board();
             (b.width as i32, b.height as i32)
         };
+        let before = self.cursor;
         self.cursor.0 = (self.cursor.0 + dx).clamp(0, w - 1);
         self.cursor.1 = (self.cursor.1 + dy).clamp(0, h - 1);
+        if self.draw_mode && self.cursor != before {
+            self.place_current();
+        }
     }
 
     /// Moves the cursor to the cell under a screen position, if it lands on the
-    /// board (right-click handling). No-op when the click is off the board.
+    /// board (right-click handling). No-op when the click is off the board. When draw
+    /// mode is on and the cursor lands on a new cell, stamps the current thing there.
     pub(crate) fn set_cursor_at_screen(&mut self, sx: u16, sy: u16) {
         let cell = screen_to_board(self.last_board_area, &self.board(), sx, sy);
         if let Some((bx, by)) = cell {
-            self.cursor = (bx as i32, by as i32);
+            let target = (bx as i32, by as i32);
+            let moved = target != self.cursor;
+            self.cursor = target;
+            if self.draw_mode && moved {
+                self.place_current();
+            }
         }
     }
 
@@ -283,7 +339,9 @@ pub(crate) fn handle_glyph_dialog_input(event: Event, ed: &mut EditorState) {
 ///
 /// Forwards key/mouse events to the editor; on `Exit` (Esc) it closes and saves the script.
 pub(crate) fn handle_code_editor_input(event: Event, ed: &mut EditorState) {
-    let Some(editor) = ed.code_editor.as_mut() else { return };
+    let Some(editor) = ed.code_editor.as_mut() else {
+        return;
+    };
     if let CodeEditorOutcome::Exit = editor.handle_event(&event) {
         ed.close_script_editor();
     }
@@ -373,7 +431,16 @@ pub(crate) fn draw_editor(frame: &mut Frame, ed: &mut EditorState, ui: &mut Ui)
         "[esc] menu",
         Style::default().fg(Color::DarkGray),
     )));
-    frame.render_widget(Paragraph::new(lines), sb_inner);
+    // Split the sidebar: the menu fills the top, the drawing-controls footer (the
+    // current thing being drawn) is pinned to the bottom regardless of menu level.
+    let [menu_area, footer_area] =
+        Layout::vertical([Constraint::Min(0), Constraint::Length(DRAW_FOOTER_HEIGHT)])
+            .areas(sb_inner);
+    frame.render_widget(Paragraph::new(lines), menu_area);
+    frame.render_widget(
+        Paragraph::new(draw_footer_lines(ed, key_style, label_style, sep_style)),
+        footer_area,
+    );
 
     // ── Log panel (full width, below board + sidebar) ─────────────────────────
     if let Some(log_area) = log_area {
@@ -381,6 +448,46 @@ pub(crate) fn draw_editor(frame: &mut Frame, ed: &mut EditorState, ui: &mut Ui)
     }
 }
 
+/// Builds the drawing-controls footer: the current archetype name, the glyph control
+/// (label + a live preview of the current drawing glyph), and the place / draw-mode
+/// key hints. Shown at the bottom of the sidebar regardless of the open menu level.
+fn draw_footer_lines<'a>(
+    ed: &EditorState,
+    key_style: Style,
+    label_style: Style,
+    sep_style: Style,
+) -> Vec<Line<'a>> {
+    // A one-cell preview of the current glyph in its own fg/bg colors.
+    let preview = Span::styled(
+        tile_to_char(ed.current_glyph.tile).to_string(),
+        Style::default()
+            .fg(rgba8_to_color(ed.current_glyph.fg))
+            .bg(rgba8_to_color(ed.current_glyph.bg)),
+    );
+    vec![
+        // Separator marking off the footer from the menu above.
+        Line::from(Span::styled("─".repeat(64), sep_style)),
+        // The archetype currently being drawn (no UI to change it yet).
+        Line::from(Span::styled(ed.current_archetype.name(), label_style)),
+        Line::from(vec![
+            Span::styled("[g] ", key_style),
+            Span::styled("Glyph ", label_style),
+            preview,
+        ]),
+        Line::from(vec![
+            Span::styled("[spc] ", key_style),
+            Span::styled("Place", label_style),
+        ]),
+        Line::from(vec![
+            Span::styled("[tab] ", key_style),
+            Span::styled(
+                format!("Draw mode ({})", if ed.draw_mode { "on" } else { "off" }),
+                label_style,
+            ),
+        ]),
+    ]
+}
+
 /// Computes the board / sidebar / optional-log rects for the editor.
 ///
 /// When the log is open the screen splits vertically first (so the log spans the

kiln-tui/src/input.rs

@@ -126,8 +126,11 @@ pub(crate) fn handle_editor_input(event: Event, term_w: u16, ed: &mut EditorStat
             KeyCode::Left => ed.move_cursor(-1, 0),
             KeyCode::Right => ed.move_cursor(1, 0),
             KeyCode::Char('l') => ui.log.toggle(),
-            // `g` opens the glyph picker for the cell under the cursor.
+            // `g` opens the glyph picker to edit the current drawing glyph.
             KeyCode::Char('g') => ed.open_glyph_picker(),
+            // Space stamps the current thing; Tab toggles draw mode.
+            KeyCode::Char(' ') => ed.place_current(),
+            KeyCode::Tab => ed.toggle_draw_mode(),
             // A menu letter opens its dialog; unmatched letters are ignored.
             KeyCode::Char(c) => {
                 ed.menu_key(c);