The tile list in the tilemap section is a palette of pictures: each tile shows its lone tile (the four convex corners for floor and wall, the picture itself for none) with its name below, laid out with the image-picker grid (#139)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -38,7 +38,7 @@ npm run build        # writes dist/ and regenerates index.html; the folder is wh
 The browser suite and the three example games need a machine with a GPU:
 
 ```bash
-node tools/seed-e2e.mjs && node tools/e2e.mjs      # the editor, 1021 checks (GM_STEPS=20 for one step)
+node tools/seed-e2e.mjs && node tools/e2e.mjs      # the editor, 1023 checks (GM_STEPS=20 for one step)
 node tools/seed-jumprun.mjs && node tools/smoke-jumprun.mjs
 node tools/seed-tetris.mjs && node tools/smoke-tetris.mjs
 node tools/seed-actor.mjs && node tools/smoke-actor.mjs

src/core/model/autotile.ts

@@ -118,6 +118,14 @@ const NO_NEIGHBOURS: Neighbours = {
   nw: false,
 };
 
+/**
+ * The tile standing for its kind in a palette (#139): the lone tile, all four convex corners. It is
+ * the one RPG Maker shows too – the block's top-left tile, which is pixel for pixel the same.
+ */
+export function loneTileQuadrants(kind: TileKind): TileQuadrants {
+  return tileQuadrants(kind, NO_NEIGHBOURS);
+}
+
 const SIDES = ['n', 'e', 's', 'w'] as const;
 const DIAGONALS = ['ne', 'se', 'sw', 'nw'] as const;
 

src/editor/debugHook.ts

@@ -559,9 +559,13 @@ export function installDebugHook(app: Application, state: EditorState, editor: E
         const button = currentTilemapSection()?.tools.get(tool as TilemapTool);
         return button ? centreOf(button) : null;
       },
-      tileButtonAt: (assetId: string) => {
+      tileButtonAt: (assetId: string) =>
-        const button = currentTilemapSection()?.tiles.get(assetId);
+        currentTilemapSection()?.palette?.swatchGlobal(assetId)?.centre ?? null,
-        return button ? centreOf(button) : null;
+      /** A tile's box in the palette: its centre, where its picture sits and the palette's columns (#139). */
+      tileSwatch: (assetId: string) => {
+        const palette = currentTilemapSection()?.palette;
+        const swatch = palette?.swatchGlobal(assetId);
+        return palette && swatch ? { ...swatch, columns: palette.columns } : null;
       },
       addLayerAt: () => {
         const button = currentTilemapSection()?.addLayer;

src/editor/inspector/tilemapSection.ts

@@ -16,6 +16,7 @@ import type { TilemapAsset } from '../../core/model/Asset';
 import { isLayerVisible } from '../../core/model/tilemap';
 import { Button, Checkbox, HStack, Theme } from '../../ui';
 import type { EditorState, TilemapTool } from '../state';
+import { TilePalette } from '../tile/TilePalette';
 import { addGap, addNote, addTitle, type InspectorHost } from './host';
 
 const TOOLS: { tool: TilemapTool; label: string; hint: string }[] = [
@@ -42,7 +43,8 @@ export function paintedLayerId(state: EditorState, asset: TilemapAsset): string
  */
 export interface TilemapSectionWidgets {
   tools: Map<TilemapTool, Button>;
-  tiles: Map<string, Button>;
+  /** Null while the project has no tile. */
+  palette: TilePalette | null;
   layers: { id: string; name: Button; visible: Checkbox; up: Button; down: Button; remove: Button }[];
   addLayer: Button;
 }
@@ -58,7 +60,7 @@ export function buildTilemapSection(host: InspectorHost, asset: TilemapAsset): v
   const paint = state.tilemapPaint;
   const widgets: TilemapSectionWidgets = {
     tools: new Map(),
-    tiles: new Map(),
+    palette: null,
     layers: [],
     addLayer: new Button('Add layer', {
       onClick: () => state.execute(new AddTilemapLayerCommand(asset.id)),
@@ -79,23 +81,19 @@ export function buildTilemapSection(host: InspectorHost, asset: TilemapAsset): v
   addNote(host, 'Shift-drag still pans the view.', 'small');
 
   addTitle(host, 'TILES');
-  const tiles = state.project.assets.filter((a) => a.type === 'tile');
+  const tiles = tileIdsOf(state);
   if (tiles.length === 0) addNote(host, 'The project has no tile yet.');
-  for (const tile of tiles) {
+  else {
-    const button = new Button(tile.name, {
-      align: 'left',
     // Choosing a tile is how one starts painting, so it reaches for the brush by itself.
-      onClick: () =>
+    widgets.palette = new TilePalette(state, tiles, paint.tileId, (tileId) =>
       state.setTilemapPaint({
-          tileId: tile.id,
+        tileId,
         tool: paint.tool === 'select' || paint.tool === 'erase' ? 'brush' : paint.tool,
       }),
-    });
+    );
-    button.toggled = paint.tileId === tile.id;
+    host.body.add(widgets.palette);
-    widgets.tiles.set(tile.id, button);
-    host.body.add(button);
   }
-  if (tiles.length > 0 && !tiles.some((a) => a.id === paint.tileId))
+  if (tiles.length > 0 && !tiles.includes(paint.tileId))
     addNote(host, 'Choose a tile to paint with.', 'small');
 
   addTitle(host, 'LAYERS');
@@ -140,13 +138,19 @@ export function buildTilemapSection(host: InspectorHost, asset: TilemapAsset): v
   host.body.add(widgets.addLayer);
 }
 
+function tileIdsOf(state: EditorState): string[] {
+  return state.project.assets.filter((a) => a.type === 'tile').map((a) => a.id);
+}
+
 /**
- * What the section is built from, for the inspector's rebuild check: the layers and what is
+ * What the section is built from, for the inspector's rebuild check: the layers, the tiles on offer
- * painted with. The cells themselves are deliberately absent – a stroke must not rebuild the
+ * and what is painted with. The cells themselves are deliberately absent – a stroke must not
- * panel under the pointer that is drawing it.
+ * rebuild the panel under the pointer that is drawing it – and so are the tiles' pictures and
+ * names, which the palette repaints by itself.
  */
 export function tilemapSignature(state: EditorState, asset: TilemapAsset): string {
   const paint = state.tilemapPaint;
   const layers = asset.layers.map((l) => `${l.id}:${l.name}:${isLayerVisible(l) ? 1 : 0}`).join(',');
-  return `${paint.tool}|${paint.tileId}|${paintedLayerId(state, asset)}|${layers}`;
+  const tiles = tileIdsOf(state).join(',');
+  return `${paint.tool}|${paint.tileId}|${paintedLayerId(state, asset)}|${layers}|${tiles}`;
 }

src/editor/texture/imageGrid.ts

@@ -26,10 +26,21 @@ export interface GridMetrics {
   height: number;
 }
 
-export function gridMetrics(width: number, count: number, gap = TILE_GAP): GridMetrics {
+/** How small and how large a tile may get; the tile palette of a tilemap wants smaller ones (#139). */
-  const columns = Math.max(1, Math.floor((width + gap) / (TILE_MIN + gap)));
+export interface TileSizes {
+  min: number;
+  max: number;
+}
+
+export function gridMetrics(
+  width: number,
+  count: number,
+  gap = TILE_GAP,
+  sizes: TileSizes = { min: TILE_MIN, max: TILE_MAX },
+): GridMetrics {
+  const columns = Math.max(1, Math.floor((width + gap) / (sizes.min + gap)));
   const spread = (width - gap * (columns - 1)) / columns;
-  const tile = Math.max(TILE_MIN, Math.min(TILE_MAX, Math.floor(spread)));
+  const tile = Math.max(sizes.min, Math.min(sizes.max, Math.floor(spread)));
   const rows = Math.ceil(count / columns);
   const height = rows * (tile + CAPTION_HEIGHT) + Math.max(0, rows - 1) * gap;
   return { columns, tile, rows, height };

src/editor/tile/TilePalette.ts

@@ -0,0 +1,213 @@
+import { Container, type FederatedPointerEvent, Graphics, Sprite, Text } from 'pixi.js';
+import { loneTileQuadrants } from '../../core/model/autotile';
+import { findAssetOf } from '../../core/model/Project';
+import { quadrantRef, readTile } from '../../core/model/tile';
+import {
+  drawControlBox,
+  ScrollContainer,
+  type Size,
+  Stack,
+  Theme,
+  textStyle,
+  truncate,
+  Widget,
+} from '../../ui';
+import { textureLibrary } from '../../viewport/TextureLibrary';
+import { gridMetrics, type GridMetrics, tileAt, tileRect } from '../texture/imageGrid';
+import type { EditorState } from '../state';
+
+/** Smaller than the image picker's: a tile is 48 px, and a palette should show several in a row. */
+const SIZES = { min: 56, max: 72 };
+const GAP = 6;
+/** Inset of the picture inside its box, so the selection frame stays visible around it. */
+const PAD = 4;
+
+interface Swatch {
+  box: Container;
+  background: Graphics;
+  sprites: [Sprite, Sprite, Sprite, Sprite];
+  /** Stands where the picture would be while the tile has none that fits. */
+  empty: Text;
+  caption: Text;
+}
+
+/**
+ * The tiles of the project as a grid of pictures (#139), in the painting section of a tilemap: one
+ * sees what one paints with, and it takes a fraction of the room a list of buttons did. Each tile is
+ * shown alone – for an autotile the lone tile of its block, the one RPG Maker shows as well – and
+ * as its first picture: the inspector has no clock, and a still picture names a tile well enough.
+ *
+ * The tiles are fixed when it is built; the section rebuilds when that list changes. A picture
+ * edited or a texture arriving only repaints.
+ */
+export class TilePalette extends Widget {
+  private metrics: GridMetrics = gridMetrics(0, 0, GAP, SIZES);
+  private readonly swatches: Swatch[] = [];
+  private hoveredIndex = -1;
+  private pressedIndex = -1;
+  /** The width a relayout was last asked for, so a height that will not settle cannot loop. */
+  private askedAt = -1;
+  private readonly stops: (() => void)[];
+
+  constructor(
+    private readonly state: EditorState,
+    private readonly tileIds: readonly string[],
+    private readonly selectedId: string,
+    private readonly onPick: (tileId: string) => void,
+  ) {
+    super();
+    this.cursor = Theme.hoverCursor;
+    for (const _ of tileIds) this.swatches.push(this.buildSwatch());
+    this.stops = [
+      state.on('project', () => this.invalidate()),
+      textureLibrary.onChange(() => this.invalidate()),
+    ];
+
+    this.on('pointermove', (e: FederatedPointerEvent) => this.hover(this.indexUnder(e)));
+    this.on('pointerout', () => {
+      this.pressedIndex = -1;
+      this.hover(-1);
+    });
+    this.on('pointerdown', (e: FederatedPointerEvent) => {
+      if (e.button === 0) this.pressedIndex = this.indexUnder(e);
+    });
+    this.on('pointerup', (e: FederatedPointerEvent) => {
+      const index = this.indexUnder(e);
+      const pressed = this.pressedIndex;
+      this.pressedIndex = -1;
+      if (e.button === 0 && index >= 0 && index === pressed) this.onPick(this.tileIds[index]!);
+    });
+  }
+
+  /** Where a tile's box and its picture sit on screen (test hook); null when it is not offered. */
+  swatchGlobal(
+    tileId: string,
+  ): { centre: { x: number; y: number }; picture: { x: number; y: number; w: number } } | null {
+    const index = this.tileIds.indexOf(tileId);
+    if (index < 0) return null;
+    const rect = tileRect(index, this.metrics, GAP);
+    const origin = this.getGlobalPosition();
+    const x = origin.x + rect.x;
+    const y = origin.y + rect.y;
+    return {
+      centre: { x: x + rect.w / 2, y: y + this.metrics.tile / 2 },
+      picture: { x: x + PAD, y: y + PAD, w: this.metrics.tile - PAD * 2 },
+    };
+  }
+
+  /** How many tiles share a row – the check scripts read this. */
+  get columns(): number {
+    return this.metrics.columns;
+  }
+
+  override measure(): Size {
+    const width = this.w || this.expectedWidth();
+    return { w: this.minWidth, h: gridMetrics(width, this.tileIds.length, GAP, SIZES).height };
+  }
+
+  /**
+   * The height depends on the width, and the first measure comes before any width was given. So
+   * the palette guesses it from the scroll area it sits in, less the padding of the stacks between.
+   */
+  private expectedWidth(): number {
+    let inset = 0;
+    for (let parent = this.parent; parent; parent = parent.parent) {
+      if (parent instanceof ScrollContainer) return Math.max(0, parent.w - inset);
+      if (parent instanceof Stack) inset += parent.padding * 2;
+    }
+    return 0;
+  }
+
+  override layout(): void {
+    this.metrics = gridMetrics(this.w, this.tileIds.length, GAP, SIZES);
+    this.swatches.forEach((swatch, index) => {
+      const rect = tileRect(index, this.metrics, GAP);
+      swatch.box.position.set(rect.x, rect.y);
+    });
+    // The guess was off – a scrollbar took its width, or the column was dragged narrower – so the
+    // grid needs another number of rows than it was given. The scroll area measures again.
+    if (this.metrics.height !== this.h && this.askedAt !== this.w) {
+      this.askedAt = this.w;
+      queueMicrotask(() => {
+        if (!this.destroyed) this.scrollArea()?.relayoutContent();
+      });
+    }
+  }
+
+  private scrollArea(): ScrollContainer | null {
+    for (let parent = this.parent; parent; parent = parent.parent)
+      if (parent instanceof ScrollContainer) return parent;
+    return null;
+  }
+
+  override redraw(): void {
+    const side = this.metrics.tile;
+    this.swatches.forEach((swatch, index) => this.drawSwatch(swatch, this.tileIds[index]!, index, side));
+  }
+
+  private drawSwatch(swatch: Swatch, tileId: string, index: number, side: number): void {
+    const selected = tileId === this.selectedId;
+    const hovered = index === this.hoveredIndex;
+    swatch.background.clear();
+    drawControlBox(swatch.background, side, side, {
+      fill: selected ? Theme.colors.selection : hovered ? Theme.colors.controlHover : Theme.colors.control,
+      border: selected ? Theme.colors.accent : Theme.colors.border,
+    });
+
+    const asset = findAssetOf(this.state.project, tileId, 'tile');
+    const info = asset ? readTile(this.state.project, asset) : null;
+    const picture = info?.problem === '' ? info.pictures[0] : undefined;
+    const quadrants = info ? loneTileQuadrants(info.kind) : null;
+    const half = (side - PAD * 2) / 2;
+    swatch.sprites.forEach((sprite, corner) => {
+      const texture =
+        picture && info && quadrants
+          ? textureLibrary.get(quadrantRef(picture, info.quad, quadrants[corner]!))
+          : null;
+      sprite.visible = texture !== null;
+      if (!texture) return;
+      sprite.texture = texture;
+      sprite.position.set(PAD + (corner % 2) * half, PAD + Math.floor(corner / 2) * half);
+      sprite.width = half;
+      sprite.height = half;
+    });
+    // A tile without a usable picture still has to be pickable, and look like it is missing something.
+    swatch.empty.visible = !picture;
+    swatch.empty.position.set(
+      Math.round((side - swatch.empty.width) / 2),
+      Math.round((side - swatch.empty.height) / 2),
+    );
+
+    swatch.caption.style = textStyle(selected ? 'accent' : 'muted');
+    swatch.caption.text = truncate(asset?.name ?? '', swatch.caption.style, side);
+    swatch.caption.position.set(0, side + 1);
+  }
+
+  private buildSwatch(): Swatch {
+    const box = new Container();
+    const background = new Graphics();
+    const sprites = [new Sprite(), new Sprite(), new Sprite(), new Sprite()] as Swatch['sprites'];
+    const empty = new Text({ text: '?', style: textStyle('muted') });
+    const caption = new Text({ style: textStyle('small') });
+    box.addChild(background, ...sprites, empty, caption);
+    box.eventMode = 'none';
+    this.addChild(box);
+    return { box, background, sprites, empty, caption };
+  }
+
+  private indexUnder(e: FederatedPointerEvent): number {
+    const local = this.toLocal(e.global);
+    return tileAt(local.x, local.y, this.tileIds.length, this.metrics, GAP);
+  }
+
+  private hover(index: number): void {
+    if (index === this.hoveredIndex) return;
+    this.hoveredIndex = index;
+    this.invalidate();
+  }
+
+  override destroy(): void {
+    for (const stop of this.stops) stop();
+    super.destroy({ children: true });
+  }
+}

tests/core/tile.test.ts

@@ -14,6 +14,7 @@ import type { TileAsset } from '../../src/core/model/Asset';
 import { isPlaceableType } from '../../src/core/model/AssetTypes';
 import {
   autotileCombinations,
+  loneTileQuadrants,
   type Neighbours,
   neighboursAt,
   SAMPLE_PATTERN,
@@ -249,6 +250,28 @@ describe('autotile blocks', () => {
     expect([corner.n, corner.e, corner.ne]).toEqual([true, true, false]);
     expect(tileQuadrants('floor', corner)[1]).toEqual({ x: 3, y: 0 });
   });
+
+  it('shows each kind in the palette as its lone tile, the four convex corners (#139)', () => {
+    expect(loneTileQuadrants('floor')).toEqual([
+      { x: 0, y: 2 },
+      { x: 3, y: 2 },
+      { x: 0, y: 5 },
+      { x: 3, y: 5 },
+    ]);
+    expect(loneTileQuadrants('wall')).toEqual([
+      { x: 0, y: 0 },
+      { x: 3, y: 0 },
+      { x: 0, y: 3 },
+      { x: 3, y: 3 },
+    ]);
+    // A plain tile is its picture as it is, each corner its own quarter.
+    expect(loneTileQuadrants('none')).toEqual([
+      { x: 0, y: 0 },
+      { x: 1, y: 0 },
+      { x: 0, y: 1 },
+      { x: 1, y: 1 },
+    ]);
+  });
 });
 
 describe('tile asset', () => {

tests/editor/image-grid.test.ts

@@ -28,6 +28,19 @@ describe('gridMetrics', () => {
     expect(gridMetrics(140, 1).tile).toBe(TILE_MAX);
   });
 
+  it('takes other limits for the tile size, as the tile palette of a tilemap does (#139)', () => {
+    const sizes = { min: 56, max: 72 };
+    // A 300 px inspector column: four boxes of 56 fit, spread to 70 each.
+    const m = gridMetrics(300, 5, 6, sizes);
+    expect(m.columns).toBe(4);
+    expect(m.tile).toBe(70);
+    expect(m.rows).toBe(2);
+    expect(m.height).toBe(2 * (70 + CAPTION_HEIGHT) + 6);
+    // 170 px hold two columns of 82 – capped at the upper limit, not at the picker's.
+    expect(gridMetrics(170, 5, 6, sizes).tile).toBe(72);
+    expect(tileAt(tileRect(1, m, 6).x + 2, 2, 5, m, 6)).toBe(1);
+  });
+
   it('reports the height the scroll container has to give it', () => {
     const m = gridMetrics(WIDTH, 7);
     expect(m.rows).toBe(2);

tools/e2e/40-tilemap.mjs

@@ -112,6 +112,33 @@ export async function tilemap(t) {
     section.tools && section.grass && Boolean(section.layers),
     JSON.stringify(section),
   );
+  // The tiles are a grid of pictures (#139), and each shows its block's lone tile: the four convex
+  // corners, read off the palette in one call like a cell of the map.
+  await inInspector(t, '__gm.tilemap.tileButtonAt("at-grass")');
+  const swatch = await json(`(() => {
+    const s = __gm.tilemap.tileSwatch("at-grass");
+    if (!s) return null;
+    const q = s.picture.w / 4;
+    const points = [[q, q], [3 * q, q], [q, 3 * q], [3 * q, 3 * q]]
+      .map(([x, y]) => [Math.round(s.picture.x + x), Math.round(s.picture.y + y)]);
+    return { columns: s.columns, read: points.map(([x, y]) => __gm.pixelAt(x, y)) };
+  })()`);
+  const lone = [
+    [0, 2],
+    [3, 2],
+    [0, 5],
+    [3, 5],
+  ].map(([qx, qy]) => quadColour('floor', qx, qy));
+  check(
+    'the palette shows a tile as its picture, the lone tile of the block',
+    swatch !== null && swatch.read.every((colour, i) => colourDistance(colour, lone[i]) <= 12),
+    JSON.stringify({ swatch, want: lone }),
+  );
+  check(
+    'and puts several tiles side by side in the inspector',
+    swatch !== null && swatch.columns >= 3,
+    JSON.stringify(swatch),
+  );
   // Clicked through the hook rather than by its text: the tile's own row in the asset panel
   // reads "Grass" as well, and a click there would only select the tile.
   check(