feuerwerk/tests/viewport/sort-by-y.test.ts

import { describe, expect, it } from 'vitest';
import { CreateAssetCommand, SetAssetPropertyCommand } from '../../src/core/commands/assetCommands';
import { AddFrameCommand, SetFrameSortLineCommand } from '../../src/core/commands/frameCommands';
import { MoveSceneObjectCommand } from '../../src/core/commands/sceneObjectCommands';
import {
  AddTilemapLayerCommand,
  PaintTilesCommand,
  RenameTilemapLayerCommand,
  SetTilemapLayerSortByYCommand,
} from '../../src/core/commands/tilemapCommands';
import type { TextureAsset, TileAsset, TilemapAsset } from '../../src/core/model/Asset';
import { findAsset } from '../../src/core/model/Project';
import { frameSortLine } from '../../src/core/model/texture';
import { TILE_SORT_OFFSET_KEY, tileSortOffset } from '../../src/core/model/tile';
import { deserializeProject, serializeProject } from '../../src/core/store/serialize';
import { type DrawSlot, drawSlots, layerRows } from '../../src/viewport/drawOrder';
import { collectHolderItems, collectWorldItems } from '../../src/viewport/items';
import { stackAt } from '../../src/viewport/pick';
import { groupByTile } from '../../src/viewport/tilemapMesh';
import { sortLineAt, sortLineY } from '../../src/editor/texture/sheetView';
import { makeSpriteScene, place, roundTrip, startWorld } from '../helpers';

/**
 * A 20 × 15 map of 48-unit cells at the origin, so row `r` ends at `-360 + (r + 1) * 48`: row 5 at
 * -72, row 8 at 72. "Ground" is a plain layer; "Trees" holds a trunk at (2,5), its crown at (2,4)
 * and a bush at (7,8). The sprite "Box" is 100 tall and stands with its bottom at `feet`.
 */
function makeScene(feet: number, crownOffset = 1) {
  const f = makeSpriteScene('Box');
  const map = new CreateAssetCommand('tilemap', 'Forest');
  f.stack.execute(map);
  const mapId = map.asset.id;
  const assetOf = () => findAsset(f.project, mapId) as TilemapAsset;
  const ground = assetOf().layers[0]!.id;
  f.stack.execute(new RenameTilemapLayerCommand(mapId, ground, 'Ground'));
  const treesAdd = new AddTilemapLayerCommand(mapId);
  f.stack.execute(treesAdd);
  const trees = treesAdd.layerId;
  f.stack.execute(new RenameTilemapLayerCommand(mapId, trees, 'Trees'));
  const tile = (name: string, props = {}) => {
    const created = new CreateAssetCommand('tile', name, props);
    f.stack.execute(created);
    return created.asset.id;
  };
  const trunk = tile('Trunk');
  const crown = tile('Crown', { [TILE_SORT_OFFSET_KEY]: crownOffset });
  f.stack.execute(new PaintTilesCommand(mapId, ground, [{ x: 0, y: 0, tileId: trunk }]));
  f.stack.execute(
    new PaintTilesCommand(mapId, trees, [
      { x: 2, y: 5, tileId: trunk },
      { x: 2, y: 4, tileId: crown },
      { x: 7, y: 8, tileId: trunk },
    ]),
  );
  const mapObject = place(f, mapId, { x: 0, y: 0, z: 0 });
  const box = place(f, f.spriteId, { x: 0, y: feet - 50, z: 0 });
  const names = new Map([
    [mapObject, 'map'],
    [box, 'box'],
  ]);
  const layerNames = new Map([
    [ground, 'Ground'],
    [trees, 'Trees'],
  ]);
  const sortTrees = () => f.stack.execute(new SetTilemapLayerSortByYCommand(mapId, trees, true));
  return { f, mapId, mapObject, box, ground, trees, crown, assetOf, names, layerNames, sortTrees };
}

type Scene = ReturnType<typeof makeScene>;

function readable(s: Scene, slots: DrawSlot[]): string[] {
  return slots.map((slot) => {
    if (!slot.layerId) return s.names.get(slot.id) ?? slot.id;
    const name = s.layerNames.get(slot.layerId)!;
    return slot.row === null ? name : `${name} ${slot.row}`;
  });
}

function sceneOrder(s: Scene): string[] {
  return readable(s, drawSlots(collectHolderItems(s.f.project, s.f.sceneOf(), 0).items));
}

describe('a tilemap layer sorted by Y (#228)', () => {
  it('is off by default, and the map then draws as one piece per layer as before', () => {
    const s = makeScene(-50);
    expect(s.assetOf().layers.map((l) => l.sortByY)).toEqual([undefined, undefined]);
    expect(sceneOrder(s)).toEqual(['map', 'Ground', 'Trees', 'box']);
  });

  it('sets, undoes and redoes, and stores off as nothing', () => {
    const s = makeScene(-50);
    const trees = () => s.assetOf().layers[1]!;
    s.sortTrees();
    expect(trees().sortByY).toBe(true);
    s.f.stack.execute(new SetTilemapLayerSortByYCommand(s.mapId, s.trees, false));
    expect('sortByY' in trees()).toBe(false);
    s.f.stack.undo();
    expect(trees().sortByY).toBe(true);
    s.f.stack.undo();
    expect('sortByY' in trees()).toBe(false);
    s.f.stack.redo();
    expect(trees().sortByY).toBe(true);
  });

  it('survives a round trip, and loading keeps only a literal true', () => {
    const s = makeScene(-50);
    s.sortTrees();
    const back = findAsset(roundTrip(s.f.project), s.mapId) as TilemapAsset;
    expect(back.layers.map((l) => l.sortByY)).toEqual([undefined, true]);

    const saved = serializeProject(s.f.project) as {
      assets: { id: string; layers?: Record<string, unknown>[] }[];
    };
    const layers = saved.assets.find((a) => a.id === s.mapId)!.layers!;
    for (const [raw, kept] of [
      [true, true],
      ['true', undefined],
      [1, undefined],
      [false, undefined],
    ] as const) {
      layers[1]!.sortByY = raw;
      const loaded = findAsset(deserializeProject(saved), s.mapId) as TilemapAsset;
      expect(loaded.layers[1]!.sortByY, `stored ${String(raw)}`).toBe(kept);
    }
  });

  it('puts a figure in front of a row whose bottom is above its feet, behind one below', () => {
    const between = makeScene(-50);
    between.sortTrees();
    expect(sceneOrder(between)).toEqual(['map', 'Ground', 'Trees 5', 'box', 'Trees 8']);

    const behind = makeScene(-100);
    behind.sortTrees();
    expect(sceneOrder(behind)).toEqual(['map', 'Ground', 'box', 'Trees 5', 'Trees 8']);

    const front = makeScene(100);
    front.sortTrees();
    expect(sceneOrder(front)).toEqual(['map', 'Ground', 'Trees 5', 'Trees 8', 'box']);
  });

  it('sorts a crown with the trunk its sort offset points to, and on its own row without one', () => {
    const offset = makeScene(-80);
    offset.sortTrees();
    // Feet at -80: below the crown's own row (ends at -120), above the trunk's (ends at -72).
    expect(sceneOrder(offset)).toEqual(['map', 'Ground', 'box', 'Trees 5', 'Trees 8']);

    const plain = makeScene(-80, 0);
    plain.sortTrees();
    expect(sceneOrder(plain)).toEqual(['map', 'Ground', 'Trees 4', 'box', 'Trees 5', 'Trees 8']);
  });

  it('hands out the very same rows while cells and offsets stay, and new ones when either changes', () => {
    const s = makeScene(-80);
    s.sortTrees();
    const rows = () => {
      const draw = collectHolderItems(s.f.project, s.f.sceneOf(), 0).items.find(
        (item) => item.id === s.mapObject,
      )!.tilemap!;
      return layerRows(
        draw,
        draw.layers.find((layer) => layer.id === s.trees)!,
      );
    };
    const first = rows();
    expect(rows()).toBe(first);
    expect([...first.keys()]).toEqual([5, 8]);
    expect(groupByTile(first.get(5)!)).toBe(groupByTile(rows().get(5)!));

    s.f.stack.execute(new SetAssetPropertyCommand(s.crown, TILE_SORT_OFFSET_KEY, 0));
    const moved = rows();
    expect(moved).not.toBe(first);
    expect([...moved.keys()]).toEqual([4, 5, 8]);

    s.f.stack.execute(new PaintTilesCommand(s.mapId, s.trees, [{ x: 3, y: 9, tileId: s.crown }]));
    expect(rows()).not.toBe(moved);
    expect([...rows().keys()]).toEqual([4, 5, 8, 9]);
  });

  it('sorts objects on that z among each other by their feet, too', () => {
    const s = makeScene(100);
    s.sortTrees();
    const far = place(s.f, s.f.spriteId, { x: 0, y: -150, z: 0 });
    s.names.set(far, 'far');
    // `far` comes after `box` in the hierarchy but stands further up, so it is drawn first.
    expect(sceneOrder(s)).toEqual(['map', 'Ground', 'far', 'Trees 5', 'Trees 8', 'box']);
  });

  it('leaves everything on another z as it was', () => {
    const s = makeScene(-50);
    s.sortTrees();
    s.f.stack.execute(new MoveSceneObjectCommand(s.f.sceneId, s.box, { x: 0, y: -100, z: 3 }));
    expect(sceneOrder(s)).toEqual(['map', 'Ground', 'Trees 5', 'Trees 8', 'box']);
  });

  it('holds in the running game, and follows a figure that walks past a row', () => {
    const s = makeScene(-100);
    s.sortTrees();
    const { world } = startWorld(s.f);
    const gameOrder = () => readable(s, drawSlots(collectWorldItems(world).items));
    expect(gameOrder()).toEqual(['map', 'Ground', 'box', 'Trees 5', 'Trees 8']);
    world.entities.find((e) => e.objectId === s.box)!.y = 0;
    expect(gameOrder()).toEqual(['map', 'Ground', 'Trees 5', 'box', 'Trees 8']);
  });

  it('picks the figure over a row behind it and the row over a figure behind it', () => {
    const cellHit = (s: Scene) => ({
      id: s.mapObject,
      layers: [s.ground, s.trees],
      rows: new Map([[s.trees, 5]]),
    });
    const pick = (s: Scene) =>
      stackAt(collectHolderItems(s.f.project, s.f.sceneOf(), 0).items, [
        { id: s.box, layers: null },
        cellHit(s),
      ]).map((id) => s.names.get(id));

    const inFront = makeScene(-50);
    inFront.sortTrees();
    expect(pick(inFront)).toEqual(['box', 'map']);

    const behind = makeScene(-100);
    behind.sortTrees();
    expect(pick(behind)).toEqual(['map', 'box']);
  });
});

/**
 * The scene above with "Box" wearing a frame of a 50 px tall picture, so one image pixel is two
 * units of its 100-unit box. "Stand" has the sort line under test, "Plain" has none.
 */
function withFrames(feet: number, line: number) {
  const s = makeScene(feet);
  const texture = new CreateAssetCommand('texture', 'Hero');
  s.f.stack.execute(texture);
  const sheet = findAsset(s.f.project, texture.asset.id) as TextureAsset;
  sheet.file = `${'a'.repeat(64)}.png`;
  sheet.width = 64;
  sheet.height = 50;
  const stand = new AddFrameCommand(texture.asset.id, { x: 0, y: 0, w: 32, h: 50 }, 'Stand');
  const plain = new AddFrameCommand(texture.asset.id, { x: 32, y: 0, w: 32, h: 50 }, 'Plain');
  s.f.stack.execute(stand);
  s.f.stack.execute(plain);
  s.f.stack.execute(new SetFrameSortLineCommand(texture.asset.id, stand.frameId, line));
  const wear = (frameId: string) =>
    s.f.stack.execute(new SetAssetPropertyCommand(s.f.spriteId, 'texture', frameId));
  wear(stand.frameId);
  const frameOf = (id: string) => sheet.frames.find((fr) => fr.id === id)!;
  return { ...s, textureId: texture.asset.id, stand: stand.frameId, plain: plain.frameId, wear, frameOf };
}

describe('the sort line of a texture frame (#228)', () => {
  it('lifts where a sprite wearing the frame stands by its share of the box', () => {
    // Feet at -50 are below row 5 (ends at -72); 15 px of 50 lift them 30 units, to -80, above it.
    const lifted = withFrames(-50, 15);
    lifted.sortTrees();
    expect(sceneOrder(lifted)).toEqual(['map', 'Ground', 'box', 'Trees 5', 'Trees 8']);
    const low = withFrames(-50, 5);
    low.sortTrees();
    expect(sceneOrder(low)).toEqual(['map', 'Ground', 'Trees 5', 'box', 'Trees 8']);
  });

  it('belongs to the frame: another frame of the same picture stands on its bottom edge', () => {
    const s = withFrames(-50, 15);
    s.sortTrees();
    s.wear(s.plain);
    expect(sceneOrder(s)).toEqual(['map', 'Ground', 'Trees 5', 'box', 'Trees 8']);
    s.wear(s.stand);
    expect(sceneOrder(s)).toEqual(['map', 'Ground', 'box', 'Trees 5', 'Trees 8']);
  });

  it('holds in the running game', () => {
    const s = withFrames(-50, 15);
    s.sortTrees();
    const { world } = startWorld(s.f);
    expect(readable(s, drawSlots(collectWorldItems(world).items))).toEqual([
      'map',
      'Ground',
      'box',
      'Trees 5',
      'Trees 8',
    ]);
  });

  it('sets, undoes and redoes, and stores 0 as nothing', () => {
    const s = withFrames(0, 12);
    const stand = () => s.frameOf(s.stand);
    expect(stand().sortLine).toBe(12);
    s.f.stack.execute(new SetFrameSortLineCommand(s.textureId, s.stand, 0));
    expect('sortLine' in stand()).toBe(false);
    s.f.stack.undo();
    expect(stand().sortLine).toBe(12);
    s.f.stack.redo();
    expect('sortLine' in stand()).toBe(false);
    expect('sortLine' in s.frameOf(s.plain)).toBe(false);

    const fresh = withFrames(0, 0);
    fresh.f.stack.execute(new SetFrameSortLineCommand(fresh.textureId, fresh.stand, 7));
    fresh.f.stack.undo();
    expect('sortLine' in fresh.frameOf(fresh.stand)).toBe(false);
  });

  it('is held to whole pixels inside the frame, also when loaded', () => {
    const s = withFrames(0, 0);
    for (const [raw, kept] of [
      [2.6, 3],
      [-4, 0],
      [80, 50],
    ] as const) {
      s.f.stack.execute(new SetFrameSortLineCommand(s.textureId, s.stand, raw));
      expect(frameSortLine(s.frameOf(s.stand)), String(raw)).toBe(kept);
    }
    const saved = serializeProject(s.f.project) as {
      assets: { id: string; frames?: Record<string, unknown>[] }[];
    };
    const frames = saved.assets.find((a) => a.id === s.textureId)!.frames!;
    frames[0]!.sortLine = 70;
    frames[1]!.sortLine = 'x';
    const loaded = findAsset(deserializeProject(saved), s.textureId) as TextureAsset;
    expect(loaded.frames.map((fr) => fr.sortLine)).toEqual([50, undefined]);
    const back = findAsset(roundTrip(s.f.project), s.textureId) as TextureAsset;
    expect(back.frames.map((fr) => fr.sortLine)).toEqual([50, undefined]);
  });

  it('is grabbed by its knob left of the frame, or on the line inside it', () => {
    const rect = { x: 10, y: 20, w: 30, h: 40 };
    expect(sortLineY(rect, 0)).toBe(60);
    expect(sortLineY(rect, 6)).toBe(54);
    expect(sortLineAt(rect, 6, { x: 4, y: 54 }, 1, 1, 8)).toBe('knob');
    expect(sortLineAt(rect, 6, { x: 25, y: 54.5 }, 1, 1, 8)).toBe('line');
    expect(sortLineAt(rect, 6, { x: 25, y: 57 }, 1, 1, 8)).toBeNull();
    expect(sortLineAt(rect, 6, { x: 0, y: 54 }, 1, 1, 8)).toBeNull();
    expect(sortLineAt(rect, 6, { x: 45, y: 54 }, 1, 1, 8)).toBeNull();
  });

  it('takes the middle of its knob even where the corner handle reaches over it', () => {
    // The editor's sizes at zoom 1: handles grab 8 px around the corner, the knob is drawn from
    // 4 to 12 px left of the frame, so its middle sits exactly 8 px out – on the handle's edge.
    const rect = { x: 100, y: 20, w: 24, h: 24 };
    expect(sortLineAt(rect, 0, { x: 92, y: 44 }, 8, 4, 14)).toBe('knob');
    expect(sortLineAt(rect, 0, { x: 97, y: 44 }, 8, 4, 14)).toBeNull();
  });
});

describe('the sort offset of a tile (#228)', () => {
  it('is 0 by default and held to whole rows between -16 and 16', () => {
    const s = makeScene(0);
    const crown = () => findAsset(s.f.project, s.crown) as TileAsset;
    expect(tileSortOffset({ ...crown(), props: {} })).toBe(0);
    for (const [raw, kept] of [
      [1, 1],
      [2.4, 2],
      [-3, -3],
      [40, 16],
      [-40, -16],
      ['x', 0],
    ] as const)
      expect(tileSortOffset({ ...crown(), props: { [TILE_SORT_OFFSET_KEY]: raw } }), String(raw)).toBe(kept);
  });
});