initial commit

src/game/GameStore.ts

@@ -0,0 +1,405 @@
+import { makeAutoObservable } from 'mobx';
+import type { Inventory, LogDrop, TreeState, Vec2 } from './types';
+import {
+  INTERACTION_RADIUS,
+  LOG_COLLECT_ARC_HEIGHT,
+  LOG_COLLECT_DURATION,
+  LOG_EJECT_RADIUS,
+  LOG_FALL_ARC_HEIGHT,
+  LOG_FALL_DURATION,
+  LOGS_PER_TREE,
+  TREE_COUNT,
+  TREE_EDGE_MARGIN,
+  TREE_MIN_DISTANCE_BETWEEN,
+  TREE_MIN_DISTANCE_FROM_CENTER,
+} from './constants';
+import { loadSave, writeSave } from './persistence';
+import { costForNextLevel, UPGRADES, type UpgradeId } from './upgrades';
+
+/** How often (seconds of played time) the game autosaves while running. */
+const AUTOSAVE_INTERVAL = 2;
+
+function randomId(prefix: string): string {
+  return `${prefix}-${Math.random().toString(36).slice(2)}`;
+}
+
+export class GameStore {
+  character: Vec2 = { x: 0, y: 0 };
+  trees: TreeState[] = [];
+  logDrops: LogDrop[] = [];
+  inventory: Inventory = { logs: 0, coins: 0 };
+  heldTreeId: string | null = null;
+  /** Free-form walk destination set by pressing on empty map, mutually exclusive with heldTreeId. */
+  moveTarget: Vec2 | null = null;
+  upgradeLevels: Record<UpgradeId, number> = {
+    moveSpeed: 1,
+    chopSpeed: 1,
+    logValue: 1,
+    pickupRadius: 1,
+    coinSpeed: 1,
+  };
+
+  private chopProgress = 0;
+  private coinProgress = 0;
+  private saveProgress = 0;
+  private lastTimestamp: number | null = null;
+  private rafId: number | null = null;
+
+  constructor() {
+    // autoBind so methods stay correctly bound when passed as bare references (event handlers,
+    // e.g. `onPointerUp={store.release}` or `window.addEventListener('blur', store.release)`).
+    // Deliberately no side effects (e.g. global event listener registration) here beyond
+    // makeAutoObservable: React StrictMode double-invokes `useState(() => new GameStore())`'s
+    // initializer in dev, constructing (and discarding) an extra instance — any listener
+    // registered in the constructor would leak and fire for that discarded instance too. Global
+    // listeners like beforeunload belong in a useEffect instead (see GameMap), which StrictMode
+    // handles correctly via its mount/cleanup/remount cycle.
+    makeAutoObservable(this, {}, { autoBind: true });
+  }
+
+  get heldTree(): TreeState | undefined {
+    return this.trees.find((tree) => tree.id === this.heldTreeId);
+  }
+
+  /** Whether the character is currently in chopping range of the held tree (as opposed to still walking to it). */
+  get isChopping(): boolean {
+    const tree = this.heldTree;
+    if (!tree)
+      return false;
+    return Math.hypot(tree.x - this.character.x, tree.y - this.character.y) <= INTERACTION_RADIUS;
+  }
+
+  /** Whether the character is actively walking (toward a held tree or a free-form move target). */
+  get isMoving(): boolean {
+    if (this.heldTreeId)
+      return !this.isChopping;
+    if (this.moveTarget)
+      return Math.hypot(this.moveTarget.x - this.character.x, this.moveTarget.y - this.character.y) > 0.5;
+    return false;
+  }
+
+  get characterSpeed(): number {
+    return UPGRADES.moveSpeed.effectAtLevel(this.upgradeLevels.moveSpeed);
+  }
+
+  get chopInterval(): number {
+    const logsPerSecond = UPGRADES.chopSpeed.effectAtLevel(this.upgradeLevels.chopSpeed);
+    return 1 / logsPerSecond;
+  }
+
+  get coinsPerLog(): number {
+    return UPGRADES.logValue.effectAtLevel(this.upgradeLevels.logValue);
+  }
+
+  get pickupRadiusPx(): number {
+    return UPGRADES.pickupRadius.effectAtLevel(this.upgradeLevels.pickupRadius);
+  }
+
+  get coinConversionInterval(): number {
+    const logsPerSecond = UPGRADES.coinSpeed.effectAtLevel(this.upgradeLevels.coinSpeed);
+    return 1 / logsPerSecond;
+  }
+
+  /** Buys the next level of the given upgrade if there are enough coins. Returns whether it bought. */
+  buyUpgrade(id: UpgradeId): boolean {
+    const level = this.upgradeLevels[id];
+    const cost = costForNextLevel(UPGRADES[id], level);
+    if (this.inventory.coins < cost)
+      return false;
+
+    this.inventory.coins -= cost;
+    this.upgradeLevels[id] = level + 1;
+    return true;
+  }
+
+  /** (Re)initializes the game for a map of the given size. Restores a saved game (character/trees/
+   * logs/progress) if one exists; otherwise places the character in the center and scatters
+   * fresh trees. */
+  initialize(width: number, height: number) {
+    this.heldTreeId = null;
+    this.moveTarget = null;
+    this.chopProgress = 0;
+    this.coinProgress = 0;
+    this.saveProgress = 0;
+
+    const save = loadSave();
+    if (save?.character && save.trees && save.logDrops) {
+      this.character = { ...save.character };
+      this.trees = save.trees.map((tree) => ({ ...tree }));
+      this.logDrops = save.logDrops.map((log) => ({ ...log, flight: log.flight ? { ...log.flight } : undefined }));
+    } else {
+      this.character = { x: width / 2, y: height / 2 };
+      this.trees = this.spawnTrees(width, height);
+      this.logDrops = [];
+    }
+
+    this.inventory = save ? { ...save.inventory } : { logs: 0, coins: 0 };
+    if (save)
+      this.upgradeLevels = { ...this.upgradeLevels, ...save.upgradeLevels };
+  }
+
+  /** Persists the full game (world state + progress) to localStorage right away. */
+  save() {
+    writeSave({
+      version: 1,
+      inventory: { ...this.inventory },
+      upgradeLevels: { ...this.upgradeLevels },
+      character: { ...this.character },
+      trees: this.trees.map((tree) => ({ ...tree })),
+      logDrops: this.logDrops.map((log) => ({ ...log, flight: log.flight ? { ...log.flight } : undefined })),
+    });
+  }
+
+  private spawnTrees(width: number, height: number): TreeState[] {
+    const centerX = width / 2;
+    const centerY = height / 2;
+    const trees: TreeState[] = [];
+    let attempts = 0;
+
+    while (trees.length < TREE_COUNT && attempts < 1000) {
+      attempts++;
+      const x = TREE_EDGE_MARGIN + Math.random() * Math.max(0, width - TREE_EDGE_MARGIN * 2);
+      const y = TREE_EDGE_MARGIN + Math.random() * Math.max(0, height - TREE_EDGE_MARGIN * 2);
+
+      if (Math.hypot(x - centerX, y - centerY) < TREE_MIN_DISTANCE_FROM_CENTER)
+        continue;
+      if (trees.some((tree) => Math.hypot(tree.x - x, tree.y - y) < TREE_MIN_DISTANCE_BETWEEN))
+        continue;
+
+      trees.push({ id: randomId('tree'), x, y, logsRemaining: LOGS_PER_TREE });
+    }
+
+    return trees;
+  }
+
+  holdTree(id: string) {
+    if (this.trees.some((tree) => tree.id === id)) {
+      this.moveTarget = null;
+      this.heldTreeId = id;
+    }
+  }
+
+  /** Starts walking freely toward an arbitrary point on the map (e.g. a click on empty ground). */
+  moveTo(x: number, y: number) {
+    this.heldTreeId = null;
+    this.chopProgress = 0;
+    this.moveTarget = { x, y };
+  }
+
+  release() {
+    this.heldTreeId = null;
+    this.moveTarget = null;
+    this.chopProgress = 0;
+  }
+
+  start() {
+    if (this.rafId !== null)
+      return;
+    this.lastTimestamp = null;
+
+    const loop = (timestamp: number) => {
+      const last = this.lastTimestamp ?? timestamp;
+      // Cap the per-frame step so a stalled/backgrounded tab doesn't cause a huge catch-up jump
+      // (e.g. character teleporting across the map) once it resumes.
+      const deltaTime = Math.min((timestamp - last) / 1000, 0.1);
+      this.lastTimestamp = timestamp;
+      this.tick(deltaTime);
+      this.rafId = requestAnimationFrame(loop);
+    };
+    this.rafId = requestAnimationFrame(loop);
+  }
+
+  stop() {
+    if (this.rafId !== null) {
+      cancelAnimationFrame(this.rafId);
+      this.rafId = null;
+    }
+    this.lastTimestamp = null;
+  }
+
+  private tick(deltaTime: number) {
+    this.updateMovementAndChopping(deltaTime);
+    this.updateLogFlights(deltaTime);
+    this.updatePickups();
+    this.updateCoinConversion(deltaTime);
+    this.updateAutosave(deltaTime);
+  }
+
+  private updateAutosave(deltaTime: number) {
+    this.saveProgress += deltaTime;
+    if (this.saveProgress < AUTOSAVE_INTERVAL)
+      return;
+    this.saveProgress = 0;
+    this.save();
+  }
+
+  private updateMovementAndChopping(deltaTime: number) {
+    const tree = this.heldTree;
+    if (tree) {
+      this.walkTowardTree(tree, deltaTime);
+      return;
+    }
+
+    if (this.moveTarget) {
+      this.walkTowardPoint(this.moveTarget, deltaTime);
+      return;
+    }
+
+    this.chopProgress = 0;
+  }
+
+  private walkTowardPoint(target: Vec2, deltaTime: number) {
+    const dx = target.x - this.character.x;
+    const dy = target.y - this.character.y;
+    const distance = Math.hypot(dx, dy);
+
+    if (distance <= 0.5) {
+      this.character = { x: target.x, y: target.y };
+      return;
+    }
+
+    const step = Math.min(this.characterSpeed * deltaTime, distance);
+    const ratio = step / distance;
+    this.character = {
+      x: this.character.x + dx * ratio,
+      y: this.character.y + dy * ratio,
+    };
+  }
+
+  private walkTowardTree(tree: TreeState, deltaTime: number) {
+    const dx = tree.x - this.character.x;
+    const dy = tree.y - this.character.y;
+    const distance = Math.hypot(dx, dy);
+
+    // A small tolerance keeps the character from flip-flopping between "walking" and "chopping"
+    // every frame once it's essentially at the interaction radius, which floating-point error on
+    // the two-axis step below can otherwise cause (each flip resets chopProgress, so chopping
+    // could stall forever right at the boundary).
+    if (distance > INTERACTION_RADIUS + 0.5) {
+      const step = Math.min(this.characterSpeed * deltaTime, distance - INTERACTION_RADIUS);
+      const ratio = step / distance;
+      this.character = {
+        x: this.character.x + dx * ratio,
+        y: this.character.y + dy * ratio,
+      };
+      this.chopProgress = 0;
+      return;
+    }
+
+    const chopInterval = this.chopInterval;
+    this.chopProgress += deltaTime;
+    while (this.chopProgress >= chopInterval && tree.logsRemaining > 0) {
+      this.chopProgress -= chopInterval;
+      tree.logsRemaining -= 1;
+
+      // Eject the log on a ballistic arc to a random spot within a circle around the tree; it
+      // only becomes pickable once it lands (see updateLogFlights/updatePickups).
+      const angle = Math.random() * Math.PI * 2;
+      const landDistance = Math.random() * LOG_EJECT_RADIUS;
+      const toX = tree.x + Math.cos(angle) * landDistance;
+      const toY = tree.y + Math.sin(angle) * landDistance;
+      this.logDrops.push({
+        id: randomId('log'),
+        x: tree.x,
+        y: tree.y,
+        z: 0,
+        phase: 'falling',
+        flight: {
+          fromX: tree.x,
+          fromY: tree.y,
+          toX,
+          toY,
+          elapsed: 0,
+          duration: LOG_FALL_DURATION,
+          arcHeight: LOG_FALL_ARC_HEIGHT,
+        },
+      });
+
+      if (tree.logsRemaining <= 0) {
+        this.trees = this.trees.filter((t) => t.id !== tree.id);
+        this.heldTreeId = null;
+        this.chopProgress = 0;
+        break;
+      }
+    }
+  }
+
+  /** Advances every log currently in a ballistic flight (falling from a tree, or flying into the
+   * inventory once collected), landing/collecting it once its flight completes. Mutates logs in
+   * place and only reassigns the `logDrops` array when one is actually removed (collected) — a
+   * landed log sitting idle, or the array being rebuilt every tick regardless, would otherwise
+   * force every observer of `logDrops` (i.e. the whole map) to re-render every animation frame. */
+  private updateLogFlights(deltaTime: number) {
+    if (this.logDrops.length === 0)
+      return;
+
+    let collectedIds: Set<string> | null = null;
+    for (const log of this.logDrops) {
+      if (log.phase === 'landed')
+        continue;
+
+      const flight = log.flight!;
+      flight.elapsed += deltaTime;
+      const t = Math.min(1, flight.elapsed / flight.duration);
+      log.x = flight.fromX + (flight.toX - flight.fromX) * t;
+      log.y = flight.fromY + (flight.toY - flight.fromY) * t;
+      log.z = flight.arcHeight * 4 * t * (1 - t);
+
+      if (t < 1)
+        continue;
+
+      if (log.phase === 'falling') {
+        log.phase = 'landed';
+        log.flight = undefined;
+        log.z = 0;
+      } else {
+        // Collecting flight finished: the log has reached the character.
+        (collectedIds ??= new Set()).add(log.id);
+        this.inventory.logs += 1;
+      }
+    }
+
+    if (collectedIds)
+      this.logDrops = this.logDrops.filter((log) => !collectedIds!.has(log.id));
+  }
+
+  /** Starts a landed log flying into the inventory once the character gets close enough. */
+  private updatePickups() {
+    const pickupRadius = this.pickupRadiusPx;
+    for (const log of this.logDrops) {
+      if (log.phase !== 'landed')
+        continue;
+
+      const distance = Math.hypot(log.x - this.character.x, log.y - this.character.y);
+      if (distance > pickupRadius)
+        continue;
+
+      log.phase = 'collecting';
+      log.flight = {
+        fromX: log.x,
+        fromY: log.y,
+        toX: this.character.x,
+        toY: this.character.y,
+        elapsed: 0,
+        duration: LOG_COLLECT_DURATION,
+        arcHeight: LOG_COLLECT_ARC_HEIGHT,
+      };
+    }
+  }
+
+  private updateCoinConversion(deltaTime: number) {
+    if (this.inventory.logs <= 0) {
+      this.coinProgress = 0;
+      return;
+    }
+
+    const coinsPerLog = this.coinsPerLog;
+    const conversionInterval = this.coinConversionInterval;
+    this.coinProgress += deltaTime;
+    while (this.coinProgress >= conversionInterval && this.inventory.logs > 0) {
+      this.coinProgress -= conversionInterval;
+      this.inventory.logs -= 1;
+      this.inventory.coins += coinsPerLog;
+    }
+  }
+}

src/game/constants.ts

@@ -0,0 +1,29 @@
+export const TREE_COUNT = 5;
+export const LOGS_PER_TREE = 5;
+
+/** How close the character must get to a tree's center to start chopping it. */
+export const INTERACTION_RADIUS = 56;
+
+/** Radius of the circle around a tree that ejected logs can land in. */
+export const LOG_EJECT_RADIUS = 70;
+
+/** Seconds for a log's ballistic flight from the tree to its landing spot. */
+export const LOG_FALL_DURATION = 0.5;
+
+/** Peak height (px) of a log's arc while falling from the tree. */
+export const LOG_FALL_ARC_HEIGHT = 40;
+
+/** Seconds for a landed log's flight into the character's inventory. */
+export const LOG_COLLECT_DURATION = 0.25;
+
+/** Peak height (px) of a log's little hop while flying into the inventory. */
+export const LOG_COLLECT_ARC_HEIGHT = 16;
+
+/** Trees won't spawn closer than this to the character's starting position. */
+export const TREE_MIN_DISTANCE_FROM_CENTER = 140;
+
+/** Trees won't spawn closer than this to each other. */
+export const TREE_MIN_DISTANCE_BETWEEN = 100;
+
+/** Trees won't spawn within this many px of the map edge. */
+export const TREE_EDGE_MARGIN = 70;

src/game/persistence.ts

@@ -0,0 +1,51 @@
+import type { Inventory, LogDrop, TreeState, Vec2 } from './types';
+import type { UpgradeId } from './upgrades';
+
+const STORAGE_KEY = 'forest-save-v1';
+
+export interface SaveData {
+  version: 1;
+  inventory: Inventory;
+  upgradeLevels: Record<UpgradeId, number>;
+  /** World state (character/trees/logs) is optional so older saves without it still load fine —
+   * progress is restored either way, just with a freshly spawned world. */
+  character?: Vec2;
+  trees?: TreeState[];
+  logDrops?: LogDrop[];
+}
+
+function isValidSave(value: unknown): value is SaveData {
+  if (!value || typeof value !== 'object')
+    return false;
+  const data = value as Partial<SaveData>;
+  return (
+    data.version === 1
+    && typeof data.inventory === 'object' && data.inventory !== null
+    && typeof data.inventory.logs === 'number'
+    && typeof data.inventory.coins === 'number'
+    && typeof data.upgradeLevels === 'object' && data.upgradeLevels !== null
+  );
+}
+
+/** Reads the saved game from localStorage, or null if there's none / it's corrupted. */
+export function loadSave(): SaveData | null {
+  try {
+    const raw = localStorage.getItem(STORAGE_KEY);
+    if (!raw)
+      return null;
+    const parsed: unknown = JSON.parse(raw);
+    return isValidSave(parsed) ? parsed : null;
+  } catch {
+    // localStorage unavailable (private mode, disabled) or corrupted JSON — treat as no save.
+    return null;
+  }
+}
+
+/** Writes the save to localStorage. Best-effort: silently no-ops if storage is unavailable/full. */
+export function writeSave(data: SaveData): void {
+  try {
+    localStorage.setItem(STORAGE_KEY, JSON.stringify(data));
+  } catch {
+    // Ignore — e.g. private browsing mode or quota exceeded.
+  }
+}

src/game/sprites.ts

@@ -0,0 +1,135 @@
+/** Pixel grids for 8-bit-style sprites. Each cell is a CSS color, or '' for transparent. */
+export type PixelGrid = string[][];
+
+function grid(rows: string[], palette: Record<string, string>): PixelGrid {
+  return rows.map((row) => [...row].map((ch) => palette[ch] ?? ''));
+}
+
+const CHARACTER_PALETTE = {
+  O: '#1b1611',
+  H: '#4a2f1c',
+  S: '#f0c090',
+  s: '#d9a873',
+  B: '#3f6fb0',
+  b: '#2f5488',
+  P: '#2c2c3e',
+  p: '#20202e',
+  F: '#2a1f14',
+};
+
+export const CHARACTER_SPRITE: PixelGrid = grid(
+  [
+    '....OOOOOOOO....',
+    '..OHHHHHHHHHHO..',
+    '.OHHHHHHHHHHHHO.',
+    'OHHHHHHHHHHHHHHO',
+    'OHHSSSSSSSSSSHHO',
+    'OSSSSOSSSSOSSSSO',
+    'OSSSSSSssSSSSSSO',
+    '.OSSSSSSSSSSSSO.',
+    '......OSSO......',
+    '...OBBBBBBBBO...',
+    '..OBBBBBBBBBBO..',
+    '.OSBBBBBBBBBBSO.',
+    '.OSBBbBBBBbBBSO.',
+    '.OSBBbBBBBbBBSO.',
+    '..OBBbBBBBbBBO..',
+    '..OPPpPPPPpPPO..',
+    '..OPPpPPPPpPPO..',
+    '..OPPpO..OpPPO..',
+    '..OPPpO..OpPPO..',
+    '..OPPpO..OpPPO..',
+    '..OFFFO..OFFFO..',
+    '.OFFFFO..OFFFFO.',
+  ],
+  CHARACTER_PALETTE,
+);
+
+const TREE_PALETTE = {
+  O: '#14290f',
+  G: '#2e7d32',
+  g: '#1b5e20',
+  H: '#66bb6a',
+  T: '#6b4226',
+  t: '#4e2f1a',
+  n: '#8a5a34',
+};
+
+export const TREE_SPRITE: PixelGrid = grid(
+  [
+    '......OggO......',
+    '....OGGggGGO....',
+    '..OGGGGggGGGGO..',
+    '.OGgGGGHHGGGgGO.',
+    'OGgGGGGHHGGGGgGO',
+    'OGGgGGGggGGGgGGO',
+    'OGgGGGgGGgGGGgGO',
+    'OGGgGGGGGGGGgGGO',
+    'OGgGGGGggGGGGgGO',
+    '.OGgGGGggGGGgGO.',
+    '..OGgGGggGGgGO..',
+    '...OGgGggGgGO...',
+    '....OGgGGgGO....',
+    '......OggO......',
+    '......OTTO......',
+    '......TTTT......',
+    '......TttT......',
+    '......tnnt......',
+    '......TTTT......',
+    '......TOOT......',
+  ],
+  TREE_PALETTE,
+);
+
+const LOG_PALETTE = {
+  O: '#2a1a0d',
+  B: '#7a4a2b',
+  C: '#a9703f',
+};
+
+export const LOG_SPRITE: PixelGrid = grid(
+  [
+    '..OOOOOOOOOOOOOOOO..',
+    'OBBBBBBBBBBBBBBBBBBO',
+    'OBCCCCCCCCCCCCCCCCBO',
+    'OBBBBBBBBBBBBBBBBBBO',
+    'OBCCCCCCCCCCCCCCCCBO',
+    'OBBBBBBBBBBBBBBBBBBO',
+    'OBCCCCCCCCCCCCCCCCBO',
+    'OBBBBBBBBBBBBBBBBBBO',
+    'OBCCCCCCCCCCCCCCCCBO',
+    'OBBBBBBBBBBBBBBBBBBO',
+    'OBCCCCCCCCCCCCCCCCBO',
+    '..OOOOOOOOOOOOOOOO..',
+  ],
+  LOG_PALETTE,
+);
+
+const COIN_PALETTE = {
+  Y: '#f5c518',
+  D: '#c99a0e',
+  W: '#fff2b0',
+  E: '#a97c08',
+};
+
+export const COIN_SPRITE: PixelGrid = grid(
+  [
+    '.....YYYYYY.....',
+    '...YYYYYYYYYY...',
+    '..YWWYYYYYYYYY..',
+    '.YYWWYYYYYYYYYY.',
+    '.YYYYYYYYYYYYYY.',
+    'YYYYYDDDDDDYYYYY',
+    'YYYYYDYYYYDYYYYY',
+    'YYYYYDYYYYDYYYYY',
+    'YYYYYDYYYYDYYYYY',
+    'YYYYYDYYYYDYYYYY',
+    'YYYYYDDDDDDYYYYY',
+    '.YYYYYYYYYYYYYY.',
+    '.YYYYYYYYYYEEYY.',
+    '..YYYYYYYYYEEY..',
+    '...YYYYYYYYYY...',
+    '.....YYYYYY.....',
+  ],
+  COIN_PALETTE,
+);

src/game/types.ts

@@ -0,0 +1,38 @@
+export interface Vec2 {
+  x: number;
+  y: number;
+}
+
+export interface TreeState {
+  id: string;
+  x: number;
+  y: number;
+  logsRemaining: number;
+}
+
+export type LogPhase = 'falling' | 'landed' | 'collecting';
+
+export interface LogFlight {
+  fromX: number;
+  fromY: number;
+  toX: number;
+  toY: number;
+  elapsed: number;
+  duration: number;
+  arcHeight: number;
+}
+
+export interface LogDrop {
+  id: string;
+  x: number;
+  y: number;
+  /** Visual height above ground during a flight, for the ballistic arc. 0 once landed. */
+  z: number;
+  phase: LogPhase;
+  flight?: LogFlight;
+}
+
+export interface Inventory {
+  logs: number;
+  coins: number;
+}

src/game/upgrades.ts

@@ -0,0 +1,63 @@
+export type UpgradeId = 'moveSpeed' | 'chopSpeed' | 'logValue' | 'pickupRadius' | 'coinSpeed';
+
+export interface UpgradeDef {
+  id: UpgradeId;
+  name: string;
+  baseCost: number;
+  costGrowth: number;
+  /** The upgrade's stat value at a given level (levels start at 1, unbounded above). */
+  effectAtLevel: (level: number) => number;
+  formatEffect: (value: number) => string;
+}
+
+export const UPGRADE_LIST: UpgradeDef[] = [
+  {
+    id: 'moveSpeed',
+    name: 'Скорость движения',
+    baseCost: 5,
+    costGrowth: 1.35,
+    effectAtLevel: (level) => 160 + (level - 1) * 20,
+    formatEffect: (v) => `${Math.round(v)} px/с`,
+  },
+  {
+    id: 'chopSpeed',
+    name: 'Скорость рубки',
+    baseCost: 6,
+    costGrowth: 1.35,
+    effectAtLevel: (level) => (1 / 0.6) * Math.pow(1.15, level - 1),
+    formatEffect: (v) => `${v.toFixed(2)} бревен/с`,
+  },
+  {
+    id: 'logValue',
+    name: 'Стоимость бревна',
+    baseCost: 8,
+    costGrowth: 1.4,
+    effectAtLevel: (level) => level,
+    formatEffect: (v) => `${v} монет/бревно`,
+  },
+  {
+    id: 'pickupRadius',
+    name: 'Радиус подбора',
+    baseCost: 5,
+    costGrowth: 1.3,
+    effectAtLevel: (level) => 46 + (level - 1) * 6,
+    formatEffect: (v) => `${Math.round(v)} px`,
+  },
+  {
+    id: 'coinSpeed',
+    name: 'Скорость обмена на монеты',
+    baseCost: 7,
+    costGrowth: 1.35,
+    effectAtLevel: (level) => Math.pow(1.15, level - 1),
+    formatEffect: (v) => `${v.toFixed(2)} бревен/с`,
+  },
+];
+
+export const UPGRADES: Record<UpgradeId, UpgradeDef> = Object.fromEntries(
+  UPGRADE_LIST.map((def) => [def.id, def]),
+) as Record<UpgradeId, UpgradeDef>;
+
+/** Cost (in coins) to go from `currentLevel` to `currentLevel + 1`. */
+export function costForNextLevel(def: UpgradeDef, currentLevel: number): number {
+  return Math.ceil(def.baseCost * Math.pow(def.costGrowth, currentLevel - 1));
+}