Show an actual board for the village and allow building on specific tiles.

src/App.svelte

@@ -1,63 +1,7 @@
 <script lang="ts">
-    import { onMount } from "svelte";
-
-    import Resources from "./hud/Resources.svelte";
-    import moves from "./moves";
-    import update from "./update";
-    import village from "./village";
-    import BuildingCreator from "./hud/BuildingCreator.svelte";
-
-
-    onMount(() => {
-        let frame: number;
-
-        function loop(timestamp: number) {
-            frame = requestAnimationFrame(loop);
-            update(timestamp);
-        }
-        frame = requestAnimationFrame(loop);
-
-        return () => {
-            cancelAnimationFrame(frame);
-        }
-    });
-
-
-    function upgradeBuilding(id: number) {
-        moves.upgradeBuilding(id);
-    }
-
-    let showBuildingCreator = false;
+    import Game from "./hud/Game.svelte";
 </script>
 
-{ #if showBuildingCreator }
-<BuildingCreator close={ () => { showBuildingCreator = false } } />
-{ /if }
 <main>
-    <header>
-        <Resources />
-    </header>
-    <div>
-        <button on:click={ () => { showBuildingCreator = true } }>Create building</button>
-    </div>
-    <div class="buildings">
-        { #each $village.buildings as building }
-        <div>
-            <p>{ building.name } ({ building.level })</p>
-            <p>
-                <button on:click={ () => upgradeBuilding(building.id) }>
-                    Upgrade
-                </button>
-            </p>
-        </div>
-        { /each }
-    </div>
+    <Game />
 </main>
-
-<style>
-    .buildings {
-        display: grid;
-        gap: 1em;
-        grid-template-columns: repeat(4, 1fr);
-    }
-</style>

src/app.css

@@ -62,6 +62,13 @@ button:focus-visible {
     outline: 4px auto -webkit-focus-ring-color;
 }
 
+button.invisible,
+button:disabled.invisible,
+button:active.invisible,
+button:focus.invisible {
+    all: unset;
+}
+
 @media (prefers-color-scheme: light) {
     :root {
         color: #213547;

src/board/Tile.svelte

@@ -0,0 +1,88 @@
+<script lang="ts">
+    export let empty = false;
+    export let onTileClick: () => void;
+</script>
+
+<button
+    class="invisible"
+    on:click={ onTileClick }
+>
+    <div
+        class={ "hexagon" }
+        class:empty
+    >
+        <div class="content">
+            <slot></slot>
+        </div>
+    </div>
+</button>
+
+<style>
+    /* Source: https://codepen.io/gpyne/pen/iElhp */
+    .hexagon {
+        background-color: hsl(220, 75%, 75%);
+        cursor: pointer;
+        display: inline-block;
+        font-size: 1.2vmin;
+        margin: -0.8em 2.7em;
+        position: relative;
+        text-align: center;
+        rotate: 90deg;
+    }
+    .hexagon,
+    .hexagon::before,
+    .hexagon::after {
+        width: 6.7em;
+        height: 11.6em;
+        border-radius: 20%/5%;
+    }
+    .hexagon::before {
+        background-color: inherit;
+        content: "";
+        position: absolute;
+        left: 0;
+        transform: rotate(-60deg);
+    }
+    .hexagon::after {
+        background-color: inherit;
+        content: "";
+        position: absolute;
+        left: 0;
+        transform: rotate(60deg);
+    }
+    .hexagon:nth-child(even) {
+        top: 5.9em;
+    }
+    .hexagon:hover {
+        background-color: hsl(60, 75%, 75%);
+        z-index: 105;
+    }
+    .hexagon:active {
+        background-color: hsl(60, 75%, 50%);
+        z-index: 110;
+    }
+    .hexagon.empty {
+        position: relative;
+        display: none;
+        width: 6.7em;
+        height: 11.6em;
+        margin: 0.1em 1.8em;
+    }
+    .hexagon.empty:nth-child(even) {
+        top: 5.9em;
+    }
+    .hexagon .content {
+        position: absolute;
+        display: grid;
+        top: 5%;
+        left: -40%;
+        font-size: 4vmin;
+        height: 90%;
+        line-height: 1.2;
+        width: 180%;
+        z-index: 100;
+    }
+    .hexagon .content > * {
+        margin: auto;
+    }
+</style>

src/board/Village.svelte

@@ -0,0 +1,52 @@
+<script lang="ts">
+    import { Hex } from "../hexgrid";
+    import moves from "../moves";
+    import showBuildingCreator from "../stores/showBuildingCreator";
+    import { getKeysAsNumbers } from "../utils";
+    import village from "../village";
+    import Tile from "./Tile.svelte";
+
+
+    function upgradeBuilding(id: number) {
+        moves.upgradeBuilding(id);
+    }
+
+
+    function openBuildingCreator(tile: Hex) {
+        showBuildingCreator.set(tile);
+    }
+</script>
+
+<section class="village-map">
+    <div>
+        { #each getKeysAsNumbers($village.villageTiles) as y }
+        <div>
+            { #each getKeysAsNumbers($village.villageTiles[y]) as x }
+                { #if $village.villageTiles[y][x] >= 0 }
+                    <Tile
+                        onTileClick={ () => {} }
+                    >
+                        <p>{ $village.buildings.find(b => b.id === $village.villageTiles[y][x])?.name }</p>
+                    </Tile>
+                { :else }
+                    <Tile
+                        onTileClick={ () => openBuildingCreator(new Hex(x, y)) }
+                    />
+                { /if }
+            { /each }
+        </div>
+        { /each }
+    </div>
+</section>
+
+<style>
+    .village-map {
+        display: grid;
+        height: 100%;
+        position: relative;
+    }
+
+    .village-map > div {
+        margin: auto;
+    }
+</style>

src/create.ts

@@ -1,3 +1,4 @@
+import { Hex } from "./hexgrid";
 import type { Building, BuildingSource } from "./types";
 
 
@@ -7,7 +8,8 @@ let uid = 0;
 export function createBuilding(building: BuildingSource): Building {
     return {
         ...building,
-        level: 1,
         id: uid++,
+        level: 1,
+        tile: new Hex(0, 0),
     };
 }

src/hexgrid.ts

@@ -0,0 +1,135 @@
+/**
+ * A class representing coordinates in a hexagonal grid with 2 dimensions.
+ * Offset system is "odd-r".
+ */
+export class Hex {
+    x: number;
+    y: number;
+
+    constructor(x: number | { x: number, y: number }, y?: number) {
+        if (typeof x === "number") {
+            this.x = x as number;
+            this.y = y || 0;
+        }
+        else {
+            this.x = x.x;
+            this.y = x.y;
+        }
+    }
+
+    toCube() {
+        const q = this.x - (this.y - (this.y&1)) / 2;
+        const r = this.y;
+        return new Cube(q, r, -q - r);
+    }
+}
+
+
+/**
+ * A class representing coordinates in a hexagonal grid with 3 dimensions.
+ * Mostly used as a transient value for easier algorithms.
+ */
+class Cube {
+    q: number;
+    r: number;
+    s: number;
+
+    constructor(q: number, r: number, s: number) {
+        this.q = q;
+        this.r = r;
+        this.s = s;
+    }
+
+    toHex() {
+        return new Hex(
+            this.q + (this.r - (this.r&1)) / 2,
+            this.r
+        );
+    }
+
+    add(cube: Cube) {
+        return new Cube(this.q + cube.q, this.r + cube.r, this.s + cube.s);
+    }
+
+    subtract(cube: Cube) {
+        return new Cube(this.q - cube.q, this.r - cube.r, this.s - cube.s);
+    }
+}
+
+
+export function getCornersAtDistance(distance: number) {
+    const results: Hex[] = [];
+    for (let q = -distance; q <= distance; q++) {
+        for (let r = Math.max(-distance, -q - distance); r <= Math.min(distance, -q + distance); r++) {
+            const s = -q - r;
+            if (
+                (q === 0 || r === 0 || s === 0)
+                && Math.max(Math.abs(q), Math.abs(r), Math.abs(s)) === distance
+            ) {
+                const cube = new Cube(q, r, s);
+                results.push(cube.toHex());
+            }
+        }
+    }
+    return results;
+}
+
+
+export function getTilesAtDistance(distance: number) {
+    const results: Hex[] = [];
+    for (let q = -distance; q <= distance; q++) {
+        for (let r = Math.max(-distance, -q - distance); r <= Math.min(distance, -q + distance); r++) {
+            const s = -q - r;
+            if (Math.max(Math.abs(q), Math.abs(r), Math.abs(s)) === distance) {
+                const cube = new Cube(q, r, s);
+                results.push(cube.toHex());
+            }
+        }
+    }
+    return results;
+}
+
+
+const adjacentVectors = [
+    new Cube(+1, 0, -1), new Cube(+1, -1, 0), new Cube(0, -1, +1),
+    new Cube(-1, 0, +1), new Cube(-1, +1, 0), new Cube(0, +1, -1),
+];
+
+
+/**
+ * Return all coordinates adjacent to a given one.
+ * @param tile Hex - 2D coordinates in a hexagonal grid.
+ * @returns Array of 6 2D coordinates.
+ */
+export function getAdjacentCoords(tile: Hex): Hex[] {
+    const origin = tile.toCube();
+    return adjacentVectors.map(vec => origin.add(vec).toHex());
+}
+
+
+/**
+ * Return a position on the 3D board based on coordinates of a tile on our grid.
+ * @param x The x coordinate in the grid.
+ * @param y The y coordinate in the grid.
+ * @returns An array containing the 3 coordinates (x, y, z) of that tile on a 3D board.
+ */
+export function getPositionOnBoard(x: number, y: number): [number, number, number] {
+    const posX = x * 2 + (y % 2 ? 1 : 0);
+    const posY = 0;
+    const posZ = y * 1.72;
+    return [ posX, posY, posZ ];
+}
+
+
+/**
+ * Return the distance between two cells.
+ * @param a Hex - 2D coordinates in a hexagonal grid.
+ * @param b Hex - 2D coordinates in a hexagonal grid.
+ * @returns Distance between the two coordinates.
+ */
+export function distanceBetween(a: Hex, b: Hex): number {
+    const aCube = a.toCube();
+    const bCube = b.toCube();
+    const vector = aCube.subtract(bCube);
+    return (Math.abs(vector.q) + Math.abs(vector.r) + Math.abs(vector.s)) / 2;
+}

src/hud/BuildingCreator.svelte

@@ -1,17 +1,25 @@
 <script lang="ts">
     import buildings from "../buildings";
     import moves from "../moves";
+    import showBuildingCreator from "../stores/showBuildingCreator";
 
-    export let close: () => void;
+    function close() {
+        showBuildingCreator.set(null);
+    }
 
 
     function build(type: string) {
-        if (moves.build(type)) {
+        if ($showBuildingCreator === null) {
+            return;
+        }
+
+        if (moves.build(type, $showBuildingCreator)) {
             close();
         }
     }
 </script>
 
+{ #if $showBuildingCreator !== null }
 <section>
     <div class="building-creator">
         <header>
@@ -30,6 +38,7 @@
         </div>
     </div>
 </section>
+{ /if }
 
 <style>
     section {

src/hud/Game.svelte

@@ -0,0 +1,47 @@
+<script lang="ts">
+    import { onMount } from "svelte";
+
+    import Village from "../board/Village.svelte";
+    import update from "../update";
+    import BuildingCreator from "./BuildingCreator.svelte";
+    import Resources from "./Resources.svelte";
+
+
+    onMount(() => {
+        let frame: number;
+
+        function loop(timestamp: number) {
+            frame = requestAnimationFrame(loop);
+            update(timestamp);
+        }
+        frame = requestAnimationFrame(loop);
+
+        return () => {
+            cancelAnimationFrame(frame);
+        }
+    });
+</script>
+
+<section class="hud">
+    <header>
+        <Resources />
+    </header>
+    <div class="buildings">
+        <Village />
+    </div>
+</section>
+<section class="overlay">
+    <BuildingCreator />
+</section>
+
+<style>
+    .buildings {
+        margin-top: 2em;
+    }
+
+    .overlay {
+        left: 0;
+        position: absolute;
+        top: 0;
+    }
+</style>

src/moves/build.ts

@@ -1,9 +1,10 @@
 import buildings from "../buildings";
 import { createBuilding } from "../create";
-import type { VillageState } from "../village";
+import type { Hex } from "../hexgrid";
+import { DEFAULT_TILE, type VillageState } from "../village";
 
 
-export default function build(V: VillageState, buildingType: keyof typeof buildings) {
+export default function build(V: VillageState, buildingType: keyof typeof buildings, tile: Hex) {
     const building = buildings[buildingType];
     const cost = building.cost(1);
 
@@ -16,12 +17,20 @@ export default function build(V: VillageState, buildingType: keyof typeof buildi
         return false;
     }
 
+    if (V.villageTiles[tile.y][tile.x] !== DEFAULT_TILE) {
+        return false;
+    }
+
     V.resources.wood -= cost.wood;
     V.resources.stone -= cost.stone;
     V.resources.iron -= cost.iron;
     V.resources.food -= cost.food;
 
-    V.buildings.push(createBuilding(building));
+    const newBuilding = createBuilding(building);
+    newBuilding.tile = tile;
+
+    V.buildings.push(newBuilding);
+    V.villageTiles[tile.y][tile.x] = newBuilding.id;
 
     return true;
 }

src/stores/showBuildingCreator.ts

@@ -0,0 +1,5 @@
+import { writable } from "svelte/store";
+import type { Hex } from "../hexgrid";
+
+
+export default writable<Hex | null>(null);

src/types.ts

@@ -1,3 +1,5 @@
+import type { Hex } from "./hexgrid";
+
 export interface Cost {
     wood: number;
     stone: number;
@@ -22,4 +24,5 @@ export interface BuildingSource {
 export interface Building extends BuildingSource {
     id: number;
     level: number;
+    tile: Hex;
 }

src/utils.ts

@@ -44,3 +44,8 @@ export function getStorage(villageState: VillageState): Production {
         })
         .reduce(_reduceResources, getEmptyResources());
 }
+
+
+export function getKeysAsNumbers(dict: Object): Array<number> {
+    return Object.keys(dict).map(i => parseInt(i)).sort((a, b) => a - b);
+}

src/village.ts

@@ -3,6 +3,14 @@ import { writable } from "svelte/store";
 import buildings from "./buildings";
 import { createBuilding } from "./create";
 import type { Building } from "./types";
+import { getTilesAtDistance } from "./hexgrid";
+
+
+type Board = {
+    [key: number]: {
+        [key: number]: number;
+    }
+}
 
 
 export interface VillageState {
@@ -14,25 +22,73 @@ export interface VillageState {
         food: number;
         culture: number;
     };
+    villageTiles: Board;
+    outsideTiles: Board;
 }
 
 
-const village = writable<VillageState>({
-    buildings: [
-        createBuilding(buildings.townhall),
-        createBuilding(buildings.woodcutter),
-        createBuilding(buildings.pit),
-        createBuilding(buildings.mine),
-        createBuilding(buildings.field),
-    ],
-    resources: {
-        wood: 60,
-        stone: 60,
-        iron: 60,
-        food: 50,
-        culture: 0,
-    },
-});
+export const DEFAULT_TILE = -1;
+export const VILLAGE_TILE = -2;
+
+
+function getInitialVillageBoard() {
+    const board: Board = {
+        0: { 0: DEFAULT_TILE },
+    };
+    for (let i = 1; i <= 2; i++) {
+        getTilesAtDistance(i).forEach(tile => {
+            if (board[tile.y] === undefined) {
+                board[tile.y] = {};
+            }
+
+            board[tile.y][tile.x] = DEFAULT_TILE;
+        });
+    }
+    return board;
+}
+
+
+function getInitialOutsideBoard() {
+    const board: Board = {
+        0: { 0: VILLAGE_TILE },
+    };
+    for (let i = 1; i <= 2; i++) {
+        getTilesAtDistance(i).forEach(tile => {
+            if (board[tile.y] === undefined) {
+                board[tile.y] = {};
+            }
+
+            board[tile.y][tile.x] = DEFAULT_TILE;
+        });
+    }
+    return board;
+}
+
+
+function getInitialState() {
+    const townhall = createBuilding(buildings.townhall);
+    const state = {
+        buildings: [
+            townhall,
+        ],
+        resources: {
+            wood: 60,
+            stone: 60,
+            iron: 60,
+            food: 50,
+            culture: 0,
+        },
+        villageTiles: getInitialVillageBoard(),
+        outsideTiles: getInitialOutsideBoard(),
+    };
+
+    state.villageTiles[0][0] = townhall.id;
+
+    return state;
+}
+
+
+const village = writable<VillageState>(getInitialState());
 
 
 export default village;