Feat: Alphanumeric Coordinate Grid on Alternate View

resources/lang/en.json

@@ -466,6 +466,8 @@
     "attack_ratio_desc": "What percentage of your troops to send in an attack (1–100%)",
     "territory_patterns_label": "🏳️ Territory Skins",
     "territory_patterns_desc": "Choose whether to display territory skin designs in game",
+    "coordinate_grid_label": "Coordinate Grid",
+    "coordinate_grid_desc": "Show the alphanumeric grid in Alternate View",
     "performance_overlay_label": "Performance Overlay",
     "performance_overlay_desc": "Toggle the performance overlay. When enabled, the performance overlay will be displayed. Press shift-D during game to toggle.",
     "easter_writing_speed_label": "Writing Speed Multiplier",

src/client/UserSettingModal.ts

@@ -370,6 +370,13 @@ export class UserSettingModal extends BaseModal {
     console.log("🏳️ Territory Patterns:", enabled ? "ON" : "OFF");
   }
 
+  private toggleCoordinateGrid(e: CustomEvent<{ checked: boolean }>) {
+    const enabled = e.detail?.checked;
+    if (typeof enabled !== "boolean") return;
+
+    this.userSettings.set("settings.coordinateGridEnabled", enabled);
+  }
+
   private togglePerformanceOverlay(e: CustomEvent<{ checked: boolean }>) {
     const enabled = e.detail?.checked;
     if (typeof enabled !== "boolean") return;
@@ -875,6 +882,15 @@ export class UserSettingModal extends BaseModal {
         @change=${this.toggleTerritoryPatterns}
       ></setting-toggle>
 
+      <!-- 🧭 Coordinate Grid -->
+      <setting-toggle
+        label="${translateText("user_setting.coordinate_grid_label")}"
+        description="${translateText("user_setting.coordinate_grid_desc")}"
+        id="coordinate-grid-toggle"
+        .checked=${this.userSettings.coordinateGridEnabled()}
+        @change=${this.toggleCoordinateGrid}
+      ></setting-toggle>
+
       <!-- 📱 Performance Overlay -->
       <setting-toggle
         label="${translateText("user_setting.performance_overlay_label")}"

src/client/graphics/GameRenderer.ts

@@ -12,6 +12,7 @@ import { BuildMenu } from "./layers/BuildMenu";
 import { ChatDisplay } from "./layers/ChatDisplay";
 import { ChatModal } from "./layers/ChatModal";
 import { ControlPanel } from "./layers/ControlPanel";
+import { CoordinateGridLayer } from "./layers/CoordinateGridLayer";
 import { DynamicUILayer } from "./layers/DynamicUILayer";
 import { EmojiTable } from "./layers/EmojiTable";
 import { EventsDisplay } from "./layers/EventsDisplay";
@@ -251,6 +252,7 @@ export function createRenderer(
     new TerrainLayer(game, transformHandler),
     new TerritoryLayer(game, eventBus, transformHandler, userSettings),
     new RailroadLayer(game, eventBus, transformHandler),
+    new CoordinateGridLayer(game, eventBus, transformHandler, userSettings),
     structureLayer,
     samRadiusLayer,
     new UnitLayer(game, eventBus, transformHandler),

src/client/graphics/layers/CoordinateGridLayer.ts

@@ -0,0 +1,240 @@
+import { EventBus } from "../../../core/EventBus";
+import { Cell } from "../../../core/game/Game";
+import { GameView } from "../../../core/game/GameView";
+import { UserSettings } from "../../../core/game/UserSettings";
+import { AlternateViewEvent } from "../../InputHandler";
+import { TransformHandler } from "../TransformHandler";
+import { Layer } from "./Layer";
+
+const BASE_CELL_COUNT = 10;
+const MAX_COLUMNS = 50;
+const MIN_ROWS = 2;
+const LABEL_PADDING = 8;
+
+const toAlphaLabel = (index: number): string => {
+  let value = index;
+  let label = "";
+  do {
+    label = String.fromCharCode(65 + (value % 26)) + label;
+    value = Math.floor(value / 26) - 1;
+  } while (value >= 0);
+  return label;
+};
+
+const computeGrid = (width: number, height: number) => {
+  // Initial square-ish estimate
+  let cellSize = Math.min(width, height) / BASE_CELL_COUNT;
+  let rows = Math.max(1, Math.round(height / cellSize));
+  let cols = Math.max(1, Math.round(width / cellSize));
+
+  // Cap columns and adjust rows accordingly
+  if (cols > MAX_COLUMNS) {
+    const maxRowsForCols = Math.floor((MAX_COLUMNS * height) / width);
+    rows = Math.max(MIN_ROWS, Math.min(rows, maxRowsForCols));
+    cols = MAX_COLUMNS;
+  }
+
+  cellSize = Math.min(width / cols, height / rows);
+  const fullCols = Math.max(1, Math.floor(width / cellSize));
+  const fullRows = Math.max(1, Math.floor(height / cellSize));
+
+  const remainderX = Math.max(0, width - fullCols * cellSize);
+  const remainderY = Math.max(0, height - fullRows * cellSize);
+
+  const hasExtraCol = remainderX > 0.001;
+  const hasExtraRow = remainderY > 0.001;
+
+  const totalCols = fullCols + (hasExtraCol ? 1 : 0);
+  const totalRows = fullRows + (hasExtraRow ? 1 : 0);
+
+  const lastColWidth = hasExtraCol ? remainderX : cellSize;
+  const lastRowHeight = hasExtraRow ? remainderY : cellSize;
+
+  return {
+    cellSize,
+    rows: totalRows,
+    cols: totalCols,
+    fullCols,
+    fullRows,
+    lastColWidth,
+    lastRowHeight,
+    hasExtraCol,
+    hasExtraRow,
+    gridWidth: width,
+    gridHeight: height,
+  };
+};
+
+export class CoordinateGridLayer implements Layer {
+  private isVisible = false;
+
+  constructor(
+    private game: GameView,
+    private eventBus: EventBus,
+    private transformHandler: TransformHandler,
+    private userSettings: UserSettings,
+  ) {}
+
+  init() {
+    this.eventBus.on(AlternateViewEvent, (event) => {
+      this.isVisible = event.alternateView;
+    });
+  }
+
+  shouldTransform(): boolean {
+    return false;
+  }
+
+  renderLayer(context: CanvasRenderingContext2D) {
+    if (!this.isVisible || !this.userSettings.coordinateGridEnabled()) return;
+
+    const width = this.game.width();
+    const height = this.game.height();
+    if (width <= 0 || height <= 0) return;
+
+    const {
+      cellSize,
+      rows,
+      cols,
+      fullCols,
+      fullRows,
+      lastColWidth,
+      lastRowHeight,
+      hasExtraCol,
+      hasExtraRow,
+      gridWidth,
+      gridHeight,
+    } = computeGrid(width, height);
+    const cellWidth = cellSize;
+    const cellHeight = cellSize;
+    const canvasWidth = context.canvas.width;
+    const canvasHeight = context.canvas.height;
+
+    const mapTopScreenRaw = this.transformHandler.worldToScreenCoordinates(
+      new Cell(0, 0),
+    ).y;
+    const mapBottomScreenRaw = this.transformHandler.worldToScreenCoordinates(
+      new Cell(0, height),
+    ).y;
+    const mapLeftScreenRaw = this.transformHandler.worldToScreenCoordinates(
+      new Cell(0, 0),
+    ).x;
+    const mapRightScreenRaw = this.transformHandler.worldToScreenCoordinates(
+      new Cell(width, 0),
+    ).x;
+
+    const mapTopScreen = Math.min(mapTopScreenRaw, mapBottomScreenRaw);
+    const mapLeftScreen = Math.min(mapLeftScreenRaw, mapRightScreenRaw);
+    const mapTopWorld = 0;
+    const mapLeftWorld = 0;
+
+    context.save();
+    context.strokeStyle = "rgba(255, 255, 255, 0.35)";
+    context.lineWidth = 1.25;
+    context.beginPath();
+
+    for (let col = 0; col <= fullCols; col++) {
+      const worldX = col * cellWidth + mapLeftWorld;
+      const screenX = this.transformHandler.worldToScreenCoordinates(
+        new Cell(worldX, mapTopWorld),
+      ).x;
+      if (screenX < -1 || screenX > canvasWidth + 1) continue;
+      const screenBottom = this.transformHandler.worldToScreenCoordinates(
+        new Cell(worldX, gridHeight),
+      ).y;
+      context.moveTo(screenX, mapTopScreen);
+      context.lineTo(screenX, screenBottom);
+    }
+    // Final vertical line at map right edge only if grid fits perfectly
+    if (!hasExtraCol) {
+      const mapRightLine = this.transformHandler.worldToScreenCoordinates(
+        new Cell(gridWidth, mapTopWorld),
+      ).x;
+      context.moveTo(mapRightLine, mapTopScreen);
+      context.lineTo(
+        mapRightLine,
+        this.transformHandler.worldToScreenCoordinates(
+          new Cell(gridWidth, gridHeight),
+        ).y,
+      );
+    }
+
+    for (let row = 0; row <= fullRows; row++) {
+      const worldY = row * cellHeight + mapTopWorld;
+      const screenY = this.transformHandler.worldToScreenCoordinates(
+        new Cell(mapLeftWorld, worldY),
+      ).y;
+      if (screenY < -1 || screenY > canvasHeight + 1) continue;
+      const screenRight = this.transformHandler.worldToScreenCoordinates(
+        new Cell(gridWidth, worldY),
+      ).x;
+      context.moveTo(mapLeftScreen, screenY);
+      context.lineTo(screenRight, screenY);
+    }
+    // Final horizontal line at map bottom edge only if grid fits perfectly
+    if (!hasExtraRow) {
+      const mapBottomLine = this.transformHandler.worldToScreenCoordinates(
+        new Cell(mapLeftWorld, gridHeight),
+      ).y;
+      context.moveTo(mapLeftScreen, mapBottomLine);
+      context.lineTo(
+        this.transformHandler.worldToScreenCoordinates(
+          new Cell(gridWidth, gridHeight),
+        ).x,
+        mapBottomLine,
+      );
+    }
+
+    context.stroke();
+
+    context.font = "12px monospace";
+
+    const drawLabel = (text: string, x: number, y: number) => {
+      context.textAlign = "left";
+      context.textBaseline = "top";
+      context.fillStyle = "rgba(20, 20, 20, 0.9)";
+      context.fillText(text, x, y);
+    };
+
+    // Render per-cell labels (like A1, B1, etc.) at cell top-left
+    const fontSize = Math.min(
+      16,
+      Math.max(9, 10 + (this.transformHandler.scale - 1) * 1.2),
+    );
+    context.font = `${fontSize}px monospace`;
+    for (let row = 0; row < rows; row++) {
+      const rowLabel = toAlphaLabel(row);
+      const startY = row * cellHeight;
+      const rowHeight = row < fullRows ? cellHeight : lastRowHeight;
+      const centerY = startY + rowHeight / 2;
+      const screenY = this.transformHandler.worldToScreenCoordinates(
+        new Cell(0, centerY),
+      ).y;
+      if (screenY < -LABEL_PADDING || screenY > canvasHeight + LABEL_PADDING)
+        continue;
+
+      for (let col = 0; col < cols; col++) {
+        const startX = col * cellWidth;
+        const colWidth = col < fullCols ? cellWidth : lastColWidth;
+        const centerX = startX + colWidth / 2;
+        const screenX = this.transformHandler.worldToScreenCoordinates(
+          new Cell(centerX, centerY),
+        ).x;
+        if (screenX < -LABEL_PADDING || screenX > canvasWidth + LABEL_PADDING)
+          continue;
+
+        // Position at cell top-left in screen space
+        const cellTopLeft = this.transformHandler.worldToScreenCoordinates(
+          new Cell(startX, startY),
+        );
+        drawLabel(
+          `${rowLabel}${col + 1}`,
+          cellTopLeft.x + LABEL_PADDING,
+          cellTopLeft.y + LABEL_PADDING,
+        );
+      }
+    }
+
+    context.restore();
+  }
+}

src/client/graphics/layers/SettingsModal.ts

@@ -13,6 +13,7 @@ import darkModeIcon from "/images/DarkModeIconWhite.svg?url";
 import emojiIcon from "/images/EmojiIconWhite.svg?url";
 import exitIcon from "/images/ExitIconWhite.svg?url";
 import explosionIcon from "/images/ExplosionIconWhite.svg?url";
+import gridIcon from "/images/GridIconWhite.svg?url";
 import mouseIcon from "/images/MouseIconWhite.svg?url";
 import ninjaIcon from "/images/NinjaIconWhite.svg?url";
 import settingsIcon from "/images/SettingIconWhite.svg?url";
@@ -120,6 +121,11 @@ export class SettingsModal extends LitElement implements Layer {
     this.requestUpdate();
   }
 
+  private onToggleCoordinateGridButtonClick() {
+    this.userSettings.toggleCoordinateGrid();
+    this.requestUpdate();
+  }
+
   private onToggleStructureSpritesButtonClick() {
     this.userSettings.toggleStructureSprites();
     this.requestUpdate();
@@ -286,6 +292,26 @@ export class SettingsModal extends LitElement implements Layer {
               </div>
             </button>
 
+            <button
+              class="flex gap-3 items-center w-full text-left p-3 hover:bg-slate-700 rounded-sm text-white transition-colors"
+              @click="${this.onToggleCoordinateGridButtonClick}"
+            >
+              <img src=${gridIcon} alt="gridIcon" width="20" height="20" />
+              <div class="flex-1">
+                <div class="font-medium">
+                  ${translateText("user_setting.coordinate_grid_label")}
+                </div>
+                <div class="text-sm text-slate-400">
+                  ${translateText("user_setting.coordinate_grid_desc")}
+                </div>
+              </div>
+              <div class="text-sm text-slate-400">
+                ${this.userSettings.coordinateGridEnabled()
+                  ? translateText("user_setting.on")
+                  : translateText("user_setting.off")}
+              </div>
+            </button>
+
             <button
               class="flex gap-3 items-center w-full text-left p-3 hover:bg-slate-700 rounded-sm text-white transition-colors"
               @click="${this.onToggleEmojisButtonClick}"

src/core/game/UserSettings.ts

@@ -73,6 +73,10 @@ export class UserSettings {
     return this.get("settings.territoryPatterns", true);
   }
 
+  coordinateGridEnabled() {
+    return this.get("settings.coordinateGridEnabled", true);
+  }
+
   cursorCostLabel() {
     const legacy = this.get("settings.ghostPricePill", true);
     return this.get("settings.cursorCostLabel", legacy);
@@ -128,6 +132,10 @@ export class UserSettings {
     this.set("settings.territoryPatterns", !this.territoryPatterns());
   }
 
+  toggleCoordinateGrid() {
+    this.set("settings.coordinateGridEnabled", !this.coordinateGridEnabled());
+  }
+
   toggleDarkMode() {
     this.set("settings.darkMode", !this.darkMode());
     if (this.darkMode()) {