feat: add Position utility for alignment

src/utils/Position.ts

@@ -0,0 +1,73 @@
+import Game from "@/core/Game";
+
+type HorizontalAlign = "left" | "center" | "right" | number;
+type VerticalAlign = "top" | "center" | "bottom" | number;
+
+interface PositionOptions {
+  x?: number;
+  y?: number;
+}
+
+class Position {
+  private game: Game;
+
+  constructor() {
+    this.game = Game.getInstance();
+  }
+
+  get(
+    hAlign: HorizontalAlign,
+    vAlign: VerticalAlign,
+    options?: PositionOptions
+  ): { x: number; y: number } {
+    const { width, height } = this.game.getInfo();
+
+    let x: number;
+    let y: number;
+
+    // 水平对齐
+    if (hAlign === "left") {
+      x = 0;
+    } else if (hAlign === "center") {
+      x = width / 2;
+    } else if (hAlign === "right") {
+      x = width;
+    } else {
+      x = hAlign;
+    }
+
+    // 垂直对齐
+    if (vAlign === "top") {
+      y = 0;
+    } else if (vAlign === "center") {
+      y = height / 2;
+    } else if (vAlign === "bottom") {
+      y = height;
+    } else {
+      y = vAlign;
+    }
+
+    // 添加偏移
+    if (options) {
+      x += options.x ?? 0;
+      y += options.y ?? 0;
+    }
+
+    return { x, y };
+  }
+
+  center(options?: PositionOptions): { x: number; y: number } {
+    return this.get("center", "center", options);
+  }
+
+  centerX(y: VerticalAlign, options?: PositionOptions): { x: number; y: number } {
+    return this.get("center", y, options);
+  }
+
+  centerY(x: HorizontalAlign, options?: PositionOptions): { x: number; y: number } {
+    return this.get(x, "center", options);
+  }
+}
+
+export const position = new Position();
+export default position;