update game engine

app/nose/bin/game.tsx

@@ -3,8 +3,7 @@
 
 export const game = true
 
-import type { InputState } from "@/shared/types"
-import type { GameContext } from "@/shared/game"
+import type { GameContext, InputState } from "@/shared/game"
 import { rng } from "@/shared/utils.ts"
 
 const WIDTH = 960

app/src/shared/game.ts

@@ -1,14 +1,37 @@
+export type InputState = { key: string, shift: boolean, ctrl: boolean, meta: boolean, pressed: Set<string> }
 
 export class GameContext {
   constructor(public ctx: CanvasRenderingContext2D) { }
 
-  get width() { return this.ctx.canvas.width }
-  get height() { return this.ctx.canvas.height }
+  width = 960
+  height = 540
 
   clear() {
     this.ctx.clearRect(0, 0, this.ctx.canvas.width, this.ctx.canvas.height)
   }
 
+  text(msg: string, x: number, y: number, color = "black", size = 16, font = "monospace") {
+    const c = this.ctx
+    c.save()
+    c.fillStyle = color
+    c.font = `${size}px ${font}`
+    c.textBaseline = "top"
+    c.fillText(msg, x, y)
+    c.restore()
+  }
+
+  centerText(msg: string, y: number, color = "black", size = 16, font = "monospace") {
+    const c = this.ctx
+    c.save()
+    c.fillStyle = color
+    c.font = `${size}px ${font}`
+    c.textBaseline = "middle"
+    const metrics = c.measureText(msg)
+    const x = (this.width - metrics.width) / 2
+    c.fillText(msg, x, y)
+    c.restore()
+  }
+
   circ(x: number, y: number, r: number, color = "black") {
     const c = this.ctx
     c.save()

app/src/shared/types.ts

@@ -15,5 +15,3 @@ export type CommandResult = {
     status: "ok" | "error"
     output: CommandOutput
 }
-
-export type InputState = { key: string, shift: boolean, ctrl: boolean, meta: boolean, pressed: Set<string> }