improve some drawing

src/richtext.ts

@@ -0,0 +1,25 @@
+// type RichnessNodeDefinition<N extends {type: string}> = {
+// 	type: N["type"]
+// 	measure(context: CanvasRenderingContext2D, node: N): Promise<TextMetrics>;
+// 	render(
+// 		context: CanvasRenderingContext2D,
+// 		node: N,
+// 		x: number,
+// 		y: number
+// 	): Promise<void>;
+// };
+
+// type Richness<N extends {type: string}> = {[K in N["type"]]: RichnessNodeDefinition<N & {type: K}>}
+
+// const drawRichText = <N extends {type: string}>(
+// 	context: CanvasRenderingContext2D,
+// 	richness: Richness<N>,
+// 	richText: N[],
+// 	x: number,
+// 	y: number,
+// 	maxWidth: number,
+// ) => {
+// 	context.save();
+// 	const
+// 	context.restore();
+// };