Move immutable parts of EntityContext into a new EntityView class

1 files changed, 62 insertions, 25 deletions

diff --git a/src/view/entity.ts b/src/view/entity.ts
index 3b30e3c..ec91503 100644
--- a/src/view/entity.ts
+++ b/src/view/entity.ts
@@ -3,33 +3,70 @@ import { Renderer } from './renderer/renderer';
 import { SpriteCoords, SpriteView, SpriteViewBuilder } from './sprite';
 import { loadImage, mkTexture } from './util/image';
 
+import { getJSON } from '../util';
+
 import { vec2 } from 'gl-matrix';
 
-export async function loadEntity(
-	r: Renderer,
-	data: EntityData,
-): Promise<SpriteView[]> {
-	const tile = await loadImage(`resources/sprite/entity/${data.sprite}.png`);
-	const [texture, size] = mkTexture(r, tile);
-	const frameSize = [size[0], size[1] / data.frames];
-
-	const offset = vec2.mul(vec2.create(), frameSize, data.anchor);
-	r.snapToGrid(offset, offset);
-
-	const coords: SpriteCoords = [
-		-offset[0],
-		-offset[1],
-		-offset[0] + frameSize[0],
-		-offset[1] + frameSize[1],
-	];
-
-	const sprites: SpriteView[] = [];
-
-	for (let frame = 0; frame < data.frames; frame++) {
-		const builder = new SpriteViewBuilder(r, texture);
-		builder.addSprite(coords, [0, frame / data.frames, 1, (frame + 1) / data.frames]);
-		sprites.push(builder.build());
+export class EntityView {
+	public static async load(r: Renderer, name: string): Promise<EntityView> {
+		const data = new EntityData(await getJSON(`resources/entity/${name}.json`));
+		const tile = await loadImage(`resources/sprite/entity/${data.sprite}.png`);
+
+		const [texture, size] = mkTexture(r, tile);
+		const frameSize = [size[0], size[1] / data.frames];
+
+		const offset = vec2.mul(vec2.create(), frameSize, data.anchor);
+		r.snapToGrid(offset, offset);
+
+		const coords: SpriteCoords = [
+			-offset[0],
+			-offset[1],
+			-offset[0] + frameSize[0],
+			-offset[1] + frameSize[1],
+		];
+
+		const sprites: SpriteView[] = [];
+
+		for (let frame = 0; frame < data.frames; frame++) {
+			const builder = new SpriteViewBuilder(r, texture);
+			builder.addSprite(coords, [0, frame / data.frames, 1, (frame + 1) / data.frames]);
+			sprites.push(builder.build());
+		}
+
+		return new EntityView(
+			data,
+			sprites,
+		);
+	}
+
+	private readonly totalTime: number;
+
+	private constructor(
+		public readonly data: EntityData,
+		public readonly sprites: SpriteView[],
+	) {
+		if (data.animation)
+			this.totalTime = data.animation.sequence.reduce((a, s) => a + s[0], 0);
+		else
+			this.totalTime = 0;
+	}
+
+	public getSpriteByTime(time: number): SpriteView {
+		time %= this.totalTime;
+
+		if (this.data.animation) {
+			for (const [len, sprite] of this.data.animation.sequence) {
+				time -= len;
+				if (time < 0)
+					return this.sprites[sprite];
+			}
+		}
+
+		return this.sprites[0];
+	}
+
+	public renderByTime(time: number) {
+		this.getSpriteByTime(time).render();
 	}
 
-	return sprites;
 }