Canvas rendering system

src/common/rpg/systems/render/canvas.ts

@@ -0,0 +1,61 @@
+import { BrickDisplay, BrickDisplayImage } from "@common/display/brick";
+import { createCanvas } from "@common/display/canvas";
+import { Position } from "@common/rpg/components/position";
+import { BrickSprite } from "@common/rpg/components/render/brick";
+import { Hidden, Sprite } from "@common/rpg/components/sprite";
+import { System, World } from "@common/rpg/core/world";
+import { Resources } from "@common/rpg/utils/resources";
+
+export class CanvasDisplaySystem extends System {
+    public readonly canvas: HTMLCanvasElement;
+    public readonly ctx: CanvasRenderingContext2D;
+
+    constructor();
+    constructor(canvas: HTMLCanvasElement);
+    constructor(width: number, height: number);
+    constructor(canvasOrWidth?: HTMLCanvasElement | number, height?: number) {
+        super();
+        const width = typeof canvasOrWidth === 'number' ? canvasOrWidth : undefined;
+        let canvas = canvasOrWidth instanceof HTMLCanvasElement ? canvasOrWidth : undefined;
+        if (canvas == null) {
+            if (width == null || height == null) {
+                throw new Error('Canvas or width/height must be provided');
+            }
+            canvas = createCanvas(width, height);
+        }
+        this.canvas = canvas;
+        const ctx = canvas.getContext('2d');
+        if (ctx == null) {
+            throw new Error('Could not create canvas context');
+        }
+        this.ctx = ctx;
+    }
+
+    override update(world: World) {
+        const sprites = Array.from(world.query(Sprite, Position)).sort((a, b) => a[2].state.z - b[2].state.z);
+        for (const [e, sprite, pos] of sprites) {
+            if (e.has(Hidden)) continue;
+
+            const { x, y } = pos.state;
+            const imageId = sprite.image;
+
+            const image: CanvasImageSource | undefined =
+                Resources.get(HTMLImageElement, imageId)
+                ?? Resources.get(HTMLVideoElement, imageId)
+                ?? Resources.get(HTMLCanvasElement, imageId)
+                ?? Resources.get(SVGImageElement, imageId)
+                ?? Resources.get(ImageBitmap, imageId)
+                ?? Resources.get(OffscreenCanvas, imageId)
+                ?? Resources.get(VideoFrame, imageId)
+
+            const data = Resources.get(ImageData, imageId);
+            if (image) {
+                this.ctx.drawImage(image, x, y);
+            } else if (data) {
+                this.ctx.putImageData(data, x, y);
+            } else {
+                throw new Error(`No image data found for id ${imageId}`);
+            }
+        }
+    }
+}