⚡ postpone update to next microtask

src/nodes/Canvas2d/Canvas2d.js

@@ -12,6 +12,12 @@ export default class Canvas2d extends Node {
             Object.assign({
                 image: {
                     type: 'Image',
+                },
+                width: {
+                    type: 'Number',
+                },
+                height: {
+                    type: 'Number',
                 }
             }, outputDefiniton),
             options
@@ -19,7 +25,7 @@ export default class Canvas2d extends Node {
         this.__canvas = document.createElement('canvas');
     }
 
-    async __update() {
+    async _update() {
         const values = {};
         for (let name of Object.keys(this.in.variables)) {
             values[name] = await waitForMedia(this.in[name].value);
@@ -28,7 +34,12 @@ export default class Canvas2d extends Node {
         if (this.__canvas.width > 0 && this.__canvas.height > 0) {
             ctx.clearRect(0,0,this.__canvas.width, this.__canvas.height);
         }
-        await this.render(values, this.__canvas, ctx);
+        const result = await this.render(values, this.__canvas, ctx);
+        if (result instanceof ImageBitmap) {
+            this.__out.image.value = result;
+            this.out.width.value = this.out.image.value.width;
+            this.out.height.value = this.out.image.value.height;
+        }
     }
 
 
@@ -37,8 +48,9 @@ export default class Canvas2d extends Node {
      * @param {any} values
      * @param {HTMLCanvasElement} canvas
      * @param {CanvasRenderingContext2D} ctx
+     * @returns {Promise<ImageBitmap|null>}
      */
     async render(values, canvas, ctx) {
-
+        return null;
     }
 }