feat(dl-asset): add downloadCanvas()

packages/dl-asset/package.json

@@ -64,6 +64,9 @@
         "./api": {
             "import": "./api.js"
         },
+        "./canvas": {
+            "import": "./canvas.js"
+        },
         "./download": {
             "import": "./download.js"
         },

packages/dl-asset/src/canvas.ts

@@ -0,0 +1,28 @@
+import { downloadWithMime } from "./raw.js";
+
+/**
+ * Triggers canvas-to-blob conversion for given file type (and opt. `quality`),
+ * then triggers download via {@link downloadWithMime}. Default file type is
+ * `png`. Default quality is 0.95 (only used for JPEG/WebP).
+ *
+ * @param canvas
+ * @param baseName
+ * @param type
+ * @param quality
+ */
+export const downloadCanvas = (
+    canvas: HTMLCanvasElement,
+    baseName: string,
+    type: "png" | "jpeg" | "webp" = "png",
+    quality = 0.95
+) => {
+    const mime = `image/${type}`;
+    canvas.toBlob(
+        (blob) =>
+            blob
+                ? downloadWithMime(`${baseName}.${type}`, blob, { mime })
+                : console.warn("can't download canvas"),
+        mime,
+        quality
+    );
+};

packages/dl-asset/src/index.ts

@@ -1,3 +1,4 @@
 export * from "./api.js";
+export * from "./canvas.js";
 export * from "./download.js";
 export * from "./raw.js";