From 43ecff853ea99c756a721e0fecafbe62a9dd31c1 Mon Sep 17 00:00:00 2001
From: Pihkaal <pihkaal@proton.me>
Date: Sat, 12 Oct 2024 18:44:12 +0200
Subject: [PATCH] refactor(renderer): create canvas in renderer

---
 app.vue             |  6 ++---
 server/api/index.ts |  6 ++---
 utils/renderer.ts   | 59 ++++++++++++++++++++++++---------------------
 3 files changed, 35 insertions(+), 36 deletions(-)

diff --git a/app.vue b/app.vue
index 744edf9..bfc994f 100644
--- a/app.vue
+++ b/app.vue
@@ -2,7 +2,6 @@
 import { renderQRCodeToCanvas } from "@/utils/renderer";
 import { IMAGE_FORMATS, LOGOS } from "@/utils/settings";
 
-const canvas = ref(null);
 const form = ref(null);
 const qrCode = ref(undefined);
 
@@ -49,9 +48,9 @@ const updateQRCode = async () => {
   if (!isValidState.value) return;
 
   const logoUrl = state.hasLogo ? `/logos/${state.logo}.png` : undefined;
-  await renderQRCodeToCanvas(canvas.value, state.content, logoUrl);
+  const canvas = await renderQRCodeToCanvas(state.content, logoUrl);
 
-  qrCode.value = canvas.value.toDataURL(`image/${state.format}`);
+  qrCode.value = canvas.toDataURL(`image/${state.format}`);
 };
 
 const copyUrl = async () => {
@@ -106,7 +105,6 @@ const arrayToUnion = (array: string[]) =>
 <template>
   <div role="main" class="flex h-[100vh] items-center justify-center">
     <NuxtRouteAnnouncer />
-    <canvas ref="canvas" class="hidden" />
 
     <div
       class="p-5 w-full max-w-[850px] flex flex-col justify-center space-y-4"
diff --git a/server/api/index.ts b/server/api/index.ts
index 14f0079..942b8d4 100644
--- a/server/api/index.ts
+++ b/server/api/index.ts
@@ -1,7 +1,6 @@
-import { createCanvas } from "canvas";
 import { resolve } from "path";
 import sharp from "sharp";
-import { CANVAS_SIZE, renderQRCodeToCanvas } from "~/utils/renderer";
+import { renderQRCodeToCanvas } from "~/utils/renderer";
 import { settingsSchema } from "~/utils/settings";
 
 export default defineEventHandler(async (event) => {
@@ -21,9 +20,8 @@ export default defineEventHandler(async (event) => {
 
   const { format, logo, content } = parsed.data;
 
-  const canvas = createCanvas(CANVAS_SIZE, CANVAS_SIZE);
   const logoUrl = logo ? resolve("public", `logos/${logo}.png`) : undefined;
-  await renderQRCodeToCanvas(canvas, content, logoUrl);
+  const canvas = await renderQRCodeToCanvas(content, logoUrl);
 
   let image = canvas.toBuffer();
   if (format !== "png") {
diff --git a/utils/renderer.ts b/utils/renderer.ts
index 0d2ef4b..ad061c3 100644
--- a/utils/renderer.ts
+++ b/utils/renderer.ts
@@ -1,47 +1,50 @@
-import { loadImage, type Canvas, type CanvasRenderingContext2D } from "canvas";
+import { createCanvas, loadImage } from "canvas";
 import QRCode from "qrcode";
 
-export const CANVAS_SIZE = 1000;
-export const LOGO_PADDING = 1;
+const CANVAS_SIZE = 1000;
+const LOGO_PADDING = 1;
 
 export const renderQRCodeToCanvas = async (
-  canvas: HTMLCanvasElement | Canvas,
   content: string,
   logoUrl: string | undefined,
 ) => {
+  const canvas = createCanvas(CANVAS_SIZE, CANVAS_SIZE);
+
   await QRCode.toCanvas(canvas, content, {
     errorCorrectionLevel: "H",
     width: CANVAS_SIZE,
     margin: 1,
   });
 
-  if (logoUrl) {
-    const qrCode = QRCode.create(content, { errorCorrectionLevel: "H" });
-    const moduleCount = qrCode.modules.size + 2;
+  if (!logoUrl) return canvas;
 
-    const logoImage = await loadImage(logoUrl);
+  const qrCode = QRCode.create(content, { errorCorrectionLevel: "H" });
+  const moduleCount = qrCode.modules.size + 2;
 
-    const moduleSize = CANVAS_SIZE / moduleCount;
+  const logoImage = await loadImage(logoUrl);
 
-    let logoModules = Math.floor(moduleCount * 0.3);
-    if (logoModules % 2 !== moduleCount % 2) {
-      logoModules += 1;
-    }
+  const moduleSize = CANVAS_SIZE / moduleCount;
 
-    const backgroundSize = logoModules * moduleSize + 1;
-    const backgroundPosition = (moduleSize * (moduleCount - logoModules)) / 2;
-
-    const logoSize = backgroundSize - LOGO_PADDING * 2;
-    const logoPosition = backgroundPosition + LOGO_PADDING;
-
-    const ctx = canvas.getContext("2d") as CanvasRenderingContext2D;
-    ctx.fillStyle = "white";
-    ctx.fillRect(
-      backgroundPosition,
-      backgroundPosition,
-      backgroundSize,
-      backgroundSize,
-    );
-    ctx.drawImage(logoImage, logoPosition, logoPosition, logoSize, logoSize);
+  let logoModules = Math.floor(moduleCount * 0.3);
+  if (logoModules % 2 !== moduleCount % 2) {
+    logoModules += 1;
   }
+
+  const backgroundSize = logoModules * moduleSize + 1;
+  const backgroundPosition = (moduleSize * (moduleCount - logoModules)) / 2;
+
+  const logoSize = backgroundSize - LOGO_PADDING * 2;
+  const logoPosition = backgroundPosition + LOGO_PADDING;
+
+  const ctx = canvas.getContext("2d");
+  ctx.fillStyle = "white";
+  ctx.fillRect(
+    backgroundPosition,
+    backgroundPosition,
+    backgroundSize,
+    backgroundSize,
+  );
+  ctx.drawImage(logoImage, logoPosition, logoPosition, logoSize, logoSize);
+
+  return canvas;
 };