picaを使用しないようにして、iOSでの処理の分岐をやめた

package.json

@@ -38,7 +38,6 @@
     "highlight.js": "^11.10.0",
     "idb-keyval": "^6.2.0",
     "mitt": "^3.0.0",
-    "pica": "^9.0.1",
     "skyway-js": "^4.4.5",
     "text-field-edit": "^3.2.0",
     "throttle-debounce": "^5.0.2",
@@ -59,7 +58,6 @@
     "@types/katex": "^0.16.7",
     "@types/markdown-it": "^12.2.3",
     "@types/node": "^20.14.10",
-    "@types/pica": "^9.0.4",
     "@types/punycode": "^2.1.4",
     "@types/serviceworker": "^0.0.99",
     "@types/throttle-debounce": "^5.0.2",

src/lib/resize/canvas.ts

@@ -22,7 +22,9 @@ export const resetCanvas = (
   $canvas.width = width
   $canvas.height = height
   if ($img) {
-    $canvas.getContext('2d')?.drawImage($img, 0, 0)
+    $canvas
+      .getContext('2d')
+      ?.drawImage($img, 0, 0, $canvas.width, $canvas.height)
   }
 }
 

src/lib/resize/index.ts

@@ -1,40 +1,21 @@
-import { loadPica } from './pica'
 import { deleteCanvas, loadImage, resetCanvas } from './canvas'
-import type { Dimensions } from './size'
 import { needResize, getThumbnailDimensions } from './size'
-import { isIOS } from '/@/lib/dom/browser'
 import { mimeToFileType } from '/@/lib/basic/file'
-import { createMutex } from '/@/lib/basic/async'
-
-const mutex = createMutex()
 
 export const canResize = (mime: string) =>
   ['image/png', 'image/jpeg'].includes(mime)
 export const isJpeg = (mime: string) => mime === 'image/jpeg'
 
-const iOSFlag = isIOS()
-// iOSではcanvasサイズの上限が決まっているため
-// Canvas area exceeds the maximum limit (width * height > 16777216).
-const cannotResizeWhenIOS = ({ width, height }: Readonly<Dimensions>) =>
-  iOSFlag && width * height > 16777216
-
 const resize = async (
   inputFile: Readonly<File>
 ): Promise<File | 'cannot resize' | 'error' | null> => {
-  // picaでは一つの画像を並列で処理するため、複数の画像を同時に処理しないようにする
-  await mutex.lock()
-
   const inputUrl = URL.createObjectURL(inputFile as File)
 
-  const pica = await loadPica()
   const $input = document.createElement('canvas')
-  const $output = document.createElement('canvas')
 
   const finish = <T>(result: T) => {
     deleteCanvas($input)
-    deleteCanvas($output)
     URL.revokeObjectURL(inputUrl)
-    mutex.unlock()
     return result
   }
 
@@ -48,19 +29,16 @@ const resize = async (
       return finish(null)
     }
 
-    if (cannotResizeWhenIOS(inputSize)) {
-      return finish('cannot resize')
-    }
-
-    resetCanvas($input, inputSize, $img)
+    resetCanvas($input, getThumbnailDimensions(inputSize), $img)
 
-    const outputSize = getThumbnailDimensions(inputSize)
-    resetCanvas($output, outputSize)
-    await pica.resize($input, $output, {
-      filter: 'mks2013'
+    const output = await await new Promise<Blob | null>(resolve => {
+      $input.toBlob(resolve, inputFile.type)
     })
 
-    const output = await pica.toBlob($output, inputFile.type)
+    if (output === null) {
+      return finish('cannot resize')
+    }
+
     const outputFile = new File([output], inputFile.name, {
       type: inputFile.type,
       lastModified: inputFile.lastModified
@@ -81,7 +59,7 @@ const tooLargeFileMessage =
   window.traQConfig.tooLargeFileMessage ??
   '大きい%sの共有には別のサービスを利用してください。'
 
-const IMAGE_MAX_SIZE_EXCEEDED_MESSAGE = `画像サイズは20MBまでです\n${tooLargeFileMessage.replace(
+const IMAGE_MAX_SIZE_EXCEEDED_MESSAGE = `リサイズ後の画像サイズが20MBを超えています\n${tooLargeFileMessage.replace(
   '%s',
   '画像'
 )}`
@@ -93,10 +71,7 @@ const FILE_MAX_SIZE_EXCEEDED_MESSAGE = `ファイルサイズは30MBまでです
 export const getResizedFile = async (file: File) => {
   const fileType = mimeToFileType(file.type)
 
-  if (fileType === 'image' && file.size > IMAGE_SIZE_LIMIT) {
-    throw new Error(IMAGE_MAX_SIZE_EXCEEDED_MESSAGE)
-  }
-  if (file.size > FILE_SIZE_LIMIT) {
+  if (fileType !== 'image' && file.size > FILE_SIZE_LIMIT) {
     throw new Error(FILE_MAX_SIZE_EXCEEDED_MESSAGE)
   }
 
@@ -110,11 +85,18 @@ export const getResizedFile = async (file: File) => {
   }
 
   const res = await resize(file)
+
   if (res === 'cannot resize') {
-    throw new Error('画像が大きいためサムネイルは生成されません')
+    throw new Error('画像のリサイズに失敗しました')
   }
   if (res === 'error') {
     throw new Error('画像の形式が不正なためサムネイルは生成されません')
   }
-  return res ?? file
+  if (res === null) {
+    return file
+  }
+  if (res.size > IMAGE_SIZE_LIMIT) {
+    throw new Error(IMAGE_MAX_SIZE_EXCEEDED_MESSAGE)
+  }
+  return res
 }