From 7013aef2861b080710efb17bb4ed4ce019d92a8c Mon Sep 17 00:00:00 2001
From: Christian Pauly <christian-pauly@posteo.de>
Date: Thu, 14 Apr 2022 10:37:56 +0200
Subject: [PATCH] feat: Faster image resizing

---
 lib/utils/client_manager.dart       |  2 +
 lib/utils/custom_image_resizer.dart | 63 +++++++++++++++++++++++++++++
 pubspec.lock                        |  9 +++++
 pubspec.yaml                        |  2 +
 4 files changed, 76 insertions(+)
 create mode 100644 lib/utils/custom_image_resizer.dart

diff --git a/lib/utils/client_manager.dart b/lib/utils/client_manager.dart
index 1e9e0cf9..5dc0c5ac 100644
--- a/lib/utils/client_manager.dart
+++ b/lib/utils/client_manager.dart
@@ -7,6 +7,7 @@ import 'package:matrix/encryption/utils/key_verification.dart';
 import 'package:matrix/matrix.dart';
 import 'package:path_provider/path_provider.dart';
 
+import 'package:fluffychat/utils/custom_image_resizer.dart';
 import 'package:fluffychat/utils/platform_infos.dart';
 import 'famedlysdk_store.dart';
 import 'matrix_sdk_extensions.dart/fluffybox_database.dart';
@@ -99,5 +100,6 @@ abstract class ClientManager {
             AuthenticationTypes.sso
         },
         compute: compute,
+        customImageResizer: PlatformInfos.isMobile ? customImageResizer : null,
       );
 }
diff --git a/lib/utils/custom_image_resizer.dart b/lib/utils/custom_image_resizer.dart
new file mode 100644
index 00000000..677d7e8e
--- /dev/null
+++ b/lib/utils/custom_image_resizer.dart
@@ -0,0 +1,63 @@
+import 'dart:typed_data';
+import 'dart:ui';
+
+import 'package:matrix/matrix.dart';
+import 'package:native_imaging/native_imaging.dart' as native;
+
+Future<MatrixImageFileResizedResponse?> customImageResizer(
+    MatrixImageFileResizeArguments arguments) async {
+  await native.init();
+  late native.Image nativeImg;
+
+  try {
+    nativeImg = await native.Image.loadEncoded(arguments.bytes); // load on web
+  } on UnsupportedError {
+    try {
+      // for the other platforms
+      final dartCodec = await instantiateImageCodec(arguments.bytes);
+      final dartFrame = await dartCodec.getNextFrame();
+      final rgbaData = await dartFrame.image.toByteData();
+      if (rgbaData == null) {
+        return null;
+      }
+      final rgba = Uint8List.view(
+          rgbaData.buffer, rgbaData.offsetInBytes, rgbaData.lengthInBytes);
+
+      final width = dartFrame.image.width;
+      final height = dartFrame.image.height;
+
+      dartFrame.image.dispose();
+      dartCodec.dispose();
+
+      nativeImg = native.Image.fromRGBA(width, height, rgba);
+    } catch (e, s) {
+      Logs().e("Could not generate preview", e, s);
+      rethrow;
+    }
+  }
+
+  final width = nativeImg.width;
+  final height = nativeImg.height;
+
+  final max = arguments.maxDimension;
+  if (width > max || height > max) {
+    var w = max, h = max;
+    if (width > height) {
+      h = max * height ~/ width;
+    } else {
+      w = max * width ~/ height;
+    }
+
+    final scaledImg = nativeImg.resample(w, h, native.Transform.lanczos);
+    nativeImg.free();
+    nativeImg = scaledImg;
+  }
+  final jpegBytes = await nativeImg.toJpeg(75);
+
+  return MatrixImageFileResizedResponse(
+    bytes: jpegBytes,
+    width: nativeImg.width,
+    height: nativeImg.height,
+    blurhash: arguments.calcBlurhash ? nativeImg.toBlurhash(3, 3) : null,
+  );
+}
diff --git a/pubspec.lock b/pubspec.lock
index 37036074..cba62a45 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1047,6 +1047,15 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.0.2"
+  native_imaging:
+    dependency: "direct main"
+    description:
+      path: "."
+      ref: HEAD
+      resolved-ref: "8c6a5afe2c965b79b5959bb4b49c4aad020cb980"
+      url: "https://gitlab.com/famedly/company/frontend/libraries/native_imaging.git"
+    source: git
+    version: "0.1.0"
   nested:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index 8e2e8750..f4a9a10b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -60,6 +60,8 @@ dependencies:
   lottie: ^1.2.2
   matrix: ^0.8.18
   matrix_link_text: ^1.0.2
+  native_imaging:
+    git: https://gitlab.com/famedly/company/frontend/libraries/native_imaging.git
   open_noti_settings: ^0.4.0
   package_info_plus: ^1.3.0
   path_provider: ^2.0.9