fluffychat/lib/utils/custom_image_resizer.dart
2022-04-14 11:31:48 +02:00

64 lines
1.8 KiB
Dart

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,
);
}