Change orientation of an image in editor

app/lib/l10n/app_en.arb

@@ -1326,6 +1326,26 @@
 	"@imageEditTitle": {
 		"description": "Title of the image editor"
 	},
+	"imageEditToolbarColorLabel": "Color",
+	"@imageEditToolbarColorLabel": {
+		"description": "Label of the color tools. These can be used to adjust the color of an image"
+	},
+	"imageEditToolbarTransformLabel": "Transform",
+	"@imageEditToolbarTransformLabel": {
+		"description": "Label of the transformation tools. These can be used to transform an image, e.g., rotate it"
+	},
+	"imageEditTransformOrientation": "Orientation",
+	"@imageEditTransformOrientation": {
+		"description": "Change the orientation of the image, 90 degree per step"
+	},
+	"imageEditTransformOrientationClockwise": "cw",
+	"@imageEditTransformOrientationClockwise": {
+		"description": "Indicate a clockwise rotation. This text must be short as there's only minimal space"
+	},
+	"imageEditTransformOrientationCounterclockwise": "ccw",
+	"@imageEditTransformOrientationCounterclockwise": {
+		"description": "Indicate a counterclockwise rotation. This text must be short as there's only minimal space"
+	},
 	"categoriesLabel": "Categories",
 	"searchLandingPeopleListEmptyText": "Press help to learn how to setup",
 	"@searchLandingPeopleListEmptyText": {
@@ -1414,6 +1434,7 @@
 	"@collectionPlacesLabel": {
 		"description": "Browse photos grouped by place"
 	},
+
 	"errorUnauthenticated": "Unauthenticated access. Please sign-in again if the problem continues",
 	"@errorUnauthenticated": {
 		"description": "Error message when server responds with HTTP401"

app/lib/l10n/untranslated-messages.txt

@@ -129,6 +129,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -298,6 +303,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -348,6 +358,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -379,6 +394,11 @@
     "settingsMemoriesRangeTitle",
     "settingsMemoriesRangeValueText",
     "rootPickerSkipConfirmationDialogContent2",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "showAllButtonLabel",
     "gpsPlaceText",
     "gpsPlaceAboutDialogTitle",
@@ -391,6 +411,11 @@
     "settingsPhotosPageTitle",
     "settingsMemoriesRangeTitle",
     "settingsMemoriesRangeValueText",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "gpsPlaceText",
     "gpsPlaceAboutDialogTitle",
     "gpsPlaceAboutDialogContent",
@@ -447,6 +472,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -538,6 +568,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -608,6 +643,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -678,6 +718,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -748,6 +793,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",
@@ -818,6 +868,11 @@
     "imageEditColorWarmth",
     "imageEditColorTint",
     "imageEditTitle",
+    "imageEditToolbarColorLabel",
+    "imageEditToolbarTransformLabel",
+    "imageEditTransformOrientation",
+    "imageEditTransformOrientationClockwise",
+    "imageEditTransformOrientationCounterclockwise",
     "categoriesLabel",
     "searchLandingPeopleListEmptyText",
     "searchLandingCategoryVideosLabel",

app/lib/widget/image_editor.dart

@@ -15,6 +15,7 @@ import 'package:nc_photos/theme.dart';
 import 'package:nc_photos/url_launcher_util.dart';
 import 'package:nc_photos/widget/handler/permission_handler.dart';
 import 'package:nc_photos/widget/image_editor/color_toolbar.dart';
+import 'package:nc_photos/widget/image_editor/transform_toolbar.dart';
 import 'package:nc_photos_plugin/nc_photos_plugin.dart';
 
 class ImageEditorArguments {
@@ -120,13 +121,24 @@ class _ImageEditorState extends State<ImageEditor> {
                     )
                   : Container(),
             ),
-            ColorToolbar(
+            if (_activeTool == _ToolType.color)
-              initialState: _colorFilters,
+              ColorToolbar(
-              onActiveFiltersChanged: (colorFilters) {
+                initialState: _colorFilters,
-                _colorFilters = colorFilters.toList();
+                onActiveFiltersChanged: (colorFilters) {
-                _applyFilters();
+                  _colorFilters = colorFilters.toList();
-              },
+                  _applyFilters();
-            ),
+                },
+              )
+            else if (_activeTool == _ToolType.transform)
+              TransformToolbar(
+                initialState: _transformFilters,
+                onActiveFiltersChanged: (transformFilters) {
+                  _transformFilters = transformFilters.toList();
+                  _applyFilters();
+                },
+              ),
+            const SizedBox(height: 4),
+            _buildToolBar(context),
           ],
         ),
       ),
@@ -156,6 +168,41 @@ class _ImageEditorState extends State<ImageEditor> {
         ],
       );
 
+  Widget _buildToolBar(BuildContext context) {
+    return Align(
+      alignment: AlignmentDirectional.centerStart,
+      child: SingleChildScrollView(
+        scrollDirection: Axis.horizontal,
+        child: Row(
+          children: [
+            const SizedBox(width: 16),
+            _ToolButton(
+              icon: Icons.palette_outlined,
+              label: L10n.global().imageEditToolbarColorLabel,
+              isSelected: _activeTool == _ToolType.color,
+              onPressed: () {
+                setState(() {
+                  _activeTool = _ToolType.color;
+                });
+              },
+            ),
+            _ToolButton(
+              icon: Icons.transform_outlined,
+              label: L10n.global().imageEditToolbarTransformLabel,
+              isSelected: _activeTool == _ToolType.transform,
+              onPressed: () {
+                setState(() {
+                  _activeTool = _ToolType.transform;
+                });
+              },
+            ),
+            const SizedBox(width: 16),
+          ],
+        ),
+      ),
+    );
+  }
+
   Future<void> _onBackButton(BuildContext context) async {
     if (!_isModified) {
       Navigator.of(context).pop();
@@ -203,7 +250,10 @@ class _ImageEditorState extends State<ImageEditor> {
   }
 
   List<ImageFilter> _buildFilterList() {
-    return _colorFilters.map((f) => f.toImageFilter()).toList();
+    return [
+      ..._transformFilters.map((f) => f.toImageFilter()),
+      ..._colorFilters.map((f) => f.toImageFilter()),
+    ];
   }
 
   Future<void> _applyFilters() async {
@@ -213,11 +263,79 @@ class _ImageEditorState extends State<ImageEditor> {
     });
   }
 
-  bool get _isModified => _colorFilters.isNotEmpty;
+  bool get _isModified =>
+      _transformFilters.isNotEmpty || _colorFilters.isNotEmpty;
 
   bool _isDoneInit = false;
   late final Rgba8Image _src;
   Rgba8Image? _dst;
+  var _activeTool = _ToolType.color;
 
   var _colorFilters = <ColorArguments>[];
+  var _transformFilters = <TransformArguments>[];
+}
+
+enum _ToolType {
+  color,
+  transform,
+}
+
+class _ToolButton extends StatelessWidget {
+  const _ToolButton({
+    Key? key,
+    required this.icon,
+    required this.label,
+    required this.onPressed,
+    this.isSelected = false,
+  }) : super(key: key);
+
+  @override
+  build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 4),
+      child: ClipRRect(
+        borderRadius: const BorderRadius.all(Radius.circular(24)),
+        child: Material(
+          type: MaterialType.transparency,
+          child: InkWell(
+            onTap: onPressed,
+            child: Container(
+              decoration: BoxDecoration(
+                color: isSelected ? Colors.white24 : null,
+                // borderRadius: const BorderRadius.all(Radius.circular(24)),
+              ),
+              padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+              alignment: Alignment.center,
+              child: Row(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  Icon(
+                    icon,
+                    color: isSelected
+                        ? Colors.white
+                        : AppTheme.unfocusedIconColorDark,
+                    size: 18,
+                  ),
+                  const SizedBox(width: 4),
+                  Text(
+                    label,
+                    style: TextStyle(
+                      color: isSelected
+                          ? Colors.white
+                          : AppTheme.unfocusedIconColorDark,
+                    ),
+                  ),
+                ],
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  final IconData icon;
+  final String label;
+  final VoidCallback? onPressed;
+  final bool isSelected;
 }

app/lib/widget/image_editor/transform_toolbar.dart

@@ -0,0 +1,253 @@
+import 'package:flutter/material.dart';
+import 'package:nc_photos/app_localizations.dart';
+import 'package:nc_photos/theme.dart';
+import 'package:nc_photos/widget/image_editor/toolbar_button.dart';
+import 'package:nc_photos_plugin/nc_photos_plugin.dart';
+
+enum TransformToolType {
+  orientation,
+}
+
+abstract class TransformArguments {
+  ImageFilter toImageFilter();
+
+  TransformToolType _getToolType();
+}
+
+class TransformToolbar extends StatefulWidget {
+  const TransformToolbar({
+    Key? key,
+    required this.initialState,
+    required this.onActiveFiltersChanged,
+  }) : super(key: key);
+
+  @override
+  createState() => _TransformToolbarState();
+
+  final List<TransformArguments> initialState;
+  final ValueChanged<Iterable<TransformArguments>> onActiveFiltersChanged;
+}
+
+class _TransformToolbarState extends State<TransformToolbar> {
+  @override
+  initState() {
+    super.initState();
+    for (final s in widget.initialState) {
+      _filters[s._getToolType()] = s;
+    }
+  }
+
+  @override
+  build(BuildContext context) => Column(
+        children: [
+          _buildFilterOption(context),
+          _buildFilterBar(context),
+        ],
+      );
+
+  Widget _buildFilterOption(BuildContext context) {
+    Widget? child;
+    switch (_selectedFilter) {
+      case TransformToolType.orientation:
+        child = _buildOrientationOption(context);
+        break;
+
+      case null:
+        child = null;
+        break;
+    }
+    return Container(
+      height: 80,
+      alignment: Alignment.bottomCenter,
+      child: child,
+    );
+  }
+
+  Widget _buildFilterBar(BuildContext context) {
+    return Align(
+      alignment: AlignmentDirectional.centerStart,
+      child: Material(
+        type: MaterialType.transparency,
+        child: SingleChildScrollView(
+          scrollDirection: Axis.horizontal,
+          child: Row(
+            children: [
+              const SizedBox(width: 16),
+              ToolbarButton(
+                icon: Icons.rotate_90_degrees_ccw_outlined,
+                label: L10n.global().imageEditTransformOrientation,
+                onPressed: _onOrientationPressed,
+                isSelected: _selectedFilter == TransformToolType.orientation,
+                activationOrder:
+                    _filters.containsKey(TransformToolType.orientation)
+                        ? -1
+                        : null,
+              ),
+              const SizedBox(width: 16),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget _buildOrientationOption(BuildContext context) {
+    final value =
+        (_filters[TransformToolType.orientation] as _OrientationArguments)
+            .value;
+    return Padding(
+      padding: const EdgeInsets.all(8),
+      child: Wrap(
+        children: [
+          Flex(
+            direction: Axis.horizontal,
+            children: [
+              Flexible(
+                flex: 1,
+                fit: FlexFit.tight,
+                child: _OrientationButton(
+                  label:
+                      "180\n${L10n.global().imageEditTransformOrientationCounterclockwise}",
+                  isSelected: value == 180,
+                  onPressed: () => _onOrientationOptionPressed(180),
+                ),
+              ),
+              Flexible(
+                flex: 1,
+                fit: FlexFit.tight,
+                child: _OrientationButton(
+                  label:
+                      "90\n${L10n.global().imageEditTransformOrientationCounterclockwise}",
+                  isSelected: value == 90,
+                  onPressed: () => _onOrientationOptionPressed(90),
+                ),
+              ),
+              Flexible(
+                flex: 1,
+                fit: FlexFit.tight,
+                child: _OrientationButton(
+                  label: "0\n ",
+                  isSelected: value == 0,
+                  onPressed: () => _onOrientationOptionPressed(0),
+                ),
+              ),
+              Flexible(
+                flex: 1,
+                fit: FlexFit.tight,
+                child: _OrientationButton(
+                  label:
+                      "90\n${L10n.global().imageEditTransformOrientationClockwise}",
+                  isSelected: value == -90,
+                  onPressed: () => _onOrientationOptionPressed(-90),
+                ),
+              ),
+              Flexible(
+                flex: 1,
+                fit: FlexFit.tight,
+                child: _OrientationButton(
+                  label:
+                      "180\n${L10n.global().imageEditTransformOrientationClockwise}",
+                  isSelected: value == -180,
+                  onPressed: () => _onOrientationOptionPressed(-180),
+                ),
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _onFilterPressed(TransformToolType type, TransformArguments defArgs) {
+    if (_selectedFilter == type) {
+      // deactivate filter
+      setState(() {
+        _selectedFilter = null;
+        _filters.remove(type);
+      });
+    } else {
+      setState(() {
+        _selectedFilter = type;
+        _filters[type] ??= defArgs;
+      });
+    }
+    _notifyFiltersChanged();
+  }
+
+  void _onOrientationPressed() => _onFilterPressed(
+      TransformToolType.orientation, const _OrientationArguments(0));
+
+  void _onOrientationOptionPressed(int value) {
+    setState(() {
+      _filters[TransformToolType.orientation] = _OrientationArguments(value);
+    });
+    _notifyFiltersChanged();
+  }
+
+  void _notifyFiltersChanged() {
+    widget.onActiveFiltersChanged.call(_filters.values);
+  }
+
+  final _filters = <TransformToolType, TransformArguments>{};
+  TransformToolType? _selectedFilter;
+}
+
+class _OrientationArguments implements TransformArguments {
+  const _OrientationArguments(this.value);
+
+  @override
+  toImageFilter() => TransformOrientationFilter(value);
+
+  @override
+  _getToolType() => TransformToolType.orientation;
+
+  final int value;
+}
+
+class _OrientationButton extends StatelessWidget {
+  const _OrientationButton({
+    Key? key,
+    required this.label,
+    required this.onPressed,
+    this.isSelected = false,
+  }) : super(key: key);
+
+  @override
+  build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 4),
+      child: ClipRRect(
+        borderRadius: const BorderRadius.all(Radius.circular(24)),
+        child: Material(
+          type: MaterialType.transparency,
+          child: InkWell(
+            onTap: onPressed,
+            child: Container(
+              decoration: BoxDecoration(
+                color: isSelected
+                    ? AppTheme.primarySwatchDark[500]!.withOpacity(0.7)
+                    : null,
+                // borderRadius: const BorderRadius.all(Radius.circular(24)),
+              ),
+              padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+              alignment: Alignment.center,
+              child: Text(
+                label,
+                textAlign: TextAlign.center,
+                style: TextStyle(
+                  color: isSelected
+                      ? Colors.white
+                      : AppTheme.unfocusedIconColorDark,
+                ),
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  final String label;
+  final VoidCallback? onPressed;
+  final bool isSelected;
+}

plugin/android/src/main/cpp/CMakeLists.txt

@@ -38,6 +38,7 @@ add_library( # Sets the name of the library.
              filter/contrast.cpp
              filter/curve.cpp
              filter/hslhsv.cpp
+             filter/orientation.cpp
              filter/saturation.cpp
              filter/tint.cpp
              filter/warmth.cpp

plugin/android/src/main/cpp/filter/orientation.cpp

@@ -0,0 +1,136 @@
+#include <cstdint>
+#include <exception>
+#include <jni.h>
+#include <vector>
+
+#include "../exception.h"
+#include "../log.h"
+#include "../util.h"
+
+using namespace plugin;
+using namespace std;
+
+namespace {
+
+class Orientation {
+public:
+  std::vector<uint8_t> apply(const uint8_t *rgba8, const size_t width,
+                             const size_t height, const int degree);
+
+private:
+  std::vector<uint8_t> apply90Ccw(const uint8_t *rgba8, const size_t width,
+                                  const size_t height);
+  std::vector<uint8_t> apply90Cw(const uint8_t *rgba8, const size_t width,
+                                 const size_t height);
+  std::vector<uint8_t> apply180(const uint8_t *rgba8, const size_t width,
+                                const size_t height);
+
+  static constexpr const char *TAG = "Orientation";
+};
+
+} // namespace
+
+extern "C" JNIEXPORT jbyteArray JNICALL
+Java_com_nkming_nc_1photos_plugin_image_1processor_Orientation_applyNative(
+    JNIEnv *env, jobject *thiz, jbyteArray rgba8, jint width, jint height,
+    jint degree) {
+  try {
+    initOpenMp();
+    RaiiContainer<jbyte> cRgba8(
+        [&]() { return env->GetByteArrayElements(rgba8, nullptr); },
+        [&](jbyte *obj) {
+          env->ReleaseByteArrayElements(rgba8, obj, JNI_ABORT);
+        });
+    const auto result = Orientation().apply(
+        reinterpret_cast<uint8_t *>(cRgba8.get()), width, height, degree);
+    auto resultAry = env->NewByteArray(result.size());
+    env->SetByteArrayRegion(resultAry, 0, result.size(),
+                            reinterpret_cast<const int8_t *>(result.data()));
+    return resultAry;
+  } catch (const exception &e) {
+    throwJavaException(env, e.what());
+    return nullptr;
+  }
+}
+
+namespace {
+
+vector<uint8_t> Orientation::apply(const uint8_t *rgba8, const size_t width,
+                                   const size_t height, const int degree) {
+  LOGI(TAG, "[apply] degree: %d", degree);
+  if (degree == 0) {
+    // shortcut
+    return vector<uint8_t>(rgba8, rgba8 + width * height * 4);
+  }
+
+  if (degree == 90) {
+    return apply90Ccw(rgba8, width, height);
+  } else if (degree == -90) {
+    return apply90Cw(rgba8, width, height);
+  } else {
+    return apply180(rgba8, width, height);
+  }
+}
+
+vector<uint8_t> Orientation::apply90Ccw(const uint8_t *rgba8,
+                                        const size_t width,
+                                        const size_t height) {
+  vector<uint8_t> output(width * height * 4);
+#pragma omp parallel for
+  for (size_t y = 0; y < height; ++y) {
+    const auto yI = y * width * 4;
+    for (size_t x = 0; x < width; ++x) {
+      const auto p = x * 4 + yI;
+      const auto desY = width - x - 1;
+      const auto desX = y;
+      const auto desP = (desY * height + desX) * 4;
+      output[desP + 0] = rgba8[p + 0];
+      output[desP + 1] = rgba8[p + 1];
+      output[desP + 2] = rgba8[p + 2];
+      output[desP + 3] = rgba8[p + 3];
+    }
+  }
+  return output;
+}
+
+vector<uint8_t> Orientation::apply90Cw(const uint8_t *rgba8, const size_t width,
+                                       const size_t height) {
+  vector<uint8_t> output(width * height * 4);
+#pragma omp parallel for
+  for (size_t y = 0; y < height; ++y) {
+    const auto yI = y * width * 4;
+    for (size_t x = 0; x < width; ++x) {
+      const auto p = x * 4 + yI;
+      const auto desY = width - x - 1;
+      const auto desX = height - y - 1;
+      const auto desP = (desY * height + desX) * 4;
+      output[desP + 0] = rgba8[p + 0];
+      output[desP + 1] = rgba8[p + 1];
+      output[desP + 2] = rgba8[p + 2];
+      output[desP + 3] = rgba8[p + 3];
+    }
+  }
+  return output;
+}
+
+vector<uint8_t> Orientation::apply180(const uint8_t *rgba8, const size_t width,
+                                      const size_t height) {
+  vector<uint8_t> output(width * height * 4);
+#pragma omp parallel for
+  for (size_t y = 0; y < height; ++y) {
+    const auto yI = y * width * 4;
+    for (size_t x = 0; x < width; ++x) {
+      const auto p = x * 4 + yI;
+      const auto desY = height - y - 1;
+      const auto desX = width - x - 1;
+      const auto desP = (desY * width + desX) * 4;
+      output[desP + 0] = rgba8[p + 0];
+      output[desP + 1] = rgba8[p + 1];
+      output[desP + 2] = rgba8[p + 2];
+      output[desP + 3] = rgba8[p + 3];
+    }
+  }
+  return output;
+}
+
+} // namespace

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/ImageProcessorChannelHandler.kt

@@ -237,6 +237,7 @@ interface ImageFilter {
 				"saturation" -> Saturation((json["weight"] as Double).toFloat())
 				"warmth" -> Warmth((json["weight"] as Double).toFloat())
 				"tint" -> Tint((json["weight"] as Double).toFloat())
+				"orientation" -> Orientation(json["degree"] as Int)
 				else -> throw IllegalArgumentException(
 					"Unknown type: ${json["type"]}"
 				)

plugin/android/src/main/kotlin/com/nkming/nc_photos/plugin/image_processor/Orientation.kt

@@ -0,0 +1,18 @@
+package com.nkming.nc_photos.plugin.image_processor
+
+import com.nkming.nc_photos.plugin.ImageFilter
+import kotlin.math.abs
+
+class Orientation(val degree: Int) : ImageFilter {
+	override fun apply(rgba8: Rgba8Image): Rgba8Image {
+		val data = applyNative(rgba8.pixel, rgba8.width, rgba8.height, degree)
+		return Rgba8Image(
+			data, if (abs(degree) == 90) rgba8.height else rgba8.width,
+			if (abs(degree) == 90) rgba8.width else rgba8.height
+		)
+	}
+
+	private external fun applyNative(
+		rgba8: ByteArray, width: Int, height: Int, degree: Int
+	): ByteArray
+}

plugin/lib/src/image_processor.dart

@@ -44,6 +44,18 @@ class ColorTintFilter extends _SingleWeightFilter {
   const ColorTintFilter(double weight) : super("tint", weight);
 }
 
+class TransformOrientationFilter implements ImageFilter {
+  const TransformOrientationFilter(this.degree);
+
+  @override
+  toJson() => {
+        "type": "orientation",
+        "degree": degree,
+      };
+
+  final int degree;
+}
+
 class ImageProcessor {
   static Future<void> zeroDce(
     String fileUrl,