Implement invertColors

flutter · May 17, 2023 · 0553179 · 0553179
1 parent 163ce3b
commit 0553179
Show file tree

Hide file tree

Showing 5 changed files with 84 additions and 8 deletions.
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/filters.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/filters.dart
@@ -95,6 +95,11 @@ class SkwasmColorFilter {
       }),
     };
 
+  factory SkwasmColorFilter.composed(
+    SkwasmColorFilter outer,
+    SkwasmColorFilter inner,
+  ) => SkwasmColorFilter._(colorFilterCompose(outer.handle, inner.handle));
+
   void dispose() {
     if (!_isDisposed) {
       colorFilterDispose(handle);

diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paint.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/paint.dart
@@ -27,6 +27,17 @@ class SkwasmPaint implements ui.Paint {
 
   ui.MaskFilter? _maskFilter;
 
+  bool _invertColors = false;
+
+  static final SkwasmColorFilter _invertColorFilter = SkwasmColorFilter.fromEngineColorFilter(
+    const EngineColorFilter.matrix(<double>[
+      -1.0, 0, 0, 1.0, 0, // row
+      0, -1.0, 0, 1.0, 0, // row
+      0, 0, -1.0, 1.0, 0, // row
+      1.0, 1.0, 1.0, 1.0, 0
+    ])
+  );
+
   @override
   ui.BlendMode get blendMode {
     return _cachedBlendMode;
@@ -113,18 +124,32 @@ class SkwasmPaint implements ui.Paint {
   @override
   ui.ColorFilter? get colorFilter => _colorFilter;
 
-  @override
-  set colorFilter(ui.ColorFilter? filter) {
-    _colorFilter = filter as EngineColorFilter?;
-    if (filter == null) {
-      paintSetColorFilter(handle, nullptr);
-    } else {
-      final SkwasmColorFilter nativeFilter = SkwasmColorFilter.fromEngineColorFilter(filter);
+  void _setEffectiveColorFilter() {
+    final SkwasmColorFilter? nativeFilter = _colorFilter != null
+      ? SkwasmColorFilter.fromEngineColorFilter(_colorFilter!) : null;
+    if (_invertColors) {
+      if (nativeFilter != null) {
+        final SkwasmColorFilter composedFilter = SkwasmColorFilter.composed(_invertColorFilter, nativeFilter);
+        nativeFilter.dispose();
+        paintSetColorFilter(handle, composedFilter.handle);
+        composedFilter.dispose();
+      } else {
+        paintSetColorFilter(handle, _invertColorFilter.handle);
+      }
+    } else if (nativeFilter != null) {
       paintSetColorFilter(handle, nativeFilter.handle);
       nativeFilter.dispose();
+    } else {
+      paintSetColorFilter(handle, nullptr);
     }
   }
 
+  @override
+  set colorFilter(ui.ColorFilter? filter) {
+    _colorFilter = filter as EngineColorFilter?;
+    _setEffectiveColorFilter();
+  }
+
   @override
   ui.MaskFilter? get maskFilter => _maskFilter;
 
@@ -141,5 +166,14 @@ class SkwasmPaint implements ui.Paint {
   }
 
   @override
-  bool invertColors = false;
+  bool get invertColors => _invertColors;
+
+  @override
+  set invertColors(bool invertColors) {
+    if (_invertColors == invertColors) {
+      return;
+    }
+    _invertColors = invertColors;
+    _setEffectiveColorFilter();
+  }
 }
diff --git a/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/raw_filters.dart b/lib/web_ui/lib/src/engine/skwasm/skwasm_impl/raw/raw_filters.dart
@@ -95,6 +95,15 @@ external ColorFilterHandle colorFilterCreateSRGBToLinearGamma();
 @Native<ColorFilterHandle Function()>(symbol: 'colorFilter_createLinearToSRGBGamma', isLeaf: true)
 external ColorFilterHandle colorFilterCreateLinearToSRGBGamma();
 
+@Native<ColorFilterHandle Function(
+  ColorFilterHandle,
+  ColorFilterHandle
+)>(symbol: 'colorFilter_compose', isLeaf: true)
+external ColorFilterHandle colorFilterCompose(
+  ColorFilterHandle outer,
+  ColorFilterHandle inner,
+);
+
 @Native<Void Function(ColorFilterHandle)>(symbol: 'colorFilter_dispose', isLeaf: true)
 external void colorFilterDispose(ColorFilterHandle handle);
 

diff --git a/lib/web_ui/skwasm/filters.cpp b/lib/web_ui/skwasm/filters.cpp
@@ -82,6 +82,15 @@ SKWASM_EXPORT SkColorFilter* colorFilter_createLinearToSRGBGamma() {
   return SkColorFilters::LinearToSRGBGamma().release();
 }
 
+SKWASM_EXPORT SkColorFilter* colorFilter_compose(SkColorFilter* outer,
+                                                 SkColorFilter* inner) {
+  outer->ref();
+  inner->ref();
+  return SkColorFilters::Compose(sk_sp<SkColorFilter>(outer),
+                                 sk_sp<SkColorFilter>(inner))
+      .release();
+}
+
 SKWASM_EXPORT void colorFilter_dispose(SkColorFilter* filter) {
   filter->unref();
 }

diff --git a/lib/web_ui/test/ui/filters_test.dart b/lib/web_ui/test/ui/filters_test.dart
@@ -166,6 +166,25 @@ Future<void> testMain() async {
     await matchGoldenFile('ui_filter_matrix_colorfilter.png', region: region);
   });
 
+  test('invert colors', () async {
+    await drawTestImageWithPaint(ui.Paint()..invertColors = true);
+    await matchGoldenFile('ui_filter_invert_colors.png', region: region);
+  });
+
+  test('invert colors with color filter', () async {
+    const ui.ColorFilter sepia = ui.ColorFilter.matrix(<double>[
+      0.393, 0.769, 0.189, 0, 0,
+      0.349, 0.686, 0.168, 0, 0,
+      0.272, 0.534, 0.131, 0, 0,
+      0,     0,     0,     1, 0,
+    ]);
+
+    await drawTestImageWithPaint(ui.Paint()
+      ..invertColors = true
+      ..colorFilter = sepia);
+    await matchGoldenFile('ui_filter_invert_colors_with_colorfilter.png', region: region);
+  });
+
   test('mask filter', () async {
     const ui.MaskFilter maskFilter = ui.MaskFilter.blur(ui.BlurStyle.normal, 25.0);
     await drawTestImageWithPaint(ui.Paint()..maskFilter = maskFilter);