From 9dd4c6e54b658f91860deace5a0bc46a35bc7a88 Mon Sep 17 00:00:00 2001
From: jonahwilliams <jonahwilliams@google.com>
Date: Thu, 16 Feb 2023 14:53:48 -0800
Subject: [PATCH 1/2] [Impeller] implement invert colors flag

---
 impeller/aiks/paint.cc                        | 21 +++++++++++++++++++
 impeller/aiks/paint.h                         |  5 ++++-
 .../display_list/display_list_dispatcher.cc   |  2 +-
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/impeller/aiks/paint.cc b/impeller/aiks/paint.cc
index 5f35cc52301eb..60dec041d1e74 100644
--- a/impeller/aiks/paint.cc
+++ b/impeller/aiks/paint.cc
@@ -61,6 +61,7 @@ std::shared_ptr<Contents> Paint::WithFilters(
     const Matrix& effect_transform) const {
   bool is_solid_color_val = is_solid_color.value_or(!color_source);
   input = WithColorFilter(input);
+  input = WithInvertFilter(input);
   input = WithMaskBlur(input, is_solid_color_val, effect_transform);
   input = WithImageFilter(input, effect_transform);
   return input;
@@ -114,6 +115,26 @@ std::shared_ptr<Contents> Paint::WithColorFilter(
   return input;
 }
 
+/// A color matrix which inverts colors.
+// clang-format off
+constexpr Matrix kColorInversion = Matrix(
+  -1.0,    0,   0, 1.0, 0, //
+    0, -1.0,    0, 1.0, 0, //
+    0,    0, -1.0, 1.0, 0, //
+  1.0,  1.0,  1.0, 1.0, 0, //
+);
+// clang-format on
+
+std::shared_ptr<Contents> Paint::WithInvertFilter(
+    std::shared_ptr<Contents> input) const {
+  if (!invert_colors) {
+    return input;
+  }
+
+  return ColorFilterContents::MakeColorMatrix({std::move(input)},
+                                              kColorInversion);
+}
+
 std::shared_ptr<FilterContents> Paint::MaskBlurDescriptor::CreateMaskBlur(
     const FilterInput::Ref& input,
     bool is_solid_color,
diff --git a/impeller/aiks/paint.h b/impeller/aiks/paint.h
index f18aca1953c3e..07feec152a324 100644
--- a/impeller/aiks/paint.h
+++ b/impeller/aiks/paint.h
@@ -67,6 +67,7 @@ struct Paint {
   Scalar stroke_miter = 4.0;
   Style style = Style::kFill;
   BlendMode blend_mode = BlendMode::kSourceOver;
+  bool invert_colors = false;
 
   std::optional<ImageFilterProc> image_filter;
   std::optional<ColorFilterProc> color_filter;
@@ -123,6 +124,8 @@ struct Paint {
 
   std::shared_ptr<Contents> WithColorFilter(std::shared_ptr<Contents> input,
                                             bool absorb_opacity = false) const;
-};
+
+  std::shared_ptr<Contents> Paint::WithInvertFilter(
+      std::shared_ptr<Contents> input) const;
 
 }  // namespace impeller
diff --git a/impeller/display_list/display_list_dispatcher.cc b/impeller/display_list/display_list_dispatcher.cc
index 4e7d7ffe69882..4dd2111f442d9 100644
--- a/impeller/display_list/display_list_dispatcher.cc
+++ b/impeller/display_list/display_list_dispatcher.cc
@@ -580,7 +580,7 @@ void DisplayListDispatcher::setColorFilter(
 
 // |flutter::Dispatcher|
 void DisplayListDispatcher::setInvertColors(bool invert) {
-  UNIMPLEMENTED;
+  paint_.invert_colors = invert;
 }
 
 // |flutter::Dispatcher|

From 152287c0149be61f18e2f0e07561ce5d587abc2b Mon Sep 17 00:00:00 2001
From: jonahwilliams <jonahwilliams@google.com>
Date: Fri, 17 Feb 2023 15:20:10 -0800
Subject: [PATCH 2/2] [Impeller] add invert colors support

---
 impeller/aiks/aiks_unittests.cc | 10 ++++++++++
 impeller/aiks/paint.cc          | 18 ++++++++++--------
 impeller/aiks/paint.h           |  3 ++-
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/impeller/aiks/aiks_unittests.cc b/impeller/aiks/aiks_unittests.cc
index d7bcab300b4df..84853ce685298 100644
--- a/impeller/aiks/aiks_unittests.cc
+++ b/impeller/aiks/aiks_unittests.cc
@@ -82,6 +82,16 @@ TEST_P(AiksTest, CanRenderImage) {
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
 
+TEST_P(AiksTest, CanRenderInvertedImage) {
+  Canvas canvas;
+  Paint paint;
+  auto image = std::make_shared<Image>(CreateTextureForFixture("kalimba.jpg"));
+  paint.color = Color::Red();
+  paint.invert_colors = true;
+  canvas.DrawImage(image, Point::MakeXY(100.0, 100.0), paint);
+  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
+}
+
 bool GenerateMipmap(const std::shared_ptr<Context>& context,
                     std::shared_ptr<Texture> texture,
                     std::string label) {
diff --git a/impeller/aiks/paint.cc b/impeller/aiks/paint.cc
index 60dec041d1e74..bf738951cfb0e 100644
--- a/impeller/aiks/paint.cc
+++ b/impeller/aiks/paint.cc
@@ -117,12 +117,14 @@ std::shared_ptr<Contents> Paint::WithColorFilter(
 
 /// A color matrix which inverts colors.
 // clang-format off
-constexpr Matrix kColorInversion = Matrix(
-  -1.0,    0,   0, 1.0, 0, //
-    0, -1.0,    0, 1.0, 0, //
-    0,    0, -1.0, 1.0, 0, //
-  1.0,  1.0,  1.0, 1.0, 0, //
-);
+constexpr ColorFilterContents::ColorMatrix kColorInversion = {
+  .array = {
+    -1.0,    0,    0, 1.0, 0, //
+       0, -1.0,    0, 1.0, 0, //
+       0,    0, -1.0, 1.0, 0, //
+     1.0,  1.0,  1.0, 1.0, 0  //
+  }
+};
 // clang-format on
 
 std::shared_ptr<Contents> Paint::WithInvertFilter(
@@ -131,8 +133,8 @@ std::shared_ptr<Contents> Paint::WithInvertFilter(
     return input;
   }
 
-  return ColorFilterContents::MakeColorMatrix({std::move(input)},
-                                              kColorInversion);
+  return ColorFilterContents::MakeColorMatrix(
+      {FilterInput::Make(std::move(input))}, kColorInversion);
 }
 
 std::shared_ptr<FilterContents> Paint::MaskBlurDescriptor::CreateMaskBlur(
diff --git a/impeller/aiks/paint.h b/impeller/aiks/paint.h
index 07feec152a324..990f829fc4067 100644
--- a/impeller/aiks/paint.h
+++ b/impeller/aiks/paint.h
@@ -125,7 +125,8 @@ struct Paint {
   std::shared_ptr<Contents> WithColorFilter(std::shared_ptr<Contents> input,
                                             bool absorb_opacity = false) const;
 
-  std::shared_ptr<Contents> Paint::WithInvertFilter(
+  std::shared_ptr<Contents> WithInvertFilter(
       std::shared_ptr<Contents> input) const;
+};
 
 }  // namespace impeller