// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <array>
#include <cmath>
#include <cstdlib>
#include <memory>
#include <tuple>
#include <utility>
#include <vector>

#include "flutter/testing/testing.h"
#include "impeller/aiks/aiks_playground.h"
#include "impeller/aiks/canvas.h"
#include "impeller/aiks/image.h"
#include "impeller/aiks/image_filter.h"
#include "impeller/aiks/paint_pass_delegate.h"
#include "impeller/aiks/testing/context_spy.h"
#include "impeller/core/capture.h"
#include "impeller/entity/contents/color_source_contents.h"
#include "impeller/entity/contents/conical_gradient_contents.h"
#include "impeller/entity/contents/filters/inputs/filter_input.h"
#include "impeller/entity/contents/linear_gradient_contents.h"
#include "impeller/entity/contents/solid_color_contents.h"
#include "impeller/entity/contents/tiled_texture_contents.h"
#include "impeller/geometry/color.h"
#include "impeller/geometry/constants.h"
#include "impeller/geometry/geometry_asserts.h"
#include "impeller/geometry/matrix.h"
#include "impeller/geometry/path_builder.h"
#include "impeller/golden_tests/golden_playground_test.h"
#include "impeller/playground/widgets.h"
#include "impeller/renderer/command_buffer.h"
#include "impeller/renderer/snapshot.h"
#include "impeller/scene/material.h"
#include "impeller/scene/node.h"
#include "impeller/typographer/backends/skia/text_frame_skia.h"
#include "impeller/typographer/backends/skia/typographer_context_skia.h"
#include "impeller/typographer/backends/stb/text_frame_stb.h"
#include "impeller/typographer/backends/stb/typeface_stb.h"
#include "impeller/typographer/backends/stb/typographer_context_stb.h"
#include "third_party/imgui/imgui.h"
#include "third_party/skia/include/core/SkData.h"

namespace impeller {
namespace testing {

#ifdef IMPELLER_GOLDEN_TESTS
using AiksTest = GoldenPlaygroundTest;
#else
using AiksTest = AiksPlayground;
#endif
INSTANTIATE_PLAYGROUND_SUITE(AiksTest);

TEST_P(AiksTest, RotateColorFilteredPath) {
  Canvas canvas;
  canvas.Concat(Matrix::MakeTranslation({300, 300}));
  canvas.Concat(Matrix::MakeRotationZ(Radians(kPiOver2)));
  auto arrow_stem =
      PathBuilder{}.MoveTo({120, 190}).LineTo({120, 50}).TakePath();
  auto arrow_head = PathBuilder{}
                        .MoveTo({50, 120})
                        .LineTo({120, 190})
                        .LineTo({190, 120})
                        .TakePath();
  auto paint = Paint{
      .stroke_width = 15.0,
      .stroke_cap = Cap::kRound,
      .stroke_join = Join::kRound,
      .style = Paint::Style::kStroke,
      .color_filter =
          ColorFilter::MakeBlend(BlendMode::kSourceIn, Color::AliceBlue()),
  };

  canvas.DrawPath(arrow_stem, paint);
  canvas.DrawPath(arrow_head, paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanvasCTMCanBeUpdated) {
  Canvas canvas;
  Matrix identity;
  ASSERT_MATRIX_NEAR(canvas.GetCurrentTransformation(), identity);
  canvas.Translate(Size{100, 100});
  ASSERT_MATRIX_NEAR(canvas.GetCurrentTransformation(),
                     Matrix::MakeTranslation({100.0, 100.0, 0.0}));
}

TEST_P(AiksTest, CanvasCanPushPopCTM) {
  Canvas canvas;
  ASSERT_EQ(canvas.GetSaveCount(), 1u);
  ASSERT_EQ(canvas.Restore(), false);

  canvas.Translate(Size{100, 100});
  canvas.Save();
  ASSERT_EQ(canvas.GetSaveCount(), 2u);
  ASSERT_MATRIX_NEAR(canvas.GetCurrentTransformation(),
                     Matrix::MakeTranslation({100.0, 100.0, 0.0}));
  ASSERT_TRUE(canvas.Restore());
  ASSERT_EQ(canvas.GetSaveCount(), 1u);
  ASSERT_MATRIX_NEAR(canvas.GetCurrentTransformation(),
                     Matrix::MakeTranslation({100.0, 100.0, 0.0}));
}

TEST_P(AiksTest, CanRenderColoredRect) {
  Canvas canvas;
  Paint paint;
  paint.color = Color::Blue();
  canvas.DrawPath(PathBuilder{}
                      .AddRect(Rect::MakeXYWH(100.0, 100.0, 100.0, 100.0))
                      .TakePath(),
                  paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderImage) {
  Canvas canvas;
  Paint paint;
  auto image = std::make_shared<Image>(CreateTextureForFixture("kalimba.jpg"));
  paint.color = Color::Red();
  canvas.DrawImage(image, Point::MakeXY(100.0, 100.0), paint);
  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()));
}

namespace {
bool GenerateMipmap(const std::shared_ptr<Context>& context,
                    std::shared_ptr<Texture> texture,
                    std::string label) {
  auto buffer = context->CreateCommandBuffer();
  if (!buffer) {
    return false;
  }
  auto pass = buffer->CreateBlitPass();
  if (!pass) {
    return false;
  }
  pass->GenerateMipmap(std::move(texture), std::move(label));
  pass->EncodeCommands(context->GetResourceAllocator());
  return buffer->SubmitCommands();
}

void CanRenderTiledTexture(AiksTest* aiks_test,
                           Entity::TileMode tile_mode,
                           Matrix local_matrix = {}) {
  auto context = aiks_test->GetContext();
  ASSERT_TRUE(context);
  auto texture = aiks_test->CreateTextureForFixture("table_mountain_nx.png",
                                                    /*enable_mipmapping=*/true);
  GenerateMipmap(context, texture, "table_mountain_nx");
  Canvas canvas;
  canvas.Scale(aiks_test->GetContentScale());
  canvas.Translate({100.0f, 100.0f, 0});
  Paint paint;
  paint.color_source =
      ColorSource::MakeImage(texture, tile_mode, tile_mode, {}, local_matrix);
  paint.color = Color(1, 1, 1, 1);
  canvas.DrawRect({0, 0, 600, 600}, paint);

  // Should not change the image.
  constexpr auto stroke_width = 64;
  paint.style = Paint::Style::kStroke;
  paint.stroke_width = stroke_width;
  if (tile_mode == Entity::TileMode::kDecal) {
    canvas.DrawRect({stroke_width, stroke_width, 600, 600}, paint);
  } else {
    canvas.DrawRect({0, 0, 600, 600}, paint);
  }

  // Should not change the image.
  PathBuilder path_builder;
  path_builder.AddCircle({150, 150}, 150);
  path_builder.AddRoundedRect(Rect::MakeLTRB(300, 300, 600, 600), 10);
  paint.style = Paint::Style::kFill;
  canvas.DrawPath(path_builder.TakePath(), paint);

  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}
}  // namespace

TEST_P(AiksTest, CanRenderTiledTextureClamp) {
  CanRenderTiledTexture(this, Entity::TileMode::kClamp);
}

TEST_P(AiksTest, CanRenderTiledTextureRepeat) {
  CanRenderTiledTexture(this, Entity::TileMode::kRepeat);
}

TEST_P(AiksTest, CanRenderTiledTextureMirror) {
  CanRenderTiledTexture(this, Entity::TileMode::kMirror);
}

TEST_P(AiksTest, CanRenderTiledTextureDecal) {
  CanRenderTiledTexture(this, Entity::TileMode::kDecal);
}

TEST_P(AiksTest, CanRenderTiledTextureClampWithTranslate) {
  CanRenderTiledTexture(this, Entity::TileMode::kClamp,
                        Matrix::MakeTranslation({172.f, 172.f, 0.f}));
}

TEST_P(AiksTest, CanRenderImageRect) {
  Canvas canvas;
  Paint paint;
  auto image = std::make_shared<Image>(CreateTextureForFixture("kalimba.jpg"));
  auto source_rect = Rect::MakeSize(Size(image->GetSize()));

  // Render the bottom right quarter of the source image in a stretched rect.
  source_rect.size.width /= 2;
  source_rect.size.height /= 2;
  source_rect.origin.x += source_rect.size.width;
  source_rect.origin.y += source_rect.size.height;
  canvas.DrawImageRect(image, source_rect, Rect::MakeXYWH(100, 100, 600, 600),
                       paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderStrokes) {
  Canvas canvas;
  Paint paint;
  paint.color = Color::Red();
  paint.stroke_width = 20.0;
  paint.style = Paint::Style::kStroke;
  canvas.DrawPath(PathBuilder{}.AddLine({200, 100}, {800, 100}).TakePath(),
                  paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderCurvedStrokes) {
  Canvas canvas;
  Paint paint;
  paint.color = Color::Red();
  paint.stroke_width = 25.0;
  paint.style = Paint::Style::kStroke;
  canvas.DrawPath(PathBuilder{}.AddCircle({500, 500}, 250).TakePath(), paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderClips) {
  Canvas canvas;
  Paint paint;
  paint.color = Color::Fuchsia();
  canvas.ClipPath(
      PathBuilder{}.AddRect(Rect::MakeXYWH(0, 0, 500, 500)).TakePath());
  canvas.DrawPath(PathBuilder{}.AddCircle({500, 500}, 250).TakePath(), paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderNestedClips) {
  Canvas canvas;
  Paint paint;
  paint.color = Color::Fuchsia();
  canvas.Save();
  canvas.ClipPath(PathBuilder{}.AddCircle({200, 400}, 300).TakePath());
  canvas.Restore();
  canvas.ClipPath(PathBuilder{}.AddCircle({600, 400}, 300).TakePath());
  canvas.ClipPath(PathBuilder{}.AddCircle({400, 600}, 300).TakePath());
  canvas.DrawRect(Rect::MakeXYWH(200, 200, 400, 400), paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderDifferenceClips) {
  Paint paint;
  Canvas canvas;
  canvas.Translate({400, 400});

  // Limit drawing to face circle with a clip.
  canvas.ClipPath(PathBuilder{}.AddCircle(Point(), 200).TakePath());
  canvas.Save();

  // Cut away eyes/mouth using difference clips.
  canvas.ClipPath(PathBuilder{}.AddCircle({-100, -50}, 30).TakePath(),
                  Entity::ClipOperation::kDifference);
  canvas.ClipPath(PathBuilder{}.AddCircle({100, -50}, 30).TakePath(),
                  Entity::ClipOperation::kDifference);
  canvas.ClipPath(PathBuilder{}
                      .AddQuadraticCurve({-100, 50}, {0, 150}, {100, 50})
                      .TakePath(),
                  Entity::ClipOperation::kDifference);

  // Draw a huge yellow rectangle to prove the clipping works.
  paint.color = Color::Yellow();
  canvas.DrawRect(Rect::MakeXYWH(-1000, -1000, 2000, 2000), paint);

  // Remove the difference clips and draw hair that partially covers the eyes.
  canvas.Restore();
  paint.color = Color::Maroon();
  canvas.DrawPath(PathBuilder{}
                      .MoveTo({200, -200})
                      .HorizontalLineTo(-200)
                      .VerticalLineTo(-40)
                      .CubicCurveTo({0, -40}, {0, -80}, {200, -80})
                      .TakePath(),
                  paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderWithContiguousClipRestores) {
  Canvas canvas;

  // Cover the whole canvas with red.
  canvas.DrawPaint({.color = Color::Red()});

  canvas.Save();

  // Append two clips, the second resulting in empty coverage.
  canvas.ClipPath(
      PathBuilder{}.AddRect(Rect::MakeXYWH(100, 100, 100, 100)).TakePath());
  canvas.ClipPath(
      PathBuilder{}.AddRect(Rect::MakeXYWH(300, 300, 100, 100)).TakePath());

  // Restore to no clips.
  canvas.Restore();

  // Replace the whole canvas with green.
  canvas.DrawPaint({.color = Color::Green()});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, ClipsUseCurrentTransform) {
  std::array<Color, 5> colors = {Color::White(), Color::Black(),
                                 Color::SkyBlue(), Color::Red(),
                                 Color::Yellow()};
  Canvas canvas;
  Paint paint;

  canvas.Translate(Vector3(300, 300));
  for (int i = 0; i < 15; i++) {
    canvas.Scale(Vector3(0.8, 0.8));

    paint.color = colors[i % colors.size()];
    canvas.ClipPath(PathBuilder{}.AddCircle({0, 0}, 300).TakePath());
    canvas.DrawRect(Rect(-300, -300, 600, 600), paint);
  }
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanSaveLayerStandalone) {
  Canvas canvas;

  Paint red;
  red.color = Color::Red();

  Paint alpha;
  alpha.color = Color::Red().WithAlpha(0.5);

  canvas.SaveLayer(alpha);

  canvas.DrawCircle({125, 125}, 125, red);

  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

namespace {
void CanRenderLinearGradient(AiksTest* aiks_test, Entity::TileMode tile_mode) {
  Canvas canvas;
  canvas.Scale(aiks_test->GetContentScale());
  Paint paint;
  canvas.Translate({100.0f, 0, 0});

  std::vector<Color> colors = {Color{0.9568, 0.2627, 0.2118, 1.0},
                               Color{0.1294, 0.5882, 0.9529, 0.0}};
  std::vector<Scalar> stops = {0.0, 1.0};

  paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {200, 200}, std::move(colors), std::move(stops), tile_mode, {});

  paint.color = Color(1.0, 1.0, 1.0, 1.0);
  canvas.DrawRect({0, 0, 600, 600}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}
}  // namespace

TEST_P(AiksTest, CanRenderLinearGradientClamp) {
  CanRenderLinearGradient(this, Entity::TileMode::kClamp);
}
TEST_P(AiksTest, CanRenderLinearGradientRepeat) {
  CanRenderLinearGradient(this, Entity::TileMode::kRepeat);
}
TEST_P(AiksTest, CanRenderLinearGradientMirror) {
  CanRenderLinearGradient(this, Entity::TileMode::kMirror);
}
TEST_P(AiksTest, CanRenderLinearGradientDecal) {
  CanRenderLinearGradient(this, Entity::TileMode::kDecal);
}

TEST_P(AiksTest, CanRenderLinearGradientDecalWithColorFilter) {
  Canvas canvas;
  canvas.Scale(GetContentScale());
  Paint paint;
  canvas.Translate({100.0f, 0, 0});

  std::vector<Color> colors = {Color{0.9568, 0.2627, 0.2118, 1.0},
                               Color{0.1294, 0.5882, 0.9529, 0.0}};
  std::vector<Scalar> stops = {0.0, 1.0};

  paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {200, 200}, std::move(colors), std::move(stops),
      Entity::TileMode::kDecal, {});
  // Overlay the gradient with 25% green. This should appear as the entire
  // rectangle being drawn with 25% green, including the border area outside the
  // decal gradient.
  paint.color_filter = ColorFilter::MakeBlend(BlendMode::kSourceOver,
                                              Color::Green().WithAlpha(0.25));

  paint.color = Color(1.0, 1.0, 1.0, 1.0);
  canvas.DrawRect({0, 0, 600, 600}, paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

static void CanRenderLinearGradientWithDithering(AiksTest* aiks_test,
                                                 bool use_dithering) {
  Canvas canvas;
  Paint paint;
  canvas.Translate({100.0, 100.0, 0});

  // 0xffcccccc --> 0xff333333, taken from
  // https://github.com/flutter/flutter/issues/118073#issue-1521699748
  std::vector<Color> colors = {Color{0.8, 0.8, 0.8, 1.0},
                               Color{0.2, 0.2, 0.2, 1.0}};
  std::vector<Scalar> stops = {0.0, 1.0};

  paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {800, 500}, std::move(colors), std::move(stops),
      Entity::TileMode::kClamp, {});
  paint.dither = use_dithering;
  canvas.DrawRect({0, 0, 800, 500}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderLinearGradientWithDitheringDisabled) {
  CanRenderLinearGradientWithDithering(this, false);
}

TEST_P(AiksTest, CanRenderLinearGradientWithDitheringEnabled) {
  CanRenderLinearGradientWithDithering(this, true);
}  // namespace

static void CanRenderRadialGradientWithDithering(AiksTest* aiks_test,
                                                 bool use_dithering) {
  Canvas canvas;
  Paint paint;
  canvas.Translate({100.0, 100.0, 0});

  // #FFF -> #000
  std::vector<Color> colors = {Color{1.0, 1.0, 1.0, 1.0},
                               Color{0.0, 0.0, 0.0, 1.0}};
  std::vector<Scalar> stops = {0.0, 1.0};

  paint.color_source = ColorSource::MakeRadialGradient(
      {600, 600}, 600, std::move(colors), std::move(stops),
      Entity::TileMode::kClamp, {});
  paint.dither = use_dithering;
  canvas.DrawRect({0, 0, 1200, 1200}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderRadialGradientWithDitheringDisabled) {
  CanRenderRadialGradientWithDithering(this, false);
}

TEST_P(AiksTest, CanRenderRadialGradientWithDitheringEnabled) {
  CanRenderRadialGradientWithDithering(this, true);
}

static void CanRenderSweepGradientWithDithering(AiksTest* aiks_test,
                                                bool use_dithering) {
  Canvas canvas;
  canvas.Scale(aiks_test->GetContentScale());
  Paint paint;
  canvas.Translate({100.0, 100.0, 0});

  // #FFF -> #000
  std::vector<Color> colors = {Color{1.0, 1.0, 1.0, 1.0},
                               Color{0.0, 0.0, 0.0, 1.0}};
  std::vector<Scalar> stops = {0.0, 1.0};

  paint.color_source = ColorSource::MakeSweepGradient(
      {100, 100}, Degrees(45), Degrees(135), std::move(colors),
      std::move(stops), Entity::TileMode::kMirror, {});
  paint.dither = use_dithering;

  canvas.DrawRect({0, 0, 600, 600}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderSweepGradientWithDitheringDisabled) {
  CanRenderSweepGradientWithDithering(this, false);
}

TEST_P(AiksTest, CanRenderSweepGradientWithDitheringEnabled) {
  CanRenderSweepGradientWithDithering(this, true);
}

static void CanRenderConicalGradientWithDithering(AiksTest* aiks_test,
                                                  bool use_dithering) {
  Canvas canvas;
  canvas.Scale(aiks_test->GetContentScale());
  Paint paint;
  canvas.Translate({100.0, 100.0, 0});

  // #FFF -> #000
  std::vector<Color> colors = {Color{1.0, 1.0, 1.0, 1.0},
                               Color{0.0, 0.0, 0.0, 1.0}};
  std::vector<Scalar> stops = {0.0, 1.0};

  paint.color_source = ColorSource::MakeConicalGradient(
      {100, 100}, 100, std::move(colors), std::move(stops), {0, 1}, 0,
      Entity::TileMode::kMirror, {});
  paint.dither = use_dithering;

  canvas.DrawRect({0, 0, 600, 600}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderConicalGradientWithDitheringDisabled) {
  CanRenderConicalGradientWithDithering(this, false);
}

TEST_P(AiksTest, CanRenderConicalGradientWithDitheringEnabled) {
  CanRenderConicalGradientWithDithering(this, true);
}

namespace {
void CanRenderLinearGradientWithOverlappingStops(AiksTest* aiks_test,
                                                 Entity::TileMode tile_mode) {
  Canvas canvas;
  Paint paint;
  canvas.Translate({100.0, 100.0, 0});

  std::vector<Color> colors = {
      Color{0.9568, 0.2627, 0.2118, 1.0}, Color{0.9568, 0.2627, 0.2118, 1.0},
      Color{0.1294, 0.5882, 0.9529, 1.0}, Color{0.1294, 0.5882, 0.9529, 1.0}};
  std::vector<Scalar> stops = {0.0, 0.5, 0.5, 1.0};

  paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {500, 500}, std::move(colors), std::move(stops), tile_mode, {});

  paint.color = Color(1.0, 1.0, 1.0, 1.0);
  canvas.DrawRect({0, 0, 500, 500}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}
}  // namespace

// Only clamp is necessary. All tile modes are the same output.
TEST_P(AiksTest, CanRenderLinearGradientWithOverlappingStopsClamp) {
  CanRenderLinearGradientWithOverlappingStops(this, Entity::TileMode::kClamp);
}

namespace {
void CanRenderLinearGradientManyColors(AiksTest* aiks_test,
                                       Entity::TileMode tile_mode) {
  Canvas canvas;
  canvas.Scale(aiks_test->GetContentScale());
  Paint paint;
  canvas.Translate({100, 100, 0});

  std::vector<Color> colors = {
      Color{0x1f / 255.0, 0.0, 0x5c / 255.0, 1.0},
      Color{0x5b / 255.0, 0.0, 0x60 / 255.0, 1.0},
      Color{0x87 / 255.0, 0x01 / 255.0, 0x60 / 255.0, 1.0},
      Color{0xac / 255.0, 0x25 / 255.0, 0x53 / 255.0, 1.0},
      Color{0xe1 / 255.0, 0x6b / 255.0, 0x5c / 255.0, 1.0},
      Color{0xf3 / 255.0, 0x90 / 255.0, 0x60 / 255.0, 1.0},
      Color{0xff / 255.0, 0xb5 / 255.0, 0x6b / 250.0, 1.0}};
  std::vector<Scalar> stops = {
      0.0,
      (1.0 / 6.0) * 1,
      (1.0 / 6.0) * 2,
      (1.0 / 6.0) * 3,
      (1.0 / 6.0) * 4,
      (1.0 / 6.0) * 5,
      1.0,
  };

  paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {200, 200}, std::move(colors), std::move(stops), tile_mode, {});

  paint.color = Color(1.0, 1.0, 1.0, 1.0);
  canvas.DrawRect({0, 0, 600, 600}, paint);
  canvas.Restore();
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}
}  // namespace

TEST_P(AiksTest, CanRenderLinearGradientManyColorsClamp) {
  CanRenderLinearGradientManyColors(this, Entity::TileMode::kClamp);
}
TEST_P(AiksTest, CanRenderLinearGradientManyColorsRepeat) {
  CanRenderLinearGradientManyColors(this, Entity::TileMode::kRepeat);
}
TEST_P(AiksTest, CanRenderLinearGradientManyColorsMirror) {
  CanRenderLinearGradientManyColors(this, Entity::TileMode::kMirror);
}
TEST_P(AiksTest, CanRenderLinearGradientManyColorsDecal) {
  CanRenderLinearGradientManyColors(this, Entity::TileMode::kDecal);
}

namespace {
void CanRenderLinearGradientWayManyColors(AiksTest* aiks_test,
                                          Entity::TileMode tile_mode) {
  Canvas canvas;
  Paint paint;
  canvas.Translate({100.0, 100.0, 0});
  auto color = Color{0x1f / 255.0, 0.0, 0x5c / 255.0, 1.0};
  std::vector<Color> colors;
  std::vector<Scalar> stops;
  auto current_stop = 0.0;
  for (int i = 0; i < 2000; i++) {
    colors.push_back(color);
    stops.push_back(current_stop);
    current_stop += 1 / 2000.0;
  }
  stops[2000 - 1] = 1.0;

  paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {200, 200}, std::move(colors), std::move(stops), tile_mode, {});

  canvas.DrawRect({0, 0, 600, 600}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}
}  // namespace

// Only test clamp on purpose since they all look the same.
TEST_P(AiksTest, CanRenderLinearGradientWayManyColorsClamp) {
  CanRenderLinearGradientWayManyColors(this, Entity::TileMode::kClamp);
}

TEST_P(AiksTest, CanRenderLinearGradientManyColorsUnevenStops) {
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    const char* tile_mode_names[] = {"Clamp", "Repeat", "Mirror", "Decal"};
    const Entity::TileMode tile_modes[] = {
        Entity::TileMode::kClamp, Entity::TileMode::kRepeat,
        Entity::TileMode::kMirror, Entity::TileMode::kDecal};

    static int selected_tile_mode = 0;
    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    ImGui::Combo("Tile mode", &selected_tile_mode, tile_mode_names,
                 sizeof(tile_mode_names) / sizeof(char*));
    static Matrix matrix = {
        1, 0, 0, 0,  //
        0, 1, 0, 0,  //
        0, 0, 1, 0,  //
        0, 0, 0, 1   //
    };
    std::string label = "##1";
    for (int i = 0; i < 4; i++) {
      ImGui::InputScalarN(label.c_str(), ImGuiDataType_Float, &(matrix.vec[i]),
                          4, NULL, NULL, "%.2f", 0);
      label[2]++;
    }
    ImGui::End();

    Canvas canvas;
    Paint paint;
    canvas.Translate({100.0, 100.0, 0});
    auto tile_mode = tile_modes[selected_tile_mode];

    std::vector<Color> colors = {
        Color{0x1f / 255.0, 0.0, 0x5c / 255.0, 1.0},
        Color{0x5b / 255.0, 0.0, 0x60 / 255.0, 1.0},
        Color{0x87 / 255.0, 0x01 / 255.0, 0x60 / 255.0, 1.0},
        Color{0xac / 255.0, 0x25 / 255.0, 0x53 / 255.0, 1.0},
        Color{0xe1 / 255.0, 0x6b / 255.0, 0x5c / 255.0, 1.0},
        Color{0xf3 / 255.0, 0x90 / 255.0, 0x60 / 255.0, 1.0},
        Color{0xff / 255.0, 0xb5 / 255.0, 0x6b / 250.0, 1.0}};
    std::vector<Scalar> stops = {
        0.0, 2.0 / 62.0, 4.0 / 62.0, 8.0 / 62.0, 16.0 / 62.0, 32.0 / 62.0, 1.0,
    };

    paint.color_source = ColorSource::MakeLinearGradient(
        {0, 0}, {200, 200}, std::move(colors), std::move(stops), tile_mode, {});

    canvas.DrawRect({0, 0, 600, 600}, paint);
    return canvas.EndRecordingAsPicture();
  };
  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, CanRenderLinearGradientMaskBlur) {
  Canvas canvas;

  Paint paint = {
      .color = Color::White(),
      .color_source = ColorSource::MakeLinearGradient(
          {200, 200}, {400, 400},
          {Color::Red(), Color::White(), Color::Red(), Color::White(),
           Color::Red(), Color::White(), Color::Red(), Color::White(),
           Color::Red(), Color::White(), Color::Red()},
          {0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0},
          Entity::TileMode::kClamp, {}),
      .mask_blur_descriptor =
          Paint::MaskBlurDescriptor{
              .style = FilterContents::BlurStyle::kNormal,
              .sigma = Sigma(20),
          },
  };

  canvas.DrawCircle({300, 300}, 200, paint);
  canvas.DrawRect(Rect::MakeLTRB(100, 300, 500, 600), paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderRadialGradient) {
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    const char* tile_mode_names[] = {"Clamp", "Repeat", "Mirror", "Decal"};
    const Entity::TileMode tile_modes[] = {
        Entity::TileMode::kClamp, Entity::TileMode::kRepeat,
        Entity::TileMode::kMirror, Entity::TileMode::kDecal};

    static int selected_tile_mode = 0;
    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    ImGui::Combo("Tile mode", &selected_tile_mode, tile_mode_names,
                 sizeof(tile_mode_names) / sizeof(char*));
    static Matrix matrix = {
        1, 0, 0, 0,  //
        0, 1, 0, 0,  //
        0, 0, 1, 0,  //
        0, 0, 0, 1   //
    };
    std::string label = "##1";
    for (int i = 0; i < 4; i++) {
      ImGui::InputScalarN(label.c_str(), ImGuiDataType_Float, &(matrix.vec[i]),
                          4, NULL, NULL, "%.2f", 0);
      label[2]++;
    }
    ImGui::End();

    Canvas canvas;
    Paint paint;
    canvas.Translate({100.0, 100.0, 0});
    auto tile_mode = tile_modes[selected_tile_mode];

    std::vector<Color> colors = {Color{0.9568, 0.2627, 0.2118, 1.0},
                                 Color{0.1294, 0.5882, 0.9529, 1.0}};
    std::vector<Scalar> stops = {0.0, 1.0};

    paint.color_source = ColorSource::MakeRadialGradient(
        {100, 100}, 100, std::move(colors), std::move(stops), tile_mode, {});

    canvas.DrawRect({0, 0, 600, 600}, paint);
    return canvas.EndRecordingAsPicture();
  };
  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, CanRenderRadialGradientManyColors) {
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    const char* tile_mode_names[] = {"Clamp", "Repeat", "Mirror", "Decal"};
    const Entity::TileMode tile_modes[] = {
        Entity::TileMode::kClamp, Entity::TileMode::kRepeat,
        Entity::TileMode::kMirror, Entity::TileMode::kDecal};

    static int selected_tile_mode = 0;
    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    ImGui::Combo("Tile mode", &selected_tile_mode, tile_mode_names,
                 sizeof(tile_mode_names) / sizeof(char*));
    static Matrix matrix = {
        1, 0, 0, 0,  //
        0, 1, 0, 0,  //
        0, 0, 1, 0,  //
        0, 0, 0, 1   //
    };
    std::string label = "##1";
    for (int i = 0; i < 4; i++) {
      ImGui::InputScalarN(label.c_str(), ImGuiDataType_Float, &(matrix.vec[i]),
                          4, NULL, NULL, "%.2f", 0);
      label[2]++;
    }
    ImGui::End();

    Canvas canvas;
    Paint paint;
    canvas.Translate({100.0, 100.0, 0});
    auto tile_mode = tile_modes[selected_tile_mode];

    std::vector<Color> colors = {
        Color{0x1f / 255.0, 0.0, 0x5c / 255.0, 1.0},
        Color{0x5b / 255.0, 0.0, 0x60 / 255.0, 1.0},
        Color{0x87 / 255.0, 0x01 / 255.0, 0x60 / 255.0, 1.0},
        Color{0xac / 255.0, 0x25 / 255.0, 0x53 / 255.0, 1.0},
        Color{0xe1 / 255.0, 0x6b / 255.0, 0x5c / 255.0, 1.0},
        Color{0xf3 / 255.0, 0x90 / 255.0, 0x60 / 255.0, 1.0},
        Color{0xff / 255.0, 0xb5 / 255.0, 0x6b / 250.0, 1.0}};
    std::vector<Scalar> stops = {
        0.0,
        (1.0 / 6.0) * 1,
        (1.0 / 6.0) * 2,
        (1.0 / 6.0) * 3,
        (1.0 / 6.0) * 4,
        (1.0 / 6.0) * 5,
        1.0,
    };

    paint.color_source = ColorSource::MakeRadialGradient(
        {100, 100}, 100, std::move(colors), std::move(stops), tile_mode, {});

    canvas.DrawRect({0, 0, 600, 600}, paint);
    return canvas.EndRecordingAsPicture();
  };
  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

namespace {
void CanRenderSweepGradient(AiksTest* aiks_test, Entity::TileMode tile_mode) {
  Canvas canvas;
  canvas.Scale(aiks_test->GetContentScale());
  Paint paint;
  canvas.Translate({100, 100, 0});

  std::vector<Color> colors = {Color{0.9568, 0.2627, 0.2118, 1.0},
                               Color{0.1294, 0.5882, 0.9529, 1.0}};
  std::vector<Scalar> stops = {0.0, 1.0};

  paint.color_source = ColorSource::MakeSweepGradient(
      {100, 100}, Degrees(45), Degrees(135), std::move(colors),
      std::move(stops), tile_mode, {});

  canvas.DrawRect({0, 0, 600, 600}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}
}  // namespace

TEST_P(AiksTest, CanRenderSweepGradientClamp) {
  CanRenderSweepGradient(this, Entity::TileMode::kClamp);
}
TEST_P(AiksTest, CanRenderSweepGradientRepeat) {
  CanRenderSweepGradient(this, Entity::TileMode::kRepeat);
}
TEST_P(AiksTest, CanRenderSweepGradientMirror) {
  CanRenderSweepGradient(this, Entity::TileMode::kMirror);
}
TEST_P(AiksTest, CanRenderSweepGradientDecal) {
  CanRenderSweepGradient(this, Entity::TileMode::kDecal);
}

namespace {
void CanRenderSweepGradientManyColors(AiksTest* aiks_test,
                                      Entity::TileMode tile_mode) {
  Canvas canvas;
  Paint paint;
  canvas.Translate({100.0, 100.0, 0});

  std::vector<Color> colors = {
      Color{0x1f / 255.0, 0.0, 0x5c / 255.0, 1.0},
      Color{0x5b / 255.0, 0.0, 0x60 / 255.0, 1.0},
      Color{0x87 / 255.0, 0x01 / 255.0, 0x60 / 255.0, 1.0},
      Color{0xac / 255.0, 0x25 / 255.0, 0x53 / 255.0, 1.0},
      Color{0xe1 / 255.0, 0x6b / 255.0, 0x5c / 255.0, 1.0},
      Color{0xf3 / 255.0, 0x90 / 255.0, 0x60 / 255.0, 1.0},
      Color{0xff / 255.0, 0xb5 / 255.0, 0x6b / 250.0, 1.0}};
  std::vector<Scalar> stops = {
      0.0,
      (1.0 / 6.0) * 1,
      (1.0 / 6.0) * 2,
      (1.0 / 6.0) * 3,
      (1.0 / 6.0) * 4,
      (1.0 / 6.0) * 5,
      1.0,
  };

  paint.color_source = ColorSource::MakeSweepGradient(
      {100, 100}, Degrees(45), Degrees(135), std::move(colors),
      std::move(stops), tile_mode, {});

  canvas.DrawRect({0, 0, 600, 600}, paint);
  ASSERT_TRUE(aiks_test->OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}
}  // namespace

TEST_P(AiksTest, CanRenderSweepGradientManyColorsClamp) {
  CanRenderSweepGradientManyColors(this, Entity::TileMode::kClamp);
}
TEST_P(AiksTest, CanRenderSweepGradientManyColorsRepeat) {
  CanRenderSweepGradientManyColors(this, Entity::TileMode::kRepeat);
}
TEST_P(AiksTest, CanRenderSweepGradientManyColorsMirror) {
  CanRenderSweepGradientManyColors(this, Entity::TileMode::kMirror);
}
TEST_P(AiksTest, CanRenderSweepGradientManyColorsDecal) {
  CanRenderSweepGradientManyColors(this, Entity::TileMode::kDecal);
}

TEST_P(AiksTest, CanRenderConicalGradient) {
  Scalar size = 256;
  Canvas canvas;
  Paint paint;
  paint.color = Color::White();
  canvas.DrawRect({0, 0, size * 3, size * 3}, paint);
  std::vector<Color> colors = {Color::MakeRGBA8(0xF4, 0x43, 0x36, 0xFF),
                               Color::MakeRGBA8(0xFF, 0xEB, 0x3B, 0xFF),
                               Color::MakeRGBA8(0x4c, 0xAF, 0x50, 0xFF),
                               Color::MakeRGBA8(0x21, 0x96, 0xF3, 0xFF)};
  std::vector<Scalar> stops = {0.0, 1.f / 3.f, 2.f / 3.f, 1.0};
  std::array<std::tuple<Point, float, Point, float>, 8> array{
      std::make_tuple(Point{size / 2.f, size / 2.f}, 0.f,
                      Point{size / 2.f, size / 2.f}, size / 2.f),
      std::make_tuple(Point{size / 2.f, size / 2.f}, size / 4.f,
                      Point{size / 2.f, size / 2.f}, size / 2.f),
      std::make_tuple(Point{size / 4.f, size / 4.f}, 0.f,
                      Point{size / 2.f, size / 2.f}, size / 2.f),
      std::make_tuple(Point{size / 4.f, size / 4.f}, size / 2.f,
                      Point{size / 2.f, size / 2.f}, 0),
      std::make_tuple(Point{size / 4.f, size / 4.f}, size / 4.f,
                      Point{size / 2.f, size / 2.f}, size / 2.f),
      std::make_tuple(Point{size / 4.f, size / 4.f}, size / 16.f,
                      Point{size / 2.f, size / 2.f}, size / 8.f),
      std::make_tuple(Point{size / 4.f, size / 4.f}, size / 8.f,
                      Point{size / 2.f, size / 2.f}, size / 16.f),
      std::make_tuple(Point{size / 8.f, size / 8.f}, size / 8.f,
                      Point{size / 2.f, size / 2.f}, size / 8.f),
  };
  for (int i = 0; i < 8; i++) {
    canvas.Save();
    canvas.Translate({(i % 3) * size, i / 3 * size, 0});
    paint.color_source = ColorSource::MakeConicalGradient(
        std::get<0>(array[i]), std::get<1>(array[i]), colors, stops,
        std::get<2>(array[i]), std::get<3>(array[i]), Entity::TileMode::kClamp,
        {});
    canvas.DrawRect({0, 0, size, size}, paint);
    canvas.Restore();
  }
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderGradientDecalWithBackground) {
  std::vector<Color> colors = {Color::MakeRGBA8(0xF4, 0x43, 0x36, 0xFF),
                               Color::MakeRGBA8(0xFF, 0xEB, 0x3B, 0xFF),
                               Color::MakeRGBA8(0x4c, 0xAF, 0x50, 0xFF),
                               Color::MakeRGBA8(0x21, 0x96, 0xF3, 0xFF)};
  std::vector<Scalar> stops = {0.0, 1.f / 3.f, 2.f / 3.f, 1.0};

  std::array<ColorSource, 3> color_sources = {
      ColorSource::MakeLinearGradient({0, 0}, {100, 100}, colors, stops,
                                      Entity::TileMode::kDecal, {}),
      ColorSource::MakeRadialGradient({100, 100}, 100, colors, stops,
                                      Entity::TileMode::kDecal, {}),
      ColorSource::MakeSweepGradient({100, 100}, Degrees(45), Degrees(135),
                                     colors, stops, Entity::TileMode::kDecal,
                                     {}),
  };

  Canvas canvas;
  Paint paint;
  paint.color = Color::White();
  canvas.DrawRect(Rect::MakeLTRB(0, 0, 605, 205), paint);
  for (int i = 0; i < 3; i++) {
    canvas.Save();
    canvas.Translate({i * 200.0f, 0, 0});
    paint.color_source = color_sources[i];
    canvas.DrawRect(Rect::MakeLTRB(0, 0, 200, 200), paint);
    canvas.Restore();
  }
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderDifferentShapesWithSameColorSource) {
  Canvas canvas;
  Paint paint;

  std::vector<Color> colors = {Color{0.9568, 0.2627, 0.2118, 1.0},
                               Color{0.1294, 0.5882, 0.9529, 1.0}};
  std::vector<Scalar> stops = {
      0.0,
      1.0,
  };

  paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {100, 100}, std::move(colors), std::move(stops),
      Entity::TileMode::kRepeat, {});

  canvas.Save();
  canvas.Translate({100, 100, 0});
  canvas.DrawRect({0, 0, 200, 200}, paint);
  canvas.Restore();

  canvas.Save();
  canvas.Translate({100, 400, 0});
  canvas.DrawCircle({100, 100}, 100, paint);
  canvas.Restore();
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanPictureConvertToImage) {
  Canvas recorder_canvas;
  Paint paint;
  paint.color = Color{0.9568, 0.2627, 0.2118, 1.0};
  recorder_canvas.DrawRect({100.0, 100.0, 600, 600}, paint);
  paint.color = Color{0.1294, 0.5882, 0.9529, 1.0};
  recorder_canvas.DrawRect({200.0, 200.0, 600, 600}, paint);

  Canvas canvas;
  AiksContext renderer(GetContext(), nullptr);
  paint.color = Color::BlackTransparent();
  canvas.DrawPaint(paint);
  Picture picture = recorder_canvas.EndRecordingAsPicture();
  auto image = picture.ToImage(renderer, ISize{1000, 1000});
  if (image) {
    canvas.DrawImage(image, Point(), Paint());
    paint.color = Color{0.1, 0.1, 0.1, 0.2};
    canvas.DrawRect(Rect::MakeSize(ISize{1000, 1000}), paint);
  }

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, BlendModeShouldCoverWholeScreen) {
  Canvas canvas;
  Paint paint;

  paint.color = Color::Red();
  canvas.DrawPaint(paint);

  paint.blend_mode = BlendMode::kSourceOver;
  canvas.SaveLayer(paint);

  paint.color = Color::White();
  canvas.DrawRect({100, 100, 400, 400}, paint);

  paint.blend_mode = BlendMode::kSource;
  canvas.SaveLayer(paint);

  paint.color = Color::Blue();
  canvas.DrawRect({200, 200, 200, 200}, paint);

  canvas.Restore();
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderGroupOpacity) {
  Canvas canvas;

  Paint red;
  red.color = Color::Red();
  Paint green;
  green.color = Color::Green().WithAlpha(0.5);
  Paint blue;
  blue.color = Color::Blue();

  Paint alpha;
  alpha.color = Color::Red().WithAlpha(0.5);

  canvas.SaveLayer(alpha);

  canvas.DrawRect({000, 000, 100, 100}, red);
  canvas.DrawRect({020, 020, 100, 100}, green);
  canvas.DrawRect({040, 040, 100, 100}, blue);

  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CoordinateConversionsAreCorrect) {
  Canvas canvas;

  // Render a texture directly.
  {
    Paint paint;
    auto image =
        std::make_shared<Image>(CreateTextureForFixture("kalimba.jpg"));
    paint.color = Color::Red();

    canvas.Save();
    canvas.Translate({100, 200, 0});
    canvas.Scale(Vector2{0.5, 0.5});
    canvas.DrawImage(image, Point::MakeXY(100.0, 100.0), paint);
    canvas.Restore();
  }

  // Render an offscreen rendered texture.
  {
    Paint red;
    red.color = Color::Red();
    Paint green;
    green.color = Color::Green();
    Paint blue;
    blue.color = Color::Blue();

    Paint alpha;
    alpha.color = Color::Red().WithAlpha(0.5);

    canvas.SaveLayer(alpha);

    canvas.DrawRect({000, 000, 100, 100}, red);
    canvas.DrawRect({020, 020, 100, 100}, green);
    canvas.DrawRect({040, 040, 100, 100}, blue);

    canvas.Restore();
  }

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanPerformFullScreenMSAA) {
  Canvas canvas;

  Paint red;
  red.color = Color::Red();

  canvas.DrawCircle({250, 250}, 125, red);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanPerformSkew) {
  Canvas canvas;

  Paint red;
  red.color = Color::Red();

  canvas.Skew(2, 5);
  canvas.DrawRect(Rect::MakeXYWH(0, 0, 100, 100), red);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanPerformSaveLayerWithBounds) {
  Canvas canvas;

  Paint red;
  red.color = Color::Red();

  Paint green;
  green.color = Color::Green();

  Paint blue;
  blue.color = Color::Blue();

  Paint save;
  save.color = Color::Black();

  canvas.SaveLayer(save, Rect{0, 0, 50, 50});

  canvas.DrawRect({0, 0, 100, 100}, red);
  canvas.DrawRect({10, 10, 100, 100}, green);
  canvas.DrawRect({20, 20, 100, 100}, blue);

  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest,
       CanPerformSaveLayerWithBoundsAndLargerIntermediateIsNotAllocated) {
  Canvas canvas;

  Paint red;
  red.color = Color::Red();

  Paint green;
  green.color = Color::Green();

  Paint blue;
  blue.color = Color::Blue();

  Paint save;
  save.color = Color::Black().WithAlpha(0.5);

  canvas.SaveLayer(save, Rect{0, 0, 100000, 100000});

  canvas.DrawRect({0, 0, 100, 100}, red);
  canvas.DrawRect({10, 10, 100, 100}, green);
  canvas.DrawRect({20, 20, 100, 100}, blue);

  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderRoundedRectWithNonUniformRadii) {
  Canvas canvas;

  Paint paint;
  paint.color = Color::Red();

  PathBuilder::RoundingRadii radii;
  radii.top_left = {50, 25};
  radii.top_right = {25, 50};
  radii.bottom_right = {50, 25};
  radii.bottom_left = {25, 50};

  auto path =
      PathBuilder{}.AddRoundedRect(Rect{100, 100, 500, 500}, radii).TakePath();

  canvas.DrawPath(path, paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderStrokePathThatEndsAtSharpTurn) {
  Canvas canvas;

  Paint paint;
  paint.color = Color::Red();
  paint.style = Paint::Style::kStroke;
  paint.stroke_width = 200;

  Rect rect = {100, 100, 200, 200};
  PathBuilder builder;
  builder.AddArc(rect, Degrees(0), Degrees(90), false);

  canvas.DrawPath(builder.TakePath(), paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderStrokePathWithCubicLine) {
  Canvas canvas;

  Paint paint;
  paint.color = Color::Red();
  paint.style = Paint::Style::kStroke;
  paint.stroke_width = 20;

  PathBuilder builder;
  builder.AddCubicCurve({0, 200}, {50, 400}, {350, 0}, {400, 200});

  canvas.DrawPath(builder.TakePath(), paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderDifferencePaths) {
  Canvas canvas;

  Paint paint;
  paint.color = Color::Red();

  PathBuilder builder;

  PathBuilder::RoundingRadii radii;
  radii.top_left = {50, 25};
  radii.top_right = {25, 50};
  radii.bottom_right = {50, 25};
  radii.bottom_left = {25, 50};

  builder.AddRoundedRect({100, 100, 200, 200}, radii);
  builder.AddCircle({200, 200}, 50);
  auto path = builder.TakePath(FillType::kOdd);

  canvas.DrawImage(
      std::make_shared<Image>(CreateTextureForFixture("boston.jpg")), {10, 10},
      Paint{});
  canvas.DrawPath(path, paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

// Regression test for https://github.com/flutter/flutter/issues/134816.
//
// It should be possible to draw 3 lines, and not have an implicit close path.
TEST_P(AiksTest, CanDrawAnOpenPath) {
  Canvas canvas;

  // Starting at (50, 50), draw lines from:
  // 1. (50, height)
  // 2. (width, height)
  // 3. (width, 50)
  PathBuilder builder;
  builder.MoveTo({50, 50});
  builder.LineTo({50, 100});
  builder.LineTo({100, 100});
  builder.LineTo({100, 50});

  Paint paint;
  paint.color = Color::Red();
  paint.style = Paint::Style::kStroke;
  paint.stroke_width = 10;

  canvas.DrawPath(builder.TakePath(), paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanDrawAnOpenPathThatIsntARect) {
  Canvas canvas;

  // Draw a stroked path that is explicitly closed to verify
  // It doesn't become a rectangle.
  PathBuilder builder;
  builder.MoveTo({50, 50});
  builder.LineTo({520, 120});
  builder.LineTo({300, 310});
  builder.LineTo({100, 50});
  builder.Close();

  Paint paint;
  paint.color = Color::Red();
  paint.style = Paint::Style::kStroke;
  paint.stroke_width = 10;

  canvas.DrawPath(builder.TakePath(), paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

static sk_sp<SkData> OpenFixtureAsSkData(const char* fixture_name) {
  auto mapping = flutter::testing::OpenFixtureAsMapping(fixture_name);
  if (!mapping) {
    return nullptr;
  }
  auto data = SkData::MakeWithProc(
      mapping->GetMapping(), mapping->GetSize(),
      [](const void* ptr, void* context) {
        delete reinterpret_cast<fml::Mapping*>(context);
      },
      mapping.get());
  mapping.release();
  return data;
}

struct TextRenderOptions {
  Scalar font_size = 50;
  Scalar alpha = 1;
  Point position = Vector2(100, 200);
};

bool RenderTextInCanvasSkia(const std::shared_ptr<Context>& context,
                            Canvas& canvas,
                            const std::string& text,
                            const std::string& font_fixture,
                            TextRenderOptions options = {}) {
  // Draw the baseline.
  canvas.DrawRect({options.position.x - 50, options.position.y, 900, 10},
                  Paint{.color = Color::Aqua().WithAlpha(0.25)});

  // Mark the point at which the text is drawn.
  canvas.DrawCircle(options.position, 5.0,
                    Paint{.color = Color::Red().WithAlpha(0.25)});

  // Construct the text blob.
  auto mapping = OpenFixtureAsSkData(font_fixture.c_str());
  if (!mapping) {
    return false;
  }
  SkFont sk_font(SkTypeface::MakeFromData(mapping), options.font_size);
  auto blob = SkTextBlob::MakeFromString(text.c_str(), sk_font);
  if (!blob) {
    return false;
  }

  // Create the Impeller text frame and draw it at the designated baseline.
  auto frame = MakeTextFrameFromTextBlobSkia(blob);

  Paint text_paint;
  text_paint.color = Color::Yellow().WithAlpha(options.alpha);
  canvas.DrawTextFrame(frame, options.position, text_paint);
  return true;
}

bool RenderTextInCanvasSTB(const std::shared_ptr<Context>& context,
                           Canvas& canvas,
                           const std::string& text,
                           const std::string& font_fixture,
                           TextRenderOptions options = {}) {
  // Draw the baseline.
  canvas.DrawRect({options.position.x - 50, options.position.y, 900, 10},
                  Paint{.color = Color::Aqua().WithAlpha(0.25)});

  // Mark the point at which the text is drawn.
  canvas.DrawCircle(options.position, 5.0,
                    Paint{.color = Color::Red().WithAlpha(0.25)});

  // Construct the text blob.
  auto mapping = flutter::testing::OpenFixtureAsMapping(font_fixture.c_str());
  if (!mapping) {
    return false;
  }
  auto typeface_stb = std::make_shared<TypefaceSTB>(std::move(mapping));

  auto frame = MakeTextFrameSTB(
      typeface_stb, Font::Metrics{.point_size = options.font_size}, text);

  Paint text_paint;
  text_paint.color = Color::Yellow().WithAlpha(options.alpha);
  canvas.DrawTextFrame(frame, options.position, text_paint);
  return true;
}

TEST_P(AiksTest, CanRenderTextFrame) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
      "Roboto-Regular.ttf"));
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderTextFrameSTB) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
  ASSERT_TRUE(RenderTextInCanvasSTB(
      GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
      "Roboto-Regular.ttf"));

  SetTypographerContext(TypographerContextSTB::Make());
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TextFrameSubpixelAlignment) {
  std::array<Scalar, 20> phase_offsets;
  for (Scalar& offset : phase_offsets) {
    auto rand = std::rand();  // NOLINT
    offset = (static_cast<float>(rand) / static_cast<float>(RAND_MAX)) * k2Pi;
  }

  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    static float font_size = 20;
    static float phase_variation = 0.2;
    static float speed = 0.5;
    static float magnitude = 100;
    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    ImGui::SliderFloat("Font size", &font_size, 5, 50);
    ImGui::SliderFloat("Phase variation", &phase_variation, 0, 1);
    ImGui::SliderFloat("Oscillation speed", &speed, 0, 2);
    ImGui::SliderFloat("Oscillation magnitude", &magnitude, 0, 300);
    ImGui::End();

    Canvas canvas;
    canvas.Scale(GetContentScale());

    for (size_t i = 0; i < phase_offsets.size(); i++) {
      auto position = Point(
          200 + magnitude * std::sin((-phase_offsets[i] * phase_variation +
                                      GetSecondsElapsed() * speed)),  //
          200 + i * font_size * 1.1                                   //
      );
      if (!RenderTextInCanvasSkia(
              GetContext(), canvas,
              "the quick brown fox jumped over "
              "the lazy dog!.?",
              "Roboto-Regular.ttf",
              {.font_size = font_size, .position = position})) {
        return std::nullopt;
      }
    }
    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, CanRenderItalicizedText) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});

  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
      "HomemadeApple.ttf"));
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderEmojiTextFrame) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});

  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas,
                                     "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
#if FML_OS_MACOSX
                                     "Apple Color Emoji.ttc"));
#else
                                     "NotoColorEmoji.ttf"));
#endif
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderEmojiTextFrameWithAlpha) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});

  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas,
                                     "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
#if FML_OS_MACOSX
                                     "Apple Color Emoji.ttc", { .alpha = 0.5 }
#else
                                     "NotoColorEmoji.ttf", {.alpha = 0.5}
#endif
                                     ));
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderTextInSaveLayer) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});

  canvas.Translate({100, 100});
  canvas.Scale(Vector2{0.5, 0.5});

  // Blend the layer with the parent pass using kClear to expose the coverage.
  canvas.SaveLayer({.blend_mode = BlendMode::kClear});
  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
      "Roboto-Regular.ttf"));
  canvas.Restore();

  // Render the text again over the cleared coverage rect.
  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
      "Roboto-Regular.ttf"));

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderTextOutsideBoundaries) {
  Canvas canvas;
  canvas.Translate({200, 150});

  // Construct the text blob.
  auto mapping = OpenFixtureAsSkData("wtf.otf");
  ASSERT_NE(mapping, nullptr);

  Scalar font_size = 80;
  SkFont sk_font(SkTypeface::MakeFromData(mapping), font_size);

  Paint text_paint;
  text_paint.color = Color::Blue().WithAlpha(0.8);

  struct {
    Point position;
    const char* text;
  } text[] = {{Point(0, 0), "0F0F0F0"},
              {Point(1, 2), "789"},
              {Point(1, 3), "456"},
              {Point(1, 4), "123"},
              {Point(0, 6), "0F0F0F0"}};
  for (auto& t : text) {
    canvas.Save();
    canvas.Translate(t.position * Point(font_size * 2, font_size * 1.1));
    {
      auto blob = SkTextBlob::MakeFromString(t.text, sk_font);
      ASSERT_NE(blob, nullptr);
      auto frame = MakeTextFrameFromTextBlobSkia(blob);
      canvas.DrawTextFrame(frame, Point(), text_paint);
    }
    canvas.Restore();
  }

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TextRotated) {
  Canvas canvas;
  canvas.Scale(GetContentScale());
  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});

  canvas.Transform(Matrix(0.25, -0.3, 0, -0.002,  //
                          0, 0.5, 0, 0,           //
                          0, 0, 0.3, 0,           //
                          100, 100, 0, 1.3));
  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
      "Roboto-Regular.ttf"));

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanDrawPaint) {
  Canvas canvas;
  canvas.Scale(Vector2(0.2, 0.2));
  canvas.DrawPaint({.color = Color::MediumTurquoise()});
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanDrawPaintMultipleTimes) {
  Canvas canvas;
  canvas.Scale(Vector2(0.2, 0.2));
  canvas.DrawPaint({.color = Color::MediumTurquoise()});
  canvas.DrawPaint({.color = Color::Color::OrangeRed().WithAlpha(0.5)});
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanDrawPaintWithAdvancedBlend) {
  Canvas canvas;
  canvas.Scale(Vector2(0.2, 0.2));
  canvas.DrawPaint({.color = Color::MediumTurquoise()});
  canvas.DrawPaint({.color = Color::Color::OrangeRed().WithAlpha(0.5),
                    .blend_mode = BlendMode::kHue});
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, DrawPaintWithAdvancedBlendOverFilter) {
  Paint filtered = {
      .color = Color::Black(),
      .mask_blur_descriptor =
          Paint::MaskBlurDescriptor{
              .style = FilterContents::BlurStyle::kNormal,
              .sigma = Sigma(60),
          },
  };

  Canvas canvas;
  canvas.DrawPaint({.color = Color::White()});
  canvas.DrawCircle({300, 300}, 200, filtered);
  canvas.DrawPaint({.color = Color::Green(), .blend_mode = BlendMode::kScreen});
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

#define BLEND_MODE_TUPLE(blend_mode) {#blend_mode, BlendMode::k##blend_mode},

struct BlendModeSelection {
  std::vector<const char*> blend_mode_names;
  std::vector<BlendMode> blend_mode_values;
};

static BlendModeSelection GetBlendModeSelection() {
  std::vector<const char*> blend_mode_names;
  std::vector<BlendMode> blend_mode_values;
  {
    const std::vector<std::tuple<const char*, BlendMode>> blends = {
        IMPELLER_FOR_EACH_BLEND_MODE(BLEND_MODE_TUPLE)};
    assert(blends.size() ==
           static_cast<size_t>(Entity::kLastAdvancedBlendMode) + 1);
    for (const auto& [name, mode] : blends) {
      blend_mode_names.push_back(name);
      blend_mode_values.push_back(mode);
    }
  }

  return {blend_mode_names, blend_mode_values};
}

TEST_P(AiksTest, CanDrawPaintMultipleTimesInteractive) {
  auto modes = GetBlendModeSelection();

  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    static Color background = Color::MediumTurquoise();
    static Color foreground = Color::Color::OrangeRed().WithAlpha(0.5);
    static int current_blend_index = 3;

    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    {
      ImGui::ColorEdit4("Background", reinterpret_cast<float*>(&background));
      ImGui::ColorEdit4("Foreground", reinterpret_cast<float*>(&foreground));
      ImGui::ListBox("Blend mode", &current_blend_index,
                     modes.blend_mode_names.data(),
                     modes.blend_mode_names.size());
    }
    ImGui::End();

    Canvas canvas;
    canvas.Scale(Vector2(0.2, 0.2));
    canvas.DrawPaint({.color = background});
    canvas.DrawPaint(
        {.color = foreground,
         .blend_mode = static_cast<BlendMode>(current_blend_index)});
    return canvas.EndRecordingAsPicture();
  };
  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, PaintBlendModeIsRespected) {
  Paint paint;
  Canvas canvas;
  // Default is kSourceOver.
  paint.color = Color(1, 0, 0, 0.5);
  canvas.DrawCircle(Point(150, 200), 100, paint);
  paint.color = Color(0, 1, 0, 0.5);
  canvas.DrawCircle(Point(250, 200), 100, paint);

  paint.blend_mode = BlendMode::kPlus;
  paint.color = Color::Red();
  canvas.DrawCircle(Point(450, 250), 100, paint);
  paint.color = Color::Green();
  canvas.DrawCircle(Point(550, 250), 100, paint);
  paint.color = Color::Blue();
  canvas.DrawCircle(Point(500, 150), 100, paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, ColorWheel) {
  // Compare with https://fiddle.skia.org/c/@BlendModes

  BlendModeSelection blend_modes = GetBlendModeSelection();

  auto draw_color_wheel = [](Canvas& canvas) {
    /// color_wheel_sampler: r=0 -> fuchsia, r=2pi/3 -> yellow, r=4pi/3 ->
    /// cyan domain: r >= 0 (because modulo used is non euclidean)
    auto color_wheel_sampler = [](Radians r) {
      Scalar x = r.radians / k2Pi + 1;

      // https://www.desmos.com/calculator/6nhjelyoaj
      auto color_cycle = [](Scalar x) {
        Scalar cycle = std::fmod(x, 6.0f);
        return std::max(0.0f, std::min(1.0f, 2 - std::abs(2 - cycle)));
      };
      return Color(color_cycle(6 * x + 1),  //
                   color_cycle(6 * x - 1),  //
                   color_cycle(6 * x - 3),  //
                   1);
    };

    Paint paint;
    paint.blend_mode = BlendMode::kSourceOver;

    // Draw a fancy color wheel for the backdrop.
    // https://www.desmos.com/calculator/xw7kafthwd
    const int max_dist = 900;
    for (int i = 0; i <= 900; i++) {
      Radians r(kPhi / k2Pi * i);
      Scalar distance = r.radians / std::powf(4.12, 0.0026 * r.radians);
      Scalar normalized_distance = static_cast<Scalar>(i) / max_dist;

      paint.color =
          color_wheel_sampler(r).WithAlpha(1.0f - normalized_distance);
      Point position(distance * std::sin(r.radians),
                     -distance * std::cos(r.radians));

      canvas.DrawCircle(position, 9 + normalized_distance * 3, paint);
    }
  };

  std::shared_ptr<Image> color_wheel_image;
  Matrix color_wheel_transform;

  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    // UI state.
    static bool cache_the_wheel = true;
    static int current_blend_index = 3;
    static float dst_alpha = 1;
    static float src_alpha = 1;
    static Color color0 = Color::Red();
    static Color color1 = Color::Green();
    static Color color2 = Color::Blue();

    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    {
      ImGui::Checkbox("Cache the wheel", &cache_the_wheel);
      ImGui::ListBox("Blending mode", &current_blend_index,
                     blend_modes.blend_mode_names.data(),
                     blend_modes.blend_mode_names.size());
      ImGui::SliderFloat("Source alpha", &src_alpha, 0, 1);
      ImGui::ColorEdit4("Color A", reinterpret_cast<float*>(&color0));
      ImGui::ColorEdit4("Color B", reinterpret_cast<float*>(&color1));
      ImGui::ColorEdit4("Color C", reinterpret_cast<float*>(&color2));
      ImGui::SliderFloat("Destination alpha", &dst_alpha, 0, 1);
    }
    ImGui::End();

    static Point content_scale;
    Point new_content_scale = GetContentScale();

    if (!cache_the_wheel || new_content_scale != content_scale) {
      content_scale = new_content_scale;

      // Render the color wheel to an image.

      Canvas canvas;
      canvas.Scale(content_scale);

      canvas.Translate(Vector2(500, 400));
      canvas.Scale(Vector2(3, 3));

      draw_color_wheel(canvas);
      auto color_wheel_picture = canvas.EndRecordingAsPicture();
      auto snapshot = color_wheel_picture.Snapshot(renderer);
      if (!snapshot.has_value() || !snapshot->texture) {
        return std::nullopt;
      }
      color_wheel_image = std::make_shared<Image>(snapshot->texture);
      color_wheel_transform = snapshot->transform;
    }

    Canvas canvas;

    // Blit the color wheel backdrop to the screen with managed alpha.
    canvas.SaveLayer({.color = Color::White().WithAlpha(dst_alpha),
                      .blend_mode = BlendMode::kSource});
    {
      canvas.DrawPaint({.color = Color::White()});

      canvas.Save();
      canvas.Transform(color_wheel_transform);
      canvas.DrawImage(color_wheel_image, Point(), Paint());
      canvas.Restore();
    }
    canvas.Restore();

    canvas.Scale(content_scale);
    canvas.Translate(Vector2(500, 400));
    canvas.Scale(Vector2(3, 3));

    // Draw 3 circles to a subpass and blend it in.
    canvas.SaveLayer(
        {.color = Color::White().WithAlpha(src_alpha),
         .blend_mode = blend_modes.blend_mode_values[current_blend_index]});
    {
      Paint paint;
      paint.blend_mode = BlendMode::kPlus;
      const Scalar x = std::sin(k2Pi / 3);
      const Scalar y = -std::cos(k2Pi / 3);
      paint.color = color0;
      canvas.DrawCircle(Point(-x, y) * 45, 65, paint);
      paint.color = color1;
      canvas.DrawCircle(Point(0, -1) * 45, 65, paint);
      paint.color = color2;
      canvas.DrawCircle(Point(x, y) * 45, 65, paint);
    }
    canvas.Restore();

    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, TransformMultipliesCorrectly) {
  Canvas canvas;
  ASSERT_MATRIX_NEAR(canvas.GetCurrentTransformation(), Matrix());

  // clang-format off
  canvas.Translate(Vector3(100, 200));
  ASSERT_MATRIX_NEAR(
    canvas.GetCurrentTransformation(),
    Matrix(  1,   0,   0,   0,
             0,   1,   0,   0,
             0,   0,   1,   0,
           100, 200,   0,   1));

  canvas.Rotate(Radians(kPiOver2));
  ASSERT_MATRIX_NEAR(
    canvas.GetCurrentTransformation(),
    Matrix(  0,   1,   0,   0,
            -1,   0,   0,   0,
             0,   0,   1,   0,
           100, 200,   0,   1));

  canvas.Scale(Vector3(2, 3));
  ASSERT_MATRIX_NEAR(
    canvas.GetCurrentTransformation(),
    Matrix(  0,   2,   0,   0,
            -3,   0,   0,   0,
             0,   0,   0,   0,
           100, 200,   0,   1));

  canvas.Translate(Vector3(100, 200));
  ASSERT_MATRIX_NEAR(
    canvas.GetCurrentTransformation(),
    Matrix(   0,   2,   0,   0,
             -3,   0,   0,   0,
              0,   0,   0,   0,
           -500, 400,   0,   1));
  // clang-format on
}

TEST_P(AiksTest, SolidStrokesRenderCorrectly) {
  // Compare with https://fiddle.skia.org/c/027392122bec8ac2b5d5de00a4b9bbe2
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    static Color color = Color::Black().WithAlpha(0.5);
    static float scale = 3;
    static bool add_circle_clip = true;

    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    ImGui::ColorEdit4("Color", reinterpret_cast<float*>(&color));
    ImGui::SliderFloat("Scale", &scale, 0, 6);
    ImGui::Checkbox("Circle clip", &add_circle_clip);
    ImGui::End();

    Canvas canvas;
    canvas.Scale(GetContentScale());
    Paint paint;

    paint.color = Color::White();
    canvas.DrawPaint(paint);

    paint.color = color;
    paint.style = Paint::Style::kStroke;
    paint.stroke_width = 10;

    Path path = PathBuilder{}
                    .MoveTo({20, 20})
                    .QuadraticCurveTo({60, 20}, {60, 60})
                    .Close()
                    .MoveTo({60, 20})
                    .QuadraticCurveTo({60, 60}, {20, 60})
                    .TakePath();

    canvas.Scale(Vector2(scale, scale));

    if (add_circle_clip) {
      auto [handle_a, handle_b] = IMPELLER_PLAYGROUND_LINE(
          Point(60, 300), Point(600, 300), 20, Color::Red(), Color::Red());

      auto screen_to_canvas = canvas.GetCurrentTransformation().Invert();
      Point point_a = screen_to_canvas * handle_a * GetContentScale();
      Point point_b = screen_to_canvas * handle_b * GetContentScale();

      Point middle = (point_a + point_b) / 2;
      auto radius = point_a.GetDistance(middle);
      canvas.ClipPath(PathBuilder{}.AddCircle(middle, radius).TakePath());
    }

    for (auto join : {Join::kBevel, Join::kRound, Join::kMiter}) {
      paint.stroke_join = join;
      for (auto cap : {Cap::kButt, Cap::kSquare, Cap::kRound}) {
        paint.stroke_cap = cap;
        canvas.DrawPath(path, paint);
        canvas.Translate({80, 0});
      }
      canvas.Translate({-240, 60});
    }

    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, GradientStrokesRenderCorrectly) {
  // Compare with https://fiddle.skia.org/c/027392122bec8ac2b5d5de00a4b9bbe2
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    static float scale = 3;
    static bool add_circle_clip = true;
    const char* tile_mode_names[] = {"Clamp", "Repeat", "Mirror", "Decal"};
    const Entity::TileMode tile_modes[] = {
        Entity::TileMode::kClamp, Entity::TileMode::kRepeat,
        Entity::TileMode::kMirror, Entity::TileMode::kDecal};
    static int selected_tile_mode = 0;
    static float alpha = 1;

    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    ImGui::SliderFloat("Scale", &scale, 0, 6);
    ImGui::Checkbox("Circle clip", &add_circle_clip);
    ImGui::SliderFloat("Alpha", &alpha, 0, 1);
    ImGui::Combo("Tile mode", &selected_tile_mode, tile_mode_names,
                 sizeof(tile_mode_names) / sizeof(char*));
    ImGui::End();

    Canvas canvas;
    canvas.Scale(GetContentScale());
    Paint paint;
    paint.color = Color::White();
    canvas.DrawPaint(paint);

    paint.style = Paint::Style::kStroke;
    paint.color = Color(1.0, 1.0, 1.0, alpha);
    paint.stroke_width = 10;
    auto tile_mode = tile_modes[selected_tile_mode];

    std::vector<Color> colors = {Color{0.9568, 0.2627, 0.2118, 1.0},
                                 Color{0.1294, 0.5882, 0.9529, 1.0}};
    std::vector<Scalar> stops = {0.0, 1.0};

    paint.color_source = ColorSource::MakeLinearGradient(
        {0, 0}, {50, 50}, std::move(colors), std::move(stops), tile_mode, {});

    Path path = PathBuilder{}
                    .MoveTo({20, 20})
                    .QuadraticCurveTo({60, 20}, {60, 60})
                    .Close()
                    .MoveTo({60, 20})
                    .QuadraticCurveTo({60, 60}, {20, 60})
                    .TakePath();

    canvas.Scale(Vector2(scale, scale));

    if (add_circle_clip) {
      auto [handle_a, handle_b] = IMPELLER_PLAYGROUND_LINE(
          Point(60, 300), Point(600, 300), 20, Color::Red(), Color::Red());

      auto screen_to_canvas = canvas.GetCurrentTransformation().Invert();
      Point point_a = screen_to_canvas * handle_a * GetContentScale();
      Point point_b = screen_to_canvas * handle_b * GetContentScale();

      Point middle = (point_a + point_b) / 2;
      auto radius = point_a.GetDistance(middle);
      canvas.ClipPath(PathBuilder{}.AddCircle(middle, radius).TakePath());
    }

    for (auto join : {Join::kBevel, Join::kRound, Join::kMiter}) {
      paint.stroke_join = join;
      for (auto cap : {Cap::kButt, Cap::kSquare, Cap::kRound}) {
        paint.stroke_cap = cap;
        canvas.DrawPath(path, paint);
        canvas.Translate({80, 0});
      }
      canvas.Translate({-240, 60});
    }

    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, CoverageOriginShouldBeAccountedForInSubpasses) {
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    Canvas canvas;
    canvas.Scale(GetContentScale());

    Paint alpha;
    alpha.color = Color::Red().WithAlpha(0.5);

    auto current = Point{25, 25};
    const auto offset = Point{25, 25};
    const auto size = Size(100, 100);

    auto [b0, b1] = IMPELLER_PLAYGROUND_LINE(Point(40, 40), Point(160, 160), 10,
                                             Color::White(), Color::White());
    auto bounds = Rect::MakeLTRB(b0.x, b0.y, b1.x, b1.y);

    canvas.DrawRect(bounds, Paint{.color = Color::Yellow(),
                                  .stroke_width = 5.0f,
                                  .style = Paint::Style::kStroke});

    canvas.SaveLayer(alpha, bounds);

    canvas.DrawRect({current, size}, Paint{.color = Color::Red()});
    canvas.DrawRect({current += offset, size}, Paint{.color = Color::Green()});
    canvas.DrawRect({current += offset, size}, Paint{.color = Color::Blue()});

    canvas.Restore();

    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, DrawRectStrokesRenderCorrectly) {
  Canvas canvas;
  Paint paint;
  paint.color = Color::Red();
  paint.style = Paint::Style::kStroke;
  paint.stroke_width = 10;

  canvas.Translate({100, 100});
  canvas.DrawPath(
      PathBuilder{}.AddRect(Rect::MakeSize(Size{100, 100})).TakePath(),
      {paint});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, DrawRectStrokesWithBevelJoinRenderCorrectly) {
  Canvas canvas;
  Paint paint;
  paint.color = Color::Red();
  paint.style = Paint::Style::kStroke;
  paint.stroke_width = 10;
  paint.stroke_join = Join::kBevel;

  canvas.Translate({100, 100});
  canvas.DrawPath(
      PathBuilder{}.AddRect(Rect::MakeSize(Size{100, 100})).TakePath(),
      {paint});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, SaveLayerDrawsBehindSubsequentEntities) {
  // Compare with https://fiddle.skia.org/c/9e03de8567ffb49e7e83f53b64bcf636
  Canvas canvas;
  Paint paint;

  paint.color = Color::Black();
  Rect rect(25, 25, 25, 25);
  canvas.DrawRect(rect, paint);

  canvas.Translate({10, 10});
  canvas.SaveLayer({});

  paint.color = Color::Green();
  canvas.DrawRect(rect, paint);

  canvas.Restore();

  canvas.Translate({10, 10});
  paint.color = Color::Red();
  canvas.DrawRect(rect, paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, SiblingSaveLayerBoundsAreRespected) {
  Canvas canvas;
  Paint paint;
  Rect rect(0, 0, 1000, 1000);

  // Black, green, and red squares offset by [10, 10].
  {
    canvas.SaveLayer({}, Rect::MakeXYWH(25, 25, 25, 25));
    paint.color = Color::Black();
    canvas.DrawRect(rect, paint);
    canvas.Restore();
  }

  {
    canvas.SaveLayer({}, Rect::MakeXYWH(35, 35, 25, 25));
    paint.color = Color::Green();
    canvas.DrawRect(rect, paint);
    canvas.Restore();
  }

  {
    canvas.SaveLayer({}, Rect::MakeXYWH(45, 45, 25, 25));
    paint.color = Color::Red();
    canvas.DrawRect(rect, paint);
    canvas.Restore();
  }

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderClippedLayers) {
  Canvas canvas;

  canvas.DrawPaint({.color = Color::White()});

  // Draw a green circle on the screen.
  {
    // Increase the clip depth for the savelayer to contend with.
    canvas.ClipPath(PathBuilder{}.AddCircle({100, 100}, 50).TakePath());

    canvas.SaveLayer({}, Rect::MakeXYWH(50, 50, 100, 100));

    // Fill the layer with white.
    canvas.DrawRect(Rect::MakeSize(Size{400, 400}), {.color = Color::White()});
    // Fill the layer with green, but do so with a color blend that can't be
    // collapsed into the parent pass.
    canvas.DrawRect(
        Rect::MakeSize(Size{400, 400}),
        {.color = Color::Green(), .blend_mode = BlendMode::kColorBurn});
  }

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, SaveLayerFiltersScaleWithTransform) {
  Canvas canvas;
  canvas.Scale(GetContentScale());
  canvas.Translate(Vector2(100, 100));

  auto texture = std::make_shared<Image>(CreateTextureForFixture("boston.jpg"));
  auto draw_image_layer = [&canvas, &texture](const Paint& paint) {
    canvas.SaveLayer(paint);
    canvas.DrawImage(texture, {}, Paint{});
    canvas.Restore();
  };

  Paint effect_paint;
  effect_paint.mask_blur_descriptor = Paint::MaskBlurDescriptor{
      .style = FilterContents::BlurStyle::kNormal,
      .sigma = Sigma{6},
  };
  draw_image_layer(effect_paint);

  canvas.Translate(Vector2(300, 300));
  canvas.Scale(Vector2(3, 3));
  draw_image_layer(effect_paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

#if IMPELLER_ENABLE_3D
TEST_P(AiksTest, SceneColorSource) {
  // Load up the scene.
  auto mapping =
      flutter::testing::OpenFixtureAsMapping("flutter_logo_baked.glb.ipscene");
  ASSERT_NE(mapping, nullptr);

  std::shared_ptr<scene::Node> gltf_scene = scene::Node::MakeFromFlatbuffer(
      *mapping, *GetContext()->GetResourceAllocator());
  ASSERT_NE(gltf_scene, nullptr);

  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    Paint paint;

    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    static Scalar distance = 2;
    ImGui::SliderFloat("Distance", &distance, 0, 4);
    static Scalar y_pos = 0;
    ImGui::SliderFloat("Y", &y_pos, -3, 3);
    static Scalar fov = 45;
    ImGui::SliderFloat("FOV", &fov, 1, 180);
    ImGui::End();

    Scalar angle = GetSecondsElapsed();
    auto camera_position =
        Vector3(distance * std::sin(angle), y_pos, -distance * std::cos(angle));

    paint.color_source = ColorSource::MakeScene(
        gltf_scene,
        Matrix::MakePerspective(Degrees(fov), GetWindowSize(), 0.1, 1000) *
            Matrix::MakeLookAt(camera_position, {0, 0, 0}, {0, 1, 0}));

    Canvas canvas;
    canvas.DrawPaint(Paint{.color = Color::MakeRGBA8(0xf9, 0xf9, 0xf9, 0xff)});
    canvas.Scale(GetContentScale());
    canvas.DrawPaint(paint);
    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}
#endif  // IMPELLER_ENABLE_3D

TEST_P(AiksTest, PaintWithFilters) {
  // validate that a paint with a color filter "HasFilters", no other filters
  // impact this setting.
  Paint paint;

  ASSERT_FALSE(paint.HasColorFilter());

  paint.color_filter =
      ColorFilter::MakeBlend(BlendMode::kSourceOver, Color::Blue());

  ASSERT_TRUE(paint.HasColorFilter());

  paint.image_filter = ImageFilter::MakeBlur(Sigma(1.0), Sigma(1.0),
                                             FilterContents::BlurStyle::kNormal,
                                             Entity::TileMode::kClamp);

  ASSERT_TRUE(paint.HasColorFilter());

  paint.mask_blur_descriptor = {};

  ASSERT_TRUE(paint.HasColorFilter());

  paint.color_filter = nullptr;

  ASSERT_FALSE(paint.HasColorFilter());
}

TEST_P(AiksTest, OpacityPeepHoleApplicationTest) {
  auto entity_pass = std::make_shared<EntityPass>();
  auto rect = Rect::MakeLTRB(0, 0, 100, 100);
  Paint paint;
  paint.color = Color::White().WithAlpha(0.5);
  paint.color_filter =
      ColorFilter::MakeBlend(BlendMode::kSourceOver, Color::Blue());

  // Paint has color filter, can't elide.
  auto delegate = std::make_shared<OpacityPeepholePassDelegate>(paint);
  ASSERT_FALSE(delegate->CanCollapseIntoParentPass(entity_pass.get()));

  paint.color_filter = nullptr;
  paint.image_filter = ImageFilter::MakeBlur(Sigma(1.0), Sigma(1.0),
                                             FilterContents::BlurStyle::kNormal,
                                             Entity::TileMode::kClamp);

  // Paint has image filter, can't elide.
  delegate = std::make_shared<OpacityPeepholePassDelegate>(paint);
  ASSERT_FALSE(delegate->CanCollapseIntoParentPass(entity_pass.get()));

  paint.image_filter = nullptr;
  paint.color = Color::Red();

  // Paint has no alpha, can't elide;
  delegate = std::make_shared<OpacityPeepholePassDelegate>(paint);
  ASSERT_FALSE(delegate->CanCollapseIntoParentPass(entity_pass.get()));

  // Positive test.
  Entity entity;
  entity.SetContents(SolidColorContents::Make(
      PathBuilder{}.AddRect(rect).TakePath(), Color::Red()));
  entity_pass->AddEntity(entity);
  paint.color = Color::Red().WithAlpha(0.5);

  delegate = std::make_shared<OpacityPeepholePassDelegate>(paint);
  ASSERT_TRUE(delegate->CanCollapseIntoParentPass(entity_pass.get()));
}

TEST_P(AiksTest, DrawPaintAbsorbsClears) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color::Red(), .blend_mode = BlendMode::kSource});
  canvas.DrawPaint({.color = Color::CornflowerBlue().WithAlpha(0.75),
                    .blend_mode = BlendMode::kSourceOver});

  Picture picture = canvas.EndRecordingAsPicture();
  auto expected = Color::Red().Blend(Color::CornflowerBlue().WithAlpha(0.75),
                                     BlendMode::kSourceOver);
  ASSERT_EQ(picture.pass->GetClearColor(), expected);

  std::shared_ptr<ContextSpy> spy = ContextSpy::Make();
  std::shared_ptr<Context> real_context = GetContext();
  std::shared_ptr<ContextMock> mock_context = spy->MakeContext(real_context);
  AiksContext renderer(mock_context, nullptr);
  std::shared_ptr<Image> image = picture.ToImage(renderer, {300, 300});

  ASSERT_EQ(spy->render_passes_.size(), 1llu);
  std::shared_ptr<RenderPass> render_pass = spy->render_passes_[0];
  ASSERT_EQ(render_pass->GetCommands().size(), 0llu);
}

// This is important to enforce with texture reuse, since cached textures need
// to be cleared before reuse.
TEST_P(AiksTest,
       ParentSaveLayerCreatesRenderPassWhenChildBackdropFilterIsPresent) {
  Canvas canvas;
  canvas.SaveLayer({}, std::nullopt, ImageFilter::MakeMatrix(Matrix(), {}));
  canvas.DrawPaint({.color = Color::Red(), .blend_mode = BlendMode::kSource});
  canvas.DrawPaint({.color = Color::CornflowerBlue().WithAlpha(0.75),
                    .blend_mode = BlendMode::kSourceOver});
  canvas.Restore();

  Picture picture = canvas.EndRecordingAsPicture();

  std::shared_ptr<ContextSpy> spy = ContextSpy::Make();
  std::shared_ptr<Context> real_context = GetContext();
  std::shared_ptr<ContextMock> mock_context = spy->MakeContext(real_context);
  AiksContext renderer(mock_context, nullptr);
  std::shared_ptr<Image> image = picture.ToImage(renderer, {300, 300});

  ASSERT_EQ(spy->render_passes_.size(), 3llu);
  std::shared_ptr<RenderPass> render_pass = spy->render_passes_[0];
  ASSERT_EQ(render_pass->GetCommands().size(), 0llu);
}

TEST_P(AiksTest, DrawRectAbsorbsClears) {
  Canvas canvas;
  canvas.DrawRect({0, 0, 300, 300},
                  {.color = Color::Red(), .blend_mode = BlendMode::kSource});
  canvas.DrawRect({0, 0, 300, 300},
                  {.color = Color::CornflowerBlue().WithAlpha(0.75),
                   .blend_mode = BlendMode::kSourceOver});

  std::shared_ptr<ContextSpy> spy = ContextSpy::Make();
  Picture picture = canvas.EndRecordingAsPicture();
  std::shared_ptr<Context> real_context = GetContext();
  std::shared_ptr<ContextMock> mock_context = spy->MakeContext(real_context);
  AiksContext renderer(mock_context, nullptr);
  std::shared_ptr<Image> image = picture.ToImage(renderer, {300, 300});

  ASSERT_EQ(spy->render_passes_.size(), 1llu);
  std::shared_ptr<RenderPass> render_pass = spy->render_passes_[0];
  ASSERT_EQ(render_pass->GetCommands().size(), 0llu);
}

TEST_P(AiksTest, DrawRectAbsorbsClearsNegativeRRect) {
  Canvas canvas;
  canvas.DrawRRect({0, 0, 300, 300}, 5.0,
                   {.color = Color::Red(), .blend_mode = BlendMode::kSource});
  canvas.DrawRRect({0, 0, 300, 300}, 5.0,
                   {.color = Color::CornflowerBlue().WithAlpha(0.75),
                    .blend_mode = BlendMode::kSourceOver});

  std::shared_ptr<ContextSpy> spy = ContextSpy::Make();
  Picture picture = canvas.EndRecordingAsPicture();
  std::shared_ptr<Context> real_context = GetContext();
  std::shared_ptr<ContextMock> mock_context = spy->MakeContext(real_context);
  AiksContext renderer(mock_context, nullptr);
  std::shared_ptr<Image> image = picture.ToImage(renderer, {300, 300});

  ASSERT_EQ(spy->render_passes_.size(), 1llu);
  std::shared_ptr<RenderPass> render_pass = spy->render_passes_[0];
  ASSERT_EQ(render_pass->GetCommands().size(), 2llu);
}

TEST_P(AiksTest, DrawRectAbsorbsClearsNegativeRotation) {
  Canvas canvas;
  canvas.Translate(Vector3(150.0, 150.0, 0.0));
  canvas.Rotate(Degrees(45.0));
  canvas.Translate(Vector3(-150.0, -150.0, 0.0));
  canvas.DrawRect({0, 0, 300, 300},
                  {.color = Color::Red(), .blend_mode = BlendMode::kSource});

  std::shared_ptr<ContextSpy> spy = ContextSpy::Make();
  Picture picture = canvas.EndRecordingAsPicture();
  std::shared_ptr<Context> real_context = GetContext();
  std::shared_ptr<ContextMock> mock_context = spy->MakeContext(real_context);
  AiksContext renderer(mock_context, nullptr);
  std::shared_ptr<Image> image = picture.ToImage(renderer, {300, 300});

  ASSERT_EQ(spy->render_passes_.size(), 1llu);
  std::shared_ptr<RenderPass> render_pass = spy->render_passes_[0];
  ASSERT_EQ(render_pass->GetCommands().size(), 1llu);
}

TEST_P(AiksTest, DrawRectAbsorbsClearsNegative) {
  Canvas canvas;
  canvas.DrawRect({0, 0, 300, 300},
                  {.color = Color::Red(), .blend_mode = BlendMode::kSource});
  canvas.DrawRect({0, 0, 300, 300},
                  {.color = Color::CornflowerBlue().WithAlpha(0.75),
                   .blend_mode = BlendMode::kSourceOver});

  std::shared_ptr<ContextSpy> spy = ContextSpy::Make();
  Picture picture = canvas.EndRecordingAsPicture();
  std::shared_ptr<Context> real_context = GetContext();
  std::shared_ptr<ContextMock> mock_context = spy->MakeContext(real_context);
  AiksContext renderer(mock_context, nullptr);
  std::shared_ptr<Image> image = picture.ToImage(renderer, {301, 301});

  ASSERT_EQ(spy->render_passes_.size(), 1llu);
  std::shared_ptr<RenderPass> render_pass = spy->render_passes_[0];
  ASSERT_EQ(render_pass->GetCommands().size(), 2llu);
}

TEST_P(AiksTest, ClipRectElidesNoOpClips) {
  Canvas canvas(Rect(0, 0, 100, 100));
  canvas.ClipRect(Rect(0, 0, 100, 100));
  canvas.ClipRect(Rect(-100, -100, 300, 300));
  canvas.DrawPaint({.color = Color::Red(), .blend_mode = BlendMode::kSource});
  canvas.DrawPaint({.color = Color::CornflowerBlue().WithAlpha(0.75),
                    .blend_mode = BlendMode::kSourceOver});

  Picture picture = canvas.EndRecordingAsPicture();
  auto expected = Color::Red().Blend(Color::CornflowerBlue().WithAlpha(0.75),
                                     BlendMode::kSourceOver);
  ASSERT_EQ(picture.pass->GetClearColor(), expected);

  std::shared_ptr<ContextSpy> spy = ContextSpy::Make();
  std::shared_ptr<Context> real_context = GetContext();
  std::shared_ptr<ContextMock> mock_context = spy->MakeContext(real_context);
  AiksContext renderer(mock_context, nullptr);
  std::shared_ptr<Image> image = picture.ToImage(renderer, {300, 300});

  ASSERT_EQ(spy->render_passes_.size(), 1llu);
  std::shared_ptr<RenderPass> render_pass = spy->render_passes_[0];
  ASSERT_EQ(render_pass->GetCommands().size(), 0llu);
}

TEST_P(AiksTest, ClearColorOptimizationDoesNotApplyForBackdropFilters) {
  Canvas canvas;
  canvas.SaveLayer({}, std::nullopt,
                   ImageFilter::MakeBlur(Sigma(3), Sigma(3),
                                         FilterContents::BlurStyle::kNormal,
                                         Entity::TileMode::kClamp));
  canvas.DrawPaint({.color = Color::Red(), .blend_mode = BlendMode::kSource});
  canvas.DrawPaint({.color = Color::CornflowerBlue().WithAlpha(0.75),
                    .blend_mode = BlendMode::kSourceOver});
  canvas.Restore();

  Picture picture = canvas.EndRecordingAsPicture();

  std::optional<Color> actual_color;
  picture.pass->IterateAllElements([&](EntityPass::Element& element) -> bool {
    if (auto subpass = std::get_if<std::unique_ptr<EntityPass>>(&element)) {
      actual_color = subpass->get()->GetClearColor();
    }
    // Fail if the first element isn't a subpass.
    return true;
  });

  ASSERT_TRUE(actual_color.has_value());
  if (!actual_color) {
    return;
  }
  ASSERT_EQ(actual_color.value(), Color::BlackTransparent());
}

TEST_P(AiksTest, CollapsedDrawPaintInSubpass) {
  Canvas canvas;
  canvas.DrawPaint(
      {.color = Color::Yellow(), .blend_mode = BlendMode::kSource});
  canvas.SaveLayer({.blend_mode = BlendMode::kMultiply});
  canvas.DrawPaint({.color = Color::CornflowerBlue().WithAlpha(0.75),
                    .blend_mode = BlendMode::kSourceOver});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CollapsedDrawPaintInSubpassBackdropFilter) {
  // Bug: https://github.com/flutter/flutter/issues/131576
  Canvas canvas;
  canvas.DrawPaint(
      {.color = Color::Yellow(), .blend_mode = BlendMode::kSource});
  canvas.SaveLayer({}, {},
                   ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                         FilterContents::BlurStyle::kNormal,
                                         Entity::TileMode::kDecal));
  canvas.DrawPaint(
      {.color = Color::CornflowerBlue(), .blend_mode = BlendMode::kSourceOver});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, ForegroundBlendSubpassCollapseOptimization) {
  Canvas canvas;

  canvas.SaveLayer({
      .color_filter =
          ColorFilter::MakeBlend(BlendMode::kColorDodge, Color::Red()),
  });

  canvas.Translate({500, 300, 0});
  canvas.Rotate(Radians(2 * kPi / 3));
  canvas.DrawRect({100, 100, 200, 200}, {.color = Color::Blue()});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, ColorMatrixFilterSubpassCollapseOptimization) {
  Canvas canvas;

  canvas.SaveLayer({
      .color_filter =
          ColorFilter::MakeMatrix({.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   //
                                       }}),
  });

  canvas.Translate({500, 300, 0});
  canvas.Rotate(Radians(2 * kPi / 3));
  canvas.DrawRect({100, 100, 200, 200}, {.color = Color::Blue()});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, LinearToSrgbFilterSubpassCollapseOptimization) {
  Canvas canvas;

  canvas.SaveLayer({
      .color_filter = ColorFilter::MakeLinearToSrgb(),
  });

  canvas.Translate({500, 300, 0});
  canvas.Rotate(Radians(2 * kPi / 3));
  canvas.DrawRect({100, 100, 200, 200}, {.color = Color::Blue()});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, SrgbToLinearFilterSubpassCollapseOptimization) {
  Canvas canvas;

  canvas.SaveLayer({
      .color_filter = ColorFilter::MakeSrgbToLinear(),
  });

  canvas.Translate({500, 300, 0});
  canvas.Rotate(Radians(2 * kPi / 3));
  canvas.DrawRect({100, 100, 200, 200}, {.color = Color::Blue()});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

static Picture BlendModeTest(BlendMode blend_mode,
                             const std::shared_ptr<Image>& src_image,
                             const std::shared_ptr<Image>& dst_image) {
  Color destination_color = Color::CornflowerBlue().WithAlpha(0.75);
  auto source_colors = std::vector<Color>({Color::White().WithAlpha(0.75),
                                           Color::LimeGreen().WithAlpha(0.75),
                                           Color::Black().WithAlpha(0.75)});

  Canvas canvas;

  canvas.DrawPaint({.color = Color::Black()});

  //----------------------------------------------------------------------------
  /// 1. Save layer blending (top squares).
  ///

  canvas.Save();
  for (const auto& color : source_colors) {
    canvas.Save();
    {
      canvas.ClipRect(Rect::MakeXYWH(50, 50, 100, 100));
      // Perform the blend in a SaveLayer so that the initial backdrop color is
      // fully transparent black. SourceOver blend the result onto the parent
      // pass.
      canvas.SaveLayer({});
      {
        canvas.DrawPaint({.color = destination_color});
        // Draw the source color in an offscreen pass and blend it to the parent
        // pass.
        canvas.SaveLayer({.blend_mode = blend_mode});
        {  //
          canvas.DrawRect({50, 50, 100, 100}, {.color = color});
        }
        canvas.Restore();
      }
      canvas.Restore();
    }
    canvas.Restore();
    canvas.Translate(Vector2(100, 0));
  }
  canvas.RestoreToCount(0);

  //----------------------------------------------------------------------------
  /// 2. CPU blend modes (bottom squares).
  ///

  canvas.Save();
  canvas.Translate({0, 100});

  // Perform the blend in a SaveLayer so that the initial backdrop color is
  // fully transparent black. SourceOver blend the result onto the parent pass.
  canvas.SaveLayer({});
  // canvas.DrawPaint({.color = destination_color});
  for (const auto& color : source_colors) {
    // Simply write the CPU blended color to the pass.
    canvas.DrawRect({50, 50, 100, 100},
                    {.color = destination_color.Blend(color, blend_mode),
                     .blend_mode = BlendMode::kSourceOver});
    canvas.Translate(Vector2(100, 0));
  }
  canvas.RestoreToCount(0);

  //----------------------------------------------------------------------------
  /// 3. Image blending (top right).
  ///
  /// Compare these results with the images in the Flutter blend mode
  /// documentation: https://api.flutter.dev/flutter/dart-ui/BlendMode.html
  ///

  canvas.Save();
  // canvas.ClipRect(Rect::MakeXYWH(500, 0, 500, 500));
  canvas.SaveLayer({.blend_mode = BlendMode::kSourceOver});
  {
    canvas.DrawImage(dst_image, {400, 50}, {.blend_mode = BlendMode::kSource});
    canvas.DrawImage(src_image, {400, 50}, {.blend_mode = blend_mode});
  }
  canvas.RestoreToCount(0);

  return canvas.EndRecordingAsPicture();
}

#define BLEND_MODE_TEST(blend_mode)                                     \
  TEST_P(AiksTest, BlendMode##blend_mode) {                             \
    auto src_image = std::make_shared<Image>(                           \
        CreateTextureForFixture("blend_mode_src.png"));                 \
    auto dst_image = std::make_shared<Image>(                           \
        CreateTextureForFixture("blend_mode_dst.png"));                 \
    OpenPlaygroundHere(                                                 \
        BlendModeTest(BlendMode::k##blend_mode, src_image, dst_image)); \
  }
IMPELLER_FOR_EACH_BLEND_MODE(BLEND_MODE_TEST)

TEST_P(AiksTest, TranslucentSaveLayerDrawsCorrectly) {
  Canvas canvas;

  canvas.DrawRect(Rect::MakeXYWH(100, 100, 300, 300), {.color = Color::Blue()});

  canvas.SaveLayer({.color = Color::Black().WithAlpha(0.5)});
  canvas.DrawRect(Rect::MakeXYWH(100, 500, 300, 300), {.color = Color::Blue()});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TranslucentSaveLayerWithBlendColorFilterDrawsCorrectly) {
  Canvas canvas;

  canvas.DrawRect(Rect::MakeXYWH(100, 100, 300, 300), {.color = Color::Blue()});

  canvas.SaveLayer({
      .color = Color::Black().WithAlpha(0.5),
      .color_filter =
          ColorFilter::MakeBlend(BlendMode::kDestinationOver, Color::Red()),
  });
  canvas.DrawRect(Rect::MakeXYWH(100, 500, 300, 300), {.color = Color::Blue()});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TranslucentSaveLayerWithBlendImageFilterDrawsCorrectly) {
  Canvas canvas;

  canvas.DrawRect(Rect::MakeXYWH(100, 100, 300, 300), {.color = Color::Blue()});

  canvas.SaveLayer({
      .color = Color::Black().WithAlpha(0.5),
      .image_filter = ImageFilter::MakeFromColorFilter(
          *ColorFilter::MakeBlend(BlendMode::kDestinationOver, Color::Red())),
  });

  canvas.DrawRect(Rect::MakeXYWH(100, 500, 300, 300), {.color = Color::Blue()});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TranslucentSaveLayerWithColorAndImageFilterDrawsCorrectly) {
  Canvas canvas;

  canvas.DrawRect(Rect::MakeXYWH(100, 100, 300, 300), {.color = Color::Blue()});

  canvas.SaveLayer({
      .color = Color::Black().WithAlpha(0.5),
      .color_filter =
          ColorFilter::MakeBlend(BlendMode::kDestinationOver, Color::Red()),
  });

  canvas.DrawRect(Rect::MakeXYWH(100, 500, 300, 300), {.color = Color::Blue()});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TranslucentSaveLayerImageDrawsCorrectly) {
  Canvas canvas;

  auto image = std::make_shared<Image>(CreateTextureForFixture("airplane.jpg"));
  canvas.DrawImage(image, {100, 100}, {});

  canvas.SaveLayer({.color = Color::Black().WithAlpha(0.5)});
  canvas.DrawImage(image, {100, 500}, {});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TranslucentSaveLayerWithColorMatrixColorFilterDrawsCorrectly) {
  Canvas canvas;

  auto image = std::make_shared<Image>(CreateTextureForFixture("airplane.jpg"));
  canvas.DrawImage(image, {100, 100}, {});

  canvas.SaveLayer({
      .color = Color::Black().WithAlpha(0.5),
      .color_filter = ColorFilter::MakeMatrix({.array =
                                                   {
                                                       1, 0, 0, 0, 0,  //
                                                       0, 1, 0, 0, 0,  //
                                                       0, 0, 1, 0, 0,  //
                                                       0, 0, 0, 2, 0   //
                                                   }}),
  });
  canvas.DrawImage(image, {100, 500}, {});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TranslucentSaveLayerWithColorMatrixImageFilterDrawsCorrectly) {
  Canvas canvas;

  auto image = std::make_shared<Image>(CreateTextureForFixture("airplane.jpg"));
  canvas.DrawImage(image, {100, 100}, {});

  canvas.SaveLayer({
      .color = Color::Black().WithAlpha(0.5),
      .image_filter = ImageFilter::MakeFromColorFilter(
          *ColorFilter::MakeMatrix({.array =
                                        {
                                            1, 0, 0, 0, 0,  //
                                            0, 1, 0, 0, 0,  //
                                            0, 0, 1, 0, 0,  //
                                            0, 0, 0, 2, 0   //
                                        }})),
  });
  canvas.DrawImage(image, {100, 500}, {});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest,
       TranslucentSaveLayerWithColorFilterAndImageFilterDrawsCorrectly) {
  Canvas canvas;

  auto image = std::make_shared<Image>(CreateTextureForFixture("airplane.jpg"));
  canvas.DrawImage(image, {100, 100}, {});

  canvas.SaveLayer({
      .color = Color::Black().WithAlpha(0.5),
      .image_filter = ImageFilter::MakeFromColorFilter(
          *ColorFilter::MakeMatrix({.array =
                                        {
                                            1, 0,   0, 0,   0,  //
                                            0, 1,   0, 0,   0,  //
                                            0, 0.2, 1, 0,   0,  //
                                            0, 0,   0, 0.5, 0   //
                                        }})),
      .color_filter =
          ColorFilter::MakeBlend(BlendMode::kModulate, Color::Green()),
  });
  canvas.DrawImage(image, {100, 500}, {});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, TranslucentSaveLayerWithAdvancedBlendModeDrawsCorrectly) {
  Canvas canvas;
  canvas.DrawRect({0, 0, 400, 400}, {.color = Color::Red()});
  canvas.SaveLayer({
      .color = Color::Black().WithAlpha(0.5),
      .blend_mode = BlendMode::kLighten,
  });
  canvas.DrawCircle({200, 200}, 100, {.color = Color::Green()});
  canvas.Restore();
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

/// This is a regression check for https://github.com/flutter/engine/pull/41129
/// The entire screen is green if successful. If failing, no frames will render,
/// or the entire screen will be transparent black.
TEST_P(AiksTest, CanRenderTinyOverlappingSubpasses) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color::Red()});

  // Draw two overlapping subpixel circles.
  canvas.SaveLayer({});
  canvas.DrawCircle({100, 100}, 0.1, {.color = Color::Yellow()});
  canvas.Restore();
  canvas.SaveLayer({});
  canvas.DrawCircle({100, 100}, 0.1, {.color = Color::Yellow()});
  canvas.Restore();

  canvas.DrawPaint({.color = Color::Green()});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

/// Tests that the debug checkerboard displays for offscreen textures when
/// enabled. Most of the complexity here is just to future proof by making pass
/// collapsing hard.
TEST_P(AiksTest, CanRenderOffscreenCheckerboard) {
  Canvas canvas;
  canvas.debug_options.offscreen_texture_checkerboard = true;

  canvas.DrawPaint({.color = Color::AntiqueWhite()});
  canvas.DrawCircle({400, 300}, 200,
                    {.color = Color::CornflowerBlue().WithAlpha(0.75)});

  canvas.SaveLayer({.blend_mode = BlendMode::kMultiply});
  {
    canvas.DrawCircle({500, 400}, 200,
                      {.color = Color::DarkBlue().WithAlpha(0.75)});
    canvas.DrawCircle({550, 450}, 200,
                      {.color = Color::LightCoral().WithAlpha(0.75),
                       .blend_mode = BlendMode::kLuminosity});
  }
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, OpaqueEntitiesGetCoercedToSource) {
  Canvas canvas;
  canvas.Scale(Vector2(1.618, 1.618));
  canvas.DrawCircle(Point(), 10,
                    {
                        .color = Color::CornflowerBlue(),
                        .blend_mode = BlendMode::kSourceOver,
                    });
  Picture picture = canvas.EndRecordingAsPicture();

  // Extract the SolidColorSource.
  Entity entity;
  std::shared_ptr<SolidColorContents> contents;
  picture.pass->IterateAllEntities([&e = entity, &contents](Entity& entity) {
    if (ScalarNearlyEqual(entity.GetTransformation().GetScale().x, 1.618f)) {
      e = entity;
      contents =
          std::static_pointer_cast<SolidColorContents>(entity.GetContents());
      return false;
    }
    return true;
  });

  ASSERT_TRUE(contents->IsOpaque());
  ASSERT_EQ(entity.GetBlendMode(), BlendMode::kSource);
}

TEST_P(AiksTest, CanRenderDestructiveSaveLayer) {
  Canvas canvas;

  canvas.DrawPaint({.color = Color::Red()});
  // Draw an empty savelayer with a destructive blend mode, which will replace
  // the entire red screen with fully transparent black, except for the green
  // circle drawn within the layer.
  canvas.SaveLayer({.blend_mode = BlendMode::kSource});
  canvas.DrawCircle({300, 300}, 100, {.color = Color::Green()});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderMaskBlurHugeSigma) {
  Canvas canvas;
  canvas.DrawCircle({400, 400}, 300,
                    {.color = Color::Green(),
                     .mask_blur_descriptor = Paint::MaskBlurDescriptor{
                         .style = FilterContents::BlurStyle::kNormal,
                         .sigma = Sigma(99999),
                     }});
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderBackdropBlurInteractive) {
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    auto [a, b] = IMPELLER_PLAYGROUND_LINE(Point(50, 50), Point(300, 200), 30,
                                           Color::White(), Color::White());

    Canvas canvas;
    canvas.DrawCircle({100, 100}, 50, {.color = Color::CornflowerBlue()});
    canvas.DrawCircle({300, 200}, 100, {.color = Color::GreenYellow()});
    canvas.DrawCircle({140, 170}, 75, {.color = Color::DarkMagenta()});
    canvas.DrawCircle({180, 120}, 100, {.color = Color::OrangeRed()});
    canvas.ClipRRect(Rect::MakeLTRB(a.x, a.y, b.x, b.y), 20);
    canvas.SaveLayer({.blend_mode = BlendMode::kSource}, std::nullopt,
                     ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                           FilterContents::BlurStyle::kNormal,
                                           Entity::TileMode::kClamp));
    canvas.Restore();

    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, CanRenderBackdropBlur) {
  Canvas canvas;
  canvas.DrawCircle({100, 100}, 50, {.color = Color::CornflowerBlue()});
  canvas.DrawCircle({300, 200}, 100, {.color = Color::GreenYellow()});
  canvas.DrawCircle({140, 170}, 75, {.color = Color::DarkMagenta()});
  canvas.DrawCircle({180, 120}, 100, {.color = Color::OrangeRed()});
  canvas.ClipRRect(Rect::MakeLTRB(75, 50, 375, 275), 20);
  canvas.SaveLayer({.blend_mode = BlendMode::kSource}, std::nullopt,
                   ImageFilter::MakeBlur(Sigma(30.0), Sigma(30.0),
                                         FilterContents::BlurStyle::kNormal,
                                         Entity::TileMode::kClamp));
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderBackdropBlurHugeSigma) {
  Canvas canvas;
  canvas.DrawCircle({400, 400}, 300, {.color = Color::Green()});
  canvas.SaveLayer({.blend_mode = BlendMode::kSource}, std::nullopt,
                   ImageFilter::MakeBlur(Sigma(999999), Sigma(999999),
                                         FilterContents::BlurStyle::kNormal,
                                         Entity::TileMode::kClamp));
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderClippedBlur) {
  Canvas canvas;
  canvas.ClipRect(Rect::MakeXYWH(100, 150, 400, 400));
  canvas.DrawCircle(
      {400, 400}, 200,
      {
          .color = Color::Green(),
          .image_filter = ImageFilter::MakeBlur(
              Sigma(20.0), Sigma(20.0), FilterContents::BlurStyle::kNormal,
              Entity::TileMode::kClamp),
      });
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderForegroundBlendWithMaskBlur) {
  // This case triggers the ForegroundPorterDuffBlend path. The color filter
  // should apply to the color only, and respect the alpha mask.
  Canvas canvas;
  canvas.ClipRect(Rect::MakeXYWH(100, 150, 400, 400));
  canvas.DrawCircle({400, 400}, 200,
                    {
                        .color = Color::White(),
                        .color_filter = ColorFilter::MakeBlend(
                            BlendMode::kSource, Color::Green()),
                        .mask_blur_descriptor =
                            Paint::MaskBlurDescriptor{
                                .style = FilterContents::BlurStyle::kNormal,
                                .sigma = Radius(20),
                            },
                    });
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanRenderForegroundAdvancedBlendWithMaskBlur) {
  // This case triggers the ForegroundAdvancedBlend path. The color filter
  // should apply to the color only, and respect the alpha mask.
  Canvas canvas;
  canvas.ClipRect(Rect::MakeXYWH(100, 150, 400, 400));
  canvas.DrawCircle({400, 400}, 200,
                    {
                        .color = Color::White(),
                        .color_filter = ColorFilter::MakeBlend(
                            BlendMode::kColor, Color::Green()),
                        .mask_blur_descriptor =
                            Paint::MaskBlurDescriptor{
                                .style = FilterContents::BlurStyle::kNormal,
                                .sigma = Radius(20),
                            },
                    });
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

// Regression test for https://github.com/flutter/flutter/issues/126701 .
TEST_P(AiksTest, CanRenderClippedRuntimeEffects) {
  if (GetParam() != PlaygroundBackend::kMetal) {
    GTEST_SKIP_("This backend doesn't support runtime effects.");
  }

  auto runtime_stage =
      OpenAssetAsRuntimeStage("runtime_stage_example.frag.iplr");
  ASSERT_TRUE(runtime_stage->IsDirty());

  struct FragUniforms {
    Vector2 iResolution;
    Scalar iTime;
  } frag_uniforms = {.iResolution = Vector2(400, 400), .iTime = 100.0};
  auto uniform_data = std::make_shared<std::vector<uint8_t>>();
  uniform_data->resize(sizeof(FragUniforms));
  memcpy(uniform_data->data(), &frag_uniforms, sizeof(FragUniforms));

  std::vector<RuntimeEffectContents::TextureInput> texture_inputs;

  Paint paint;
  paint.color_source = ColorSource::MakeRuntimeEffect(
      runtime_stage, uniform_data, texture_inputs);

  Canvas canvas;
  canvas.Save();
  canvas.ClipRRect(Rect{0, 0, 400, 400}, 10.0,
                   Entity::ClipOperation::kIntersect);
  canvas.DrawRect(Rect{0, 0, 400, 400}, paint);
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, DrawPaintTransformsBounds) {
  if (GetParam() != PlaygroundBackend::kMetal) {
    GTEST_SKIP_("This backend doesn't support runtime effects.");
  }

  auto runtime_stage = OpenAssetAsRuntimeStage("gradient.frag.iplr");
  ASSERT_TRUE(runtime_stage->IsDirty());

  struct FragUniforms {
    Size size;
  } frag_uniforms = {.size = Size::MakeWH(400, 400)};
  auto uniform_data = std::make_shared<std::vector<uint8_t>>();
  uniform_data->resize(sizeof(FragUniforms));
  memcpy(uniform_data->data(), &frag_uniforms, sizeof(FragUniforms));

  std::vector<RuntimeEffectContents::TextureInput> texture_inputs;

  Paint paint;
  paint.color_source = ColorSource::MakeRuntimeEffect(
      runtime_stage, uniform_data, texture_inputs);

  Canvas canvas;
  canvas.Save();
  canvas.Scale(GetContentScale());
  canvas.DrawPaint(paint);
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanDrawPoints) {
  std::vector<Point> points = {
      {0, 0},      //
      {100, 100},  //
      {100, 0},    //
      {0, 100},    //
      {0, 0},      //
      {48, 48},    //
      {52, 52},    //
  };
  std::vector<PointStyle> caps = {
      PointStyle::kRound,
      PointStyle::kSquare,
  };
  Paint paint;
  paint.color = Color::Yellow().WithAlpha(0.5);

  Paint background;
  background.color = Color::Black();

  Canvas canvas;
  canvas.DrawPaint(background);
  canvas.Translate({200, 200});
  canvas.DrawPoints(points, 10, paint, PointStyle::kRound);
  canvas.Translate({150, 0});
  canvas.DrawPoints(points, 10, paint, PointStyle::kSquare);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

// Regression test for https://github.com/flutter/flutter/issues/127374.
TEST_P(AiksTest, DrawAtlasWithColorAdvancedAndTransform) {
  // Draws the image as four squares stiched together.
  auto atlas = CreateTextureForFixture("bay_bridge.jpg");
  auto size = atlas->GetSize();
  auto image = std::make_shared<Image>(atlas);
  // Divide image into four quadrants.
  Scalar half_width = size.width / 2;
  Scalar half_height = size.height / 2;
  std::vector<Rect> texture_coordinates = {
      Rect::MakeLTRB(0, 0, half_width, half_height),
      Rect::MakeLTRB(half_width, 0, size.width, half_height),
      Rect::MakeLTRB(0, half_height, half_width, size.height),
      Rect::MakeLTRB(half_width, half_height, size.width, size.height)};
  // Position quadrants adjacent to eachother.
  std::vector<Matrix> transforms = {
      Matrix::MakeTranslation({0, 0, 0}),
      Matrix::MakeTranslation({half_width, 0, 0}),
      Matrix::MakeTranslation({0, half_height, 0}),
      Matrix::MakeTranslation({half_width, half_height, 0})};
  std::vector<Color> colors = {Color::Red(), Color::Green(), Color::Blue(),
                               Color::Yellow()};

  Paint paint;

  Canvas canvas;
  canvas.Scale({0.25, 0.25, 1.0});
  canvas.DrawAtlas(image, transforms, texture_coordinates, colors,
                   BlendMode::kModulate, {}, std::nullopt, paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

// Regression test for https://github.com/flutter/flutter/issues/127374.
TEST_P(AiksTest, DrawAtlasAdvancedAndTransform) {
  // Draws the image as four squares stiched together.
  auto atlas = CreateTextureForFixture("bay_bridge.jpg");
  auto size = atlas->GetSize();
  auto image = std::make_shared<Image>(atlas);
  // Divide image into four quadrants.
  Scalar half_width = size.width / 2;
  Scalar half_height = size.height / 2;
  std::vector<Rect> texture_coordinates = {
      Rect::MakeLTRB(0, 0, half_width, half_height),
      Rect::MakeLTRB(half_width, 0, size.width, half_height),
      Rect::MakeLTRB(0, half_height, half_width, size.height),
      Rect::MakeLTRB(half_width, half_height, size.width, size.height)};
  // Position quadrants adjacent to eachother.
  std::vector<Matrix> transforms = {
      Matrix::MakeTranslation({0, 0, 0}),
      Matrix::MakeTranslation({half_width, 0, 0}),
      Matrix::MakeTranslation({0, half_height, 0}),
      Matrix::MakeTranslation({half_width, half_height, 0})};

  Paint paint;

  Canvas canvas;
  canvas.Scale({0.25, 0.25, 1.0});
  canvas.DrawAtlas(image, transforms, texture_coordinates, {},
                   BlendMode::kModulate, {}, std::nullopt, paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanDrawPointsWithTextureMap) {
  auto texture = CreateTextureForFixture("table_mountain_nx.png",
                                         /*enable_mipmapping=*/true);

  std::vector<Point> points = {
      {0, 0},      //
      {100, 100},  //
      {100, 0},    //
      {0, 100},    //
      {0, 0},      //
      {48, 48},    //
      {52, 52},    //
  };
  std::vector<PointStyle> caps = {
      PointStyle::kRound,
      PointStyle::kSquare,
  };
  Paint paint;
  paint.color_source = ColorSource::MakeImage(texture, Entity::TileMode::kClamp,
                                              Entity::TileMode::kClamp, {}, {});

  Canvas canvas;
  canvas.Translate({200, 200});
  canvas.DrawPoints(points, 100, paint, PointStyle::kRound);
  canvas.Translate({150, 0});
  canvas.DrawPoints(points, 100, paint, PointStyle::kSquare);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

// This currently renders solid blue, as the support for text color sources was
// moved into DLDispatching. Path data requires the SkTextBlobs which are not
// used in impeller::TextFrames.
TEST_P(AiksTest, TextForegroundShaderWithTransform) {
  auto mapping = OpenFixtureAsSkData("Roboto-Regular.ttf");
  ASSERT_NE(mapping, nullptr);

  Scalar font_size = 100;
  SkFont sk_font(SkTypeface::MakeFromData(mapping), font_size);

  Paint text_paint;
  text_paint.color = Color::Blue();

  std::vector<Color> colors = {Color{0.9568, 0.2627, 0.2118, 1.0},
                               Color{0.1294, 0.5882, 0.9529, 1.0}};
  std::vector<Scalar> stops = {
      0.0,
      1.0,
  };
  text_paint.color_source = ColorSource::MakeLinearGradient(
      {0, 0}, {100, 100}, std::move(colors), std::move(stops),
      Entity::TileMode::kRepeat, {});

  Canvas canvas;
  canvas.Translate({100, 100});
  canvas.Rotate(Radians(kPi / 4));

  auto blob = SkTextBlob::MakeFromString("Hello", sk_font);
  ASSERT_NE(blob, nullptr);
  auto frame = MakeTextFrameFromTextBlobSkia(blob);
  canvas.DrawTextFrame(frame, Point(), text_paint);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanCanvasDrawPicture) {
  Canvas subcanvas;
  subcanvas.DrawRect(Rect::MakeLTRB(-100, -50, 100, 50),
                     {.color = Color::CornflowerBlue()});
  auto picture = subcanvas.EndRecordingAsPicture();

  Canvas canvas;
  canvas.Translate({200, 200});
  canvas.Rotate(Radians(kPi / 4));
  canvas.DrawPicture(picture);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanCanvasDrawPictureWithAdvancedBlend) {
  Canvas subcanvas;
  subcanvas.DrawRect(
      Rect::MakeLTRB(-100, -50, 100, 50),
      {.color = Color::CornflowerBlue(), .blend_mode = BlendMode::kColorDodge});
  auto picture = subcanvas.EndRecordingAsPicture();

  Canvas canvas;
  canvas.DrawPaint({.color = Color::Black()});
  canvas.DrawCircle(Point::MakeXY(150, 150), 25, {.color = Color::Red()});
  canvas.DrawPicture(picture);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CanCanvasDrawPictureWithBackdropFilter) {
  Canvas subcanvas;
  subcanvas.SaveLayer({}, {},
                      ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                            FilterContents::BlurStyle::kNormal,
                                            Entity::TileMode::kDecal));
  auto image = std::make_shared<Image>(CreateTextureForFixture("kalimba.jpg"));
  Paint paint;
  paint.color = Color::Red().WithAlpha(0.5);
  subcanvas.DrawImage(image, Point::MakeXY(100.0, 100.0), paint);

  auto picture = subcanvas.EndRecordingAsPicture();

  Canvas canvas;
  canvas.DrawPaint({.color = Color::Black()});
  canvas.DrawCircle(Point::MakeXY(150, 150), 25, {.color = Color::Red()});
  canvas.DrawPicture(picture);

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, DrawPictureWithText) {
  Canvas subcanvas;
  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), subcanvas,
      "the quick brown fox jumped over the lazy dog!.?", "Roboto-Regular.ttf"));
  subcanvas.Translate({0, 10});
  subcanvas.Scale(Vector2(3, 3));
  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), subcanvas,
      "the quick brown fox jumped over the very big lazy dog!.?",
      "Roboto-Regular.ttf"));
  auto picture = subcanvas.EndRecordingAsPicture();

  Canvas canvas;
  canvas.Scale(Vector2(.2, .2));
  canvas.Save();
  canvas.Translate({200, 200});
  canvas.Scale(Vector2(3.5, 3.5));  // The text must not be blurry after this.
  canvas.DrawPicture(picture);
  canvas.Restore();

  canvas.Scale(Vector2(1.5, 1.5));
  ASSERT_TRUE(RenderTextInCanvasSkia(
      GetContext(), canvas,
      "the quick brown fox jumped over the smaller lazy dog!.?",
      "Roboto-Regular.ttf"));
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, DrawPictureClipped) {
  Canvas subcanvas;
  subcanvas.ClipRRect(Rect::MakeLTRB(100, 100, 400, 400), 15);
  subcanvas.DrawPaint({.color = Color::Red()});
  auto picture = subcanvas.EndRecordingAsPicture();

  Canvas canvas;
  canvas.DrawPaint({.color = Color::CornflowerBlue()});

  // Draw a red RRect via DrawPicture.
  canvas.DrawPicture(picture);

  // Draw over the picture with a larger green rectangle, completely covering it
  // up.
  canvas.ClipRRect(Rect::MakeLTRB(100, 100, 400, 400).Expand(20), 15);
  canvas.DrawPaint({.color = Color::Green()});

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, MatrixSaveLayerFilter) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color::Black()});
  canvas.SaveLayer({}, std::nullopt);
  {
    canvas.DrawCircle(Point(200, 200), 100,
                      {.color = Color::Green().WithAlpha(0.5),
                       .blend_mode = BlendMode::kPlus});
    // Should render a second circle, centered on the bottom-right-most edge of
    // the circle.
    canvas.SaveLayer({.image_filter = ImageFilter::MakeMatrix(
                          Matrix::MakeTranslation(Vector2(1, 1) *
                                                  (200 + 100 * k1OverSqrt2)) *
                              Matrix::MakeScale(Vector2(1, 1) * 0.5) *
                              Matrix::MakeTranslation(Vector2(-200, -200)),
                          SamplerDescriptor{})},
                     std::nullopt);
    canvas.DrawCircle(Point(200, 200), 100,
                      {.color = Color::Green().WithAlpha(0.5),
                       .blend_mode = BlendMode::kPlus});
    canvas.Restore();
  }
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, MatrixBackdropFilter) {
  Canvas canvas;
  canvas.DrawPaint({.color = Color::Black()});
  canvas.SaveLayer({}, std::nullopt);
  {
    canvas.DrawCircle(Point(200, 200), 100,
                      {.color = Color::Green().WithAlpha(0.5),
                       .blend_mode = BlendMode::kPlus});
    // Should render a second circle, centered on the bottom-right-most edge of
    // the circle.
    canvas.SaveLayer(
        {}, std::nullopt,
        ImageFilter::MakeMatrix(
            Matrix::MakeTranslation(Vector2(1, 1) * (100 + 100 * k1OverSqrt2)) *
                Matrix::MakeScale(Vector2(1, 1) * 0.5) *
                Matrix::MakeTranslation(Vector2(-100, -100)),
            SamplerDescriptor{}));
    canvas.Restore();
  }
  canvas.Restore();

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, SolidColorApplyColorFilter) {
  auto contents = SolidColorContents();
  contents.SetColor(Color::CornflowerBlue().WithAlpha(0.75));
  auto result = contents.ApplyColorFilter([](const Color& color) {
    return color.Blend(Color::LimeGreen().WithAlpha(0.75), BlendMode::kScreen);
  });
  ASSERT_TRUE(result);
  ASSERT_COLOR_NEAR(contents.GetColor(),
                    Color(0.433247, 0.879523, 0.825324, 0.75));
}

#define APPLY_COLOR_FILTER_GRADIENT_TEST(name)                                 \
  TEST_P(AiksTest, name##GradientApplyColorFilter) {                           \
    auto contents = name##GradientContents();                                  \
    contents.SetColors({Color::CornflowerBlue().WithAlpha(0.75)});             \
    auto result = contents.ApplyColorFilter([](const Color& color) {           \
      return color.Blend(Color::LimeGreen().WithAlpha(0.75),                   \
                         BlendMode::kScreen);                                  \
    });                                                                        \
    ASSERT_TRUE(result);                                                       \
                                                                               \
    std::vector<Color> expected = {Color(0.433247, 0.879523, 0.825324, 0.75)}; \
    ASSERT_COLORS_NEAR(contents.GetColors(), expected);                        \
  }

APPLY_COLOR_FILTER_GRADIENT_TEST(Linear);
APPLY_COLOR_FILTER_GRADIENT_TEST(Radial);
APPLY_COLOR_FILTER_GRADIENT_TEST(Conical);
APPLY_COLOR_FILTER_GRADIENT_TEST(Sweep);

TEST_P(AiksTest, DrawScaledTextWithPerspectiveNoSaveLayer) {
  Canvas canvas;
  // clang-format off
  canvas.Transform(Matrix(
       2.000000,       0.000000,   0.000000,  0.000000,
       1.445767,       2.637070,  -0.507928,  0.001524,
      -2.451887,      -0.534662,   0.861399, -0.002584,
    1063.481934,    1025.951416, -48.300270,  1.144901
  ));
  // clang-format on

  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas, "Hello world",
                                     "Roboto-Regular.ttf"));

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, DrawScaledTextWithPerspectiveSaveLayer) {
  Canvas canvas;
  Paint save_paint;
  canvas.SaveLayer(save_paint);
  // clang-format off
  canvas.Transform(Matrix(
       2.000000,       0.000000,   0.000000,  0.000000,
       1.445767,       2.637070,  -0.507928,  0.001524,
      -2.451887,      -0.534662,   0.861399, -0.002584,
    1063.481934,    1025.951416, -48.300270,  1.144901
  ));
  // clang-format on

  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas, "Hello world",
                                     "Roboto-Regular.ttf"));
}

TEST_P(AiksTest, PipelineBlendSingleParameter) {
  Canvas canvas;

  // Should render a green square in the middle of a blue circle.
  canvas.SaveLayer({});
  {
    canvas.Translate(Point(100, 100));
    canvas.DrawCircle(Point(200, 200), 200, {.color = Color::Blue()});
    canvas.ClipRect(Rect(100, 100, 200, 200));
    canvas.DrawCircle(Point(200, 200), 200,
                      {
                          .color = Color::Green(),
                          .blend_mode = BlendMode::kSourceOver,
                          .image_filter = ImageFilter::MakeFromColorFilter(
                              *ColorFilter::MakeBlend(BlendMode::kDestination,
                                                      Color::White())),
                      });
    canvas.Restore();
  }

  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, ClippedBlurFilterRendersCorrectlyInteractive) {
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    auto point = IMPELLER_PLAYGROUND_POINT(Point(400, 400), 20, Color::Green());

    Canvas canvas;
    canvas.Translate(point - Point(400, 400));
    Paint paint;
    paint.mask_blur_descriptor = Paint::MaskBlurDescriptor{
        .style = FilterContents::BlurStyle::kNormal,
        .sigma = Radius{120 * 3},
    };
    paint.color = Color::Red();
    PathBuilder builder{};
    builder.AddRect(Rect::MakeLTRB(0, 0, 800, 800));
    canvas.DrawPath(builder.TakePath(), paint);
    return canvas.EndRecordingAsPicture();
  };
  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

TEST_P(AiksTest, ClippedBlurFilterRendersCorrectly) {
  Canvas canvas;
  canvas.Translate(Point(0, -400));
  Paint paint;
  paint.mask_blur_descriptor = Paint::MaskBlurDescriptor{
      .style = FilterContents::BlurStyle::kNormal,
      .sigma = Radius{120 * 3},
  };
  paint.color = Color::Red();
  PathBuilder builder{};
  builder.AddRect(Rect::MakeLTRB(0, 0, 800, 800));
  canvas.DrawPath(builder.TakePath(), paint);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, CaptureContext) {
  auto capture_context = CaptureContext::MakeAllowlist({"TestDocument"});

  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    Canvas canvas;

    capture_context.Rewind();
    auto document = capture_context.GetDocument("TestDocument");

    auto color = document.AddColor("Background color", Color::CornflowerBlue());
    canvas.DrawPaint({.color = color});

    ImGui::Begin("TestDocument", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    document.GetElement()->properties.Iterate([](CaptureProperty& property) {
      property.Invoke({.color = [](CaptureColorProperty& p) {
        ImGui::ColorEdit4(p.label.c_str(), reinterpret_cast<float*>(&p.value));
      }});
    });
    ImGui::End();

    return canvas.EndRecordingAsPicture();
  };
  OpenPlaygroundHere(callback);
}

TEST_P(AiksTest, CaptureInactivatedByDefault) {
  ASSERT_FALSE(GetContext()->capture.IsActive());
}

// Regression test for https://github.com/flutter/flutter/issues/134678.
TEST_P(AiksTest, ReleasesTextureOnTeardown) {
  auto context = GetContext();
  std::weak_ptr<Texture> weak_texture;

  {
    auto texture = CreateTextureForFixture("table_mountain_nx.png");

    Canvas canvas;
    canvas.Scale(GetContentScale());
    canvas.Translate({100.0f, 100.0f, 0});

    Paint paint;
    paint.color_source = ColorSource::MakeImage(
        texture, Entity::TileMode::kClamp, Entity::TileMode::kClamp, {}, {});
    canvas.DrawRect({0, 0, 600, 600}, paint);

    ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
  }

  // See https://github.com/flutter/flutter/issues/134751.
  //
  // If the fence waiter was working this may not be released by the end of the
  // scope above. Adding a manual shutdown so that future changes to the fence
  // waiter will not flake this test.
  context->Shutdown();

  // The texture should be released by now.
  ASSERT_TRUE(weak_texture.expired()) << "When the texture is no longer in use "
                                         "by the backend, it should be "
                                         "released.";
}

}  // namespace testing
}  // namespace impeller