// 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 "flutter/impeller/aiks/aiks_unittests.h"

#include "impeller/aiks/canvas.h"
#include "impeller/entity/contents/conical_gradient_contents.h"
#include "impeller/entity/contents/filters/inputs/filter_input.h"
#include "impeller/entity/contents/solid_color_contents.h"
#include "impeller/entity/render_target_cache.h"
#include "impeller/geometry/geometry_asserts.h"
#include "impeller/geometry/path_builder.h"
#include "impeller/playground/widgets.h"
#include "impeller/renderer/testing/mocks.h"
#include "third_party/imgui/imgui.h"

////////////////////////////////////////////////////////////////////////////////
// This is for tests of Canvas that are interested the results of rendering
// blurs.
////////////////////////////////////////////////////////////////////////////////

namespace impeller {
namespace testing {

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, 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::Grey(),
                        .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()));
}

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, 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, 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::kDecal),
      });
  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, ClearBlendWithBlur) {
  Canvas canvas;
  Paint white;
  white.color = Color::Blue();
  canvas.DrawRect(Rect::MakeXYWH(0, 0, 600.0, 600.0), white);

  Paint clear;
  clear.blend_mode = BlendMode::kClear;
  clear.mask_blur_descriptor = Paint::MaskBlurDescriptor{
      .style = FilterContents::BlurStyle::kNormal,
      .sigma = Sigma(20),
  };

  canvas.DrawCircle(Point::MakeXY(300.0, 300.0), 200.0, clear);

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

TEST_P(AiksTest, BlurHasNoEdge) {
  Canvas canvas;
  canvas.Scale(GetContentScale());
  canvas.DrawPaint({});
  Paint blur = {
      .color = Color::Green(),
      .mask_blur_descriptor =
          Paint::MaskBlurDescriptor{
              .style = FilterContents::BlurStyle::kNormal,
              .sigma = Sigma(47.6),
          },
  };
  canvas.DrawRect(Rect::MakeXYWH(300, 300, 200, 200), blur);
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, BlurredRectangleWithShader) {
  Canvas canvas;
  canvas.Scale(GetContentScale());

  auto paint_lines = [&canvas](Scalar dx, Scalar dy, Paint paint) {
    auto draw_line = [&canvas, &paint](Point a, Point b) {
      canvas.DrawPath(PathBuilder{}.AddLine(a, b).TakePath(), paint);
    };
    paint.stroke_width = 5;
    paint.style = Paint::Style::kStroke;
    draw_line(Point(dx + 100, dy + 100), Point(dx + 200, dy + 200));
    draw_line(Point(dx + 100, dy + 200), Point(dx + 200, dy + 100));
    draw_line(Point(dx + 150, dy + 100), Point(dx + 200, dy + 150));
    draw_line(Point(dx + 100, dy + 150), Point(dx + 150, dy + 200));
  };

  AiksContext renderer(GetContext(), nullptr);
  Canvas recorder_canvas;
  for (int x = 0; x < 5; ++x) {
    for (int y = 0; y < 5; ++y) {
      Rect rect = Rect::MakeXYWH(x * 20, y * 20, 20, 20);
      Paint paint{.color =
                      ((x + y) & 1) == 0 ? Color::Yellow() : Color::Blue()};
      recorder_canvas.DrawRect(rect, paint);
    }
  }
  Picture picture = recorder_canvas.EndRecordingAsPicture();
  std::shared_ptr<Texture> texture =
      picture.ToImage(renderer, ISize{100, 100})->GetTexture();

  ColorSource image_source = ColorSource::MakeImage(
      texture, Entity::TileMode::kRepeat, Entity::TileMode::kRepeat, {}, {});
  std::shared_ptr<ImageFilter> blur_filter = ImageFilter::MakeBlur(
      Sigma(5), Sigma(5), FilterContents::BlurStyle::kNormal,
      Entity::TileMode::kDecal);
  canvas.DrawRect(Rect::MakeLTRB(0, 0, 300, 600),
                  Paint{.color = Color::DarkGreen()});
  canvas.DrawRect(Rect::MakeLTRB(100, 100, 200, 200),
                  Paint{.color_source = image_source});
  canvas.DrawRect(Rect::MakeLTRB(300, 0, 600, 600),
                  Paint{.color = Color::Red()});
  canvas.DrawRect(
      Rect::MakeLTRB(400, 100, 500, 200),
      Paint{.color_source = image_source, .image_filter = blur_filter});
  paint_lines(0, 300, Paint{.color_source = image_source});
  paint_lines(300, 300,
              Paint{.color_source = image_source, .image_filter = blur_filter});
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, MaskBlurWithZeroSigmaIsSkipped) {
  Canvas canvas;

  Paint paint = {
      .color = Color::Blue(),
      .mask_blur_descriptor =
          Paint::MaskBlurDescriptor{
              .style = FilterContents::BlurStyle::kNormal,
              .sigma = Sigma(0),
          },
  };

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

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

TEST_P(AiksTest, GaussianBlurAtPeripheryVertical) {
  Canvas canvas;

  canvas.Scale(GetContentScale());
  canvas.DrawRRect(Rect::MakeLTRB(0, 0, GetWindowSize().width, 100),
                   Size(10, 10), Paint{.color = Color::LimeGreen()});
  canvas.DrawRRect(Rect::MakeLTRB(0, 110, GetWindowSize().width, 210),
                   Size(10, 10), Paint{.color = Color::Magenta()});
  canvas.ClipRect(Rect::MakeLTRB(100, 0, 200, GetWindowSize().height));
  canvas.SaveLayer({.blend_mode = BlendMode::kSource}, std::nullopt,
                   ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                         FilterContents::BlurStyle::kNormal,
                                         Entity::TileMode::kClamp));
  canvas.Restore();

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

TEST_P(AiksTest, GaussianBlurAtPeripheryHorizontal) {
  Canvas canvas;

  canvas.Scale(GetContentScale());
  std::shared_ptr<Texture> boston = CreateTextureForFixture("boston.jpg");
  canvas.DrawImageRect(
      std::make_shared<Image>(boston),
      Rect::MakeXYWH(0, 0, boston->GetSize().width, boston->GetSize().height),
      Rect::MakeLTRB(0, 0, GetWindowSize().width, 100), Paint{});
  canvas.DrawRRect(Rect::MakeLTRB(0, 110, GetWindowSize().width, 210),
                   Size(10, 10), Paint{.color = Color::Magenta()});
  canvas.ClipRect(Rect::MakeLTRB(0, 50, GetWindowSize().width, 150));
  canvas.SaveLayer({.blend_mode = BlendMode::kSource}, std::nullopt,
                   ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                         FilterContents::BlurStyle::kNormal,
                                         Entity::TileMode::kClamp));
  canvas.Restore();
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

#define FLT_FORWARD(mock, real, method) \
  EXPECT_CALL(*mock, method())          \
      .WillRepeatedly(::testing::Return(real->method()));

TEST_P(AiksTest, GaussianBlurWithoutDecalSupport) {
  if (GetParam() != PlaygroundBackend::kMetal) {
    GTEST_SKIP_(
        "This backend doesn't yet support setting device capabilities.");
  }
  if (!WillRenderSomething()) {
    // Sometimes these tests are run without playgrounds enabled which is
    // pointless for this test since we are asserting that
    // `SupportsDecalSamplerAddressMode` is called.
    GTEST_SKIP_("This test requires playgrounds.");
  }

  std::shared_ptr<const Capabilities> old_capabilities =
      GetContext()->GetCapabilities();
  auto mock_capabilities = std::make_shared<MockCapabilities>();
  EXPECT_CALL(*mock_capabilities, SupportsDecalSamplerAddressMode())
      .Times(::testing::AtLeast(1))
      .WillRepeatedly(::testing::Return(false));
  FLT_FORWARD(mock_capabilities, old_capabilities, GetDefaultColorFormat);
  FLT_FORWARD(mock_capabilities, old_capabilities, GetDefaultStencilFormat);
  FLT_FORWARD(mock_capabilities, old_capabilities,
              GetDefaultDepthStencilFormat);
  FLT_FORWARD(mock_capabilities, old_capabilities, SupportsOffscreenMSAA);
  FLT_FORWARD(mock_capabilities, old_capabilities,
              SupportsImplicitResolvingMSAA);
  FLT_FORWARD(mock_capabilities, old_capabilities, SupportsReadFromResolve);
  FLT_FORWARD(mock_capabilities, old_capabilities, SupportsFramebufferFetch);
  FLT_FORWARD(mock_capabilities, old_capabilities, SupportsSSBO);
  FLT_FORWARD(mock_capabilities, old_capabilities, SupportsCompute);
  FLT_FORWARD(mock_capabilities, old_capabilities,
              SupportsTextureToTextureBlits);
  ASSERT_TRUE(SetCapabilities(mock_capabilities).ok());

  auto texture = std::make_shared<Image>(CreateTextureForFixture("boston.jpg"));
  Canvas canvas;
  canvas.Scale(GetContentScale() * 0.5);
  canvas.DrawPaint({.color = Color::Black()});
  canvas.DrawImage(
      texture, Point(200, 200),
      {
          .image_filter = ImageFilter::MakeBlur(
              Sigma(20.0), Sigma(20.0), FilterContents::BlurStyle::kNormal,
              Entity::TileMode::kDecal),
      });
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

TEST_P(AiksTest, GaussianBlurOneDimension) {
  Canvas canvas;

  canvas.Scale(GetContentScale());
  canvas.Scale({0.5, 0.5, 1.0});
  std::shared_ptr<Texture> boston = CreateTextureForFixture("boston.jpg");
  canvas.DrawImage(std::make_shared<Image>(boston), Point(100, 100), Paint{});
  canvas.SaveLayer({.blend_mode = BlendMode::kSource}, std::nullopt,
                   ImageFilter::MakeBlur(Sigma(50.0), Sigma(0.0),
                                         FilterContents::BlurStyle::kNormal,
                                         Entity::TileMode::kClamp));
  canvas.Restore();
  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
}

// Smoketest to catch issues with the coverage hint.
// Draws a rotated blurred image within a rectangle clip. The center of the clip
// rectangle is the center of the rotated image. The entire area of the clip
// rectangle should be filled with opaque colors output by the blur.
TEST_P(AiksTest, GaussianBlurRotatedAndClipped) {
  Canvas canvas;
  std::shared_ptr<Texture> boston = CreateTextureForFixture("boston.jpg");
  Rect bounds =
      Rect::MakeXYWH(0, 0, boston->GetSize().width, boston->GetSize().height);
  Vector2 image_center = Vector2(bounds.GetSize() / 2);
  Paint paint = {.image_filter =
                     ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                           FilterContents::BlurStyle::kNormal,
                                           Entity::TileMode::kDecal)};
  Vector2 clip_size = {150, 75};
  Vector2 center = Vector2(1024, 768) / 2;
  canvas.Scale(GetContentScale());
  canvas.ClipRect(
      Rect::MakeLTRB(center.x, center.y, center.x, center.y).Expand(clip_size));
  canvas.Translate({center.x, center.y, 0});
  canvas.Scale({0.6, 0.6, 1});
  canvas.Rotate(Degrees(25));

  canvas.DrawImageRect(std::make_shared<Image>(boston), /*source=*/bounds,
                       /*dest=*/bounds.Shift(-image_center), paint);

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

TEST_P(AiksTest, GaussianBlurScaledAndClipped) {
  Canvas canvas;
  std::shared_ptr<Texture> boston = CreateTextureForFixture("boston.jpg");
  Rect bounds =
      Rect::MakeXYWH(0, 0, boston->GetSize().width, boston->GetSize().height);
  Vector2 image_center = Vector2(bounds.GetSize() / 2);
  Paint paint = {.image_filter =
                     ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                           FilterContents::BlurStyle::kNormal,
                                           Entity::TileMode::kDecal)};
  Vector2 clip_size = {150, 75};
  Vector2 center = Vector2(1024, 768) / 2;
  canvas.Scale(GetContentScale());
  canvas.ClipRect(
      Rect::MakeLTRB(center.x, center.y, center.x, center.y).Expand(clip_size));
  canvas.Translate({center.x, center.y, 0});
  canvas.Scale({0.6, 0.6, 1});

  canvas.DrawImageRect(std::make_shared<Image>(boston), /*source=*/bounds,
                       /*dest=*/bounds.Shift(-image_center), paint);

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

TEST_P(AiksTest, GaussianBlurRotatedAndClippedInteractive) {
  std::shared_ptr<Texture> boston = CreateTextureForFixture("boston.jpg");

  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 float rotation = 0;
    static float scale = 0.6;
    static int selected_tile_mode = 3;

    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    {
      ImGui::SliderFloat("Rotation (degrees)", &rotation, -180, 180);
      ImGui::SliderFloat("Scale", &scale, 0, 2.0);
      ImGui::Combo("Tile mode", &selected_tile_mode, tile_mode_names,
                   sizeof(tile_mode_names) / sizeof(char*));
    }
    ImGui::End();

    Canvas canvas;
    Rect bounds =
        Rect::MakeXYWH(0, 0, boston->GetSize().width, boston->GetSize().height);
    Vector2 image_center = Vector2(bounds.GetSize() / 2);
    Paint paint = {.image_filter =
                       ImageFilter::MakeBlur(Sigma(20.0), Sigma(20.0),
                                             FilterContents::BlurStyle::kNormal,
                                             tile_modes[selected_tile_mode])};
    auto [handle_a, handle_b] = IMPELLER_PLAYGROUND_LINE(
        Point(362, 309), Point(662, 459), 20, Color::Red(), Color::Red());
    Vector2 center = Vector2(1024, 768) / 2;
    canvas.Scale(GetContentScale());
    canvas.ClipRect(
        Rect::MakeLTRB(handle_a.x, handle_a.y, handle_b.x, handle_b.y));
    canvas.Translate({center.x, center.y, 0});
    canvas.Scale({scale, scale, 1});
    canvas.Rotate(Degrees(rotation));

    canvas.DrawImageRect(std::make_shared<Image>(boston), /*source=*/bounds,
                         /*dest=*/bounds.Shift(-image_center), paint);
    return canvas.EndRecordingAsPicture();
  };

  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

// This addresses a bug where tiny blurs could result in mip maps that beyond
// the limits for the textures used for blurring.
// See also: b/323402168
TEST_P(AiksTest, GaussianBlurSolidColorTinyMipMap) {
  for (int32_t i = 1; i < 5; ++i) {
    Canvas canvas;
    Scalar fi = i;
    canvas.DrawPath(
        PathBuilder{}
            .MoveTo({100, 100})
            .LineTo({100.f + fi, 100.f + fi})
            .TakePath(),
        {.color = Color::Chartreuse(),
         .image_filter = ImageFilter::MakeBlur(
             Sigma(0.1), Sigma(0.1), FilterContents::BlurStyle::kNormal,
             Entity::TileMode::kClamp)});

    Picture picture = canvas.EndRecordingAsPicture();
    std::shared_ptr<RenderTargetCache> cache =
        std::make_shared<RenderTargetCache>(
            GetContext()->GetResourceAllocator());
    AiksContext aiks_context(GetContext(), nullptr, cache);
    std::shared_ptr<Image> image = picture.ToImage(aiks_context, {1024, 768});
    EXPECT_TRUE(image) << " length " << i;
  }
}

// This addresses a bug where tiny blurs could result in mip maps that beyond
// the limits for the textures used for blurring.
// See also: b/323402168
TEST_P(AiksTest, GaussianBlurBackdropTinyMipMap) {
  for (int32_t i = 0; i < 5; ++i) {
    Canvas canvas;
    ISize clip_size = ISize(i, i);
    canvas.ClipRect(
        Rect::MakeXYWH(400, 400, clip_size.width, clip_size.height));
    canvas.DrawCircle(
        {400, 400}, 200,
        {
            .color = Color::Green(),
            .image_filter = ImageFilter::MakeBlur(
                Sigma(0.1), Sigma(0.1), FilterContents::BlurStyle::kNormal,
                Entity::TileMode::kDecal),
        });
    canvas.Restore();

    Picture picture = canvas.EndRecordingAsPicture();
    std::shared_ptr<RenderTargetCache> cache =
        std::make_shared<RenderTargetCache>(
            GetContext()->GetResourceAllocator());
    AiksContext aiks_context(GetContext(), nullptr, cache);
    std::shared_ptr<Image> image = picture.ToImage(aiks_context, {1024, 768});
    EXPECT_TRUE(image) << " clip rect " << i;
  }
}

TEST_P(AiksTest, GaussianBlurAnimatedBackdrop) {
  // This test is for checking out how stable rendering is when content is
  // translated underneath a blur.  Animating under a blur can cause
  // *shimmering* to happen as a result of pixel alignment.
  // See also: https://github.com/flutter/flutter/issues/140193
  auto boston = std::make_shared<Image>(
      CreateTextureForFixture("boston.jpg", /*enable_mipmapping=*/true));
  ASSERT_TRUE(boston);
  int64_t count = 0;
  Scalar sigma = 20.0;
  Scalar freq = 0.1;
  Scalar amp = 50.0;
  auto callback = [&](AiksContext& renderer) -> std::optional<Picture> {
    ImGui::Begin("Controls", nullptr, ImGuiWindowFlags_AlwaysAutoResize);
    {
      ImGui::SliderFloat("Sigma", &sigma, 0, 200);
      ImGui::SliderFloat("Frequency", &freq, 0.01, 2.0);
      ImGui::SliderFloat("Amplitude", &amp, 1, 100);
    }
    ImGui::End();

    Canvas canvas;
    canvas.Scale(GetContentScale());
    Scalar y = amp * sin(freq * 2.0 * M_PI * count / 60);
    canvas.DrawImage(boston,
                     Point(1024 / 2 - boston->GetSize().width / 2,
                           (768 / 2 - boston->GetSize().height / 2) + y),
                     {});
    auto [handle_a, handle_b] = IMPELLER_PLAYGROUND_LINE(
        Point(100, 100), Point(900, 700), 20, Color::Red(), Color::Red());
    canvas.ClipRect(
        Rect::MakeLTRB(handle_a.x, handle_a.y, handle_b.x, handle_b.y));
    canvas.ClipRect(Rect::MakeLTRB(100, 100, 900, 700));
    canvas.SaveLayer({.blend_mode = BlendMode::kSource}, std::nullopt,
                     ImageFilter::MakeBlur(Sigma(sigma), Sigma(sigma),
                                           FilterContents::BlurStyle::kNormal,
                                           Entity::TileMode::kClamp));
    count += 1;
    return canvas.EndRecordingAsPicture();
  };
  ASSERT_TRUE(OpenPlaygroundHere(callback));
}

}  // namespace testing
}  // namespace impeller