Flutter Impeller
impeller::FilterContents Class Referenceabstract

#include <filter_contents.h>

Inheritance diagram for impeller::FilterContents:
impeller::Contents impeller::BorderMaskBlurFilterContents impeller::ColorFilterContents impeller::DirectionalMorphologyFilterContents impeller::GaussianBlurFilterContents impeller::LocalMatrixFilterContents impeller::MatrixFilterContents impeller::RuntimeEffectFilterContents impeller::YUVToRGBFilterContents

Public Types

enum class  BlurStyle {
  kNormal ,
  kSolid ,
  kOuter ,
  kInner
}
 
enum class  MorphType {
  kDilate ,
  kErode
}
 
- Public Types inherited from impeller::Contents
using ColorFilterProc = std::function< Color(Color)>
 
using RenderProc = std::function< bool(const ContentContext &renderer, const Entity &entity, RenderPass &pass)>
 
using CoverageProc = std::function< std::optional< Rect >(const Entity &entity)>
 

Public Member Functions

 FilterContents ()
 
 ~FilterContents () override
 
void SetInputs (FilterInput::Vector inputs)
 The input texture sources for this filter. Each input's emitted texture is expected to have premultiplied alpha colors. More...
 
void SetEffectTransform (const Matrix &effect_transform)
 Sets the transform which gets appended to the effect of this filter. Note that this is in addition to the entity's transform. More...
 
std::optional< EntityGetEntity (const ContentContext &renderer, const Entity &entity, const std::optional< Rect > &coverage_hint) const
 Create an Entity that renders this filter's output. More...
 
bool Render (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
 
std::optional< RectGetCoverage (const Entity &entity) const override
 Get the area of the render pass that will be affected when this contents is rendered. More...
 
std::optional< SnapshotRenderToSnapshot (const ContentContext &renderer, const Entity &entity, std::optional< Rect > coverage_limit=std::nullopt, const std::optional< SamplerDescriptor > &sampler_descriptor=std::nullopt, bool msaa_enabled=true, int32_t mip_count=1, std::string_view label="Filter Snapshot") const override
 Render this contents to a snapshot, respecting the entity's transform, path, clip depth, and blend mode. The result texture size is always the size of GetCoverage(entity). More...
 
std::optional< RectGetSourceCoverage (const Matrix &effect_transform, const Rect &output_limit) const
 Determines the coverage of source pixels that will be needed to produce results for the specified |output_limit| under the specified |effect_transform|. This is essentially a reverse of the |GetCoverage| method computing a source coverage from an intended |output_limit| coverage. More...
 
virtual Matrix GetLocalTransform (const Matrix &parent_transform) const
 
Matrix GetTransform (const Matrix &parent_transform) const
 
virtual void SetRenderingMode (Entity::RenderingMode rendering_mode)
 Marks this filter chain as applying in a subpass scenario. More...
 
- Public Member Functions inherited from impeller::Contents
 Contents ()
 
virtual ~Contents ()
 
void SetCoverageHint (std::optional< Rect > coverage_hint)
 Hint that specifies the coverage area of this Contents that will actually be used during rendering. This is for optimization purposes only and can not be relied on as a clip. May optionally affect the result of GetCoverage(). More...
 
const std::optional< Rect > & GetCoverageHint () const
 
virtual bool IsOpaque (const Matrix &transform) const
 Whether this Contents only emits opaque source colors from the fragment stage. This value does not account for any entity properties (e.g. the blend mode), clips/visibility culling, or inherited opacity. More...
 
std::optional< SizeGetColorSourceSize () const
 Return the color source's intrinsic size, if available. More...
 
void SetColorSourceSize (Size size)
 
virtual void SetInheritedOpacity (Scalar opacity)
 Inherit the provided opacity. More...
 
virtual std::optional< ColorAsBackgroundColor (const Entity &entity, ISize target_size) const
 Returns a color if this Contents will flood the given target_size with a color. This output color is the "Source" color that will be used for the Entity's blend operation. More...
 
virtual bool ApplyColorFilter (const ColorFilterProc &color_filter_proc)
 If possible, applies a color filter to this contents inputs on the CPU. More...
 

Static Public Member Functions

static std::shared_ptr< FilterContentsMakeGaussianBlur (const FilterInput::Ref &input, Sigma sigma_x, Sigma sigma_y, Entity::TileMode tile_mode=Entity::TileMode::kDecal, BlurStyle mask_blur_style=BlurStyle::kNormal, const Geometry *mask_geometry=nullptr)
 
static std::shared_ptr< FilterContentsMakeBorderMaskBlur (FilterInput::Ref input, Sigma sigma_x, Sigma sigma_y, BlurStyle blur_style=BlurStyle::kNormal)
 
static std::shared_ptr< FilterContentsMakeDirectionalMorphology (FilterInput::Ref input, Radius radius, Vector2 direction, MorphType morph_type)
 
static std::shared_ptr< FilterContentsMakeMorphology (FilterInput::Ref input, Radius radius_x, Radius radius_y, MorphType morph_type)
 
static std::shared_ptr< FilterContentsMakeMatrixFilter (FilterInput::Ref input, const Matrix &matrix, const SamplerDescriptor &desc)
 
static std::shared_ptr< FilterContentsMakeLocalMatrixFilter (FilterInput::Ref input, const Matrix &matrix)
 
static std::shared_ptr< FilterContentsMakeYUVToRGBFilter (std::shared_ptr< Texture > y_texture, std::shared_ptr< Texture > uv_texture, YUVColorSpace yuv_color_space)
 
static std::shared_ptr< FilterContentsMakeRuntimeEffect (FilterInput::Ref input, std::shared_ptr< RuntimeStage > runtime_stage, std::shared_ptr< std::vector< uint8_t >> uniforms, std::vector< RuntimeEffectContents::TextureInput > texture_inputs)
 
- Static Public Member Functions inherited from impeller::Contents
static std::shared_ptr< ContentsMakeAnonymous (RenderProc render_proc, CoverageProc coverage_proc)
 

Static Public Attributes

static const int32_t kBlurFilterRequiredMipCount
 

Detailed Description

Definition at line 24 of file filter_contents.h.

Member Enumeration Documentation

◆ BlurStyle

Enumerator
kNormal 

Blurred inside and outside.

kSolid 

Solid inside, blurred outside.

kOuter 

Nothing inside, blurred outside.

kInner 

Blurred inside, nothing outside.

Definition at line 28 of file filter_contents.h.

28  {
29  /// Blurred inside and outside.
30  kNormal,
31  /// Solid inside, blurred outside.
32  kSolid,
33  /// Nothing inside, blurred outside.
34  kOuter,
35  /// Blurred inside, nothing outside.
36  kInner,
37  };

◆ MorphType

Enumerator
kDilate 
kErode 

Definition at line 39 of file filter_contents.h.

39 { kDilate, kErode };

Constructor & Destructor Documentation

◆ FilterContents()

impeller::FilterContents::FilterContents ( )
default

◆ ~FilterContents()

impeller::FilterContents::~FilterContents ( )
overridedefault

Member Function Documentation

◆ GetCoverage()

std::optional< Rect > impeller::FilterContents::GetCoverage ( const Entity entity) const
overridevirtual

Get the area of the render pass that will be affected when this contents is rendered.

During rendering, coverage coordinates count pixels from the top left corner of the framebuffer.

Returns
The coverage rectangle. An std::nullopt result means that rendering this contents has no effect on the output color.

Implements impeller::Contents.

Definition at line 176 of file filter_contents.cc.

176  {
177  Entity entity_with_local_transform = entity.Clone();
178  entity_with_local_transform.SetTransform(GetTransform(entity.GetTransform()));
179 
180  return GetLocalCoverage(entity_with_local_transform);
181 }
Matrix GetTransform(const Matrix &parent_transform) const

References impeller::Entity::Clone(), impeller::Entity::GetTransform(), GetTransform(), and impeller::Entity::SetTransform().

Referenced by Render(), and impeller::testing::TEST_P().

◆ GetEntity()

std::optional< Entity > impeller::FilterContents::GetEntity ( const ContentContext renderer,
const Entity entity,
const std::optional< Rect > &  coverage_hint 
) const

Create an Entity that renders this filter's output.

Definition at line 232 of file filter_contents.cc.

235  {
236  Entity entity_with_local_transform = entity.Clone();
237  entity_with_local_transform.SetTransform(GetTransform(entity.GetTransform()));
238 
239  std::optional<Rect> coverage = GetLocalCoverage(entity_with_local_transform);
240  if (!coverage.has_value() || coverage->IsEmpty()) {
241  return std::nullopt;
242  }
243 
244  return RenderFilter(inputs_, //
245  renderer, //
246  entity_with_local_transform, //
247  effect_transform_, //
248  coverage.value(), //
249  coverage_hint //
250  );
251 }

References impeller::Entity::Clone(), impeller::Entity::GetTransform(), GetTransform(), and impeller::Entity::SetTransform().

Referenced by Render(), RenderToSnapshot(), and impeller::testing::TEST_P().

◆ GetLocalTransform()

Matrix impeller::FilterContents::GetLocalTransform ( const Matrix parent_transform) const
virtual

Reimplemented in impeller::LocalMatrixFilterContents.

Definition at line 280 of file filter_contents.cc.

280  {
281  return Matrix();
282 }

Referenced by GetTransform().

◆ GetSourceCoverage()

std::optional< Rect > impeller::FilterContents::GetSourceCoverage ( const Matrix effect_transform,
const Rect output_limit 
) const

Determines the coverage of source pixels that will be needed to produce results for the specified |output_limit| under the specified |effect_transform|. This is essentially a reverse of the |GetCoverage| method computing a source coverage from an intended |output_limit| coverage.

Both the |output_limit| and the return value are in the transformed coordinate space, and so do not need to be transformed or inverse transformed by the |effect_transform| but individual parameters on the filter might be in the untransformed space and should be transformed by the |effect_transform| before applying them to the coverages.

The method computes a result such that if the filter is applied to a set of pixels filling the computed source coverage, it should produce an output that covers the entire specified |output_limit|.

This is useful for subpass rendering scenarios where a filter will be applied to the output of the subpass and we need to determine how large of a render target to allocate in order to collect all pixels that might affect the supplied output coverage limit. While we might end up clipping the rendering of the subpass to its destination, we want to avoid clipping out any pixels that contribute to the output limit via the filtering operation.

Returns
The coverage bounds in the transformed space of any source pixel that may be needed to produce output for the indicated filter that covers the indicated |output_limit|.

Definition at line 210 of file filter_contents.cc.

212  {
213  auto filter_input_coverage =
214  GetFilterSourceCoverage(effect_transform_, output_limit);
215 
216  if (!filter_input_coverage.has_value()) {
217  return std::nullopt;
218  }
219 
220  std::optional<Rect> inputs_coverage;
221  for (const auto& input : inputs_) {
222  auto input_coverage = input->GetSourceCoverage(
223  effect_transform, filter_input_coverage.value());
224  if (!input_coverage.has_value()) {
225  return std::nullopt;
226  }
227  inputs_coverage = Rect::Union(inputs_coverage, input_coverage.value());
228  }
229  return inputs_coverage;
230 }
constexpr TRect Union(const TRect &o) const
Definition: rect.h:517

References impeller::TRect< Scalar >::Union().

◆ GetTransform()

Matrix impeller::FilterContents::GetTransform ( const Matrix parent_transform) const

Definition at line 284 of file filter_contents.cc.

284  {
285  return parent_transform * GetLocalTransform(parent_transform);
286 }
virtual Matrix GetLocalTransform(const Matrix &parent_transform) const

References GetLocalTransform().

Referenced by GetCoverage(), and GetEntity().

◆ MakeBorderMaskBlur()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeBorderMaskBlur ( FilterInput::Ref  input,
Sigma  sigma_x,
Sigma  sigma_y,
BlurStyle  blur_style = BlurStyle::kNormal 
)
static

Definition at line 50 of file filter_contents.cc.

54  {
55  auto filter = std::make_shared<BorderMaskBlurFilterContents>();
56  filter->SetInputs({std::move(input)});
57  filter->SetSigma(sigma_x, sigma_y);
58  filter->SetBlurStyle(blur_style);
59  return filter;
60 }

Referenced by impeller::testing::TEST_P().

◆ MakeDirectionalMorphology()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeDirectionalMorphology ( FilterInput::Ref  input,
Radius  radius,
Vector2  direction,
MorphType  morph_type 
)
static

Definition at line 62 of file filter_contents.cc.

66  {
67  auto filter = std::make_shared<DirectionalMorphologyFilterContents>();
68  filter->SetInputs({std::move(input)});
69  filter->SetRadius(radius);
70  filter->SetDirection(direction);
71  filter->SetMorphType(morph_type);
72  return filter;
73 }

Referenced by MakeMorphology().

◆ MakeGaussianBlur()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeGaussianBlur ( const FilterInput::Ref input,
Sigma  sigma_x,
Sigma  sigma_y,
Entity::TileMode  tile_mode = Entity::TileMode::kDecal,
FilterContents::BlurStyle  mask_blur_style = BlurStyle::kNormal,
const Geometry mask_geometry = nullptr 
)
static

Creates a gaussian blur that operates in 2 dimensions. See also: MakeDirectionalGaussianBlur

Definition at line 37 of file filter_contents.cc.

43  {
44  auto blur = std::make_shared<GaussianBlurFilterContents>(
45  sigma_x.sigma, sigma_y.sigma, tile_mode, mask_blur_style, mask_geometry);
46  blur->SetInputs({input});
47  return blur;
48 }

References impeller::Sigma::sigma.

Referenced by impeller::testing::TEST_P(), and impeller::WrapInput().

◆ MakeLocalMatrixFilter()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeLocalMatrixFilter ( FilterInput::Ref  input,
const Matrix matrix 
)
static

Definition at line 98 of file filter_contents.cc.

100  {
101  auto filter = std::make_shared<LocalMatrixFilterContents>();
102  filter->SetInputs({std::move(input)});
103  filter->SetMatrix(matrix);
104  return filter;
105 }

Referenced by impeller::WrapInput().

◆ MakeMatrixFilter()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeMatrixFilter ( FilterInput::Ref  input,
const Matrix matrix,
const SamplerDescriptor desc 
)
static

Definition at line 87 of file filter_contents.cc.

90  {
91  auto filter = std::make_shared<MatrixFilterContents>();
92  filter->SetInputs({std::move(input)});
93  filter->SetMatrix(matrix);
94  filter->SetSamplerDescriptor(desc);
95  return filter;
96 }

Referenced by impeller::testing::TEST(), and impeller::WrapInput().

◆ MakeMorphology()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeMorphology ( FilterInput::Ref  input,
Radius  radius_x,
Radius  radius_y,
MorphType  morph_type 
)
static

Definition at line 75 of file filter_contents.cc.

79  {
80  auto x_morphology = MakeDirectionalMorphology(std::move(input), radius_x,
81  Point(1, 0), morph_type);
82  auto y_morphology = MakeDirectionalMorphology(
83  FilterInput::Make(x_morphology), radius_y, Point(0, 1), morph_type);
84  return y_morphology;
85 }
static std::shared_ptr< FilterContents > MakeDirectionalMorphology(FilterInput::Ref input, Radius radius, Vector2 direction, MorphType morph_type)
static FilterInput::Ref Make(Variant input, bool msaa_enabled=true)
Definition: filter_input.cc:19
TPoint< Scalar > Point
Definition: point.h:327

References impeller::FilterInput::Make(), and MakeDirectionalMorphology().

Referenced by impeller::testing::TEST_P(), and impeller::WrapInput().

◆ MakeRuntimeEffect()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeRuntimeEffect ( FilterInput::Ref  input,
std::shared_ptr< RuntimeStage runtime_stage,
std::shared_ptr< std::vector< uint8_t >>  uniforms,
std::vector< RuntimeEffectContents::TextureInput texture_inputs 
)
static

Definition at line 118 of file filter_contents.cc.

122  {
123  auto filter = std::make_shared<impeller::RuntimeEffectFilterContents>();
124  filter->SetInputs({std::move(input)});
125  filter->SetRuntimeStage(std::move(runtime_stage));
126  filter->SetUniforms(std::move(uniforms));
127  filter->SetTextureInputs(std::move(texture_inputs));
128  return filter;
129 }

Referenced by impeller::WrapInput().

◆ MakeYUVToRGBFilter()

std::shared_ptr< FilterContents > impeller::FilterContents::MakeYUVToRGBFilter ( std::shared_ptr< Texture y_texture,
std::shared_ptr< Texture uv_texture,
YUVColorSpace  yuv_color_space 
)
static

Definition at line 107 of file filter_contents.cc.

110  {
111  auto filter = std::make_shared<impeller::YUVToRGBFilterContents>();
112  filter->SetInputs({impeller::FilterInput::Make(y_texture),
113  impeller::FilterInput::Make(uv_texture)});
114  filter->SetYUVColorSpace(yuv_color_space);
115  return filter;
116 }

References impeller::FilterInput::Make().

Referenced by impeller::DlImageImpeller::MakeFromYUVTextures(), and impeller::testing::TEST_P().

◆ Render()

bool impeller::FilterContents::Render ( const ContentContext renderer,
const Entity entity,
RenderPass pass 
) const
overridevirtual

Implements impeller::Contents.

Definition at line 147 of file filter_contents.cc.

149  {
150  auto filter_coverage = GetCoverage(entity);
151  if (!filter_coverage.has_value()) {
152  return true;
153  }
154 
155  // Run the filter.
156 
157  auto maybe_entity = GetEntity(renderer, entity, GetCoverageHint());
158  if (!maybe_entity.has_value()) {
159  return true;
160  }
161  maybe_entity->SetClipDepth(entity.GetClipDepth());
162  return maybe_entity->Render(renderer, pass);
163 }
const std::optional< Rect > & GetCoverageHint() const
Definition: contents.cc:140
std::optional< Entity > GetEntity(const ContentContext &renderer, const Entity &entity, const std::optional< Rect > &coverage_hint) const
Create an Entity that renders this filter's output.
std::optional< Rect > GetCoverage(const Entity &entity) const override
Get the area of the render pass that will be affected when this contents is rendered.

References impeller::Entity::GetClipDepth(), GetCoverage(), impeller::Contents::GetCoverageHint(), and GetEntity().

◆ RenderToSnapshot()

std::optional< Snapshot > impeller::FilterContents::RenderToSnapshot ( const ContentContext renderer,
const Entity entity,
std::optional< Rect coverage_limit = std::nullopt,
const std::optional< SamplerDescriptor > &  sampler_descriptor = std::nullopt,
bool  msaa_enabled = true,
int32_t  mip_count = 1,
std::string_view  label = "Filter Snapshot" 
) const
overridevirtual

Render this contents to a snapshot, respecting the entity's transform, path, clip depth, and blend mode. The result texture size is always the size of GetCoverage(entity).

Reimplemented from impeller::Contents.

Definition at line 253 of file filter_contents.cc.

260  {
261  // Resolve the render instruction (entity) from the filter and render it to a
262  // snapshot.
263  if (std::optional<Entity> result =
264  GetEntity(renderer, entity, coverage_limit);
265  result.has_value()) {
266  return result->GetContents()->RenderToSnapshot(
267  renderer, // renderer
268  result.value(), // entity
269  coverage_limit, // coverage_limit
270  std::nullopt, // sampler_descriptor
271  true, // msaa_enabled
272  /*mip_count=*/mip_count,
273  label // label
274  );
275  }
276 
277  return std::nullopt;
278 }

References GetEntity().

◆ SetEffectTransform()

void impeller::FilterContents::SetEffectTransform ( const Matrix effect_transform)

Sets the transform which gets appended to the effect of this filter. Note that this is in addition to the entity's transform.

This is useful for subpass rendering scenarios where it's difficult to encode the current transform of the layer into the Entity being rendered.

Definition at line 139 of file filter_contents.cc.

139  {
140  effect_transform_ = effect_transform;
141 
142  for (auto& input : inputs_) {
143  input->SetEffectTransform(effect_transform);
144  }
145 }

Referenced by impeller::testing::TEST_P().

◆ SetInputs()

void impeller::FilterContents::SetInputs ( FilterInput::Vector  inputs)

The input texture sources for this filter. Each input's emitted texture is expected to have premultiplied alpha colors.

The number of required or optional textures depends on the particular filter's implementation.

Definition at line 135 of file filter_contents.cc.

135  {
136  inputs_ = std::move(inputs);
137 }

Referenced by impeller::testing::TEST_P().

◆ SetRenderingMode()

void impeller::FilterContents::SetRenderingMode ( Entity::RenderingMode  rendering_mode)
virtual

Marks this filter chain as applying in a subpass scenario.

    Subpasses render in screenspace, and this setting informs filters
    that the current transform matrix of the entity is not stored
    in the Entity transform matrix. Instead, the effect transform
    is used in this case. 

Reimplemented in impeller::MatrixFilterContents.

Definition at line 288 of file filter_contents.cc.

288  {
289  for (auto& input : inputs_) {
290  input->SetRenderingMode(rendering_mode);
291  }
292 }

Referenced by impeller::MatrixFilterContents::SetRenderingMode().

Member Data Documentation

◆ kBlurFilterRequiredMipCount

const int32_t impeller::FilterContents::kBlurFilterRequiredMipCount
static
Initial value:

Definition at line 26 of file filter_contents.h.


The documentation for this class was generated from the following files: