impeller::MatrixFilterContents Class Reference

#include <matrix_filter_contents.h>

Inheritance diagram for impeller::MatrixFilterContents:

Public Member Functions
	MatrixFilterContents ()
	~MatrixFilterContents () override
void	SetMatrix (Matrix matrix)
void	SetRenderingMode (Entity::RenderingMode rendering_mode) override
	Marks this filter chain as applying in a subpass scenario.
bool	IsTranslationOnly () const override
	Returns true if this filter graph doesn't perform any basis transforms to the filtered content. For example: Rotating, scaling, and skewing are all basis transforms, but translating is not.
void	SetSamplerDescriptor (SamplerDescriptor desc)
std::optional< Rect >	GetFilterCoverage (const FilterInput::Vector &inputs, const Entity &entity, const Matrix &effect_transform) const override
	Internal utility method for |GetLocalCoverage| that computes the output coverage of this filter across the specified inputs, ignoring the coverage hint.
Public Member Functions inherited from impeller::FilterContents
	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.
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.
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.
bool	Render (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
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.
void	PopulateGlyphAtlas (const std::shared_ptr< LazyGlyphAtlas > &lazy_glyph_atlas, Scalar scale) override
	Add any text data to the specified lazy atlas. The scale parameter must be used again later when drawing the text.
std::optional< Snapshot >	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, const std::string &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).
const FilterContents *	AsFilter () const override
	Cast to a filter. Returns nullptr if this Contents is not a filter.
std::optional< Rect >	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.
virtual Matrix	GetLocalTransform (const Matrix &parent_transform) const
Matrix	GetTransform (const Matrix &parent_transform) const
bool	IsLeaf () const
	Returns true if this filter does not have any FilterInput children.
void	SetLeafInputs (const FilterInput::Vector &inputs)
	Replaces the set of all leaf FilterContents with a new set of FilterInputs.
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().
const std::optional< Rect > &	GetCoverageHint () const
virtual bool	IsOpaque () 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.
virtual ClipCoverage	GetClipCoverage (const Entity &entity, const std::optional< Rect > &current_clip_coverage) const
	Given the current pass space bounding rectangle of the clip buffer, return the expected clip coverage after this draw call. This should only be implemented for contents that may write to the clip buffer.
virtual bool	ShouldRender (const Entity &entity, const std::optional< Rect > clip_coverage) const
std::optional< Size >	GetColorSourceSize () const
	Return the color source's intrinsic size, if available.
void	SetColorSourceSize (Size size)
virtual bool	CanInheritOpacity (const Entity &entity) const
	Whether or not this contents can accept the opacity peephole optimization.
virtual void	SetInheritedOpacity (Scalar opacity)
	Inherit the provided opacity.
virtual std::optional< Color >	AsBackgroundColor (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.
virtual bool	ApplyColorFilter (const ColorFilterProc &color_filter_proc)
	If possible, applies a color filter to this contents inputs on the CPU.

Private Member Functions
std::optional< Entity >	RenderFilter (const FilterInput::Vector &input_textures, const ContentContext &renderer, const Entity &entity, const Matrix &effect_transform, const Rect &coverage, const std::optional< Rect > &coverage_hint) const override
	Converts zero or more filter inputs into a render instruction.
std::optional< Rect >	GetFilterSourceCoverage (const Matrix &effect_transform, const Rect &output_limit) const override
	Internal utility method for |GetSourceCoverage| that computes the inverse effect of this transform on the specified output coverage, ignoring the inputs which will be accommodated by the caller.

Additional Inherited Members
Public Types inherited from impeller::FilterContents
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)>
Static Public Member Functions inherited from impeller::FilterContents
static std::shared_ptr< FilterContents >	MakeGaussianBlur (const FilterInput::Ref &input, Sigma sigma_x, Sigma sigma_y, Entity::TileMode tile_mode=Entity::TileMode::kDecal, BlurStyle mask_blur_style=BlurStyle::kNormal, const std::shared_ptr< Geometry > &mask_geometry=nullptr)
static std::shared_ptr< FilterContents >	MakeBorderMaskBlur (FilterInput::Ref input, Sigma sigma_x, Sigma sigma_y, BlurStyle blur_style=BlurStyle::kNormal)
static std::shared_ptr< FilterContents >	MakeDirectionalMorphology (FilterInput::Ref input, Radius radius, Vector2 direction, MorphType morph_type)
static std::shared_ptr< FilterContents >	MakeMorphology (FilterInput::Ref input, Radius radius_x, Radius radius_y, MorphType morph_type)
static std::shared_ptr< FilterContents >	MakeMatrixFilter (FilterInput::Ref input, const Matrix &matrix, const SamplerDescriptor &desc)
static std::shared_ptr< FilterContents >	MakeLocalMatrixFilter (FilterInput::Ref input, const Matrix &matrix)
static std::shared_ptr< FilterContents >	MakeYUVToRGBFilter (std::shared_ptr< Texture > y_texture, std::shared_ptr< Texture > uv_texture, YUVColorSpace yuv_color_space)
Static Public Member Functions inherited from impeller::Contents
static std::shared_ptr< Contents >	MakeAnonymous (RenderProc render_proc, CoverageProc coverage_proc)
Static Public Attributes inherited from impeller::FilterContents
static const int32_t	kBlurFilterRequiredMipCount

Detailed Description

Definition at line 13 of file matrix_filter_contents.h.

Constructor & Destructor Documentation

MatrixFilterContents()

impeller::MatrixFilterContents::MatrixFilterContents ( )

default

~MatrixFilterContents()

impeller::MatrixFilterContents::~MatrixFilterContents ( )

overridedefault

Member Function Documentation

GetFilterCoverage()

std::optional< Rect > impeller::MatrixFilterContents::GetFilterCoverage ( const FilterInput::Vector &  inputs, const Entity &  entity, const Matrix &  effect_transform  ) const

overridevirtual

Internal utility method for |GetLocalCoverage| that computes the output coverage of this filter across the specified inputs, ignoring the coverage hint.

Reimplemented from impeller::FilterContents.

Definition at line 86 of file matrix_filter_contents.cc.

                                          {
  if (inputs.empty()) {
    return std::nullopt;
  }
 
  auto coverage = inputs[0]->GetCoverage(entity);
  if (!coverage.has_value()) {
    return std::nullopt;
  }
  auto& m = rendering_mode_ == Entity::RenderingMode::kSubpass
                ? effect_transform
                : inputs[0]->GetTransform(entity);
  auto transform = m *          //
                   matrix_ *    //
                   m.Invert();  //
  return coverage->TransformBounds(transform);
}

GetFilterSourceCoverage()

std::optional< Rect > impeller::MatrixFilterContents::GetFilterSourceCoverage ( const Matrix &  effect_transform, const Rect &  output_limit  ) const

overrideprivatevirtual

Internal utility method for |GetSourceCoverage| that computes the inverse effect of this transform on the specified output coverage, ignoring the inputs which will be accommodated by the caller.

Implements impeller::FilterContents.

Definition at line 73 of file matrix_filter_contents.cc.

                                    {
  auto transform = effect_transform *          //
                   matrix_ *                   //
                   effect_transform.Invert();  //
  if (transform.GetDeterminant() == 0.0) {
    return std::nullopt;
  }
  auto inverse = transform.Invert();
  return output_limit.TransformBounds(inverse);
}

IsTranslationOnly()

bool impeller::MatrixFilterContents::IsTranslationOnly ( ) const

overridevirtual

Returns true if this filter graph doesn't perform any basis transforms to the filtered content. For example: Rotating, scaling, and skewing are all basis transforms, but translating is not.

This is useful for determining whether a filtered object's space is compatible enough with the parent pass space to perform certain subpass clipping optimizations.

Reimplemented from impeller::FilterContents.

Definition at line 23 of file matrix_filter_contents.cc.

                                                   {
  return matrix_.Basis().IsIdentity() && FilterContents::IsTranslationOnly();
}

RenderFilter()

std::optional< Entity > impeller::MatrixFilterContents::RenderFilter ( const FilterInput::Vector &  inputs, const ContentContext &  renderer, const Entity &  entity, const Matrix &  effect_transform, const Rect &  coverage, const std::optional< Rect > &  coverage_hint  ) const

overrideprivatevirtual

Converts zero or more filter inputs into a render instruction.

Implements impeller::FilterContents.

Definition at line 31 of file matrix_filter_contents.cc.

                                                  {
  auto snapshot = inputs[0]->GetSnapshot("Matrix", renderer, entity);
  if (!snapshot.has_value()) {
    return std::nullopt;
  }
 
  // The filter's matrix needs to be applied within the space defined by the
  // scene's current transform matrix (CTM). For example: If the CTM is
  // scaled up, then translations applied by the matrix should be magnified
  // accordingly.
  //
  // To accomplish this, we sandwich the filter's matrix within the CTM in both
  // cases. But notice that for the subpass backdrop filter case, we use the
  // "effect transform" instead of the Entity's transform!
  //
  // That's because in the subpass backdrop filter case, the Entity's transform
  // isn't actually the captured CTM of the scene like it usually is; instead,
  // it's just a screen space translation that offsets the backdrop texture (as
  // mentioned above). And so we sneak the subpass's captured CTM in through the
  // effect transform.
 
  auto transform = rendering_mode_ == Entity::RenderingMode::kSubpass
                       ? effect_transform
                       : entity.GetTransform();
  snapshot->transform = transform *           //
                        matrix_ *             //
                        transform.Invert() *  //
                        snapshot->transform;
 
  snapshot->sampler_descriptor = sampler_descriptor_;
  if (!snapshot.has_value()) {
    return std::nullopt;
  }
  return Entity::FromSnapshot(snapshot.value(), entity.GetBlendMode());
}

SetMatrix()

void impeller::MatrixFilterContents::SetMatrix

(

Matrix

matrix

)

Definition at line 13 of file matrix_filter_contents.cc.

                                                  {
  matrix_ = matrix;
}

SetRenderingMode()

void impeller::MatrixFilterContents::SetRenderingMode ( Entity::RenderingMode  rendering_mode )

overridevirtual

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 from impeller::FilterContents.

Definition at line 17 of file matrix_filter_contents.cc.

                                        {
  rendering_mode_ = rendering_mode;
  FilterContents::SetRenderingMode(rendering_mode);
}

SetSamplerDescriptor()

void impeller::MatrixFilterContents::SetSamplerDescriptor

(

SamplerDescriptor

desc

)

Definition at line 27 of file matrix_filter_contents.cc.

                                                                      {
  sampler_descriptor_ = std::move(desc);
}

---

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

• impeller/entity/contents/filters/matrix_filter_contents.h
• impeller/entity/contents/filters/matrix_filter_contents.cc