impeller::SolidRRectBlurContents Class Reference

Draws a fast solid color blur of an rounded rectangle. Only supports RRects with fully symmetrical radii. Also produces correct results for rectangles (corner_radius=0) and circles (corner_radius=width/2=height/2). More...

#include <solid_rrect_blur_contents.h>

Inheritance diagram for impeller::SolidRRectBlurContents:

Public Member Functions
	SolidRRectBlurContents ()
	~SolidRRectBlurContents () override
void	SetRRect (std::optional< Rect > rect, Scalar corner_radius=0)
void	SetSigma (Sigma sigma)
void	SetColor (Color color)
Color	GetColor () const
std::optional< Rect >	GetCoverage (const Entity &entity) const override
	Get the screen space bounding rectangle that this contents affects. More...
bool	Render (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
bool	ApplyColorFilter (const ColorFilterProc &color_filter_proc) override
	If possible, applies a color filter to this contents inputs on the CPU. More...
Public Member Functions inherited from impeller::Contents
	Contents ()
virtual	~Contents ()
virtual void	PopulateGlyphAtlas (const std::shared_ptr< LazyGlyphAtlas > &lazy_glyph_atlas, Scalar scale)
	Add any text data to the specified lazy atlas. The scale parameter must be used again later when drawing the text. More...
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
	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...
virtual StencilCoverage	GetStencilCoverage (const Entity &entity, const std::optional< Rect > &current_stencil_coverage) const
	Given the current screen space bounding rectangle of the stencil, return the expected stencil coverage after this draw call. This should only be implemented for contents that may write to the stencil buffer. More...
virtual 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, const std::string &label="Snapshot") const
	Render this contents to a snapshot, respecting the entity's transform, path, stencil depth, and blend mode. The result texture size is always the size of GetCoverage(entity). More...
virtual bool	ShouldRender (const Entity &entity, const std::optional< Rect > &stencil_coverage) const
std::optional< Size >	GetColorSourceSize () const
	Return the color source's intrinsic size, if available. More...
void	SetColorSourceSize (Size size)
virtual bool	CanInheritOpacity (const Entity &entity) const
	Whether or not this contents can accept the opacity peephole optimization. More...
virtual void	SetInheritedOpacity (Scalar opacity)
	Inherit the provided opacity. More...
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. More...
virtual const FilterContents *	AsFilter () const
	Cast to a filter. Returns nullptr if this Contents is not a filter. More...

Additional Inherited Members
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::Contents
static std::shared_ptr< Contents >	MakeAnonymous (RenderProc render_proc, CoverageProc coverage_proc)

Detailed Description

Draws a fast solid color blur of an rounded rectangle. Only supports RRects with fully symmetrical radii. Also produces correct results for rectangles (corner_radius=0) and circles (corner_radius=width/2=height/2).

Definition at line 24 of file solid_rrect_blur_contents.h.

Constructor & Destructor Documentation

SolidRRectBlurContents()

impeller::SolidRRectBlurContents::SolidRRectBlurContents ( )

default

~SolidRRectBlurContents()

impeller::SolidRRectBlurContents::~SolidRRectBlurContents ( )

overridedefault

Member Function Documentation

ApplyColorFilter()

bool impeller::SolidRRectBlurContents::ApplyColorFilter ( const ColorFilterProc &  color_filter_proc )

overridevirtual

If possible, applies a color filter to this contents inputs on the CPU.

This method will either fully apply the color filter or perform no action. Partial/incorrect application of the color filter will never occur.

Parameters

[in]

color_filter_proc

A function that filters a given unpremultiplied color to produce a new unpremultiplied color.

Returns

True if the color filter was able to be fully applied to all all relevant inputs. Otherwise, this operation is a no-op and false is returned.

Reimplemented from impeller::Contents.

Definition at line 125 of file solid_rrect_blur_contents.cc.

                                              {
  color_ = color_filter_proc(color_);
  return true;
}

GetColor()

Color impeller::SolidRRectBlurContents::GetColor

(

)

const

Definition at line 37 of file solid_rrect_blur_contents.cc.

                                             {
  return color_;
}

GetCoverage()

std::optional< Rect > impeller::SolidRRectBlurContents::GetCoverage ( const Entity &  entity ) const

overridevirtual

Get the screen space bounding rectangle that this contents affects.

Implements impeller::Contents.

Definition at line 41 of file solid_rrect_blur_contents.cc.

                                {
  if (!rect_.has_value()) {
    return std::nullopt;
  }
 
  Scalar radius = sigma_.sigma * 2;
 
  auto ltrb = rect_->GetLTRB();
  Rect bounds = Rect::MakeLTRB(ltrb[0] - radius, ltrb[1] - radius,
                               ltrb[2] + radius, ltrb[3] + radius);
  return bounds.TransformBounds(entity.GetTransformation());
};

References impeller::Entity::GetTransformation(), impeller::TRect< Scalar >::MakeLTRB(), impeller::Sigma::sigma, and impeller::TRect< T >::TransformBounds().

Render()

bool impeller::SolidRRectBlurContents::Render ( const ContentContext &  renderer, const Entity &  entity, RenderPass &  pass  ) const

overridevirtual

Implements impeller::Contents.

Definition at line 55 of file solid_rrect_blur_contents.cc.

                                                            {
  if (!rect_.has_value()) {
    return true;
  }
 
  using VS = RRectBlurPipeline::VertexShader;
  using FS = RRectBlurPipeline::FragmentShader;
 
  VertexBufferBuilder<VS::PerVertexData> vtx_builder;
 
  // Clamp the max kernel width/height to 1000.
  auto blur_sigma = std::min(sigma_.sigma, 250.0f);
  // Increase quality by make the radius a bit bigger than the typical
  // sigma->radius conversion we use for slower blurs.
  auto blur_radius = blur_sigma * 2;
  auto positive_rect = rect_->GetPositive();
  {
    auto left = -blur_radius;
    auto top = -blur_radius;
    auto right = positive_rect.size.width + blur_radius;
    auto bottom = positive_rect.size.height + blur_radius;
 
    vtx_builder.AddVertices({
        {Point(left, top)},
        {Point(right, top)},
        {Point(left, bottom)},
        {Point(left, bottom)},
        {Point(right, top)},
        {Point(right, bottom)},
    });
  }
 
  Command cmd;
  DEBUG_COMMAND_INFO(cmd, "RRect Shadow");
  ContentContextOptions opts = OptionsFromPassAndEntity(pass, entity);
  opts.primitive_type = PrimitiveType::kTriangle;
  Color color = color_;
  if (entity.GetBlendMode() == BlendMode::kClear) {
    opts.is_for_rrect_blur_clear = true;
    color = Color::White();
  }
  cmd.pipeline = renderer.GetRRectBlurPipeline(opts);
  cmd.stencil_reference = entity.GetStencilDepth();
 
  cmd.BindVertices(vtx_builder.CreateVertexBuffer(pass.GetTransientsBuffer()));
 
  VS::FrameInfo frame_info;
  frame_info.mvp = Matrix::MakeOrthographic(pass.GetRenderTargetSize()) *
                   entity.GetTransformation() *
                   Matrix::MakeTranslation({positive_rect.origin});
  VS::BindFrameInfo(cmd, pass.GetTransientsBuffer().EmplaceUniform(frame_info));
 
  FS::FragInfo frag_info;
  frag_info.color = color;
  frag_info.blur_sigma = blur_sigma;
  frag_info.rect_size = Point(positive_rect.size);
  frag_info.corner_radius =
      std::min(corner_radius_, std::min(positive_rect.size.width / 2.0f,
                                        positive_rect.size.height / 2.0f));
  FS::BindFragInfo(cmd, pass.GetTransientsBuffer().EmplaceUniform(frag_info));
 
  if (!pass.AddCommand(std::move(cmd))) {
    return false;
  }
 
  return true;
}

References impeller::RenderPass::AddCommand(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::AddVertices(), impeller::Command::BindVertices(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::CreateVertexBuffer(), DEBUG_COMMAND_INFO, impeller::HostBuffer::EmplaceUniform(), impeller::Entity::GetBlendMode(), impeller::RenderPass::GetRenderTargetSize(), impeller::ContentContext::GetRRectBlurPipeline(), impeller::Entity::GetStencilDepth(), impeller::Entity::GetTransformation(), impeller::RenderPass::GetTransientsBuffer(), impeller::ContentContextOptions::is_for_rrect_blur_clear, impeller::kClear, impeller::kTriangle, impeller::Matrix::MakeOrthographic(), impeller::Matrix::MakeTranslation(), impeller::OptionsFromPassAndEntity(), impeller::Command::pipeline, impeller::ContentContextOptions::primitive_type, impeller::Sigma::sigma, impeller::Command::stencil_reference, and impeller::Color::White().

SetColor()

void impeller::SolidRRectBlurContents::SetColor

(

Color

color

)

Definition at line 33 of file solid_rrect_blur_contents.cc.

                                                 {
  color_ = color.Premultiply();
}

References impeller::Color::Premultiply().

SetRRect()

void impeller::SolidRRectBlurContents::SetRRect	(	std::optional< Rect >	rect,
		Scalar	corner_radius = 0
	)

Definition at line 23 of file solid_rrect_blur_contents.cc.

                                                            {
  rect_ = rect;
  corner_radius_ = corner_radius;
}

SetSigma()

void impeller::SolidRRectBlurContents::SetSigma

(

Sigma

sigma

)

Definition at line 29 of file solid_rrect_blur_contents.cc.

                                                 {
  sigma_ = sigma;
}

---

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

• impeller/entity/contents/solid_rrect_blur_contents.h
• impeller/entity/contents/solid_rrect_blur_contents.cc