#include <checkerboard_contents.h>

Inheritance diagram for impeller::CheckerboardContents:

Public Member Functions
	CheckerboardContents ()

	~CheckerboardContents () override

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	SetColor (Color color)

void	SetSquareSize (Scalar square_size)

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.

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 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="Snapshot") const
	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)`.

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 const FilterContents *	AsFilter () const
	Cast to a filter. Returns `nullptr` if this Contents is not a filter.

virtual bool	ApplyColorFilter (const ColorFilterProc &color_filter_proc)
	If possible, applies a color filter to this contents inputs on the CPU.

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

A special Contents that renders a translucent checkerboard pattern with a random color over the entire pass texture. This is useful for visualizing offscreen textures.

Definition at line 15 of file checkerboard_contents.h.

Constructor & Destructor Documentation

◆ CheckerboardContents()

impeller::CheckerboardContents::CheckerboardContents ( )

default

◆ ~CheckerboardContents()

impeller::CheckerboardContents::~CheckerboardContents ( )

overridedefault

Member Function Documentation

◆ GetCoverage()

std::optional< Rect > impeller::CheckerboardContents::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 51 of file checkerboard_contents.cc.

                                {
  return std::nullopt;
}

◆ Render()

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

overridevirtual

Implements impeller::Contents.

Definition at line 18 of file checkerboard_contents.cc.

                                                          {
  auto& host_buffer = renderer.GetTransientsBuffer();
 
  using VS = CheckerboardPipeline::VertexShader;
  using FS = CheckerboardPipeline::FragmentShader;
 
  auto options = OptionsFromPass(pass);
  options.blend_mode = BlendMode::kSourceOver;
  options.stencil_mode = ContentContextOptions::StencilMode::kIgnore;
  options.primitive_type = PrimitiveType::kTriangleStrip;
 
  VertexBufferBuilder<typename VS::PerVertexData> vtx_builder;
  vtx_builder.AddVertices({
      {Point(-1, -1)},
      {Point(1, -1)},
      {Point(-1, 1)},
      {Point(1, 1)},
  });
 
  pass.SetCommandLabel("Checkerboard");
  pass.SetPipeline(renderer.GetCheckerboardPipeline(options));
  pass.SetVertexBuffer(vtx_builder.CreateVertexBuffer(host_buffer));
 
  FS::FragInfo frag_info;
  frag_info.color = color_;
  frag_info.square_size = square_size_;
  FS::BindFragInfo(pass, host_buffer.EmplaceUniform(frag_info));
 
  return pass.Draw().ok();
}

◆ SetColor()

void impeller::CheckerboardContents::SetColor ( Color color )

Definition at line 56 of file checkerboard_contents.cc.

                                               {
  color_ = color;
}

◆ SetSquareSize()

void impeller::CheckerboardContents::SetSquareSize ( Scalar square_size )

Definition at line 60 of file checkerboard_contents.cc.

                                                           {
  square_size_ = square_size;
}

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

impeller/entity/contents/checkerboard_contents.h
impeller/entity/contents/checkerboard_contents.cc

Public Member Functions

Additional Inherited Members