#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 screen space bounding rectangle that this contents affects. More...

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. 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...

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

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 screen space bounding rectangle that this contents affects.

Implements impeller::Contents.

Definition at line 57 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 20 of file checkerboard_contents.cc.

                                                           {
   auto& host_buffer = pass.GetTransientsBuffer();
  
   using VS = CheckerboardPipeline::VertexShader;
   using FS = CheckerboardPipeline::FragmentShader;
  
   Command cmd;
   DEBUG_COMMAND_INFO(cmd, "Checkerboard");
  
   auto options = OptionsFromPass(pass);
   options.blend_mode = BlendMode::kSourceOver;
   options.stencil_compare = CompareFunction::kAlways;  // Ignore all clips.
   options.stencil_operation = StencilOperation::kKeep;
   options.primitive_type = PrimitiveType::kTriangleStrip;
   cmd.pipeline = renderer.GetCheckerboardPipeline(options);
  
   VertexBufferBuilder<typename VS::PerVertexData> vtx_builder;
   vtx_builder.AddVertices({
       {Point(-1, -1)},
       {Point(1, -1)},
       {Point(-1, 1)},
       {Point(1, 1)},
   });
   cmd.BindVertices(vtx_builder.CreateVertexBuffer(host_buffer));
  
   FS::FragInfo frag_info;
   frag_info.color = color_;
   frag_info.square_size = square_size_;
   FS::BindFragInfo(cmd, host_buffer.EmplaceUniform(frag_info));
  
   pass.AddCommand(std::move(cmd));
  
   return true;
 }

References impeller::RenderPass::AddCommand(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::AddVertices(), impeller::Command::BindVertices(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::CreateVertexBuffer(), DEBUG_COMMAND_INFO, impeller::RenderPass::GetTransientsBuffer(), impeller::kAlways, impeller::kKeep, impeller::kSourceOver, impeller::kTriangleStrip, impeller::OptionsFromPass(), and impeller::Command::pipeline.

◆ SetColor()

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

Definition at line 62 of file checkerboard_contents.cc.

                                                {
   color_ = color;
 }

◆ SetSquareSize()

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

Definition at line 66 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