impeller::AtlasTextureContents Class Reference

#include <atlas_contents.h>

Inheritance diagram for impeller::AtlasTextureContents:

Public Member Functions
	AtlasTextureContents (const AtlasContents &parent)
	~AtlasTextureContents () 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. More...
bool	Render (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
void	SetAlpha (Scalar alpha)
void	SetCoverage (Rect coverage)
void	SetTexture (std::shared_ptr< Texture > texture)
void	SetUseDestination (bool value)
void	SetSubAtlas (const std::shared_ptr< SubAtlasResult > &subatlas)
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 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. 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, clip 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 > clip_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

Definition at line 96 of file atlas_contents.h.

Constructor & Destructor Documentation

AtlasTextureContents()

impeller::AtlasTextureContents::AtlasTextureContents ( const AtlasContents &  parent )

explicit

Definition at line 322 of file atlas_contents.cc.

    : parent_(parent) {}

~AtlasTextureContents()

impeller::AtlasTextureContents::~AtlasTextureContents ( )

override

Definition at line 325 of file atlas_contents.cc.

{}

Member Function Documentation

GetCoverage()

std::optional< Rect > impeller::AtlasTextureContents::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 327 of file atlas_contents.cc.

                                {
  return coverage_.TransformBounds(entity.GetTransform());
}

References impeller::Entity::GetTransform(), and impeller::TRect< T >::TransformBounds().

Render()

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

overridevirtual

Implements impeller::Contents.

Definition at line 353 of file atlas_contents.cc.

                                                          {
  using VS = TextureFillVertexShader;
  using FS = TextureFillFragmentShader;
 
  auto texture = texture_ ? texture_ : parent_.GetTexture();
  if (texture == nullptr) {
    return true;
  }
 
  std::vector<Rect> texture_coords;
  std::vector<Matrix> transforms;
  if (subatlas_) {
    texture_coords = use_destination_ ? subatlas_->result_texture_coords
                                      : subatlas_->sub_texture_coords;
    transforms = use_destination_ ? subatlas_->result_transforms
                                  : subatlas_->sub_transforms;
  } else {
    texture_coords = parent_.GetTextureCoordinates();
    transforms = parent_.GetTransforms();
  }
 
  const Size texture_size(texture->GetSize());
  VertexBufferBuilder<VS::PerVertexData> vertex_builder;
  vertex_builder.Reserve(texture_coords.size() * 6);
  constexpr size_t indices[6] = {0, 1, 2, 1, 2, 3};
  for (size_t i = 0; i < texture_coords.size(); i++) {
    auto sample_rect = texture_coords[i];
    auto matrix = transforms[i];
    auto points = sample_rect.GetPoints();
    auto transformed_points =
        Rect::MakeSize(sample_rect.GetSize()).GetTransformedPoints(matrix);
 
    for (size_t j = 0; j < 6; j++) {
      VS::PerVertexData data;
      data.position = transformed_points[indices[j]];
      data.texture_coords = points[indices[j]] / texture_size;
      vertex_builder.AppendVertex(data);
    }
  }
 
  if (!vertex_builder.HasVertices()) {
    return true;
  }
 
  Command cmd;
  DEBUG_COMMAND_INFO(cmd, "AtlasTexture");
 
  auto& host_buffer = pass.GetTransientsBuffer();
 
  VS::FrameInfo frame_info;
  frame_info.mvp = pass.GetOrthographicTransform() * entity.GetTransform();
  frame_info.texture_sampler_y_coord_scale = texture->GetYCoordScale();
  frame_info.alpha = alpha_;
 
  auto options = OptionsFromPassAndEntity(pass, entity);
  cmd.pipeline = renderer.GetTexturePipeline(options);
  cmd.stencil_reference = entity.GetClipDepth();
  cmd.BindVertices(vertex_builder.CreateVertexBuffer(host_buffer));
  VS::BindFrameInfo(cmd, host_buffer.EmplaceUniform(frame_info));
  FS::BindTextureSampler(cmd, texture,
                         renderer.GetContext()->GetSamplerLibrary()->GetSampler(
                             parent_.GetSamplerDescriptor()));
  return pass.AddCommand(std::move(cmd));
}

References impeller::RenderPass::AddCommand(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::AppendVertex(), impeller::Command::BindVertices(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::CreateVertexBuffer(), DEBUG_COMMAND_INFO, impeller::Entity::GetClipDepth(), impeller::ContentContext::GetContext(), impeller::RenderPass::GetOrthographicTransform(), impeller::AtlasContents::GetSamplerDescriptor(), impeller::AtlasContents::GetTexture(), impeller::AtlasContents::GetTextureCoordinates(), impeller::ContentContext::GetTexturePipeline(), impeller::Entity::GetTransform(), impeller::TRect< T >::GetTransformedPoints(), impeller::AtlasContents::GetTransforms(), impeller::RenderPass::GetTransientsBuffer(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::HasVertices(), impeller::TRect< Scalar >::MakeSize(), impeller::OptionsFromPassAndEntity(), impeller::Command::pipeline, impeller::VertexBufferBuilder< VertexType_, IndexType_ >::Reserve(), and impeller::Command::stencil_reference.

SetAlpha()

void impeller::AtlasTextureContents::SetAlpha

(

Scalar

alpha

)

Definition at line 332 of file atlas_contents.cc.

                                                {
  alpha_ = alpha;
}

SetCoverage()

void impeller::AtlasTextureContents::SetCoverage

(

Rect

coverage

)

Definition at line 336 of file atlas_contents.cc.

                                                    {
  coverage_ = coverage;
}

SetSubAtlas()

void impeller::AtlasTextureContents::SetSubAtlas

(

const std::shared_ptr< SubAtlasResult > &

subatlas

)

Definition at line 344 of file atlas_contents.cc.

                                                   {
  subatlas_ = subatlas;
}

SetTexture()

void impeller::AtlasTextureContents::SetTexture

(

std::shared_ptr< Texture >

texture

)

Definition at line 349 of file atlas_contents.cc.

                                                                    {
  texture_ = std::move(texture);
}

SetUseDestination()

void impeller::AtlasTextureContents::SetUseDestination

(

bool

value

)

Definition at line 340 of file atlas_contents.cc.

                                                       {
  use_destination_ = value;
}

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

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