impeller::AtlasContents Class Reference

#include <atlas_contents.h>

Inheritance diagram for impeller::AtlasContents:

Public Member Functions
	AtlasContents ()
	~AtlasContents () override
void	SetGeometry (AtlasGeometry *geometry)
void	SetAlpha (Scalar alpha)
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
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(). More...
const std::optional< Rect > &	GetCoverageHint () const
virtual bool	IsOpaque (const Matrix &transform) 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, 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). More...
std::optional< Size >	GetColorSourceSize () const
	Return the color source's intrinsic size, if available. More...
void	SetColorSourceSize (Size size)
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 40 of file atlas_contents.h.

Constructor & Destructor Documentation

AtlasContents()

impeller::AtlasContents::AtlasContents ( )

explicitdefault

~AtlasContents()

impeller::AtlasContents::~AtlasContents ( )

overridedefault

Member Function Documentation

GetCoverage()

std::optional< Rect > impeller::AtlasContents::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 23 of file atlas_contents.cc.

                                                                       {
  if (!geometry_) {
    return std::nullopt;
  }
  return geometry_->ComputeBoundingBox().TransformBounds(entity.GetTransform());
}

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

Render()

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

overridevirtual

Implements impeller::Contents.

Definition at line 38 of file atlas_contents.cc.

                                                   {
  if (geometry_->ShouldSkip() || alpha_ <= 0.0) {
    return true;
  }
 
  auto dst_sampler_descriptor = geometry_->GetSamplerDescriptor();
  if (renderer.GetDeviceCapabilities().SupportsDecalSamplerAddressMode()) {
    dst_sampler_descriptor.width_address_mode = SamplerAddressMode::kDecal;
    dst_sampler_descriptor.height_address_mode = SamplerAddressMode::kDecal;
  }
  const std::unique_ptr<const Sampler>& dst_sampler =
      renderer.GetContext()->GetSamplerLibrary()->GetSampler(
          dst_sampler_descriptor);
 
  auto& host_buffer = renderer.GetTransientsBuffer();
  if (!geometry_->ShouldUseBlend()) {
    using VS = TextureFillVertexShader;
    using FS = TextureFillFragmentShader;
 
    auto dst_sampler_descriptor = geometry_->GetSamplerDescriptor();
 
    const std::unique_ptr<const Sampler>& dst_sampler =
        renderer.GetContext()->GetSamplerLibrary()->GetSampler(
            dst_sampler_descriptor);
 
    auto pipeline_options = OptionsFromPassAndEntity(pass, entity);
    pipeline_options.primitive_type = PrimitiveType::kTriangle;
    pipeline_options.depth_write_enabled =
        pipeline_options.blend_mode == BlendMode::kSource;
 
    pass.SetPipeline(renderer.GetTexturePipeline(pipeline_options));
    pass.SetVertexBuffer(geometry_->CreateSimpleVertexBuffer(host_buffer));
#ifdef IMPELLER_DEBUG
    pass.SetCommandLabel("DrawAtlas");
#endif  // IMPELLER_DEBUG
 
    VS::FrameInfo frame_info;
    frame_info.mvp = entity.GetShaderTransform(pass);
    frame_info.texture_sampler_y_coord_scale =
        geometry_->GetAtlas()->GetYCoordScale();
 
    VS::BindFrameInfo(pass, host_buffer.EmplaceUniform(frame_info));
 
    FS::FragInfo frag_info;
    frag_info.alpha = alpha_;
    FS::BindFragInfo(pass, host_buffer.EmplaceUniform((frag_info)));
    FS::BindTextureSampler(pass, geometry_->GetAtlas(), dst_sampler);
    return pass.Draw().ok();
  }
 
  BlendMode blend_mode = geometry_->GetBlendMode();
 
  if (blend_mode <= BlendMode::kModulate) {
    using VS = PorterDuffBlendPipeline::VertexShader;
    using FS = PorterDuffBlendPipeline::FragmentShader;
 
#ifdef IMPELLER_DEBUG
    pass.SetCommandLabel(
        SPrintF("DrawAtlas Blend (%s)", BlendModeToString(blend_mode)));
#endif  // IMPELLER_DEBUG
    pass.SetVertexBuffer(geometry_->CreateBlendVertexBuffer(host_buffer));
    pass.SetPipeline(
        renderer.GetPorterDuffBlendPipeline(OptionsFromPass(pass)));
 
    FS::FragInfo frag_info;
    VS::FrameInfo frame_info;
 
    FS::BindTextureSamplerDst(pass, geometry_->GetAtlas(), dst_sampler);
    frame_info.texture_sampler_y_coord_scale =
        geometry_->GetAtlas()->GetYCoordScale();
 
    frag_info.output_alpha = alpha_;
    frag_info.input_alpha = 1.0;
 
    auto inverted_blend_mode =
        InvertPorterDuffBlend(blend_mode).value_or(BlendMode::kSource);
    auto blend_coefficients =
        kPorterDuffCoefficients[static_cast<int>(inverted_blend_mode)];
    frag_info.src_coeff = blend_coefficients[0];
    frag_info.src_coeff_dst_alpha = blend_coefficients[1];
    frag_info.dst_coeff = blend_coefficients[2];
    frag_info.dst_coeff_src_alpha = blend_coefficients[3];
    frag_info.dst_coeff_src_color = blend_coefficients[4];
    // These values are ignored on platforms that natively support decal.
    frag_info.tmx = static_cast<int>(Entity::TileMode::kDecal);
    frag_info.tmy = static_cast<int>(Entity::TileMode::kDecal);
 
    FS::BindFragInfo(pass, host_buffer.EmplaceUniform(frag_info));
 
    frame_info.mvp = entity.GetShaderTransform(pass);
 
    auto uniform_view = host_buffer.EmplaceUniform(frame_info);
    VS::BindFrameInfo(pass, uniform_view);
 
    return pass.Draw().ok();
  }
 
  using VUS = VerticesUberShader::VertexShader;
  using FS = VerticesUberShader::FragmentShader;
 
#ifdef IMPELLER_DEBUG
  pass.SetCommandLabel(
      SPrintF("DrawAtlas Advanced Blend (%s)", BlendModeToString(blend_mode)));
#endif  // IMPELLER_DEBUG
  pass.SetVertexBuffer(geometry_->CreateBlendVertexBuffer(host_buffer));
 
  pass.SetPipeline(renderer.GetDrawVerticesUberShader(OptionsFromPass(pass)));
  FS::BindTextureSampler(pass, geometry_->GetAtlas(), dst_sampler);
 
  VUS::FrameInfo frame_info;
  FS::FragInfo frag_info;
 
  frame_info.texture_sampler_y_coord_scale =
      geometry_->GetAtlas()->GetYCoordScale();
  frame_info.mvp = entity.GetShaderTransform(pass);
 
  frag_info.alpha = alpha_;
  frag_info.blend_mode = static_cast<int>(blend_mode);
 
  // These values are ignored on platforms that natively support decal.
  frag_info.tmx = static_cast<int>(Entity::TileMode::kDecal);
  frag_info.tmy = static_cast<int>(Entity::TileMode::kDecal);
 
  FS::BindFragInfo(pass, host_buffer.EmplaceUniform(frag_info));
  VUS::BindFrameInfo(pass, host_buffer.EmplaceUniform(frame_info));
 
  return pass.Draw().ok();
}

References impeller::BlendModeToString(), impeller::AtlasGeometry::CreateBlendVertexBuffer(), impeller::AtlasGeometry::CreateSimpleVertexBuffer(), impeller::RenderPass::Draw(), impeller::AtlasGeometry::GetAtlas(), impeller::AtlasGeometry::GetBlendMode(), impeller::ContentContext::GetContext(), impeller::ContentContext::GetDeviceCapabilities(), impeller::ContentContext::GetDrawVerticesUberShader(), impeller::ContentContext::GetPorterDuffBlendPipeline(), impeller::AtlasGeometry::GetSamplerDescriptor(), impeller::Entity::GetShaderTransform(), impeller::ContentContext::GetTexturePipeline(), impeller::ContentContext::GetTransientsBuffer(), impeller::InvertPorterDuffBlend(), impeller::Entity::kDecal, impeller::kDecal, impeller::kModulate, impeller::kPorterDuffCoefficients, impeller::kSource, impeller::kTriangle, impeller::OptionsFromPass(), impeller::OptionsFromPassAndEntity(), impeller::RenderPass::SetCommandLabel(), impeller::RenderPass::SetPipeline(), impeller::RenderPass::SetVertexBuffer(), impeller::AtlasGeometry::ShouldSkip(), impeller::AtlasGeometry::ShouldUseBlend(), impeller::SPrintF(), impeller::Capabilities::SupportsDecalSamplerAddressMode(), and impeller::SamplerDescriptor::width_address_mode.

SetAlpha()

void impeller::AtlasContents::SetAlpha

(

Scalar

alpha

)

Definition at line 34 of file atlas_contents.cc.

                                         {
  alpha_ = alpha;
}

SetGeometry()

void impeller::AtlasContents::SetGeometry

(

AtlasGeometry *

geometry

)

Definition at line 30 of file atlas_contents.cc.

                                                       {
  geometry_ = geometry;
}

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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