impeller::RuntimeEffectContents Class Reference

#include <runtime_effect_contents.h>

Inheritance diagram for impeller::RuntimeEffectContents:

Classes
struct	TextureInput

Public Member Functions
void	SetRuntimeStage (std::shared_ptr< RuntimeStage > runtime_stage)
void	SetUniformData (std::shared_ptr< std::vector< uint8_t >> uniform_data)
void	SetTextureInputs (std::vector< TextureInput > texture_inputs)
bool	CanInheritOpacity (const Entity &entity) const override
	Whether or not this contents can accept the opacity peephole optimization. More...
bool	Render (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
bool	BootstrapShader (const ContentContext &renderer) const
	Load the runtime effect and ensure a default PSO is initialized. More...
Public Member Functions inherited from impeller::ColorSourceContents
	ColorSourceContents ()
	~ColorSourceContents () override
void	SetGeometry (std::shared_ptr< Geometry > geometry)
	Set the geometry that this contents will use to render. More...
const std::shared_ptr< Geometry > &	GetGeometry () const
	Get the geometry that this contents will use to render. More...
void	SetEffectTransform (Matrix matrix)
	Set the effect transform for this color source. More...
const Matrix &	GetInverseEffectTransform () const
	Set the inverted effect transform for this color source. More...
void	SetOpacityFactor (Scalar opacity)
	Set the opacity factor for this color source. More...
Scalar	GetOpacityFactor () const
	Get the opacity factor for this color source. More...
virtual bool	IsSolidColor () const
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...
void	SetInheritedOpacity (Scalar opacity) override
	Inherit the provided opacity. 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 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...
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 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)
Protected Types inherited from impeller::ColorSourceContents
using	BindFragmentCallback = std::function< bool(RenderPass &pass)>
using	PipelineBuilderMethod = std::shared_ptr< Pipeline< PipelineDescriptor > >(impeller::ContentContext::*)(ContentContextOptions) const
using	PipelineBuilderCallback = std::function< std::shared_ptr< Pipeline< PipelineDescriptor > >(ContentContextOptions)>
using	CreateGeometryCallback = std::function< GeometryResult(const ContentContext &renderer, const Entity &entity, RenderPass &pass, const Geometry &geom)>
Protected Member Functions inherited from impeller::ColorSourceContents
template<typename VertexShaderT >
bool	DrawGeometry (const ContentContext &renderer, const Entity &entity, RenderPass &pass, const PipelineBuilderCallback &pipeline_callback, typename VertexShaderT::FrameInfo frame_info, const BindFragmentCallback &bind_fragment_callback, bool force_stencil=false, const CreateGeometryCallback &create_geom_callback=DefaultCreateGeometryCallback) const
Static Protected Member Functions inherited from impeller::ColorSourceContents
static GeometryResult	DefaultCreateGeometryCallback (const ContentContext &renderer, const Entity &entity, RenderPass &pass, const Geometry &geom)

Detailed Description

Definition at line 17 of file runtime_effect_contents.h.

Member Function Documentation

BootstrapShader()

bool impeller::RuntimeEffectContents::BootstrapShader

(

const ContentContext &

renderer

)

const

Load the runtime effect and ensure a default PSO is initialized.

Definition at line 70 of file runtime_effect_contents.cc.

                                          {
  if (!RegisterShader(renderer)) {
    return false;
  }
  ContentContextOptions options;
  options.color_attachment_pixel_format =
      renderer.GetContext()->GetCapabilities()->GetDefaultColorFormat();
  CreatePipeline(renderer, options, /*async=*/true);
  return true;
}

References impeller::ContentContextOptions::color_attachment_pixel_format, and impeller::ContentContext::GetContext().

CanInheritOpacity()

bool impeller::RuntimeEffectContents::CanInheritOpacity ( const Entity &  entity ) const

overridevirtual

Whether or not this contents can accept the opacity peephole optimization.

By default all contents return false. Contents are responsible for determining whether or not their own geometries intersect in a way that makes accepting opacity impossible. It is always safe to return false, especially if computing overlap would be computationally expensive.

Reimplemented from impeller::ColorSourceContents.

Definition at line 42 of file runtime_effect_contents.cc.

                                                                        {
  return false;
}

Render()

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

overridevirtual

Get or register shader. Flutter will do this when the runtime effect is first loaded, but this check is added to supporting testing of the Aiks API and non-flutter usage of Impeller.

Fragment stage uniforms.

Now that the descriptor set layouts are known, get the pipeline.

Implements impeller::Contents.

Definition at line 188 of file runtime_effect_contents.cc.

                                                           {
  const std::shared_ptr<Context>& context = renderer.GetContext();
  const std::shared_ptr<ShaderLibrary>& library = context->GetShaderLibrary();
 
  //--------------------------------------------------------------------------
  /// Get or register shader. Flutter will do this when the runtime effect
  /// is first loaded, but this check is added to supporting testing of the
  /// Aiks API and non-flutter usage of Impeller.
  ///
  if (!RegisterShader(renderer)) {
    return false;
  }
 
  //--------------------------------------------------------------------------
  /// Fragment stage uniforms.
  ///
  BindFragmentCallback bind_callback = [this, &renderer,
                                        &context](RenderPass& pass) {
    size_t minimum_sampler_index = 100000000;
    size_t buffer_index = 0;
    size_t buffer_offset = 0;
 
    for (const auto& uniform : runtime_stage_->GetUniforms()) {
      std::shared_ptr<ShaderMetadata> metadata = MakeShaderMetadata(uniform);
 
      switch (uniform.type) {
        case kSampledImage: {
          // Sampler uniforms are ordered in the IPLR according to their
          // declaration and the uniform location reflects the correct offset to
          // be mapped to - except that it may include all proceeding float
          // uniforms. For example, a float sampler that comes after 4 float
          // uniforms may have a location of 4. To convert to the actual offset
          // we need to find the largest location assigned to a float uniform
          // and then subtract this from all uniform locations. This is more or
          // less the same operation we previously performed in the shader
          // compiler.
          minimum_sampler_index =
              std::min(minimum_sampler_index, uniform.location);
          break;
        }
        case kFloat: {
          FML_DCHECK(renderer.GetContext()->GetBackendType() !=
                     Context::BackendType::kVulkan)
              << "Uniform " << uniform.name
              << " had unexpected type kFloat for Vulkan backend.";
 
          size_t alignment =
              std::max(uniform.bit_width / 8, DefaultUniformAlignment());
          BufferView buffer_view = renderer.GetTransientsBuffer().Emplace(
              uniform_data_->data() + buffer_offset, uniform.GetSize(),
              alignment);
 
          ShaderUniformSlot uniform_slot;
          uniform_slot.name = uniform.name.c_str();
          uniform_slot.ext_res_0 = uniform.location;
          pass.BindResource(ShaderStage::kFragment,
                            DescriptorType::kUniformBuffer, uniform_slot,
                            metadata, std::move(buffer_view));
          buffer_index++;
          buffer_offset += uniform.GetSize();
          break;
        }
        case kStruct: {
          FML_DCHECK(renderer.GetContext()->GetBackendType() ==
                     Context::BackendType::kVulkan);
          ShaderUniformSlot uniform_slot;
          uniform_slot.name = uniform.name.c_str();
          uniform_slot.binding = uniform.location;
 
          // TODO(jonahwilliams): rewrite this to emplace directly into
          // HostBuffer.
          std::vector<float> uniform_buffer;
          uniform_buffer.reserve(uniform.struct_layout.size());
          size_t uniform_byte_index = 0u;
          for (const auto& byte_type : uniform.struct_layout) {
            if (byte_type == 0) {
              uniform_buffer.push_back(0.f);
            } else if (byte_type == 1) {
              uniform_buffer.push_back(reinterpret_cast<float*>(
                  uniform_data_->data())[uniform_byte_index++]);
            } else {
              FML_UNREACHABLE();
            }
          }
          size_t alignment = std::max(sizeof(float) * uniform_buffer.size(),
                                      DefaultUniformAlignment());
 
          BufferView buffer_view = renderer.GetTransientsBuffer().Emplace(
              reinterpret_cast<const void*>(uniform_buffer.data()),
              sizeof(float) * uniform_buffer.size(), alignment);
          pass.BindResource(ShaderStage::kFragment,
                            DescriptorType::kUniformBuffer, uniform_slot,
                            ShaderMetadata{}, std::move(buffer_view));
        }
      }
    }
 
    size_t sampler_index = 0;
    for (const auto& uniform : runtime_stage_->GetUniforms()) {
      std::shared_ptr<ShaderMetadata> metadata = MakeShaderMetadata(uniform);
 
      switch (uniform.type) {
        case kSampledImage: {
          FML_DCHECK(sampler_index < texture_inputs_.size());
          auto& input = texture_inputs_[sampler_index];
 
          const std::unique_ptr<const Sampler>& sampler =
              context->GetSamplerLibrary()->GetSampler(
                  input.sampler_descriptor);
 
          SampledImageSlot image_slot;
          image_slot.name = uniform.name.c_str();
          image_slot.binding = uniform.binding;
          image_slot.texture_index = uniform.location - minimum_sampler_index;
          pass.BindResource(ShaderStage::kFragment,
                            DescriptorType::kSampledImage, image_slot,
                            *metadata, input.texture, sampler);
 
          sampler_index++;
          break;
        }
        default:
          continue;
      }
    }
    return true;
  };
 
  /// Now that the descriptor set layouts are known, get the pipeline.
  using VS = RuntimeEffectVertexShader;
 
  PipelineBuilderCallback pipeline_callback =
      [&](ContentContextOptions options) {
        // Pipeline creation callback for the cache handler to call.
        return renderer.GetCachedRuntimeEffectPipeline(
            runtime_stage_->GetEntrypoint(), options, [&]() {
              return CreatePipeline(renderer, options, /*async=*/false);
            });
      };
 
  return ColorSourceContents::DrawGeometry<VS>(renderer, entity, pass,
                                               pipeline_callback,
                                               VS::FrameInfo{}, bind_callback);
}

References impeller::ShaderUniformSlot::binding, impeller::SampledImageSlot::binding, impeller::RenderPass::BindResource(), buffer_view, impeller::DefaultUniformAlignment(), impeller::HostBuffer::Emplace(), impeller::ShaderUniformSlot::ext_res_0, impeller::ContentContext::GetCachedRuntimeEffectPipeline(), impeller::ContentContext::GetContext(), impeller::ContentContext::GetTransientsBuffer(), impeller::kFloat, impeller::kFragment, impeller::kSampledImage, impeller::kStruct, impeller::kUniformBuffer, impeller::Context::kVulkan, impeller::MakeShaderMetadata(), impeller::ShaderUniformSlot::name, impeller::SampledImageSlot::name, and impeller::SampledImageSlot::texture_index.

SetRuntimeStage()

void impeller::RuntimeEffectContents::SetRuntimeStage

(

std::shared_ptr< RuntimeStage >

runtime_stage

)

Definition at line 27 of file runtime_effect_contents.cc.

                                               {
  runtime_stage_ = std::move(runtime_stage);
}

SetTextureInputs()

void impeller::RuntimeEffectContents::SetTextureInputs

(

std::vector< TextureInput >

texture_inputs

)

Definition at line 37 of file runtime_effect_contents.cc.

                                            {
  texture_inputs_ = std::move(texture_inputs);
}

SetUniformData()

void impeller::RuntimeEffectContents::SetUniformData

(

std::shared_ptr< std::vector< uint8_t >>

uniform_data

)

Definition at line 32 of file runtime_effect_contents.cc.

                                                    {
  uniform_data_ = std::move(uniform_data);
}

---

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

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