impeller::DrawImageRectAtlasGeometry Class Reference

An atlas geometry that adapts for drawImageRect. More...

#include <atlas_contents.h>

Inheritance diagram for impeller::DrawImageRectAtlasGeometry:

Public Member Functions
	DrawImageRectAtlasGeometry (std::shared_ptr< Texture > texture, const Rect &source, const Rect &destination, const Color &color, BlendMode blend_mode, const SamplerDescriptor &desc, bool use_strict_src_rect=false)
	~DrawImageRectAtlasGeometry ()
bool	ShouldUseBlend () const override
bool	ShouldSkip () const override
VertexBuffer	CreateSimpleVertexBuffer (HostBuffer &host_buffer) const override
VertexBuffer	CreateBlendVertexBuffer (HostBuffer &host_buffer) const override
Rect	ComputeBoundingBox () const override
const std::shared_ptr< Texture > &	GetAtlas () const override
const SamplerDescriptor &	GetSamplerDescriptor () const override
BlendMode	GetBlendMode () const override
bool	ShouldInvertBlendMode () const override
std::optional< Rect >	GetStrictSrcRect () const override
	The source rect of the draw in texture coordinates if a strict source rect should be applied, or nullopt.

Detailed Description

An atlas geometry that adapts for drawImageRect.

Definition at line 51 of file atlas_contents.h.

Constructor & Destructor Documentation

DrawImageRectAtlasGeometry()

impeller::DrawImageRectAtlasGeometry::DrawImageRectAtlasGeometry	(	std::shared_ptr< Texture >	texture,
		const Rect &	source,
		const Rect &	destination,
		const Color &	color,
		BlendMode	blend_mode,
		const SamplerDescriptor &	desc,
		bool	use_strict_src_rect = false
	)

Definition at line 20 of file atlas_contents.cc.

    : texture_(std::move(texture)),
      source_(source),
      destination_(destination),
      color_(color),
      blend_mode_(blend_mode),
      desc_(desc),
      use_strict_src_rect_(use_strict_src_rect) {}

~DrawImageRectAtlasGeometry()

impeller::DrawImageRectAtlasGeometry::~DrawImageRectAtlasGeometry ( )

default

Member Function Documentation

ComputeBoundingBox()

Rect impeller::DrawImageRectAtlasGeometry::ComputeBoundingBox ( ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 107 of file atlas_contents.cc.

                                                          {
  return destination_;
}

CreateBlendVertexBuffer()

VertexBuffer impeller::DrawImageRectAtlasGeometry::CreateBlendVertexBuffer ( HostBuffer &  host_buffer ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 76 of file atlas_contents.cc.

                                        {
  using VS = PorterDuffBlendVertexShader;
  constexpr size_t indices[6] = {0, 1, 2, 1, 2, 3};
 
  BufferView buffer_view = data_host_buffer.Emplace(
      sizeof(VS::PerVertexData) * 6, alignof(VS::PerVertexData),
      [&](uint8_t* raw_data) {
        VS::PerVertexData* data =
            reinterpret_cast<VS::PerVertexData*>(raw_data);
        int offset = 0;
        std::array<TPoint<float>, 4> texture_coords =
            Rect::MakeSize(texture_->GetSize()).Project(source_).GetPoints();
        std::array<TPoint<float>, 4> destination_points =
            destination_.GetPoints();
        for (size_t j = 0; j < 6; j++) {
          data[offset].vertices = destination_points[indices[j]];
          data[offset].texture_coords = texture_coords[indices[j]];
          data[offset].color = color_.Premultiply();
          offset++;
        }
      });
 
  return VertexBuffer{
      .vertex_buffer = buffer_view,
      .index_buffer = {},
      .vertex_count = 6,
      .index_type = IndexType::kNone,
  };
}

References buffer_view, data, impeller::HostBuffer::Emplace(), impeller::TRect< T >::GetPoints(), impeller::kNone, impeller::TRect< Scalar >::MakeSize(), impeller::Color::Premultiply(), impeller::TRect< T >::Project(), and impeller::VertexBuffer::vertex_buffer.

CreateSimpleVertexBuffer()

VertexBuffer impeller::DrawImageRectAtlasGeometry::CreateSimpleVertexBuffer ( HostBuffer &  host_buffer ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 46 of file atlas_contents.cc.

                                        {
  using VS = TextureFillVertexShader;
  constexpr size_t indices[6] = {0, 1, 2, 1, 2, 3};
 
  BufferView buffer_view = data_host_buffer.Emplace(
      sizeof(VS::PerVertexData) * 6, alignof(VS::PerVertexData),
      [&](uint8_t* raw_data) {
        VS::PerVertexData* data =
            reinterpret_cast<VS::PerVertexData*>(raw_data);
        int offset = 0;
        std::array<TPoint<float>, 4> destination_points =
            destination_.GetPoints();
        std::array<TPoint<float>, 4> texture_coords =
            Rect::MakeSize(texture_->GetSize()).Project(source_).GetPoints();
        for (size_t j = 0; j < 6; j++) {
          data[offset].position = destination_points[indices[j]];
          data[offset].texture_coords = texture_coords[indices[j]];
          offset++;
        }
      });
 
  return VertexBuffer{
      .vertex_buffer = buffer_view,
      .index_buffer = {},
      .vertex_count = 6,
      .index_type = IndexType::kNone,
  };
}

References buffer_view, data, impeller::HostBuffer::Emplace(), impeller::TRect< T >::GetPoints(), impeller::kNone, impeller::TRect< Scalar >::MakeSize(), impeller::TRect< T >::Project(), and impeller::VertexBuffer::vertex_buffer.

GetAtlas()

const std::shared_ptr< Texture > & impeller::DrawImageRectAtlasGeometry::GetAtlas ( ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 111 of file atlas_contents.cc.

                                                                         {
  return texture_;
}

GetBlendMode()

BlendMode impeller::DrawImageRectAtlasGeometry::GetBlendMode ( ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 120 of file atlas_contents.cc.

                                                         {
  return blend_mode_;
}

GetSamplerDescriptor()

const SamplerDescriptor & impeller::DrawImageRectAtlasGeometry::GetSamplerDescriptor ( ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 115 of file atlas_contents.cc.

          {
  return desc_;
}

GetStrictSrcRect()

std::optional< Rect > impeller::DrawImageRectAtlasGeometry::GetStrictSrcRect ( ) const

overridevirtual

The source rect of the draw in texture coordinates if a strict source rect should be applied, or nullopt.

See also Canvas::AttemptColorFilterOptimization

Reimplemented from impeller::AtlasGeometry.

Definition at line 128 of file atlas_contents.cc.

                                                                     {
  if (use_strict_src_rect_) {
    // For a strict source rect, shrink the texture coordinate range by half a
    // texel to ensure that linear filtering does not sample anything outside
    // the source rect bounds.
    return Rect::MakeSize(texture_->GetSize()).Project(source_.Expand(-0.5));
  }
  return std::nullopt;
}

References impeller::TRect< T >::Expand(), impeller::TRect< Scalar >::MakeSize(), and impeller::TRect< T >::Project().

ShouldInvertBlendMode()

bool impeller::DrawImageRectAtlasGeometry::ShouldInvertBlendMode ( ) const

overridevirtual

Reimplemented from impeller::AtlasGeometry.

Definition at line 124 of file atlas_contents.cc.

                                                             {
  return false;
}

ShouldSkip()

bool impeller::DrawImageRectAtlasGeometry::ShouldSkip ( ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 42 of file atlas_contents.cc.

                                                  {
  return false;
}

ShouldUseBlend()

bool impeller::DrawImageRectAtlasGeometry::ShouldUseBlend ( ) const

overridevirtual

Implements impeller::AtlasGeometry.

Definition at line 38 of file atlas_contents.cc.

                                                      {
  return true;
}

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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