impeller::DecompressedImage Class Reference

#include <decompressed_image.h>

Public Types
enum class	Format {   kInvalid , kGrey , kGreyAlpha , kRGB ,   kRGBA }

Public Member Functions
	DecompressedImage ()
	DecompressedImage (ISize size, Format format, std::shared_ptr< const fml::Mapping > allocation)
	~DecompressedImage ()
const ISize &	GetSize () const
bool	IsValid () const
Format	GetFormat () const
const std::shared_ptr< const fml::Mapping > &	GetAllocation () const
DecompressedImage	ConvertToRGBA () const

Detailed Description

Definition at line 17 of file decompressed_image.h.

Member Enumeration Documentation

Format

enum class impeller::DecompressedImage::Format

strong

Enumerator
kInvalid
kGrey
kGreyAlpha
kRGB
kRGBA

Definition at line 19 of file decompressed_image.h.

                    {
    kInvalid,
    kGrey,
    kGreyAlpha,
    kRGB,
    kRGBA,
  };

Constructor & Destructor Documentation

DecompressedImage() [1/2]

impeller::DecompressedImage::DecompressedImage ( )

default

DecompressedImage() [2/2]

impeller::DecompressedImage::DecompressedImage	(	ISize	size,
		Format	format,
		std::shared_ptr< const fml::Mapping >	allocation
	)

Definition at line 16 of file decompressed_image.cc.

    : size_(size), format_(format), allocation_(std::move(allocation)) {
  if (!allocation_ || size.IsEmpty() || format_ == Format::kInvalid) {
    return;
  }
  is_valid_ = true;
}

~DecompressedImage()

impeller::DecompressedImage::~DecompressedImage ( )

default

Member Function Documentation

ConvertToRGBA()

DecompressedImage impeller::DecompressedImage::ConvertToRGBA

(

)

const

Definition at line 62 of file decompressed_image.cc.

                                                         {
  if (!is_valid_) {
    return {};
  }
 
  if (format_ == Format::kRGBA) {
    return DecompressedImage{size_, format_, allocation_};
  }
 
  const auto bpp = GetBytesPerPixel(format_);
  const auto source_byte_size = size_.Area() * bpp;
  if (allocation_->GetSize() < source_byte_size) {
    return {};
  }
 
  auto rgba_allocation = std::make_shared<Allocation>();
  if (!rgba_allocation->Truncate(size_.Area() * 4u, false)) {
    return {};
  }
 
  const uint8_t* source = allocation_->GetMapping();
  uint8_t* dest = rgba_allocation->GetBuffer();
 
  for (size_t i = 0, j = 0; i < source_byte_size; i += bpp, j += 4u) {
    switch (format_) {
      case DecompressedImage::Format::kGrey:
        dest[j + 0] = source[i];
        dest[j + 1] = source[i];
        dest[j + 2] = source[i];
        dest[j + 3] = std::numeric_limits<uint8_t>::max();
        break;
      case DecompressedImage::Format::kGreyAlpha:
        dest[j + 0] = std::numeric_limits<uint8_t>::max();
        dest[j + 1] = std::numeric_limits<uint8_t>::max();
        dest[j + 2] = std::numeric_limits<uint8_t>::max();
        dest[j + 3] = source[i];
        break;
      case DecompressedImage::Format::kRGB:
        dest[j + 0] = source[i + 0];
        dest[j + 1] = source[i + 1];
        dest[j + 2] = source[i + 2];
        dest[j + 3] = std::numeric_limits<uint8_t>::max();
        break;
      case DecompressedImage::Format::kInvalid:
      case DecompressedImage::Format::kRGBA:
        // Should never happen. The necessary checks have already been
        // performed.
        FML_CHECK(false);
        break;
    }
  }
 
  return DecompressedImage{
      size_, Format::kRGBA,
      std::make_shared<fml::NonOwnedMapping>(
          rgba_allocation->GetBuffer(),      //
          rgba_allocation->GetLength(),      //
          [rgba_allocation](auto, auto) {})  //
  };
}

GetAllocation()

const std::shared_ptr< const fml::Mapping > & impeller::DecompressedImage::GetAllocation

(

)

const

Definition at line 41 of file decompressed_image.cc.

          {
  return allocation_;
}

GetFormat()

DecompressedImage::Format impeller::DecompressedImage::GetFormat

(

)

const

Definition at line 37 of file decompressed_image.cc.

                                                           {
  return format_;
}

GetSize()

const ISize & impeller::DecompressedImage::GetSize

(

)

const

Definition at line 33 of file decompressed_image.cc.

                                              {
  return size_;
}

IsValid()

bool impeller::DecompressedImage::IsValid

(

)

const

Definition at line 29 of file decompressed_image.cc.

                                      {
  return is_valid_;
}

---

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

• impeller/playground/image/decompressed_image.h
• impeller/playground/image/decompressed_image.cc