impeller::AHBTextureSourceVK Class Reference

A texture source that wraps an instance of AHardwareBuffer. More...

#include <ahb_texture_source_vk.h>

Inheritance diagram for impeller::AHBTextureSourceVK:

Public Member Functions
	AHBTextureSourceVK (const std::shared_ptr< ContextVK > &context, struct AHardwareBuffer *hardware_buffer, const AHardwareBuffer_Desc &hardware_buffer_desc)
	~AHBTextureSourceVK () override
vk::Image	GetImage () const override
	Get the image handle for this texture source.
vk::ImageView	GetImageView () const override
	Retrieve the image view used for sampling/blitting/compute with this texture source.
vk::ImageView	GetRenderTargetView () const override
	Retrieve the image view used for render target attachments with this texture source.
bool	IsValid () const
bool	IsSwapchainImage () const override
	Determines if swapchain image. That is, an image used as the root render target.
std::shared_ptr< YUVConversionVK >	GetYUVConversion () const override
	When sampling from textures whose formats are not known to Vulkan, a custom conversion is necessary to setup custom samplers. This accessor provides this conversion if one is present. Most texture source have none.
Public Member Functions inherited from impeller::TextureSourceVK
virtual	~TextureSourceVK ()
const TextureDescriptor &	GetTextureDescriptor () const
	Gets the texture descriptor for this image source.
fml::Status	SetLayout (const BarrierVK &barrier) const
	Encodes the layout transition barrier to barrier.cmd_buffer for the image.
vk::ImageLayout	SetLayoutWithoutEncoding (vk::ImageLayout layout) const
	Store the layout of the image.
vk::ImageLayout	GetLayout () const
	Get the last layout assigned to the TextureSourceVK.
void	SetCachedFramebuffer (const SharedHandleVK< vk::Framebuffer > &framebuffer)
void	SetCachedRenderPass (const SharedHandleVK< vk::RenderPass > &render_pass)
SharedHandleVK< vk::Framebuffer >	GetCachedFramebuffer () const
SharedHandleVK< vk::RenderPass >	GetCachedRenderPass () const

Additional Inherited Members
Protected Member Functions inherited from impeller::TextureSourceVK
	TextureSourceVK (TextureDescriptor desc)
Protected Attributes inherited from impeller::TextureSourceVK
const TextureDescriptor	desc_

Detailed Description

A texture source that wraps an instance of AHardwareBuffer.

        The formats and conversions supported by Android Hardware
        Buffers are a superset of those supported by Impeller (and
        Vulkan for that matter). Impeller and Vulkan descriptors
        obtained from the these texture sources are advisory and it
        usually isn't possible to create copies of images and image
        views held in these texture sources using the inferred
        descriptors. The objects are meant to be used directly (either
        as render targets or sources for sampling), not copied.

Definition at line 34 of file ahb_texture_source_vk.h.

Constructor & Destructor Documentation

AHBTextureSourceVK()

impeller::AHBTextureSourceVK::AHBTextureSourceVK	(	const std::shared_ptr< ContextVK > &	context,
		struct AHardwareBuffer *	hardware_buffer,
		const AHardwareBuffer_Desc &	hardware_buffer_desc
	)

Definition at line 282 of file ahb_texture_source_vk.cc.

    : TextureSourceVK(ToTextureDescriptor(ahb_desc)) {
  if (!context) {
    VALIDATION_LOG << "Invalid context.";
    return;
  }
 
  const auto& device = context->GetDevice();
  const auto& physical_device = context->GetPhysicalDevice();
 
  AHBProperties ahb_props;
 
  if (device.getAndroidHardwareBufferPropertiesANDROID(ahb, &ahb_props.get()) !=
      vk::Result::eSuccess) {
    VALIDATION_LOG << "Could not determine properties of the Android hardware "
                      "buffer.";
    return;
  }
 
  const auto& ahb_format =
      ahb_props.get<vk::AndroidHardwareBufferFormatPropertiesANDROID>();
 
  // Create an image to refer to our external image.
  auto image =
      CreateVKImageWrapperForAndroidHarwareBuffer(device, ahb_props, ahb_desc);
  if (!image) {
    return;
  }
 
  // Create a device memory allocation to refer to our external image.
  auto device_memory = ImportVKDeviceMemoryFromAndroidHarwareBuffer(
      device, physical_device, image.get(), ahb, ahb_props);
  if (!device_memory) {
    return;
  }
 
  // Bind the image to the image memory.
  if (auto result = device.bindImageMemory(image.get(), device_memory.get(), 0);
      result != vk::Result::eSuccess) {
    VALIDATION_LOG << "Could not bind external device memory to image : "
                   << vk::to_string(result);
    return;
  }
 
  // Figure out how to perform YUV conversions.
  auto yuv_conversion = CreateYUVConversion(*context, ahb_props);
  if (!yuv_conversion || !yuv_conversion->IsValid()) {
    return;
  }
 
  // Create image view for the newly created image.
  auto image_view = CreateVKImageView(device,                           //
                                      image.get(),                      //
                                      yuv_conversion->GetConversion(),  //
                                      ahb_props,                        //
                                      ahb_desc                          //
  );
  if (!image_view) {
    return;
  }
 
  needs_yuv_conversion_ = ahb_format.format == vk::Format::eUndefined;
  device_memory_ = std::move(device_memory);
  image_ = std::move(image);
  yuv_conversion_ = std::move(yuv_conversion);
  image_view_ = std::move(image_view);
 
#ifdef IMPELLER_DEBUG
  context->SetDebugName(device_memory_.get(), "AHB Device Memory");
  context->SetDebugName(image_.get(), "AHB Image");
  context->SetDebugName(yuv_conversion_->GetConversion(), "AHB YUV Conversion");
  context->SetDebugName(image_view_.get(), "AHB ImageView");
#endif  // IMPELLER_DEBUG
 
  is_valid_ = true;
}

~AHBTextureSourceVK()

impeller::AHBTextureSourceVK::~AHBTextureSourceVK ( )

overridedefault

Member Function Documentation

GetImage()

vk::Image impeller::AHBTextureSourceVK::GetImage ( ) const

overridevirtual

Get the image handle for this texture source.

Returns

The image.

Implements impeller::TextureSourceVK.

Definition at line 370 of file ahb_texture_source_vk.cc.

                                           {
  return image_.get();
}

GetImageView()

vk::ImageView impeller::AHBTextureSourceVK::GetImageView ( ) const

overridevirtual

Retrieve the image view used for sampling/blitting/compute with this texture source.

Returns

The image view.

Implements impeller::TextureSourceVK.

Definition at line 375 of file ahb_texture_source_vk.cc.

                                                   {
  return image_view_.get();
}

GetRenderTargetView()

vk::ImageView impeller::AHBTextureSourceVK::GetRenderTargetView ( ) const

overridevirtual

Retrieve the image view used for render target attachments with this texture source.

ImageViews used as render target attachments cannot have any mip levels. In cases where we want to generate mipmaps with the result of this texture, we need to create multiple image views.

Returns

The render target view.

Implements impeller::TextureSourceVK.

Definition at line 380 of file ahb_texture_source_vk.cc.

                                                          {
  return image_view_.get();
}

GetYUVConversion()

std::shared_ptr< YUVConversionVK > impeller::AHBTextureSourceVK::GetYUVConversion ( ) const

overridevirtual

When sampling from textures whose formats are not known to Vulkan, a custom conversion is necessary to setup custom samplers. This accessor provides this conversion if one is present. Most texture source have none.

Returns

The sampler conversion.

Reimplemented from impeller::TextureSourceVK.

Definition at line 390 of file ahb_texture_source_vk.cc.

                                                                          {
  return needs_yuv_conversion_ ? yuv_conversion_ : nullptr;
}

IsSwapchainImage()

bool impeller::AHBTextureSourceVK::IsSwapchainImage ( ) const

overridevirtual

Determines if swapchain image. That is, an image used as the root render target.

Returns

Whether or not this is a swapchain image.

Implements impeller::TextureSourceVK.

Definition at line 385 of file ahb_texture_source_vk.cc.

                                                {
  return false;
}

IsValid()

bool impeller::AHBTextureSourceVK::IsValid

(

)

const

Definition at line 365 of file ahb_texture_source_vk.cc.

                                       {
  return is_valid_;
}

---

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

• impeller/renderer/backend/vulkan/android/ahb_texture_source_vk.h
• impeller/renderer/backend/vulkan/android/ahb_texture_source_vk.cc