impeller::RenderTargetCache Class Reference

An implementation of the [RenderTargetAllocator] that caches all allocated texture data for one frame. More...

#include <render_target_cache.h>

Inheritance diagram for impeller::RenderTargetCache:

Public Member Functions
	RenderTargetCache (std::shared_ptr< Allocator > allocator)
	~RenderTargetCache ()=default
void	Start () override
	Mark the beginning of a frame workload. More...
void	End () override
	Mark the end of a frame workload. More...
std::shared_ptr< Texture >	CreateTexture (const TextureDescriptor &desc) override
	Create a new render target texture, or recycle a previously allocated render target texture. More...
size_t	CachedTextureCount () const
Public Member Functions inherited from impeller::RenderTargetAllocator
	RenderTargetAllocator (std::shared_ptr< Allocator > allocator)
virtual	~RenderTargetAllocator ()=default

Detailed Description

An implementation of the [RenderTargetAllocator] that caches all allocated texture data for one frame.

Any textures unused after a frame are immediately discarded.

Definition at line 15 of file render_target_cache.h.

Constructor & Destructor Documentation

RenderTargetCache()

impeller::RenderTargetCache::RenderTargetCache ( std::shared_ptr< Allocator >  allocator )

explicit

Definition at line 10 of file render_target_cache.cc.

    : RenderTargetAllocator(std::move(allocator)) {}

~RenderTargetCache()

impeller::RenderTargetCache::~RenderTargetCache ( )

default

Member Function Documentation

CachedTextureCount()

size_t impeller::RenderTargetCache::CachedTextureCount

(

)

const

Definition at line 30 of file render_target_cache.cc.

                                                   {
  return texture_data_.size();
}

CreateTexture()

std::shared_ptr< Texture > impeller::RenderTargetCache::CreateTexture ( const TextureDescriptor &  desc )

overridevirtual

Create a new render target texture, or recycle a previously allocated render target texture.

Reimplemented from impeller::RenderTargetAllocator.

Definition at line 34 of file render_target_cache.cc.

                                   {
  FML_DCHECK(desc.storage_mode != StorageMode::kHostVisible);
  FML_DCHECK(desc.usage &
             static_cast<TextureUsageMask>(TextureUsage::kRenderTarget));
 
  for (auto& td : texture_data_) {
    const auto other_desc = td.texture->GetTextureDescriptor();
    FML_DCHECK(td.texture != nullptr);
    if (!td.used_this_frame && desc == other_desc) {
      td.used_this_frame = true;
      return td.texture;
    }
  }
  auto result = RenderTargetAllocator::CreateTexture(desc);
  if (result == nullptr) {
    return result;
  }
  texture_data_.push_back(
      TextureData{.used_this_frame = true, .texture = result});
  return result;
}

References impeller::RenderTargetAllocator::CreateTexture(), impeller::kHostVisible, impeller::kRenderTarget, impeller::TextureDescriptor::storage_mode, and impeller::TextureDescriptor::usage.

End()

void impeller::RenderTargetCache::End ( )

overridevirtual

Mark the end of a frame workload.

   This may be used to deallocate any unused textures. 

Reimplemented from impeller::RenderTargetAllocator.

Definition at line 19 of file render_target_cache.cc.

                            {
  std::vector<TextureData> retain;
 
  for (const auto& td : texture_data_) {
    if (td.used_this_frame) {
      retain.push_back(td);
    }
  }
  texture_data_.swap(retain);
}

Start()

void impeller::RenderTargetCache::Start ( )

overridevirtual

Mark the beginning of a frame workload.

  This may be used to reset any tracking state on whether or not a
  particular texture instance is still in use. 

Reimplemented from impeller::RenderTargetAllocator.

Definition at line 13 of file render_target_cache.cc.

                              {
  for (auto& td : texture_data_) {
    td.used_this_frame = false;
  }
}

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

• impeller/entity/render_target_cache.h
• impeller/entity/render_target_cache.cc