Flutter Impeller
impeller::RenderTargetAllocator Class Reference

a wrapper around the impeller [Allocator] instance that can be used to provide caching of allocated render target textures. More...

#include <render_target.h>

Inheritance diagram for impeller::RenderTargetAllocator:
impeller::RenderTargetCache

Public Member Functions

 RenderTargetAllocator (std::shared_ptr< Allocator > allocator)
 
virtual ~RenderTargetAllocator ()=default
 
virtual RenderTarget CreateOffscreen (const Context &context, ISize size, int mip_count, std::string_view label="Offscreen", RenderTarget::AttachmentConfig color_attachment_config=RenderTarget::kDefaultColorAttachmentConfig, std::optional< RenderTarget::AttachmentConfig > stencil_attachment_config=RenderTarget::kDefaultStencilAttachmentConfig, const std::shared_ptr< Texture > &existing_color_texture=nullptr, const std::shared_ptr< Texture > &existing_depth_stencil_texture=nullptr)
 
virtual RenderTarget CreateOffscreenMSAA (const Context &context, ISize size, int mip_count, std::string_view label="Offscreen MSAA", RenderTarget::AttachmentConfigMSAA color_attachment_config=RenderTarget::kDefaultColorAttachmentConfigMSAA, std::optional< RenderTarget::AttachmentConfig > stencil_attachment_config=RenderTarget::kDefaultStencilAttachmentConfig, const std::shared_ptr< Texture > &existing_color_msaa_texture=nullptr, const std::shared_ptr< Texture > &existing_color_resolve_texture=nullptr, const std::shared_ptr< Texture > &existing_depth_stencil_texture=nullptr)
 
virtual void DisableCache ()
 Disable any caching until the next call to EnabledCache. More...
 
virtual void EnableCache ()
 Re-enable any caching if disabled. More...
 
virtual void Start ()
 Mark the beginning of a frame workload. More...
 
virtual void End ()
 Mark the end of a frame workload. More...
 

Detailed Description

a wrapper around the impeller [Allocator] instance that can be used to provide caching of allocated render target textures.

Definition at line 149 of file render_target.h.

Constructor & Destructor Documentation

◆ RenderTargetAllocator()

impeller::RenderTargetAllocator::RenderTargetAllocator ( std::shared_ptr< Allocator allocator)
explicit

Definition at line 314 of file render_target.cc.

316  : allocator_(std::move(allocator)) {}

◆ ~RenderTargetAllocator()

virtual impeller::RenderTargetAllocator::~RenderTargetAllocator ( )
virtualdefault

Member Function Documentation

◆ CreateOffscreen()

RenderTarget impeller::RenderTargetAllocator::CreateOffscreen ( const Context context,
ISize  size,
int  mip_count,
std::string_view  label = "Offscreen",
RenderTarget::AttachmentConfig  color_attachment_config = RenderTarget::kDefaultColorAttachmentConfig,
std::optional< RenderTarget::AttachmentConfig stencil_attachment_config = RenderTarget::kDefaultStencilAttachmentConfig,
const std::shared_ptr< Texture > &  existing_color_texture = nullptr,
const std::shared_ptr< Texture > &  existing_depth_stencil_texture = nullptr 
)
virtual

Reimplemented in impeller::RenderTargetCache.

Definition at line 322 of file render_target.cc.

330  {
331  if (size.IsEmpty()) {
332  return {};
333  }
334 
335  RenderTarget target;
336 
337  std::shared_ptr<Texture> color0_tex;
338  if (existing_color_texture) {
339  color0_tex = existing_color_texture;
340  } else {
341  PixelFormat pixel_format =
342  context.GetCapabilities()->GetDefaultColorFormat();
343  TextureDescriptor color0_tex_desc;
344  color0_tex_desc.storage_mode = color_attachment_config.storage_mode;
345  color0_tex_desc.format = pixel_format;
346  color0_tex_desc.size = size;
347  color0_tex_desc.mip_count = mip_count;
348  color0_tex_desc.usage =
350  color0_tex = allocator_->CreateTexture(color0_tex_desc);
351  if (!color0_tex) {
352  return {};
353  }
354  }
355  color0_tex->SetLabel(label, "Color Texture");
356 
357  ColorAttachment color0;
358  color0.clear_color = color_attachment_config.clear_color;
359  color0.load_action = color_attachment_config.load_action;
360  color0.store_action = color_attachment_config.store_action;
361  color0.texture = color0_tex;
362  target.SetColorAttachment(color0, 0u);
363 
364  if (stencil_attachment_config.has_value()) {
365  target.SetupDepthStencilAttachments(
366  context, *allocator_, size, false, label,
367  stencil_attachment_config.value(), existing_depth_stencil_texture);
368  } else {
369  target.SetStencilAttachment(std::nullopt);
370  target.SetDepthAttachment(std::nullopt);
371  }
372 
373  return target;
374 }
PixelFormat
The Pixel formats supported by Impeller. The naming convention denotes the usage of the component,...
Definition: formats.h:99

References impeller::ColorAttachment::clear_color, impeller::RenderTarget::AttachmentConfig::clear_color, impeller::TextureDescriptor::format, impeller::Context::GetCapabilities(), impeller::TSize< T >::IsEmpty(), impeller::kRenderTarget, impeller::kShaderRead, impeller::Attachment::load_action, impeller::RenderTarget::AttachmentConfig::load_action, impeller::TextureDescriptor::mip_count, impeller::RenderTarget::SetColorAttachment(), impeller::RenderTarget::SetDepthAttachment(), impeller::RenderTarget::SetStencilAttachment(), impeller::RenderTarget::SetupDepthStencilAttachments(), impeller::TextureDescriptor::size, impeller::TextureDescriptor::storage_mode, impeller::RenderTarget::AttachmentConfig::storage_mode, impeller::Attachment::store_action, impeller::RenderTarget::AttachmentConfig::store_action, impeller::Attachment::texture, and impeller::TextureDescriptor::usage.

Referenced by impeller::RenderTargetCache::CreateOffscreen(), impeller::DisplayListToTexture(), and impeller::testing::TEST_P().

◆ CreateOffscreenMSAA()

RenderTarget impeller::RenderTargetAllocator::CreateOffscreenMSAA ( const Context context,
ISize  size,
int  mip_count,
std::string_view  label = "Offscreen MSAA",
RenderTarget::AttachmentConfigMSAA  color_attachment_config = RenderTarget::kDefaultColorAttachmentConfigMSAA,
std::optional< RenderTarget::AttachmentConfig stencil_attachment_config = RenderTarget::kDefaultStencilAttachmentConfig,
const std::shared_ptr< Texture > &  existing_color_msaa_texture = nullptr,
const std::shared_ptr< Texture > &  existing_color_resolve_texture = nullptr,
const std::shared_ptr< Texture > &  existing_depth_stencil_texture = nullptr 
)
virtual

Reimplemented in impeller::RenderTargetCache.

Definition at line 376 of file render_target.cc.

385  {
386  if (size.IsEmpty()) {
387  return {};
388  }
389 
390  RenderTarget target;
391  PixelFormat pixel_format = context.GetCapabilities()->GetDefaultColorFormat();
392 
393  // Create MSAA color texture.
394  std::shared_ptr<Texture> color0_msaa_tex;
395  if (existing_color_msaa_texture) {
396  color0_msaa_tex = existing_color_msaa_texture;
397  } else {
398  TextureDescriptor color0_tex_desc;
399  color0_tex_desc.storage_mode = color_attachment_config.storage_mode;
400  color0_tex_desc.type = TextureType::kTexture2DMultisample;
401  color0_tex_desc.sample_count = SampleCount::kCount4;
402  color0_tex_desc.format = pixel_format;
403  color0_tex_desc.size = size;
404  color0_tex_desc.usage = TextureUsage::kRenderTarget;
405  if (context.GetCapabilities()->SupportsImplicitResolvingMSAA()) {
406  // See below ("SupportsImplicitResolvingMSAA") for more details.
407  color0_tex_desc.storage_mode = StorageMode::kDevicePrivate;
408  }
409  color0_msaa_tex = allocator_->CreateTexture(color0_tex_desc);
410  if (!color0_msaa_tex) {
411  VALIDATION_LOG << "Could not create multisample color texture.";
412  return {};
413  }
414  }
415  color0_msaa_tex->SetLabel(label, "Color Texture (Multisample)");
416 
417  // Create color resolve texture.
418  std::shared_ptr<Texture> color0_resolve_tex;
419  if (existing_color_resolve_texture) {
420  color0_resolve_tex = existing_color_resolve_texture;
421  } else {
422  TextureDescriptor color0_resolve_tex_desc;
423  color0_resolve_tex_desc.storage_mode =
424  color_attachment_config.resolve_storage_mode;
425  color0_resolve_tex_desc.format = pixel_format;
426  color0_resolve_tex_desc.size = size;
427  color0_resolve_tex_desc.compression_type = CompressionType::kLossy;
428  color0_resolve_tex_desc.usage =
430  color0_resolve_tex_desc.mip_count = mip_count;
431  color0_resolve_tex = allocator_->CreateTexture(color0_resolve_tex_desc);
432  if (!color0_resolve_tex) {
433  VALIDATION_LOG << "Could not create color texture.";
434  return {};
435  }
436  }
437  color0_resolve_tex->SetLabel(label, "Color Texture");
438 
439  // Color attachment.
440 
441  ColorAttachment color0;
442  color0.clear_color = color_attachment_config.clear_color;
443  color0.load_action = color_attachment_config.load_action;
444  color0.store_action = color_attachment_config.store_action;
445  color0.texture = color0_msaa_tex;
446  color0.resolve_texture = color0_resolve_tex;
447 
448  if (context.GetCapabilities()->SupportsImplicitResolvingMSAA()) {
449  // If implicit MSAA is supported, then the resolve texture is not needed
450  // because the multisample texture is automatically resolved. We instead
451  // provide a view of the multisample texture as the resolve texture (because
452  // the HAL does expect a resolve texture).
453  //
454  // In practice, this is used for GLES 2.0 EXT_multisampled_render_to_texture
455  // https://registry.khronos.org/OpenGL/extensions/EXT/EXT_multisampled_render_to_texture.txt
456  color0.resolve_texture = color0_msaa_tex;
457  }
458 
459  target.SetColorAttachment(color0, 0u);
460 
461  // Create MSAA stencil texture.
462 
463  if (stencil_attachment_config.has_value()) {
464  target.SetupDepthStencilAttachments(context, *allocator_, size, true, label,
465  stencil_attachment_config.value(),
466  existing_depth_stencil_texture);
467  } else {
468  target.SetDepthAttachment(std::nullopt);
469  target.SetStencilAttachment(std::nullopt);
470  }
471 
472  return target;
473 }
#define VALIDATION_LOG
Definition: validation.h:91

References impeller::ColorAttachment::clear_color, impeller::RenderTarget::AttachmentConfigMSAA::clear_color, impeller::TextureDescriptor::compression_type, impeller::TextureDescriptor::format, impeller::Context::GetCapabilities(), impeller::TSize< T >::IsEmpty(), impeller::kCount4, impeller::kDevicePrivate, impeller::kLossy, impeller::kRenderTarget, impeller::kShaderRead, impeller::kTexture2DMultisample, impeller::Attachment::load_action, impeller::RenderTarget::AttachmentConfigMSAA::load_action, impeller::TextureDescriptor::mip_count, impeller::RenderTarget::AttachmentConfigMSAA::resolve_storage_mode, impeller::Attachment::resolve_texture, impeller::TextureDescriptor::sample_count, impeller::RenderTarget::SetColorAttachment(), impeller::RenderTarget::SetDepthAttachment(), impeller::RenderTarget::SetStencilAttachment(), impeller::RenderTarget::SetupDepthStencilAttachments(), impeller::TextureDescriptor::size, impeller::TextureDescriptor::storage_mode, impeller::RenderTarget::AttachmentConfigMSAA::storage_mode, impeller::Attachment::store_action, impeller::RenderTarget::AttachmentConfigMSAA::store_action, impeller::Attachment::texture, impeller::TextureDescriptor::type, impeller::TextureDescriptor::usage, and VALIDATION_LOG.

Referenced by impeller::RenderTargetCache::CreateOffscreenMSAA(), impeller::DisplayListToTexture(), impeller::ContextVK::InitializeCommonlyUsedShadersIfNeeded(), and impeller::testing::TEST().

◆ DisableCache()

virtual void impeller::RenderTargetAllocator::DisableCache ( )
inlinevirtual

Disable any caching until the next call to EnabledCache.

Reimplemented in impeller::RenderTargetCache.

Definition at line 181 of file render_target.h.

181 {}

◆ EnableCache()

virtual void impeller::RenderTargetAllocator::EnableCache ( )
inlinevirtual

Re-enable any caching if disabled.

Reimplemented in impeller::RenderTargetCache.

Definition at line 184 of file render_target.h.

184 {}

◆ End()

void impeller::RenderTargetAllocator::End ( )
virtual

Mark the end of a frame workload.

   This may be used to deallocate any unused textures. 

Reimplemented in impeller::RenderTargetCache.

Definition at line 320 of file render_target.cc.

320 {}

◆ Start()

void impeller::RenderTargetAllocator::Start ( )
virtual

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 in impeller::RenderTargetCache.

Definition at line 318 of file render_target.cc.

318 {}

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