| Flutter Impeller |

Public Member Functions | List of all members
impeller::AtlasTextureContents Class Referencefinal

`#include <atlas_contents.h>`

Inheritance diagram for impeller::AtlasTextureContents:

## Public Member Functions
| AtlasTextureContents (const AtlasContents &parent)
| ~AtlasTextureContents () override
std::optional< Rect > | GetCoverage (const Entity &entity) const override
| Get the area of the render pass that will be affected when this contents is rendered. More...
bool | Render (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
void | SetAlpha (Scalar alpha)
void | SetCoverage (Rect coverage)
void | SetTexture (std::shared_ptr< Texture > texture)
void | SetUseDestination (bool value)
void | SetSubAtlas (const std::shared_ptr< SubAtlasResult > &subatlas)
Public Member Functions inherited from impeller::Contents
| Contents ()
virtual | ~Contents ()
virtual void | PopulateGlyphAtlas (const std::shared_ptr< LazyGlyphAtlas > &lazy_glyph_atlas, Scalar scale)
| Add any text data to the specified lazy atlas. The scale parameter must be used again later when drawing the text. More...
void | SetCoverageHint (std::optional< Rect > coverage_hint)
| Hint that specifies the coverage area of this Contents that will actually be used during rendering. This is for optimization purposes only and can not be relied on as a clip. May optionally affect the result of `GetCoverage()`. More...
const std::optional< Rect > & | GetCoverageHint () const
virtual bool | IsOpaque () const
| Whether this Contents only emits opaque source colors from the fragment stage. This value does not account for any entity properties (e.g. the blend mode), clips/visibility culling, or inherited opacity. More...
virtual ClipCoverage | GetClipCoverage (const Entity &entity, const std::optional< Rect > &current_clip_coverage) const
| Given the current pass space bounding rectangle of the clip buffer, return the expected clip coverage after this draw call. This should only be implemented for contents that may write to the clip buffer. More...
virtual std::optional< Snapshot > | RenderToSnapshot (const ContentContext &renderer, const Entity &entity, std::optional< Rect > coverage_limit=std::nullopt, const std::optional< SamplerDescriptor > &sampler_descriptor=std::nullopt, bool msaa_enabled=true, int32_t mip_count=1, const std::string &label="Snapshot") const
| Render this contents to a snapshot, respecting the entity's transform, path, clip depth, and blend mode. The result texture size is always the size of `GetCoverage(entity)`. More...
virtual bool | ShouldRender (const Entity &entity, const std::optional< Rect > clip_coverage) const
std::optional< Size > | GetColorSourceSize () const
| Return the color source's intrinsic size, if available. More...
void | SetColorSourceSize (Size size)
virtual bool | CanInheritOpacity (const Entity &entity) const
| Whether or not this contents can accept the opacity peephole optimization. More...
virtual void | SetInheritedOpacity (Scalar opacity)
| Inherit the provided opacity. More...
virtual std::optional< Color > | AsBackgroundColor (const Entity &entity, ISize target_size) const
| Returns a color if this Contents will flood the given `target_size` with a color. This output color is the "Source" color that will be used for the Entity's blend operation. More...
virtual const FilterContents * | AsFilter () const
| Cast to a filter. Returns `nullptr` if this Contents is not a filter. More...
virtual bool | ApplyColorFilter (const ColorFilterProc &color_filter_proc)
| If possible, applies a color filter to this contents inputs on the CPU. More...

## Additional Inherited Members
Public Types inherited from impeller::Contents
using | ColorFilterProc = std::function< Color(Color)>
using | RenderProc = std::function< bool(const ContentContext &renderer, const Entity &entity, RenderPass &pass)>
using | CoverageProc = std::function< std::optional< Rect >(const Entity &entity)>
Static Public Member Functions inherited from impeller::Contents
static std::shared_ptr< Contents > | MakeAnonymous (RenderProc render_proc, CoverageProc coverage_proc)

## Detailed Description

Definition at line 96 of file atlas_contents.h.

## Constructor & Destructor Documentation

## ◆ AtlasTextureContents()

impeller::AtlasTextureContents::AtlasTextureContents | ( | const AtlasContents & | parent | ) |
| explicit

Definition at line 325 of file atlas_contents.cc.

326 : parent_(parent) {}

## ◆ ~AtlasTextureContents()

impeller::AtlasTextureContents::~AtlasTextureContents | ( |  | ) |
| override

Definition at line 328 of file atlas_contents.cc.

328 {}

## Member Function Documentation

## ◆ GetCoverage()

std::optional< Rect > impeller::AtlasTextureContents::GetCoverage | ( | const Entity & | entity | ) | const
| override virtual

Get the area of the render pass that will be affected when this contents is rendered.

During rendering, coverage coordinates count pixels from the top left corner of the framebuffer.

Returns
  The coverage rectangle. An `std::nullopt` result means that rendering this contents has no effect on the output color.

Implements impeller::Contents.

Definition at line 330 of file atlas_contents.cc.

331 {
332 return coverage_.TransformBounds(entity.GetTransform());
333 }

References impeller::Entity::GetTransform(), and impeller::TRect< T >::TransformBounds().

## ◆ Render()

bool impeller::AtlasTextureContents::Render | ( | const ContentContext & | renderer,
|  | const Entity & | entity,
|  | RenderPass & | pass
| ) |  | const
| override virtual

Implements impeller::Contents.

Definition at line 356 of file atlas_contents.cc.

358 {
359 using VS = TextureFillVertexShader;
360 using FS = TextureFillFragmentShader;
361
362 auto texture = texture_ ? texture_ : parent_.GetTexture();
363 if (texture == nullptr) {
364 return true;
365 }
366
367 std::vector<Rect> texture_coords;
368 std::vector<Matrix> transforms;
369 if (subatlas_) {
370 texture_coords = use_destination_ ? subatlas_->result_texture_coords
371 : subatlas_->sub_texture_coords;
372 transforms = use_destination_ ? subatlas_->result_transforms
373 : subatlas_->sub_transforms;
374 } else {
375 texture_coords = parent_.GetTextureCoordinates();
376 transforms = parent_.GetTransforms();
377 }
378
379 const Size texture_size(texture->GetSize());
380 VertexBufferBuilder<VS::PerVertexData> vertex_builder;
381 vertex_builder.Reserve(texture_coords.size() * 6);
382 constexpr size_t indices[6] = {0, 1, 2, 1, 2, 3};
383 for (size_t i = 0; i < texture_coords.size(); i++) {
384 auto sample_rect = texture_coords[i];
385 auto matrix = transforms[i];
386 auto points = sample_rect.GetPoints();
387 auto transformed_points =
388 Rect::MakeSize(sample_rect.GetSize()).GetTransformedPoints(matrix);
389
390 for (size_t j = 0; j < 6; j++) {
391 VS::PerVertexData data;
392 data.position = transformed_points[indices[j]];
393 data.texture_coords = points[indices[j]] / texture_size;
394 vertex_builder.AppendVertex(data);
395 }
396 }
397
398 if (!vertex_builder.HasVertices()) {
399 return true;
400 }
401
402 pass.SetCommandLabel("AtlasTexture");
403
404 auto& host_buffer = renderer.GetTransientsBuffer();
405
406 VS::FrameInfo frame_info;
407 frame_info.mvp = entity.GetShaderTransform(pass);
408 frame_info.texture_sampler_y_coord_scale = texture->GetYCoordScale();
409 frame_info.alpha = alpha_;
410
411 auto options = OptionsFromPassAndEntity(pass, entity);
412 pass.SetPipeline(renderer.GetTexturePipeline(options));
413 pass.SetStencilReference(entity.GetClipDepth());
414 pass.SetVertexBuffer(vertex_builder.CreateVertexBuffer(host_buffer));
415 VS::BindFrameInfo(pass, host_buffer.EmplaceUniform(frame_info));
416 FS::BindTextureSampler(pass, texture,
417 renderer.GetContext()->GetSamplerLibrary()->GetSampler(
418 parent_.GetSamplerDescriptor()));
419 return pass.Draw().ok();
420 }

References impeller::VertexBufferBuilder< VertexType_, IndexType_ >::AppendVertex(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::CreateVertexBuffer(), impeller::RenderPass::Draw(), impeller::Entity::GetClipDepth(), impeller::ContentContext::GetContext(), impeller::AtlasContents::GetSamplerDescriptor(), impeller::Entity::GetShaderTransform(), impeller::AtlasContents::GetTexture(), impeller::AtlasContents::GetTextureCoordinates(), impeller::ContentContext::GetTexturePipeline(), impeller::TRect< T >::GetTransformedPoints(), impeller::AtlasContents::GetTransforms(), impeller::ContentContext::GetTransientsBuffer(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::HasVertices(), impeller::TRect< Scalar >::MakeSize(), impeller::OptionsFromPassAndEntity(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::Reserve(), impeller::RenderPass::SetCommandLabel(), impeller::RenderPass::SetPipeline(), impeller::RenderPass::SetStencilReference(), and impeller::RenderPass::SetVertexBuffer().

## ◆ SetAlpha()

void impeller::AtlasTextureContents::SetAlpha | ( | Scalar | alpha | ) |

Definition at line 335 of file atlas_contents.cc.

335 {
336 alpha_ = alpha;
337 }

## ◆ SetCoverage()

void impeller::AtlasTextureContents::SetCoverage | ( | Rect | coverage | ) |

Definition at line 339 of file atlas_contents.cc.

339 {
340 coverage_ = coverage;
341 }

## ◆ SetSubAtlas()

void impeller::AtlasTextureContents::SetSubAtlas | ( | const std::shared_ptr< SubAtlasResult > & | subatlas | ) |

Definition at line 347 of file atlas_contents.cc.

348 {
349 subatlas_ = subatlas;
350 }

## ◆ SetTexture()

void impeller::AtlasTextureContents::SetTexture | ( | std::shared_ptr< Texture > | texture | ) |

Definition at line 352 of file atlas_contents.cc.

352 {
353 texture_ = std::move(texture);
354 }

## ◆ SetUseDestination()

void impeller::AtlasTextureContents::SetUseDestination | ( | bool | value | ) |

Definition at line 343 of file atlas_contents.cc.

343 {
344 use_destination_ = value;
345 }

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

- impeller/entity/contents/atlas_contents.h
- impeller/entity/contents/atlas_contents.cc

impeller::TRect::TransformBounds
constexpr TRect TransformBounds(const Matrix &transform) const
Creates a new bounding box that contains this transformed rectangle.
Definition: rect.h:405
impeller::Size
TSize< Scalar > Size
Definition: size.h:137
impeller::VS
SolidFillVertexShader VS
Definition: stroke_path_geometry.cc:15
impeller::OptionsFromPassAndEntity
ContentContextOptions OptionsFromPassAndEntity(const RenderPass &pass, const Entity &entity)
Definition: contents.cc:37
impeller::TRect::GetTransformedPoints
constexpr std::array< TPoint< T >, 4 > GetTransformedPoints(const Matrix &transform) const
Definition: rect.h:394
impeller::AtlasContents::GetTransforms
const std::vector< Matrix > & GetTransforms() const
Definition: atlas_contents.cc:173
impeller::AtlasContents::GetTextureCoordinates
const std::vector< Rect > & GetTextureCoordinates() const
Definition: atlas_contents.cc:177
impeller::AtlasContents::GetTexture
std::shared_ptr< Texture > GetTexture() const
Definition: atlas_contents.cc:32
impeller::TRect< Scalar >::MakeSize
constexpr static TRect MakeSize(const TSize< U > &size)
Definition: rect.h:146
impeller::AtlasContents::GetSamplerDescriptor
const SamplerDescriptor & GetSamplerDescriptor() const
Definition: atlas_contents.cc:169