| Flutter Impeller |

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

`#include <atlas_contents.h>`

Inheritance diagram for impeller::AtlasColorContents:

## Public Member Functions
| AtlasColorContents (const AtlasContents &parent)
| ~AtlasColorContents () 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 | 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 133 of file atlas_contents.h.

## Constructor & Destructor Documentation

## ◆ AtlasColorContents()

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

Definition at line 425 of file atlas_contents.cc.

426 : parent_(parent) {}

## ◆ ~AtlasColorContents()

impeller::AtlasColorContents::~AtlasColorContents | ( |  | ) |
| override

Definition at line 428 of file atlas_contents.cc.

428 {}

## Member Function Documentation

## ◆ GetCoverage()

std::optional< Rect > impeller::AtlasColorContents::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 430 of file atlas_contents.cc.

431 {
432 return coverage_.TransformBounds(entity.GetTransform());
433 }

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

## ◆ Render()

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

Implements impeller::Contents.

Definition at line 448 of file atlas_contents.cc.

450 {
451 using VS = GeometryColorPipeline::VertexShader;
452 using FS = GeometryColorPipeline::FragmentShader;
453
454 std::vector<Rect> texture_coords;
455 std::vector<Matrix> transforms;
456 std::vector<Color> colors;
457 if (subatlas_) {
458 texture_coords = subatlas_->sub_texture_coords;
459 colors = subatlas_->sub_colors;
460 transforms = subatlas_->sub_transforms;
461 } else {
462 texture_coords = parent_.GetTextureCoordinates();
463 transforms = parent_.GetTransforms();
464 colors = parent_.GetColors();
465 }
466
467 VertexBufferBuilder<VS::PerVertexData> vertex_builder;
468 vertex_builder.Reserve(texture_coords.size() * 6);
469 constexpr size_t indices[6] = {0, 1, 2, 1, 2, 3};
470 for (size_t i = 0; i < texture_coords.size(); i++) {
471 auto sample_rect = texture_coords[i];
472 auto matrix = transforms[i];
473 auto transformed_points =
474 Rect::MakeSize(sample_rect.GetSize()).GetTransformedPoints(matrix);
475
476 for (size_t j = 0; j < 6; j++) {
477 VS::PerVertexData data;
478 data.position = transformed_points[indices[j]];
479 data.color = colors[i].Premultiply();
480 vertex_builder.AppendVertex(data);
481 }
482 }
483
484 if (!vertex_builder.HasVertices()) {
485 return true;
486 }
487
488 pass.SetCommandLabel("AtlasColors");
489
490 auto& host_buffer = renderer.GetTransientsBuffer();
491
492 VS::FrameInfo frame_info;
493 frame_info.mvp = entity.GetShaderTransform(pass);
494
495 FS::FragInfo frag_info;
496 frag_info.alpha = alpha_;
497
498 auto opts = OptionsFromPassAndEntity(pass, entity);
499 opts.blend_mode = BlendMode::kSourceOver;
500 pass.SetPipeline(renderer.GetGeometryColorPipeline(opts));
501 pass.SetStencilReference(entity.GetClipDepth());
502 pass.SetVertexBuffer(vertex_builder.CreateVertexBuffer(host_buffer));
503 VS::BindFrameInfo(pass, host_buffer.EmplaceUniform(frame_info));
504 FS::BindFragInfo(pass, host_buffer.EmplaceUniform(frag_info));
505 return pass.Draw().ok();
506 }

References impeller::VertexBufferBuilder< VertexType_, IndexType_ >::AppendVertex(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::CreateVertexBuffer(), impeller::RenderPass::Draw(), impeller::Entity::GetClipDepth(), impeller::AtlasContents::GetColors(), impeller::ContentContext::GetGeometryColorPipeline(), impeller::Entity::GetShaderTransform(), impeller::AtlasContents::GetTextureCoordinates(), impeller::TRect< T >::GetTransformedPoints(), impeller::AtlasContents::GetTransforms(), impeller::ContentContext::GetTransientsBuffer(), impeller::VertexBufferBuilder< VertexType_, IndexType_ >::HasVertices(), impeller::kSourceOver, 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::AtlasColorContents::SetAlpha | ( | Scalar | alpha | ) |

Definition at line 435 of file atlas_contents.cc.

435 {
436 alpha_ = alpha;
437 }

## ◆ SetCoverage()

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

Definition at line 439 of file atlas_contents.cc.

439 {
440 coverage_ = coverage;
441 }

## ◆ SetSubAtlas()

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

Definition at line 443 of file atlas_contents.cc.

444 {
445 subatlas_ = subatlas;
446 }

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::RenderPipelineT::FragmentShader
FragmentShader_ FragmentShader
Definition: pipeline.h:94
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::TRect< Scalar >::MakeSize
constexpr static TRect MakeSize(const TSize< U > &size)
Definition: rect.h:146
impeller::RenderPipelineT::VertexShader
VertexShader_ VertexShader
Definition: pipeline.h:93
impeller::BlendMode::kSourceOver
@ kSourceOver
impeller::AtlasContents::GetColors
const std::vector< Color > & GetColors() const
Definition: atlas_contents.cc:181