| Flutter Impeller |

Classes | Public Types | Public Member Functions | Static Public Attributes | List of all members
impeller::Canvas Class Reference

`#include <canvas.h>`

## Classes
struct | SaveLayerState

## Public Types
using | BackdropFilterProc = std::function< std::shared_ptr< FilterContents >(FilterInput::Ref, const Matrix &effect_transform, Entity::RenderingMode rendering_mode)>

## Public Member Functions
| Canvas (ContentContext &renderer, const RenderTarget &render_target, bool is_onscreen, bool requires_readback)
| Canvas (ContentContext &renderer, const RenderTarget &render_target, bool is_onscreen, bool requires_readback, Rect cull_rect)
| Canvas (ContentContext &renderer, const RenderTarget &render_target, bool is_onscreen, bool requires_readback, IRect32 cull_rect)
| ~Canvas ()=default
void | SetBackdropData (std::unordered_map< int64_t, BackdropData > backdrop_data, size_t backdrop_count)
| Update the backdrop data used to group together backdrop filters within the same layer. More...
std::optional< Rect > | GetLocalCoverageLimit () const
| Return the culling bounds of the current render target, or nullopt if there is no coverage. More...
void | Save (uint32_t total_content_depth=kMaxDepth)
void | SaveLayer (const Paint &paint, std::optional< Rect > bounds=std::nullopt, const flutter::DlImageFilter *backdrop_filter=nullptr, ContentBoundsPromise bounds_promise=ContentBoundsPromise::kUnknown, uint32_t total_content_depth=kMaxDepth, bool can_distribute_opacity=false, std::optional< int64_t > backdrop_id=std::nullopt)
bool | Restore ()
size_t | GetSaveCount () const
void | RestoreToCount (size_t count)
const Matrix & | GetCurrentTransform () const
void | ResetTransform ()
void | Transform (const Matrix &transform)
void | Concat (const Matrix &transform)
void | PreConcat (const Matrix &transform)
void | Translate (const Vector3 &offset)
void | Scale (const Vector2 &scale)
void | Scale (const Vector3 &scale)
void | Skew (Scalar sx, Scalar sy)
void | Rotate (Radians radians)
void | DrawPath (const flutter::DlPath &path, const Paint &paint)
void | DrawPaint (const Paint &paint)
void | DrawLine (const Point &p0, const Point &p1, const Paint &paint, bool reuse_depth=false)
void | DrawDashedLine (const Point &p0, const Point &p1, Scalar on_length, Scalar off_length, const Paint &paint)
void | DrawRect (const Rect &rect, const Paint &paint)
void | DrawOval (const Rect &rect, const Paint &paint)
void | DrawArc (const Arc &arc, const Paint &paint)
void | DrawRoundRect (const RoundRect &rect, const Paint &paint)
void | DrawDiffRoundRect (const RoundRect &outer, const RoundRect &inner, const Paint &paint)
void | DrawRoundSuperellipse (const RoundSuperellipse &rse, const Paint &paint)
void | DrawCircle (const Point &center, Scalar radius, const Paint &paint)
void | DrawPoints (const Point points[], uint32_t count, Scalar radius, const Paint &paint, PointStyle point_style)
void | DrawImage (const std::shared_ptr< Texture > &image, Point offset, const Paint &paint, const SamplerDescriptor &sampler={})
void | DrawImageRect (const std::shared_ptr< Texture > &image, Rect source, Rect dest, const Paint &paint, const SamplerDescriptor &sampler={}, SourceRectConstraint src_rect_constraint=SourceRectConstraint::kFast)
void | DrawTextFrame (const std::shared_ptr< TextFrame > &text_frame, Point position, const Paint &paint)
void | DrawVertices (const std::shared_ptr< VerticesGeometry > &vertices, BlendMode blend_mode, const Paint &paint)
void | DrawAtlas (const std::shared_ptr< AtlasContents > &atlas_contents, const Paint &paint)
void | ClipGeometry (const Geometry &geometry, Entity::ClipOperation clip_op, bool is_aa=true)
void | EndReplay ()
uint64_t | GetOpDepth () const
uint64_t | GetMaxOpDepth () const
bool | RequiresReadback () const
bool | SupportsBlitToOnscreen () const
bool | EnsureFinalMipmapGeneration () const

## Static Public Attributes
static constexpr uint32_t | kMaxDepth = 1 << 24

## Detailed Description

Definition at line 118 of file canvas.h.

## Member Typedef Documentation

## ◆ BackdropFilterProc

using impeller::Canvas::BackdropFilterProc = std::function<std::shared_ptr<FilterContents>( FilterInput::Ref, const Matrix& effect_transform, Entity::RenderingMode rendering_mode)>

Definition at line 122 of file canvas.h.

## Constructor & Destructor Documentation

## ◆ Canvas() [1/3]

impeller::Canvas::Canvas | ( | ContentContext & | renderer,
|  | const RenderTarget & | render_target,
|  | bool | is_onscreen,
|  | bool | requires_readback
| ) |  |

Definition at line 199 of file canvas.cc.

203 : renderer_(renderer),
204 render_target_(render_target),
205 is_onscreen_(is_onscreen),
206 requires_readback_(requires_readback),
207 clip_coverage_stack_(EntityPassClipStack(
208 Rect::MakeSize(render_target.GetRenderTargetSize()))) {
209 Initialize(std::nullopt);
210 SetupRenderPass();
211 }
impeller::TRect< Scalar >::MakeSize
constexpr static TRect MakeSize(const TSize< U > &size)
Definition: rect.h:150

## ◆ Canvas() [2/3]

impeller::Canvas::Canvas | ( | ContentContext & | renderer,
|  | const RenderTarget & | render_target,
|  | bool | is_onscreen,
|  | bool | requires_readback,
|  | Rect | cull_rect
| ) |  |
| explicit

Definition at line 213 of file canvas.cc.

218 : renderer_(renderer),
219 render_target_(render_target),
220 is_onscreen_(is_onscreen),
221 requires_readback_(requires_readback),
222 clip_coverage_stack_(EntityPassClipStack(
223 Rect::MakeSize(render_target.GetRenderTargetSize()))) {
224 Initialize(cull_rect);
225 SetupRenderPass();
226 }

## ◆ Canvas() [3/3]

impeller::Canvas::Canvas | ( | ContentContext & | renderer,
|  | const RenderTarget & | render_target,
|  | bool | is_onscreen,
|  | bool | requires_readback,
|  | IRect32 | cull_rect
| ) |  |
| explicit

Definition at line 228 of file canvas.cc.

233 : renderer_(renderer),
234 render_target_(render_target),
235 is_onscreen_(is_onscreen),
236 requires_readback_(requires_readback),
237 clip_coverage_stack_(EntityPassClipStack(
238 Rect::MakeSize(render_target.GetRenderTargetSize()))) {
239 Initialize(Rect::MakeLTRB(cull_rect.GetLeft(), cull_rect.GetTop(),
240 cull_rect.GetRight(), cull_rect.GetBottom()));
241 SetupRenderPass();
242 }
impeller::TRect< Scalar >::MakeLTRB
constexpr static TRect MakeLTRB(Type left, Type top, Type right, Type bottom)
Definition: rect.h:129

References impeller::TRect< T >::GetBottom(), impeller::TRect< T >::GetLeft(), impeller::TRect< T >::GetRight(), impeller::TRect< T >::GetTop(), and impeller::TRect< Scalar >::MakeLTRB().

## ◆ ~Canvas()

impeller::Canvas::~Canvas | ( |  | ) |
| default

## Member Function Documentation

## ◆ ClipGeometry()

void impeller::Canvas::ClipGeometry | ( | const Geometry & | geometry,
|  | Entity::ClipOperation | clip_op,
|  | bool | is_aa = `true`
| ) |  |

Definition at line 858 of file canvas.cc.

860 {
861 if (IsSkipping()) {
862 return;
863 }
864
865 // Ideally the clip depth would be greater than the current rendering
866 // depth because any rendering calls that follow this clip operation will
867 // pre-increment the depth and then be rendering above our clip depth,
868 // but that case will be caught by the CHECK in AddRenderEntity above.
869 // In practice we sometimes have a clip set with no rendering after it
870 // and in such cases the current depth will equal the clip depth.
871 // Eventually the DisplayList should optimize these out, but it is hard
872 // to know if a clip will actually be used in advance of storing it in
873 // the DisplayList buffer.
874 // See https://github.com/flutter/flutter/issues/147021
875 FML_DCHECK(current_depth_ <= transform_stack_.back().clip_depth)
876 << current_depth_ << " <=? " << transform_stack_.back().clip_depth;
877 uint32_t clip_depth = transform_stack_.back().clip_depth;
878
879 const Matrix clip_transform =
880 Matrix::MakeTranslation(Vector3(-GetGlobalPassPosition())) *
881 GetCurrentTransform();
882
883 std::optional<Rect> clip_coverage = geometry.GetCoverage(clip_transform);
884 if (!clip_coverage.has_value()) {
885 return;
886 }
887
888 ClipContents clip_contents(
889 clip_coverage.value(),
890 /*is_axis_aligned_rect=*/geometry.IsAxisAlignedRect() &&
891 GetCurrentTransform().IsTranslationScaleOnly());
892 clip_contents.SetClipOperation(clip_op);
893
894 EntityPassClipStack::ClipStateResult clip_state_result =
895 clip_coverage_stack_.RecordClip(
896 clip_contents, //
897 /*transform=*/clip_transform, //
898 /*global_pass_position=*/GetGlobalPassPosition(), //
899 /*clip_depth=*/clip_depth, //
900 /*clip_height_floor=*/GetClipHeightFloor(), //
901 /*is_aa=*/is_aa);
902
903 if (clip_state_result.clip_did_change) {
904 // We only need to update the pass scissor if the clip state has changed.
905 SetClipScissor(
906 clip_coverage_stack_.CurrentClipCoverage(),
907 *render_passes_.back().GetInlinePassContext()->GetRenderPass(),
908 GetGlobalPassPosition());
909 }
910
911 ++transform_stack_.back().clip_height;
912 ++transform_stack_.back().num_clips;
913
914 if (!clip_state_result.should_render) {
915 return;
916 }
917
918 // Note: this is a bit of a hack. Its not possible to construct a geometry
919 // result without begninning the render pass. We should refactor the geometry
920 // objects so that they only need a reference to the render pass size and/or
921 // orthographic transform.
922 Entity entity;
923 entity.SetTransform(clip_transform);
924 entity.SetClipDepth(clip_depth);
925
926 GeometryResult geometry_result = geometry.GetPositionBuffer(
927 renderer_, //
928 entity, //
929 *render_passes_.back().GetInlinePassContext()->GetRenderPass() //
930 );
931 clip_contents.SetGeometry(geometry_result);
932 clip_coverage_stack_.GetLastReplayResult().clip_contents.SetGeometry(
933 geometry_result);
934
935 clip_contents.Render(
936 renderer_, *render_passes_.back().GetInlinePassContext()->GetRenderPass(),
937 clip_depth);
938 }
impeller::Canvas::GetCurrentTransform
const Matrix & GetCurrentTransform() const
Definition: canvas.cc:273
impeller::ClipContents::SetGeometry
void SetGeometry(GeometryResult geometry)
Set the pre-tessellated clip geometry.
Definition: clip_contents.cc:37
impeller::EntityPassClipStack::CurrentClipCoverage
std::optional< Rect > CurrentClipCoverage() const
Definition: entity_pass_clip_stack.cc:24
impeller::EntityPassClipStack::GetLastReplayResult
ReplayResult & GetLastReplayResult()
Definition: entity_pass_clip_stack.h:61
impeller::EntityPassClipStack::RecordClip
ClipStateResult RecordClip(const ClipContents &clip_contents, Matrix transform, Point global_pass_position, uint32_t clip_depth, size_t clip_height_floor, bool is_aa)
Definition: entity_pass_clip_stack.cc:100
impeller::EntityPassClipStack::ReplayResult::clip_contents
ClipContents clip_contents
Definition: entity_pass_clip_stack.h:26
impeller::Matrix::MakeTranslation
static constexpr Matrix MakeTranslation(const Vector3 &t)
Definition: matrix.h:95

References impeller::EntityPassClipStack::ReplayResult::clip_contents, impeller::EntityPassClipStack::ClipStateResult::clip_did_change, impeller::EntityPassClipStack::CurrentClipCoverage(), impeller::Geometry::GetCoverage(), GetCurrentTransform(), impeller::EntityPassClipStack::GetLastReplayResult(), impeller::Geometry::GetPositionBuffer(), impeller::Geometry::IsAxisAlignedRect(), impeller::Matrix::MakeTranslation(), impeller::EntityPassClipStack::RecordClip(), impeller::ClipContents::Render(), impeller::Entity::SetClipDepth(), impeller::ClipContents::SetClipOperation(), impeller::ClipContents::SetGeometry(), impeller::Entity::SetTransform(), and impeller::EntityPassClipStack::ClipStateResult::should_render.

Referenced by impeller::DlDispatcherBase::clipOval(), impeller::DlDispatcherBase::clipPath(), impeller::DlDispatcherBase::clipRect(), impeller::DlDispatcherBase::clipRoundRect(), and impeller::DlDispatcherBase::clipRoundSuperellipse().

## ◆ Concat()

void impeller::Canvas::Concat | ( | const Matrix & | transform | ) |

Definition at line 257 of file canvas.cc.

257 {
258 transform_stack_.back().transform = GetCurrentTransform() * transform;
259 }
transform
Matrix transform
Definition: gaussian_blur_filter_contents.cc:214

References GetCurrentTransform(), and transform.

Referenced by DrawTextFrame(), Rotate(), Scale(), Skew(), Transform(), and Translate().

## ◆ DrawArc()

void impeller::Canvas::DrawArc | ( | const Arc & | arc,
|  | const Paint & | paint
| ) |  |

Definition at line 709 of file canvas.cc.

709 {
710 Entity entity;
711 entity.SetTransform(GetCurrentTransform());
712 entity.SetBlendMode(paint.blend_mode);
713
714 if (paint.style == Paint::Style::kFill) {
715 ArcGeometry geom(arc);
716 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
717 return;
718 }
719
720 const Rect& oval_bounds = arc.GetOvalBounds();
721 if (paint.stroke.width > oval_bounds.GetSize().MaxDimension()) {
722 // This is a special case for rendering arcs whose stroke width is so large
723 // you are effectively drawing a sector of a circle.
724 // https://github.com/flutter/flutter/issues/158567
725 Arc expanded_arc(oval_bounds.Expand(Size(paint.stroke.width * 0.5f)),
726 arc.GetStart(), arc.GetSweep(), true);
727
728 ArcGeometry geom(expanded_arc);
729 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
730 return;
731 }
732
733 // IncludeCenter incurs lots of extra work for stroking an arc, including:
734 // - It introduces segments to/from the center point (not too hard).
735 // - It introduces joins on those segments (a bit more complicated).
736 // - Even if the sweep is >=360 degrees, we still draw the segment to
737 // the center and it basically looks like a pie cut into the complete
738 // boundary circle, as if the slice were cut, but not extracted
739 // (hard to express as a continuous kTriangleStrip).
740 if (!arc.IncludeCenter()) {
741 if (arc.IsFullCircle()) {
742 return DrawOval(oval_bounds, paint);
743 }
744
745 // Our fast stroking code only works for circular bounds as it assumes
746 // that the inner and outer radii can be scaled along each angular step
747 // of the arc - which is not true for elliptical arcs where the inner
748 // and outer samples are perpendicular to the traveling direction of the
749 // elliptical curve which may not line up with the center of the bounds.
750 if (oval_bounds.IsSquare()) {
751 ArcGeometry geom(arc, paint.stroke);
752 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
753 return;
754 }
755 }
756
757 ArcStrokeGeometry geom(arc, paint.stroke);
758 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
759 }
impeller::Canvas::DrawOval
void DrawOval(const Rect &rect, const Paint &paint)
Definition: canvas.cc:680
impeller::Rect
TRect< Scalar > Rect
Definition: rect.h:788
impeller::Size
TSize< Scalar > Size
Definition: size.h:159
impeller::Paint::Style::kFill
@ kFill

References impeller::Paint::blend_mode, DrawOval(), impeller::TRect< T >::Expand(), GetCurrentTransform(), impeller::Arc::GetOvalBounds(), impeller::TRect< T >::GetSize(), impeller::Arc::GetStart(), impeller::Arc::GetSweep(), impeller::Arc::IncludeCenter(), impeller::Arc::IsFullCircle(), impeller::TRect< T >::IsSquare(), impeller::Paint::kFill, impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, impeller::Paint::style, and impeller::StrokeParameters::width.

Referenced by impeller::DlDispatcherBase::drawArc().

## ◆ DrawAtlas()

void impeller::Canvas::DrawAtlas | ( | const std::shared_ptr< AtlasContents > & | atlas_contents,
|  | const Paint & | paint
| ) |  |

Definition at line 1151 of file canvas.cc.

1152 {
1153 atlas_contents->SetAlpha(paint.color.alpha);
1154
1155 Entity entity;
1156 entity.SetTransform(GetCurrentTransform());
1157 entity.SetBlendMode(paint.blend_mode);
1158 entity.SetContents(paint.WithFilters(atlas_contents));
1159
1160 AddRenderEntityToCurrentPass(entity);
1161 }

References impeller::Color::alpha, impeller::Paint::blend_mode, impeller::Paint::color, GetCurrentTransform(), impeller::Entity::SetBlendMode(), impeller::Entity::SetContents(), impeller::Entity::SetTransform(), and impeller::Paint::WithFilters().

Referenced by impeller::DlDispatcherBase::drawAtlas().

## ◆ DrawCircle()

void impeller::Canvas::DrawCircle | ( | const Point & | center,
|  | Scalar | radius,
|  | const Paint & | paint
| ) |  |

Definition at line 831 of file canvas.cc.

833 {
834 Size half_size(radius, radius);
835 if (AttemptDrawBlurredRRect(
836 Rect::MakeOriginSize(center - half_size, half_size * 2),
837 {radius, radius}, paint)) {
838 return;
839 }
840
841 if (AttemptDrawAntialiasedCircle(center, radius, paint)) {
842 return;
843 }
844
845 Entity entity;
846 entity.SetTransform(GetCurrentTransform());
847 entity.SetBlendMode(paint.blend_mode);
848
849 if (paint.style == Paint::Style::kStroke) {
850 CircleGeometry geom(center, radius, paint.stroke.width);
851 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
852 } else {
853 CircleGeometry geom(center, radius);
854 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
855 }
856 }
impeller::Paint::Style::kStroke
@ kStroke
impeller::TRect< Scalar >::MakeOriginSize
constexpr static TRect MakeOriginSize(const TPoint< Type > &origin, const TSize< Type > &size)
Definition: rect.h:144

References impeller::Paint::blend_mode, GetCurrentTransform(), impeller::Paint::kStroke, impeller::TRect< Scalar >::MakeOriginSize(), impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, impeller::Paint::style, and impeller::StrokeParameters::width.

Referenced by impeller::DlDispatcherBase::drawCircle(), and DrawOval().

## ◆ DrawDashedLine()

void impeller::Canvas::DrawDashedLine | ( | const Point & | p0,
|  | const Point & | p1,
|  | Scalar | on_length,
|  | Scalar | off_length,
|  | const Paint & | paint
| ) |  |

Definition at line 636 of file canvas.cc.

640 {
641 // Reasons to defer to regular DrawLine:
642 // - performance for degenerate and "regular line" cases
643 // - length is non-positive - DrawLine will draw appropriate "dot"
644 // - off_length is non-positive - no gaps, DrawLine will draw it solid
645 // - on_length is negative - invalid dashing
646 //
647 // Note that a 0 length "on" dash will draw "dot"s every "off" distance
648 // apart so we proceed with the dashing process in that case.
649 Scalar length = p0.GetDistance(p1);
650 if (length > 0.0f && on_length >= 0.0f && off_length > 0.0f) {
651 Entity entity;
652 entity.SetTransform(GetCurrentTransform());
653 entity.SetBlendMode(paint.blend_mode);
654
655 StrokeDashedLineGeometry geom(p0, p1, on_length, off_length, paint.stroke);
656 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
657 } else {
658 DrawLine(p0, p1, paint);
659 }
660 }
impeller::Canvas::DrawLine
void DrawLine(const Point &p0, const Point &p1, const Paint &paint, bool reuse_depth=false)
Definition: canvas.cc:614
impeller::Scalar
float Scalar
Definition: scalar.h:19

References impeller::Paint::blend_mode, DrawLine(), GetCurrentTransform(), impeller::TPoint< T >::GetDistance(), impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), and impeller::Paint::stroke.

Referenced by impeller::DlDispatcherBase::drawDashedLine().

## ◆ DrawDiffRoundRect()

void impeller::Canvas::DrawDiffRoundRect | ( | const RoundRect & | outer,
|  | const RoundRect & | inner,
|  | const Paint & | paint
| ) |  |

Definition at line 793 of file canvas.cc.

795 {
796 Entity entity;
797 entity.SetTransform(GetCurrentTransform());
798 entity.SetBlendMode(paint.blend_mode);
799
800 if (paint.style == Paint::Style::kFill) {
801 FillDiffRoundRectGeometry geom(outer, inner);
802 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
803 } else {
804 StrokeDiffRoundRectGeometry geom(outer, inner, paint.stroke);
805 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
806 }
807 }

References impeller::Paint::blend_mode, GetCurrentTransform(), impeller::Paint::kFill, impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, and impeller::Paint::style.

Referenced by impeller::DlDispatcherBase::drawDiffRoundRect().

## ◆ DrawImage()

void impeller::Canvas::DrawImage | ( | const std::shared_ptr< Texture > & | image,
|  | Point | offset,
|  | const Paint & | paint,
|  | const SamplerDescriptor & | sampler = `{}`
| ) |  |

Definition at line 958 of file canvas.cc.

961 {
962 if (!image) {
963 return;
964 }
965
966 const Rect source = Rect::MakeSize(image->GetSize());
967 const Rect dest = source.Shift(offset);
968
969 DrawImageRect(image, source, dest, paint, sampler);
970 }
impeller::Canvas::DrawImageRect
void DrawImageRect(const std::shared_ptr< Texture > &image, Rect source, Rect dest, const Paint &paint, const SamplerDescriptor &sampler={}, SourceRectConstraint src_rect_constraint=SourceRectConstraint::kFast)
Definition: canvas.cc:972
impeller::TRect::Shift
constexpr TRect< T > Shift(T dx, T dy) const
Returns a new rectangle translated by the given offset.
Definition: rect.h:602

References DrawImageRect(), impeller::TRect< Scalar >::MakeSize(), and impeller::TRect< T >::Shift().

## ◆ DrawImageRect()

void impeller::Canvas::DrawImageRect | ( | const std::shared_ptr< Texture > & | image,
|  | Rect | source,
|  | Rect | dest,
|  | const Paint & | paint,
|  | const SamplerDescriptor & | sampler = `{}`,
|  | SourceRectConstraint | src_rect_constraint = `SourceRectConstraint::kFast`
| ) |  |

Definition at line 972 of file canvas.cc.

977 {
978 if (!image || source.IsEmpty() || dest.IsEmpty()) {
979 return;
980 }
981
982 ISize size = image->GetSize();
983 if (size.IsEmpty()) {
984 return;
985 }
986
987 std::optional<Rect> clipped_source =
988 source.Intersection(Rect::MakeSize(size));
989 if (!clipped_source) {
990 return;
991 }
992
993 if (AttemptColorFilterOptimization(image, source, dest, paint, sampler,
994 src_rect_constraint)) {
995 return;
996 }
997
998 if (*clipped_source != source) {
999 Scalar sx = dest.GetWidth() / source.GetWidth();
1000 Scalar sy = dest.GetHeight() / source.GetHeight();
1001 Scalar tx = dest.GetLeft() - source.GetLeft() * sx;
1002 Scalar ty = dest.GetTop() - source.GetTop() * sy;
1003 Matrix src_to_dest = Matrix::MakeTranslateScale({sx, sy, 1}, {tx, ty, 0});
1004 dest = clipped_source->TransformBounds(src_to_dest);
1005 }
1006
1007 auto texture_contents = TextureContents::MakeRect(dest);
1008 texture_contents->SetTexture(image);
1009 texture_contents->SetSourceRect(*clipped_source);
1010 texture_contents->SetStrictSourceRect(src_rect_constraint ==
1011 SourceRectConstraint::kStrict);
1012 texture_contents->SetSamplerDescriptor(sampler);
1013 texture_contents->SetOpacity(paint.color.alpha);
1014 texture_contents->SetDeferApplyingOpacity(paint.HasColorFilter());
1015
1016 Entity entity;
1017 entity.SetBlendMode(paint.blend_mode);
1018 entity.SetTransform(GetCurrentTransform());
1019
1020 if (!paint.mask_blur_descriptor.has_value()) {
1021 entity.SetContents(paint.WithFilters(std::move(texture_contents)));
1022 AddRenderEntityToCurrentPass(entity);
1023 return;
1024 }
1025
1026 FillRectGeometry out_rect(Rect{});
1027
1028 entity.SetContents(paint.WithFilters(
1029 paint.mask_blur_descriptor->CreateMaskBlur(texture_contents, &out_rect)));
1030 AddRenderEntityToCurrentPass(entity);
1031 }
impeller::TextureContents::MakeRect
static std::shared_ptr< TextureContents > MakeRect(Rect destination)
Definition: texture_contents.cc:28
impeller::SourceRectConstraint::kStrict
@ kStrict
Sample only within the source rectangle. May be slower.
impeller::ISize
ISize64 ISize
Definition: size.h:162
impeller::Matrix::MakeTranslateScale
static constexpr Matrix MakeTranslateScale(const Vector3 &s, const Vector3 &t)
Definition: matrix.h:113

References impeller::Color::alpha, impeller::Paint::blend_mode, impeller::Paint::color, GetCurrentTransform(), impeller::TRect< T >::GetHeight(), impeller::TRect< T >::GetLeft(), impeller::TRect< T >::GetTop(), impeller::TRect< T >::GetWidth(), impeller::Paint::HasColorFilter(), impeller::TRect< T >::Intersection(), impeller::TRect< T >::IsEmpty(), impeller::TSize< T >::IsEmpty(), impeller::kStrict, impeller::TextureContents::MakeRect(), impeller::TRect< Scalar >::MakeSize(), impeller::Matrix::MakeTranslateScale(), impeller::Paint::mask_blur_descriptor, impeller::Entity::SetBlendMode(), impeller::Entity::SetContents(), impeller::Entity::SetTransform(), impeller::TRect< T >::TransformBounds(), and impeller::Paint::WithFilters().

Referenced by DrawImage(), impeller::DlDispatcherBase::drawImageRect(), and impeller::NinePatchConverter::DrawNinePatch().

## ◆ DrawLine()

void impeller::Canvas::DrawLine | ( | const Point & | p0,
|  | const Point & | p1,
|  | const Paint & | paint,
|  | bool | reuse_depth = `false`
| ) |  |

Definition at line 614 of file canvas.cc.

617 {
618 Entity entity;
619 entity.SetTransform(GetCurrentTransform());
620 entity.SetBlendMode(paint.blend_mode);
621
622 auto geometry = std::make_unique<LineGeometry>(p0, p1, paint.stroke);
623
624 if (renderer_.GetContext()->GetFlags().antialiased_lines &&
625 !paint.color_filter && !paint.invert_colors && !paint.image_filter &&
626 !paint.mask_blur_descriptor.has_value() && !paint.color_source) {
627 auto contents = LineContents::Make(std::move(geometry), paint.color);
628 entity.SetContents(std::move(contents));
629 AddRenderEntityToCurrentPass(entity, reuse_depth);
630 } else {
631 AddRenderEntityWithFiltersToCurrentPass(entity, geometry.get(), paint,
632 /*reuse_depth=*/reuse_depth);
633 }
634 }
impeller::ContentContext::GetContext
std::shared_ptr< Context > GetContext() const
Definition: content_context.cc:962
impeller::LineContents::Make
static std::unique_ptr< LineContents > Make(std::unique_ptr< LineGeometry > geometry, Color color)
Definition: line_contents.cc:137

References impeller::Paint::blend_mode, impeller::Paint::color, impeller::Paint::color_filter, impeller::Paint::color_source, impeller::ContentContext::GetContext(), GetCurrentTransform(), impeller::Paint::image_filter, impeller::Paint::invert_colors, impeller::LineContents::Make(), impeller::Paint::mask_blur_descriptor, impeller::Entity::SetBlendMode(), impeller::Entity::SetContents(), impeller::Entity::SetTransform(), and impeller::Paint::stroke.

Referenced by DrawDashedLine(), impeller::DlDispatcherBase::drawLine(), impeller::DlDispatcherBase::drawPoints(), and impeller::DlDispatcherBase::SimplifyOrDrawPath().

## ◆ DrawOval()

void impeller::Canvas::DrawOval | ( | const Rect & | rect,
|  | const Paint & | paint
| ) |  |

Definition at line 680 of file canvas.cc.

680 {
681 // TODO(jonahwilliams): This additional condition avoids an assert in the
682 // stroke circle geometry generator. I need to verify the condition that this
683 // assert prevents.
684 if (rect.IsSquare() && (paint.style == Paint::Style::kFill ||
685 (paint.style == Paint::Style::kStroke &&
686 paint.stroke.width < rect.GetWidth()))) {
687 // Circles have slightly less overhead and can do stroking
688 DrawCircle(rect.GetCenter(), rect.GetWidth() * 0.5f, paint);
689 return;
690 }
691
692 if (AttemptDrawBlurredRRect(rect, rect.GetSize() * 0.5f, paint)) {
693 return;
694 }
695
696 Entity entity;
697 entity.SetTransform(GetCurrentTransform());
698 entity.SetBlendMode(paint.blend_mode);
699
700 if (paint.style == Paint::Style::kStroke) {
701 StrokeEllipseGeometry geom(rect, paint.stroke);
702 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
703 } else {
704 EllipseGeometry geom(rect);
705 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
706 }
707 }
impeller::Canvas::DrawCircle
void DrawCircle(const Point &center, Scalar radius, const Paint &paint)
Definition: canvas.cc:831

References impeller::Paint::blend_mode, DrawCircle(), impeller::TRect< T >::GetCenter(), GetCurrentTransform(), impeller::TRect< T >::GetSize(), impeller::TRect< T >::GetWidth(), impeller::TRect< T >::IsSquare(), impeller::Paint::kFill, impeller::Paint::kStroke, impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, impeller::Paint::style, and impeller::StrokeParameters::width.

Referenced by DrawArc(), impeller::DlDispatcherBase::drawOval(), and impeller::DlDispatcherBase::SimplifyOrDrawPath().

## ◆ DrawPaint()

void impeller::Canvas::DrawPaint | ( | const Paint & | paint | ) |

Definition at line 342 of file canvas.cc.

342 {
343 Entity entity;
344 entity.SetTransform(GetCurrentTransform());
345 entity.SetBlendMode(paint.blend_mode);
346
347 CoverGeometry geom;
348 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
349 }

References impeller::Paint::blend_mode, GetCurrentTransform(), impeller::Entity::SetBlendMode(), and impeller::Entity::SetTransform().

Referenced by impeller::DlDispatcherBase::drawColor(), and impeller::DlDispatcherBase::drawPaint().

## ◆ DrawPath()

void impeller::Canvas::DrawPath | ( | const flutter::DlPath & | path,
|  | const Paint & | paint
| ) |  |

Definition at line 328 of file canvas.cc.

328 {
329 Entity entity;
330 entity.SetTransform(GetCurrentTransform());
331 entity.SetBlendMode(paint.blend_mode);
332
333 if (paint.style == Paint::Style::kFill) {
334 FillPathGeometry geom(path);
335 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
336 } else {
337 StrokePathGeometry geom(path, paint.stroke);
338 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
339 }
340 }

References impeller::Paint::blend_mode, GetCurrentTransform(), impeller::Paint::kFill, impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, and impeller::Paint::style.

Referenced by DrawTextFrame(), and impeller::DlDispatcherBase::SimplifyOrDrawPath().

## ◆ DrawPoints()

void impeller::Canvas::DrawPoints | ( | const Point | points[],
|  | uint32_t | count,
|  | Scalar | radius,
|  | const Paint & | paint,
|  | PointStyle | point_style
| ) |  |

Definition at line 940 of file canvas.cc.

944 {
945 if (radius <= 0) {
946 return;
947 }
948
949 Entity entity;
950 entity.SetTransform(GetCurrentTransform());
951 entity.SetBlendMode(paint.blend_mode);
952
953 PointFieldGeometry geom(points, count, radius,
954 /*round=*/point_style == PointStyle::kRound);
955 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
956 }
impeller::PointStyle::kRound
@ kRound
Points are drawn as squares.
points
std::vector< Point > points
Definition: tessellator_libtess.cc:76

References impeller::Paint::blend_mode, GetCurrentTransform(), impeller::kRound, points, impeller::Entity::SetBlendMode(), and impeller::Entity::SetTransform().

Referenced by impeller::DlDispatcherBase::drawPoints().

## ◆ DrawRect()

void impeller::Canvas::DrawRect | ( | const Rect & | rect,
|  | const Paint & | paint
| ) |  |

Definition at line 662 of file canvas.cc.

662 {
663 if (AttemptDrawBlurredRRect(rect, {}, paint)) {
664 return;
665 }
666
667 Entity entity;
668 entity.SetTransform(GetCurrentTransform());
669 entity.SetBlendMode(paint.blend_mode);
670
671 if (paint.style == Paint::Style::kStroke) {
672 StrokeRectGeometry geom(rect, paint.stroke);
673 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
674 } else {
675 FillRectGeometry geom(rect);
676 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
677 }
678 }

References impeller::Paint::blend_mode, GetCurrentTransform(), impeller::Paint::kStroke, impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, and impeller::Paint::style.

Referenced by impeller::DlDispatcherBase::drawRect(), and impeller::DlDispatcherBase::SimplifyOrDrawPath().

## ◆ DrawRoundRect()

void impeller::Canvas::DrawRoundRect | ( | const RoundRect & | rect,
|  | const Paint & | paint
| ) |  |

Definition at line 761 of file canvas.cc.

761 {
762 auto& rect = round_rect.GetBounds();
763 auto& radii = round_rect.GetRadii();
764 if (radii.AreAllCornersSame()) {
765 if (AttemptDrawBlurredRRect(rect, radii.top_left, paint)) {
766 return;
767 }
768
769 if (paint.style == Paint::Style::kFill) {
770 Entity entity;
771 entity.SetTransform(GetCurrentTransform());
772 entity.SetBlendMode(paint.blend_mode);
773
774 RoundRectGeometry geom(rect, radii.top_left);
775 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
776 return;
777 }
778 }
779
780 Entity entity;
781 entity.SetTransform(GetCurrentTransform());
782 entity.SetBlendMode(paint.blend_mode);
783
784 if (paint.style == Paint::Style::kFill) {
785 FillRoundRectGeometry geom(round_rect);
786 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
787 } else {
788 StrokeRoundRectGeometry geom(round_rect, paint.stroke);
789 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
790 }
791 }

References impeller::Paint::blend_mode, impeller::RoundRect::GetBounds(), GetCurrentTransform(), impeller::RoundRect::GetRadii(), impeller::Paint::kFill, impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, and impeller::Paint::style.

Referenced by impeller::DlDispatcherBase::drawRoundRect(), and impeller::DlDispatcherBase::SimplifyOrDrawPath().

## ◆ DrawRoundSuperellipse()

void impeller::Canvas::DrawRoundSuperellipse | ( | const RoundSuperellipse & | rse,
|  | const Paint & | paint
| ) |  |

Definition at line 809 of file canvas.cc.

810 {
811 auto& rect = round_superellipse.GetBounds();
812 auto& radii = round_superellipse.GetRadii();
813 if (radii.AreAllCornersSame() &&
814 AttemptDrawBlurredRSuperellipse(rect, radii.top_left, paint)) {
815 return;
816 }
817
818 Entity entity;
819 entity.SetTransform(GetCurrentTransform());
820 entity.SetBlendMode(paint.blend_mode);
821
822 if (paint.style == Paint::Style::kFill) {
823 RoundSuperellipseGeometry geom(rect, radii);
824 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
825 } else {
826 StrokeRoundSuperellipseGeometry geom(round_superellipse, paint.stroke);
827 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
828 }
829 }

References impeller::Paint::blend_mode, impeller::RoundSuperellipse::GetBounds(), GetCurrentTransform(), impeller::RoundSuperellipse::GetRadii(), impeller::Paint::kFill, impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, and impeller::Paint::style.

Referenced by impeller::DlDispatcherBase::drawRoundSuperellipse(), and impeller::testing::TEST_P().

## ◆ DrawTextFrame()

void impeller::Canvas::DrawTextFrame | ( | const std::shared_ptr< TextFrame > & | text_frame,
|  | Point | position,
|  | const Paint & | paint
| ) |  |

Definition at line 1703 of file canvas.cc.

1705 {
1706 Scalar max_scale = GetCurrentTransform().GetMaxBasisLengthXY();
1707 if (max_scale * text_frame->GetFont().GetMetrics().point_size >
1708 kMaxTextScale) {
1709 fml::StatusOr<flutter::DlPath> path = text_frame->GetPath();
1710 if (path.ok()) {
1711 Save(1);
1712 Concat(Matrix::MakeTranslation(position));
1713 DrawPath(path.value(), paint);
1714 Restore();
1715 return;
1716 }
1717 }
1718
1719 Entity entity;
1720 entity.SetClipDepth(GetClipHeight());
1721 entity.SetBlendMode(paint.blend_mode);
1722
1723 auto text_contents = std::make_shared<TextContents>();
1724 text_contents->SetTextFrame(text_frame);
1725 text_contents->SetForceTextColor(paint.mask_blur_descriptor.has_value());
1726 text_contents->SetScale(max_scale);
1727 text_contents->SetColor(paint.color);
1728 text_contents->SetOffset(position);
1729 text_contents->SetTextProperties(paint.color,
1730 paint.style == Paint::Style::kStroke
1731 ? std::optional(paint.stroke)
1732 : std::nullopt);
1733
1734 entity.SetTransform(GetCurrentTransform() *
1735 Matrix::MakeTranslation(position));
1736
1737 if (AttemptBlurredTextOptimization(text_frame, text_contents, entity,
1738 paint)) {
1739 return;
1740 }
1741
1742 entity.SetContents(paint.WithFilters(std::move(text_contents)));
1743 AddRenderEntityToCurrentPass(entity, false);
1744 }
impeller::Canvas::Restore
bool Restore()
Definition: canvas.cc:1511
impeller::Canvas::Concat
void Concat(const Matrix &transform)
Definition: canvas.cc:257
impeller::Canvas::DrawPath
void DrawPath(const flutter::DlPath &path, const Paint &paint)
Definition: canvas.cc:328
impeller::Canvas::Save
void Save(uint32_t total_content_depth=kMaxDepth)
Definition: canvas.cc:1219
impeller::kMaxTextScale
static constexpr Scalar kMaxTextScale
Definition: canvas.cc:1701
impeller::Matrix::GetMaxBasisLengthXY
Scalar GetMaxBasisLengthXY() const
Return the maximum scale applied specifically to either the X axis or Y axis unit vectors (the bases)...
Definition: matrix.h:328

References impeller::Paint::blend_mode, impeller::Paint::color, Concat(), DrawPath(), GetCurrentTransform(), impeller::Matrix::GetMaxBasisLengthXY(), impeller::kMaxTextScale, impeller::Paint::kStroke, impeller::Matrix::MakeTranslation(), impeller::Paint::mask_blur_descriptor, Restore(), Save(), impeller::Entity::SetBlendMode(), impeller::Entity::SetClipDepth(), impeller::Entity::SetContents(), impeller::Entity::SetTransform(), impeller::Paint::stroke, impeller::Paint::style, and impeller::Paint::WithFilters().

Referenced by impeller::DlDispatcherBase::drawText().

## ◆ DrawVertices()

void impeller::Canvas::DrawVertices | ( | const std::shared_ptr< VerticesGeometry > & | vertices,
|  | BlendMode | blend_mode,
|  | const Paint & | paint
| ) |  |

Definition at line 1037 of file canvas.cc.

1039 {
1040 // Override the blend mode with kDestination in order to match the behavior
1041 // of Skia's SK_LEGACY_IGNORE_DRAW_VERTICES_BLEND_WITH_NO_SHADER flag, which
1042 // is enabled when the Flutter engine builds Skia.
1043 if (!paint.color_source) {
1044 blend_mode = BlendMode::kDst;
1045 }
1046
1047 Entity entity;
1048 entity.SetTransform(GetCurrentTransform());
1049 entity.SetBlendMode(paint.blend_mode);
1050
1051 // If there are no vertex colors.
1052 if (UseColorSourceContents(vertices, paint)) {
1053 AddRenderEntityWithFiltersToCurrentPass(entity, vertices.get(), paint);
1054 return;
1055 }
1056
1057 // If the blend mode is destination don't bother to bind or create a texture.
1058 if (blend_mode == BlendMode::kDst) {
1059 auto contents = std::make_shared<VerticesSimpleBlendContents>();
1060 contents->SetBlendMode(blend_mode);
1061 contents->SetAlpha(paint.color.alpha);
1062 contents->SetGeometry(vertices);
1063 entity.SetContents(paint.WithFilters(std::move(contents)));
1064 AddRenderEntityToCurrentPass(entity);
1065 return;
1066 }
1067
1068 // If there is a texture, use this directly. Otherwise render the color
1069 // source to a texture.
1070 if (paint.color_source &&
1071 paint.color_source->type() == flutter::DlColorSourceType::kImage) {
1072 const flutter::DlImageColorSource* image_color_source =
1073 paint.color_source->asImage();
1074 FML_DCHECK(image_color_source &&
1075 image_color_source->image()->impeller_texture());
1076 auto texture = image_color_source->image()->impeller_texture();
1077 auto x_tile_mode = static_cast<Entity::TileMode>(
1078 image_color_source->horizontal_tile_mode());
1079 auto y_tile_mode =
1080 static_cast<Entity::TileMode>(image_color_source->vertical_tile_mode());
1081 auto sampler_descriptor =
1082 skia_conversions::ToSamplerDescriptor(image_color_source->sampling());
1083 auto effect_transform = image_color_source->matrix();
1084
1085 auto contents = std::make_shared<VerticesSimpleBlendContents>();
1086 contents->SetBlendMode(blend_mode);
1087 contents->SetAlpha(paint.color.alpha);
1088 contents->SetGeometry(vertices);
1089 contents->SetEffectTransform(effect_transform);
1090 contents->SetTexture(texture);
1091 contents->SetTileMode(x_tile_mode, y_tile_mode);
1092 contents->SetSamplerDescriptor(sampler_descriptor);
1093
1094 entity.SetContents(paint.WithFilters(std::move(contents)));
1095 AddRenderEntityToCurrentPass(entity);
1096 return;
1097 }
1098
1099 auto src_paint = paint;
1100 src_paint.color = paint.color.WithAlpha(1.0);
1101
1102 std::shared_ptr<ColorSourceContents> src_contents =
1103 src_paint.CreateContents();
1104 src_contents->SetGeometry(vertices.get());
1105
1106 // If the color source has an intrinsic size, then we use that to
1107 // create the src contents as a simplification. Otherwise we use
1108 // the extent of the texture coordinates to determine how large
1109 // the src contents should be. If neither has a value we fall back
1110 // to using the geometry coverage data.
1111 Rect src_coverage;
1112 auto size = src_contents->GetColorSourceSize();
1113 if (size.has_value()) {
1114 src_coverage = Rect::MakeXYWH(0, 0, size->width, size->height);
1115 } else {
1116 auto cvg = vertices->GetCoverage(Matrix{});
1117 FML_CHECK(cvg.has_value());
1118 auto texture_coverage = vertices->GetTextureCoordinateCoverage();
1119 if (texture_coverage.has_value()) {
1120 src_coverage =
1121 Rect::MakeOriginSize(texture_coverage->GetOrigin(),
1122 texture_coverage->GetSize().Max({1, 1}));
1123 } else {
1124 // NOLINTNEXTLINE(bugprone-unchecked-optional-access)
1125 src_coverage = cvg.value();
1126 }
1127 }
1128 src_contents = src_paint.CreateContents();
1129
1130 clip_geometry_.push_back(Geometry::MakeRect(Rect::Round(src_coverage)));
1131 src_contents->SetGeometry(clip_geometry_.back().get());
1132
1133 auto contents = std::make_shared<VerticesSimpleBlendContents>();
1134 contents->SetBlendMode(blend_mode);
1135 contents->SetAlpha(paint.color.alpha);
1136 contents->SetGeometry(vertices);
1137 contents->SetLazyTextureCoverage(src_coverage);
1138 contents->SetLazyTexture(
1139 [src_contents, src_coverage](const ContentContext& renderer) {
1140 // Applying the src coverage as the coverage limit prevents the 1px
1141 // coverage pad from adding a border that is picked up by developer
1142 // specified UVs.
1143 auto snapshot = src_contents->RenderToSnapshot(
1144 renderer, {}, {.coverage_limit = Rect::Round(src_coverage)});
1145 return snapshot.has_value() ? snapshot->texture : nullptr;
1146 });
1147 entity.SetContents(paint.WithFilters(std::move(contents)));
1148 AddRenderEntityToCurrentPass(entity);
1149 }
impeller::Entity::TileMode
TileMode
Definition: entity.h:48
impeller::Geometry::MakeRect
static std::unique_ptr< Geometry > MakeRect(const Rect &rect)
Definition: geometry.cc:83
impeller::skia_conversions::ToSamplerDescriptor
impeller::SamplerDescriptor ToSamplerDescriptor(const flutter::DlImageSampling options)
Definition: skia_conversions.cc:24
impeller::BlendMode::kDst
@ kDst
impeller::TRect< Scalar >::Round
Round(const TRect< U > &r)
Definition: rect.h:695
impeller::TRect< Scalar >::MakeXYWH
constexpr static TRect MakeXYWH(Type x, Type y, Type width, Type height)
Definition: rect.h:136

References impeller::Color::alpha, impeller::Paint::blend_mode, impeller::Paint::color, impeller::Paint::color_source, GetCurrentTransform(), impeller::kDst, impeller::TRect< Scalar >::MakeOriginSize(), impeller::Geometry::MakeRect(), impeller::TRect< Scalar >::MakeXYWH(), impeller::TRect< Scalar >::Round(), impeller::Entity::SetBlendMode(), impeller::Entity::SetContents(), impeller::Entity::SetTransform(), impeller::skia_conversions::ToSamplerDescriptor(), impeller::Color::WithAlpha(), and impeller::Paint::WithFilters().

Referenced by impeller::CanvasDlDispatcher::drawVertices(), and impeller::testing::TEST_P().

## ◆ EndReplay()

void impeller::Canvas::EndReplay | ( |  | ) |

Definition at line 2125 of file canvas.cc.

2125 {
2126 FML_DCHECK(render_passes_.size() == 1u);
2127 render_passes_.back().GetInlinePassContext()->GetRenderPass();
2128 render_passes_.back().GetInlinePassContext()->EndPass(
2129 /*is_onscreen=*/!requires_readback_ && is_onscreen_);
2130 backdrop_data_.clear();
2131
2132 // If requires_readback_ was true, then we rendered to an offscreen texture
2133 // instead of to the onscreen provided in the render target. Now we need to
2134 // draw or blit the offscreen back to the onscreen.
2135 if (requires_readback_) {
2136 BlitToOnscreen(/*is_onscreen_=*/is_onscreen_);
2137 }
2138 if (!EnsureFinalMipmapGeneration()) {
2139 VALIDATION_LOG << "Failed to generate onscreen mipmaps.";
2140 }
2141 if (!renderer_.GetContext()->FlushCommandBuffers()) {
2142 // Not much we can do.
2143 VALIDATION_LOG << "Failed to submit command buffers";
2144 }
2145 render_passes_.clear();
2146 renderer_.GetRenderTargetCache()->End();
2147 clip_geometry_.clear();
2148
2149 Reset();
2150 Initialize(initial_cull_rect_);
2151 }
impeller::Canvas::EnsureFinalMipmapGeneration
bool EnsureFinalMipmapGeneration() const
Definition: canvas.cc:2107
impeller::ContentContext::GetRenderTargetCache
const std::shared_ptr< RenderTargetAllocator > & GetRenderTargetCache() const
Definition: content_context.h:270
VALIDATION_LOG
#define VALIDATION_LOG
Definition: validation.h:91

References VALIDATION_LOG.

Referenced by impeller::CanvasDlDispatcher::FinishRecording(), and impeller::testing::TEST_P().

## ◆ EnsureFinalMipmapGeneration()

bool impeller::Canvas::EnsureFinalMipmapGeneration | ( |  | ) | const

For picture snapshots we need addition steps to verify that final mipmaps are generated.

Definition at line 2107 of file canvas.cc.

2107 {
2108 if (!render_target_.GetRenderTargetTexture()->NeedsMipmapGeneration()) {
2109 return true;
2110 }
2111 std::shared_ptr<CommandBuffer> cmd_buffer =
2112 renderer_.GetContext()->CreateCommandBuffer();
2113 if (!cmd_buffer) {
2114 return false;
2115 }
2116 std::shared_ptr<BlitPass> blit_pass = cmd_buffer->CreateBlitPass();
2117 if (!blit_pass) {
2118 return false;
2119 }
2120 blit_pass->GenerateMipmap(render_target_.GetRenderTargetTexture());
2121 blit_pass->EncodeCommands();
2122 return renderer_.GetContext()->EnqueueCommandBuffer(std::move(cmd_buffer));
2123 }
impeller::RenderTarget::GetRenderTargetTexture
std::shared_ptr< Texture > GetRenderTargetTexture() const
Definition: render_target.cc:176

## ◆ GetCurrentTransform()

const Matrix & impeller::Canvas::GetCurrentTransform | ( |  | ) | const

Definition at line 273 of file canvas.cc.

273 {
274 return transform_stack_.back().transform;
275 }

Referenced by ClipGeometry(), Concat(), DrawArc(), DrawAtlas(), DrawCircle(), DrawDashedLine(), DrawDiffRoundRect(), impeller::DlDispatcherBase::drawDisplayList(), DrawImageRect(), DrawLine(), DrawOval(), DrawPaint(), DrawPath(), DrawPoints(), DrawRect(), DrawRoundRect(), DrawRoundSuperellipse(), impeller::DlDispatcherBase::drawShadow(), DrawTextFrame(), DrawVertices(), and PreConcat().

## ◆ GetLocalCoverageLimit()

std::optional< Rect > impeller::Canvas::GetLocalCoverageLimit | ( |  | ) | const

Return the culling bounds of the current render target, or nullopt if there is no coverage.

Definition at line 1236 of file canvas.cc.

1236 {
1237 if (!clip_coverage_stack_.HasCoverage()) {
1238 // The current clip is empty. This means the pass texture won't be
1239 // visible, so skip it.
1240 return std::nullopt;
1241 }
1242
1243 std::optional<Rect> maybe_current_clip_coverage =
1244 clip_coverage_stack_.CurrentClipCoverage();
1245 if (!maybe_current_clip_coverage.has_value()) {
1246 return std::nullopt;
1247 }
1248
1249 Rect current_clip_coverage = maybe_current_clip_coverage.value();
1250
1251 FML_CHECK(!render_passes_.empty());
1252 const LazyRenderingConfig& back_render_pass = render_passes_.back();
1253 std::shared_ptr<Texture> back_texture =
1254 back_render_pass.GetInlinePassContext()->GetTexture();
1255 FML_CHECK(back_texture) << "Context is valid:"
1256 << back_render_pass.GetInlinePassContext()->IsValid();
1257
1258 // The maximum coverage of the subpass. Subpasses textures should never
1259 // extend outside the parent pass texture or the current clip coverage.
1260 std::optional<Rect> maybe_coverage_limit =
1261 Rect::MakeOriginSize(GetGlobalPassPosition(),
1262 Size(back_texture->GetSize()))
1263 .Intersection(current_clip_coverage);
1264
1265 if (!maybe_coverage_limit.has_value() || maybe_coverage_limit->IsEmpty()) {
1266 return std::nullopt;
1267 }
1268
1269 return maybe_coverage_limit->Intersection(
1270 Rect::MakeSize(render_target_.GetRenderTargetSize()));
1271 }
impeller::EntityPassClipStack::HasCoverage
bool HasCoverage() const
Definition: entity_pass_clip_stack.cc:28
impeller::RenderTarget::GetRenderTargetSize
ISize GetRenderTargetSize() const
Definition: render_target.cc:171
impeller::TRect::Intersection
constexpr std::optional< TRect > Intersection(const TRect &o) const
Definition: rect.h:528

References impeller::EntityPassClipStack::CurrentClipCoverage(), impeller::LazyRenderingConfig::GetInlinePassContext(), impeller::RenderTarget::GetRenderTargetSize(), impeller::InlinePassContext::GetTexture(), impeller::EntityPassClipStack::HasCoverage(), impeller::TRect< T >::Intersection(), impeller::InlinePassContext::IsValid(), impeller::TRect< Scalar >::MakeOriginSize(), and impeller::TRect< Scalar >::MakeSize().

Referenced by impeller::DlDispatcherBase::drawDisplayList(), and SaveLayer().

## ◆ GetMaxOpDepth()

uint64_t impeller::Canvas::GetMaxOpDepth | ( |  | ) | const
| inline

Definition at line 261 of file canvas.h.

261 { return transform_stack_.back().clip_depth; }

Referenced by impeller::CanvasDlDispatcher::saveLayer().

## ◆ GetOpDepth()

uint64_t impeller::Canvas::GetOpDepth | ( |  | ) | const
| inline

Definition at line 259 of file canvas.h.

259 { return current_depth_; }

Referenced by impeller::CanvasDlDispatcher::saveLayer().

## ◆ GetSaveCount()

size_t impeller::Canvas::GetSaveCount | ( |  | ) | const

Definition at line 312 of file canvas.cc.

312 {
313 return transform_stack_.size();
314 }

Referenced by impeller::DlDispatcherBase::drawDisplayList(), and RestoreToCount().

## ◆ PreConcat()

void impeller::Canvas::PreConcat | ( | const Matrix & | transform | ) |

Definition at line 261 of file canvas.cc.

261 {
262 transform_stack_.back().transform = transform * GetCurrentTransform();
263 }

References GetCurrentTransform(), and transform.

Referenced by impeller::DlDispatcherBase::drawShadow().

## ◆ RequiresReadback()

bool impeller::Canvas::RequiresReadback | ( |  | ) | const
| inline

Definition at line 269 of file canvas.h.

269 { return requires_readback_; }

## ◆ ResetTransform()

void impeller::Canvas::ResetTransform | ( |  | ) |

Definition at line 265 of file canvas.cc.

265 {
266 transform_stack_.back().transform = {};
267 }

Referenced by impeller::DlDispatcherBase::transformReset().

## ◆ Restore()

bool impeller::Canvas::Restore | ( |  | ) |

Definition at line 1511 of file canvas.cc.

1511 {
1512 FML_DCHECK(transform_stack_.size() > 0);
1513 if (transform_stack_.size() == 1) {
1514 return false;
1515 }
1516
1517 // This check is important to make sure we didn't exceed the depth
1518 // that the clips were rendered at while rendering any of the
1519 // rendering ops. It is OK for the current depth to equal the
1520 // outgoing clip depth because that means the clipping would have
1521 // been successful up through the last rendering op, but it cannot
1522 // be greater.
1523 // Also, we bump the current rendering depth to the outgoing clip
1524 // depth so that future rendering operations are not clipped by
1525 // any of the pixels set by the expiring clips. It is OK for the
1526 // estimates used to determine the clip depth in save/saveLayer
1527 // to be overly conservative, but we need to jump the depth to
1528 // the clip depth so that the next rendering op will get a
1529 // larger depth (it will pre-increment the current_depth_ value).
1530 FML_DCHECK(current_depth_ <= transform_stack_.back().clip_depth)
1531 << current_depth_ << " <=? " << transform_stack_.back().clip_depth;
1532 current_depth_ = transform_stack_.back().clip_depth;
1533
1534 if (IsSkipping()) {
1535 transform_stack_.pop_back();
1536 return true;
1537 }
1538
1539 if (transform_stack_.back().rendering_mode ==
1540 Entity::RenderingMode::kSubpassAppendSnapshotTransform ||
1541 transform_stack_.back().rendering_mode ==
1542 Entity::RenderingMode::kSubpassPrependSnapshotTransform) {
1543 auto lazy_render_pass = std::move(render_passes_.back());
1544 render_passes_.pop_back();
1545 // Force the render pass to be constructed if it never was.
1546 lazy_render_pass.GetInlinePassContext()->GetRenderPass();
1547
1548 SaveLayerState save_layer_state = save_layer_state_.back();
1549 save_layer_state_.pop_back();
1550 auto global_pass_position = GetGlobalPassPosition();
1551
1552 std::shared_ptr<Contents> contents = CreateContentsForSubpassTarget(
1553 save_layer_state.paint, //
1554 lazy_render_pass.GetInlinePassContext()->GetTexture(), //
1555 Matrix::MakeTranslation(Vector3{-global_pass_position}) * //
1556 transform_stack_.back().transform //
1557 );
1558
1559 lazy_render_pass.GetInlinePassContext()->EndPass();
1560
1561 // Round the subpass texture position for pixel alignment with the parent
1562 // pass render target. By default, we draw subpass textures with nearest
1563 // sampling, so aligning here is important for avoiding visual nearest
1564 // sampling errors caused by limited floating point precision when
1565 // straddling a half pixel boundary.
1566 Point subpass_texture_position;
1567 if (transform_stack_.back().did_round_out) {
1568 // Subpass coverage was rounded out, origin potentially moved "down" by
1569 // as much as a pixel.
1570 subpass_texture_position =
1571 (save_layer_state.coverage.GetOrigin() - global_pass_position)
1572 .Floor();
1573 } else {
1574 // Subpass coverage was truncated. Pick the closest phyiscal pixel.
1575 subpass_texture_position =
1576 (save_layer_state.coverage.GetOrigin() - global_pass_position)
1577 .Round();
1578 }
1579
1580 Entity element_entity;
1581 element_entity.SetClipDepth(++current_depth_);
1582 element_entity.SetContents(std::move(contents));
1583 element_entity.SetBlendMode(save_layer_state.paint.blend_mode);
1584 element_entity.SetTransform(
1585 Matrix::MakeTranslation(Vector3(subpass_texture_position)));
1586
1587 if (element_entity.GetBlendMode() > Entity::kLastPipelineBlendMode) {
1588 if (renderer_.GetDeviceCapabilities().SupportsFramebufferFetch()) {
1589 ApplyFramebufferBlend(element_entity);
1590 } else {
1591 // End the active pass and flush the buffer before rendering "advanced"
1592 // blends. Advanced blends work by binding the current render target
1593 // texture as an input ("destination"), blending with a second texture
1594 // input ("source"), writing the result to an intermediate texture, and
1595 // finally copying the data from the intermediate texture back to the
1596 // render target texture. And so all of the commands that have written
1597 // to the render target texture so far need to execute before it's bound
1598 // for blending (otherwise the blend pass will end up executing before
1599 // all the previous commands in the active pass).
1600 auto input_texture = FlipBackdrop(GetGlobalPassPosition());
1601 if (!input_texture) {
1602 return false;
1603 }
1604
1605 FilterInput::Vector inputs = {
1606 FilterInput::Make(input_texture,
1607 element_entity.GetTransform().Invert()),
1608 FilterInput::Make(element_entity.GetContents())};
1609 auto contents = ColorFilterContents::MakeBlend(
1610 element_entity.GetBlendMode(), inputs);
1611 contents->SetCoverageHint(element_entity.GetCoverage());
1612 element_entity.SetContents(std::move(contents));
1613 element_entity.SetBlendMode(BlendMode::kSrc);
1614 }
1615 }
1616
1617 element_entity.Render(
1618 renderer_, //
1619 *render_passes_.back().GetInlinePassContext()->GetRenderPass() //
1620 );
1621 clip_coverage_stack_.PopSubpass();
1622 transform_stack_.pop_back();
1623
1624 // We don't need to restore clips if a saveLayer was performed, as the clip
1625 // state is per render target, and no more rendering operations will be
1626 // performed as the render target workloaded is completed in the restore.
1627 return true;
1628 }
1629
1630 size_t num_clips = transform_stack_.back().num_clips;
1631 transform_stack_.pop_back();
1632
1633 if (num_clips > 0) {
1634 EntityPassClipStack::ClipStateResult clip_state_result =
1635 clip_coverage_stack_.RecordRestore(GetGlobalPassPosition(),
1636 GetClipHeight());
1637
1638 // Clip restores are never required with depth based clipping.
1639 FML_DCHECK(!clip_state_result.should_render);
1640 if (clip_state_result.clip_did_change) {
1641 // We only need to update the pass scissor if the clip state has changed.
1642 SetClipScissor(
1643 clip_coverage_stack_.CurrentClipCoverage(), //
1644 *render_passes_.back().GetInlinePassContext()->GetRenderPass(), //
1645 GetGlobalPassPosition() //
1646 );
1647 }
1648 }
1649
1650 return true;
1651 }
impeller::Capabilities::SupportsFramebufferFetch
virtual bool SupportsFramebufferFetch() const =0
Whether the context backend is able to support pipelines with shaders that read from the framebuffer ...
impeller::ColorFilterContents::MakeBlend
static std::shared_ptr< ColorFilterContents > MakeBlend(BlendMode blend_mode, FilterInput::Vector inputs, std::optional< Color > foreground_color=std::nullopt)
the [inputs] are expected to be in the order of dst, src.
Definition: color_filter_contents.cc:17
impeller::ContentContext::GetDeviceCapabilities
const Capabilities & GetDeviceCapabilities() const
Definition: content_context.cc:966
impeller::Entity::RenderingMode::kSubpassPrependSnapshotTransform
@ kSubpassPrependSnapshotTransform
impeller::Entity::RenderingMode::kSubpassAppendSnapshotTransform
@ kSubpassAppendSnapshotTransform
impeller::Entity::kLastPipelineBlendMode
static constexpr BlendMode kLastPipelineBlendMode
Definition: entity.h:28
impeller::EntityPassClipStack::RecordRestore
ClipStateResult RecordRestore(Point global_pass_position, size_t restore_height)
Definition: entity_pass_clip_stack.cc:54
impeller::EntityPassClipStack::PopSubpass
void PopSubpass()
Definition: entity_pass_clip_stack.cc:44
impeller::FilterInput::Make
static FilterInput::Ref Make(Variant input, bool msaa_enabled=true)
Definition: filter_input.cc:19
impeller::FilterInput::Vector
std::vector< FilterInput::Ref > Vector
Definition: filter_input.h:33
impeller::Point
TPoint< Scalar > Point
Definition: point.h:327
impeller::BlendMode::kSrc
@ kSrc

References impeller::Paint::blend_mode, impeller::EntityPassClipStack::ClipStateResult::clip_did_change, impeller::Canvas::SaveLayerState::coverage, impeller::EntityPassClipStack::CurrentClipCoverage(), impeller::Entity::GetBlendMode(), impeller::Entity::GetContents(), impeller::Entity::GetCoverage(), impeller::ContentContext::GetDeviceCapabilities(), impeller::TRect< T >::GetOrigin(), impeller::Entity::GetTransform(), impeller::Matrix::Invert(), impeller::Entity::kLastPipelineBlendMode, impeller::kSrc, impeller::Entity::kSubpassAppendSnapshotTransform, impeller::Entity::kSubpassPrependSnapshotTransform, impeller::FilterInput::Make(), impeller::ColorFilterContents::MakeBlend(), impeller::Matrix::MakeTranslation(), impeller::Canvas::SaveLayerState::paint, impeller::EntityPassClipStack::PopSubpass(), impeller::EntityPassClipStack::RecordRestore(), impeller::Entity::Render(), impeller::Entity::SetBlendMode(), impeller::Entity::SetClipDepth(), impeller::Entity::SetContents(), impeller::Entity::SetTransform(), impeller::EntityPassClipStack::ClipStateResult::should_render, and impeller::Capabilities::SupportsFramebufferFetch().

Referenced by impeller::DlDispatcherBase::drawShadow(), DrawTextFrame(), impeller::DlDispatcherBase::restore(), and RestoreToCount().

## ◆ RestoreToCount()

void impeller::Canvas::RestoreToCount | ( | size_t | count | ) |

Definition at line 320 of file canvas.cc.

320 {
321 while (GetSaveCount() > count) {
322 if (!Restore()) {
323 return;
324 }
325 }
326 }
impeller::Canvas::GetSaveCount
size_t GetSaveCount() const
Definition: canvas.cc:312

References GetSaveCount(), and Restore().

Referenced by impeller::DlDispatcherBase::drawDisplayList().

## ◆ Rotate()

void impeller::Canvas::Rotate | ( | Radians | radians | ) |

Definition at line 293 of file canvas.cc.

293 {
294 Concat(Matrix::MakeRotationZ(radians));
295 }
impeller::Matrix::MakeRotationZ
static Matrix MakeRotationZ(Radians r)
Definition: matrix.h:223

References Concat(), and impeller::Matrix::MakeRotationZ().

Referenced by impeller::DlDispatcherBase::rotate().

## ◆ Save()

void impeller::Canvas::Save | ( | uint32_t | total_content_depth = `kMaxDepth` | ) |

Definition at line 1219 of file canvas.cc.

1219 {
1220 if (IsSkipping()) {
1221 return SkipUntilMatchingRestore(total_content_depth);
1222 }
1223
1224 auto entry = CanvasStackEntry{};
1225 entry.transform = transform_stack_.back().transform;
1226 entry.clip_depth = current_depth_ + total_content_depth;
1227 entry.distributed_opacity = transform_stack_.back().distributed_opacity;
1228 FML_DCHECK(entry.clip_depth <= transform_stack_.back().clip_depth)
1229 << entry.clip_depth << " <=? " << transform_stack_.back().clip_depth
1230 << " after allocating " << total_content_depth;
1231 entry.clip_height = transform_stack_.back().clip_height;
1232 entry.rendering_mode = Entity::RenderingMode::kDirect;
1233 transform_stack_.push_back(entry);
1234 }
impeller::Entity::RenderingMode::kDirect
@ kDirect

References impeller::Entity::kDirect, and impeller::CanvasStackEntry::transform.

Referenced by impeller::DlDispatcherBase::drawDisplayList(), impeller::DlDispatcherBase::drawShadow(), DrawTextFrame(), impeller::DlDispatcherBase::save(), and SaveLayer().

## ◆ SaveLayer()

void impeller::Canvas::SaveLayer | ( | const Paint & | paint,
|  | std::optional< Rect > | bounds = `std::nullopt`,
|  | const flutter::DlImageFilter * | backdrop_filter = `nullptr`,
|  | ContentBoundsPromise | bounds_promise = `ContentBoundsPromise::kUnknown`,
|  | uint32_t | total_content_depth = `kMaxDepth`,
|  | bool | can_distribute_opacity = `false`,
|  | std::optional< int64_t > | backdrop_id = `std::nullopt`
| ) |  |

Definition at line 1273 of file canvas.cc.

1279 {
1280 TRACE_EVENT0("flutter", "Canvas::saveLayer");
1281 if (IsSkipping()) {
1282 return SkipUntilMatchingRestore(total_content_depth);
1283 }
1284
1285 auto maybe_coverage_limit = GetLocalCoverageLimit();
1286 if (!maybe_coverage_limit.has_value()) {
1287 return SkipUntilMatchingRestore(total_content_depth);
1288 }
1289 auto coverage_limit = maybe_coverage_limit.value();
1290
1291 if (can_distribute_opacity && !backdrop_filter &&
1292 Paint::CanApplyOpacityPeephole(paint) &&
1293 bounds_promise != ContentBoundsPromise::kMayClipContents) {
1294 Save(total_content_depth);
1295 transform_stack_.back().distributed_opacity *= paint.color.alpha;
1296 return;
1297 }
1298
1299 std::shared_ptr<FilterContents> filter_contents = paint.WithImageFilter(
1300 Rect(), transform_stack_.back().transform,
1301 Entity::RenderingMode::kSubpassPrependSnapshotTransform);
1302
1303 std::optional<Rect> maybe_subpass_coverage = ComputeSaveLayerCoverage(
1304 bounds.value_or(Rect::MakeMaximum()),
1305 transform_stack_.back().transform, //
1306 coverage_limit, //
1307 filter_contents, //
1308 /*flood_output_coverage=*/
1309 Entity::IsBlendModeDestructive(paint.blend_mode), //
1310 /*flood_input_coverage=*/!!backdrop_filter ||
1311 (paint.color_filter &&
1312 paint.color_filter->modifies_transparent_black()) //
1313 );
1314
1315 if (!maybe_subpass_coverage.has_value()) {
1316 return SkipUntilMatchingRestore(total_content_depth);
1317 }
1318
1319 auto subpass_coverage = maybe_subpass_coverage.value();
1320
1321 // When an image filter is present, clamp to avoid flicking due to nearest
1322 // sampled image. For other cases, round out to ensure than any geometry is
1323 // not cut off.
1324 //
1325 // See also this bug: https://github.com/flutter/flutter/issues/144213
1326 //
1327 // TODO(jonahwilliams): this could still round out for filters that use decal
1328 // sampling mode.
1329 ISize subpass_size;
1330 bool did_round_out = false;
1331 Point coverage_origin_adjustment = Point{0, 0};
1332 if (paint.image_filter) {
1333 subpass_size = ISize(subpass_coverage.GetSize());
1334 } else {
1335 did_round_out = true;
1336 subpass_size =
1337 static_cast<ISize>(IRect::RoundOut(subpass_coverage).GetSize());
1338 // If rounding out, adjust the coverage to account for the subpixel shift.
1339 coverage_origin_adjustment =
1340 Point(subpass_coverage.GetLeftTop().x -
1341 std::floor(subpass_coverage.GetLeftTop().x),
1342 subpass_coverage.GetLeftTop().y -
1343 std::floor(subpass_coverage.GetLeftTop().y));
1344 }
1345 if (subpass_size.IsEmpty()) {
1346 return SkipUntilMatchingRestore(total_content_depth);
1347 }
1348
1349 // When there are scaling filters present, these contents may exceed the
1350 // maximum texture size. Perform a clamp here, which may cause rendering
1351 // artifacts.
1352 subpass_size = subpass_size.Min(renderer_.GetContext()
1353 ->GetCapabilities()
1354 ->GetMaximumRenderPassAttachmentSize());
1355
1356 // Backdrop filter state, ignored if there is no BDF.
1357 std::shared_ptr<FilterContents> backdrop_filter_contents;
1358 Point local_position = Point(0, 0);
1359 if (backdrop_filter) {
1360 local_position = subpass_coverage.GetOrigin() - GetGlobalPassPosition();
1361 Canvas::BackdropFilterProc backdrop_filter_proc =
1362 [backdrop_filter = backdrop_filter](
1363 const FilterInput::Ref& input, const Matrix& effect_transform,
1364 Entity::RenderingMode rendering_mode) {
1365 auto filter = WrapInput(backdrop_filter, input);
1366 filter->SetEffectTransform(effect_transform);
1367 filter->SetRenderingMode(rendering_mode);
1368 return filter;
1369 };
1370
1371 std::shared_ptr<Texture> input_texture;
1372
1373 // If the backdrop ID is not nullopt and there is more than one usage
1374 // of it in the current scene, cache the backdrop texture and remove it from
1375 // the current entity pass flip.
1376 bool will_cache_backdrop_texture = false;
1377 BackdropData* backdrop_data = nullptr;
1378 // If we've reached this point, there is at least one backdrop filter. But
1379 // potentially more if there is a backdrop id. We may conditionally set this
1380 // to a higher value in the if block below.
1381 size_t backdrop_count = 1;
1382 if (backdrop_id.has_value()) {
1383 std::unordered_map<int64_t, BackdropData>::iterator backdrop_data_it =
1384 backdrop_data_.find(backdrop_id.value());
1385 if (backdrop_data_it != backdrop_data_.end()) {
1386 backdrop_data = &backdrop_data_it->second;
1387 will_cache_backdrop_texture =
1388 backdrop_data_it->second.backdrop_count > 1;
1389 backdrop_count = backdrop_data_it->second.backdrop_count;
1390 }
1391 }
1392
1393 if (!will_cache_backdrop_texture || !backdrop_data->texture_slot) {
1394 backdrop_count_ -= backdrop_count;
1395
1396 // The onscreen texture can be flipped to if:
1397 // 1. The device supports framebuffer fetch
1398 // 2. There are no more backdrop filters
1399 // 3. The current render pass is for the onscreen pass.
1400 const bool should_use_onscreen =
1401 renderer_.GetDeviceCapabilities().SupportsFramebufferFetch() &&
1402 backdrop_count_ == 0 && render_passes_.size() == 1u;
1403 input_texture = FlipBackdrop(
1404 GetGlobalPassPosition(), //
1405 /*should_remove_texture=*/will_cache_backdrop_texture, //
1406 /*should_use_onscreen=*/should_use_onscreen //
1407 );
1408 if (!input_texture) {
1409 // Validation failures are logged in FlipBackdrop.
1410 return;
1411 }
1412
1413 if (will_cache_backdrop_texture) {
1414 backdrop_data->texture_slot = input_texture;
1415 }
1416 } else {
1417 input_texture = backdrop_data->texture_slot;
1418 }
1419
1420 backdrop_filter_contents = backdrop_filter_proc(
1421 FilterInput::Make(std::move(input_texture)),
1422 transform_stack_.back().transform.Basis(),
1423 // When the subpass has a translation that means the math with
1424 // the snapshot has to be different.
1425 transform_stack_.back().transform.HasTranslation()
1426 ? Entity::RenderingMode::kSubpassPrependSnapshotTransform
1427 : Entity::RenderingMode::kSubpassAppendSnapshotTransform);
1428
1429 if (will_cache_backdrop_texture) {
1430 FML_DCHECK(backdrop_data);
1431 // If all filters on the shared backdrop layer are equal, process the
1432 // layer once.
1433 if (backdrop_data->all_filters_equal &&
1434 !backdrop_data->shared_filter_snapshot.has_value()) {
1435 // TODO(157110): compute minimum input hint.
1436 backdrop_data->shared_filter_snapshot =
1437 backdrop_filter_contents->RenderToSnapshot(renderer_, {}, {});
1438 }
1439
1440 std::optional<Snapshot> maybe_snapshot =
1441 backdrop_data->shared_filter_snapshot;
1442 if (maybe_snapshot.has_value()) {
1443 const Snapshot& snapshot = maybe_snapshot.value();
1444 std::shared_ptr<TextureContents> contents = TextureContents::MakeRect(
1445 subpass_coverage.Shift(-GetGlobalPassPosition()));
1446 auto scaled =
1447 subpass_coverage.TransformBounds(snapshot.transform.Invert());
1448 contents->SetTexture(snapshot.texture);
1449 contents->SetSourceRect(scaled);
1450 contents->SetSamplerDescriptor(snapshot.sampler_descriptor);
1451
1452 // This backdrop entity sets a depth value as it is written to the newly
1453 // flipped backdrop and not into a new saveLayer.
1454 Entity backdrop_entity;
1455 backdrop_entity.SetContents(std::move(contents));
1456 backdrop_entity.SetClipDepth(++current_depth_);
1457 backdrop_entity.SetBlendMode(paint.blend_mode);
1458
1459 backdrop_entity.Render(renderer_, GetCurrentRenderPass());
1460 Save(0);
1461 return;
1462 }
1463 }
1464 }
1465
1466 // When applying a save layer, absorb any pending distributed opacity.
1467 Paint paint_copy = paint;
1468 paint_copy.color.alpha *= transform_stack_.back().distributed_opacity;
1469 transform_stack_.back().distributed_opacity = 1.0;
1470
1471 render_passes_.push_back(
1472 LazyRenderingConfig(renderer_, //
1473 CreateRenderTarget(renderer_, //
1474 subpass_size, //
1475 Color::BlackTransparent() //
1476 )));
1477 save_layer_state_.push_back(SaveLayerState{
1478 paint_copy, subpass_coverage.Shift(-coverage_origin_adjustment)});
1479
1480 CanvasStackEntry entry;
1481 entry.transform = transform_stack_.back().transform;
1482 entry.clip_depth = current_depth_ + total_content_depth;
1483 FML_DCHECK(entry.clip_depth <= transform_stack_.back().clip_depth)
1484 << entry.clip_depth << " <=? " << transform_stack_.back().clip_depth
1485 << " after allocating " << total_content_depth;
1486 entry.clip_height = transform_stack_.back().clip_height;
1487 entry.rendering_mode = Entity::RenderingMode::kSubpassAppendSnapshotTransform;
1488 entry.did_round_out = did_round_out;
1489 transform_stack_.emplace_back(entry);
1490
1491 // Start non-collapsed subpasses with a fresh clip coverage stack limited by
1492 // the subpass coverage. This is important because image filters applied to
1493 // save layers may transform the subpass texture after it's rendered,
1494 // causing parent clip coverage to get misaligned with the actual area that
1495 // the subpass will affect in the parent pass.
1496 clip_coverage_stack_.PushSubpass(subpass_coverage, GetClipHeight());
1497
1498 if (!backdrop_filter_contents) {
1499 return;
1500 }
1501
1502 // Render the backdrop entity.
1503 Entity backdrop_entity;
1504 backdrop_entity.SetContents(std::move(backdrop_filter_contents));
1505 backdrop_entity.SetTransform(
1506 Matrix::MakeTranslation(Vector3(-local_position)));
1507 backdrop_entity.SetClipDepth(std::numeric_limits<uint32_t>::max());
1508 backdrop_entity.Render(renderer_, GetCurrentRenderPass());
1509 }
impeller::Canvas::GetLocalCoverageLimit
std::optional< Rect > GetLocalCoverageLimit() const
Return the culling bounds of the current render target, or nullopt if there is no coverage.
Definition: canvas.cc:1236
impeller::Canvas::BackdropFilterProc
std::function< std::shared_ptr< FilterContents >(FilterInput::Ref, const Matrix &effect_transform, Entity::RenderingMode rendering_mode)> BackdropFilterProc
Definition: canvas.h:125
impeller::Entity::RenderingMode
RenderingMode
Definition: entity.h:33
impeller::Entity::IsBlendModeDestructive
static bool IsBlendModeDestructive(BlendMode blend_mode)
Returns true if the blend mode is "destructive", meaning that even fully transparent source colors wo...
Definition: entity.cc:128
impeller::EntityPassClipStack::PushSubpass
void PushSubpass(std::optional< Rect > subpass_coverage, size_t clip_height)
Definition: entity_pass_clip_stack.cc:32
impeller::FilterInput::Ref
std::shared_ptr< FilterInput > Ref
Definition: filter_input.h:32
subpass_size
ISize subpass_size
The output size of the down-sampling pass.
Definition: gaussian_blur_filter_contents.cc:202
impeller::WrapInput
std::shared_ptr< FilterContents > WrapInput(const flutter::DlImageFilter *filter, const FilterInput::Ref &input)
Generate a new FilterContents using this filter's configuration.
Definition: image_filter.cc:18
impeller::ContentBoundsPromise::kMayClipContents
@ kMayClipContents
The caller claims the bounds are a subset of an estimate of the reasonably tight bounds but likely cl...
impeller::ComputeSaveLayerCoverage
std::optional< Rect > ComputeSaveLayerCoverage(const Rect &content_coverage, const Matrix &effect_transform, const Rect &coverage_limit, const std::shared_ptr< FilterContents > &image_filter, bool flood_output_coverage, bool flood_input_coverage)
Compute the coverage of a subpass in the global coordinate space.
Definition: save_layer_utils.cc:19
impeller::Color::BlackTransparent
static constexpr Color BlackTransparent()
Definition: color.h:270
impeller::Paint::CanApplyOpacityPeephole
static bool CanApplyOpacityPeephole(const Paint &paint)
Whether or not a save layer with the provided paint can perform the opacity peephole optimization.
Definition: paint.h:40
impeller::TRect::RoundOut
RoundOut(const TRect< U > &r)
Definition: rect.h:679
impeller::TRect< Scalar >::MakeMaximum
constexpr static TRect MakeMaximum()
Definition: rect.h:188

References impeller::BackdropData::all_filters_equal, impeller::Color::alpha, impeller::BackdropData::backdrop_count, impeller::Color::BlackTransparent(), impeller::Paint::blend_mode, impeller::Paint::CanApplyOpacityPeephole(), impeller::CanvasStackEntry::clip_depth, impeller::CanvasStackEntry::clip_height, impeller::Paint::color, impeller::Paint::color_filter, impeller::ComputeSaveLayerCoverage(), impeller::CanvasStackEntry::did_round_out, impeller::ContentContext::GetContext(), impeller::ContentContext::GetDeviceCapabilities(), GetLocalCoverageLimit(), impeller::Paint::image_filter, impeller::Matrix::Invert(), impeller::Entity::IsBlendModeDestructive(), impeller::kMayClipContents, impeller::Entity::kSubpassAppendSnapshotTransform, impeller::Entity::kSubpassPrependSnapshotTransform, impeller::FilterInput::Make(), impeller::TRect< Scalar >::MakeMaximum(), impeller::TextureContents::MakeRect(), impeller::Matrix::MakeTranslation(), impeller::EntityPassClipStack::PushSubpass(), impeller::Entity::Render(), impeller::CanvasStackEntry::rendering_mode, impeller::TRect< T >::RoundOut(), impeller::Snapshot::sampler_descriptor, Save(), impeller::Entity::SetBlendMode(), impeller::Entity::SetClipDepth(), impeller::Entity::SetContents(), impeller::Entity::SetTransform(), impeller::BackdropData::shared_filter_snapshot, subpass_size, impeller::Capabilities::SupportsFramebufferFetch(), impeller::Snapshot::texture, impeller::BackdropData::texture_slot, impeller::CanvasStackEntry::transform, impeller::Snapshot::transform, impeller::Paint::WithImageFilter(), and impeller::WrapInput().

Referenced by impeller::DlDispatcherBase::drawDisplayList(), and impeller::DlDispatcherBase::saveLayer().

## ◆ Scale() [1/2]

void impeller::Canvas::Scale | ( | const Vector2 & | scale | ) |

Definition at line 281 of file canvas.cc.

281 {
282 Concat(Matrix::MakeScale(scale));
283 }
impeller::Matrix::MakeScale
static constexpr Matrix MakeScale(const Vector3 &s)
Definition: matrix.h:104

References Concat(), and impeller::Matrix::MakeScale().

Referenced by impeller::DlDispatcherBase::scale().

## ◆ Scale() [2/2]

void impeller::Canvas::Scale | ( | const Vector3 & | scale | ) |

Definition at line 285 of file canvas.cc.

285 {
286 Concat(Matrix::MakeScale(scale));
287 }

References Concat(), and impeller::Matrix::MakeScale().

## ◆ SetBackdropData()

void impeller::Canvas::SetBackdropData | ( | std::unordered_map< int64_t, BackdropData > | backdrop_data,
|  | size_t | backdrop_count
| ) |  |

Update the backdrop data used to group together backdrop filters within the same layer.

Definition at line 1926 of file canvas.cc.

1928 {
1929 backdrop_data_ = std::move(backdrop_data);
1930 backdrop_count_ = backdrop_count;
1931 }

Referenced by impeller::CanvasDlDispatcher::SetBackdropData().

## ◆ Skew()

void impeller::Canvas::Skew | ( | Scalar | sx,
|  | Scalar | sy
| ) |  |

Definition at line 289 of file canvas.cc.

289 {
290 Concat(Matrix::MakeSkew(sx, sy));
291 }
impeller::Matrix::MakeSkew
static constexpr Matrix MakeSkew(Scalar sx, Scalar sy)
Definition: matrix.h:127

References Concat(), and impeller::Matrix::MakeSkew().

Referenced by impeller::DlDispatcherBase::skew().

## ◆ SupportsBlitToOnscreen()

bool impeller::Canvas::SupportsBlitToOnscreen | ( |  | ) | const

Definition at line 2049 of file canvas.cc.

2049 {
2050 return renderer_.GetContext()
2051 ->GetCapabilities()
2052 ->SupportsTextureToTextureBlits() &&
2053 renderer_.GetContext()->GetBackendType() ==
2054 Context::BackendType::kMetal;
2055 }
impeller::Context::BackendType::kMetal
@ kMetal

## ◆ Transform()

void impeller::Canvas::Transform | ( | const Matrix & | transform | ) |

Definition at line 269 of file canvas.cc.

269 {
270 Concat(transform);
271 }

References Concat(), and transform.

Referenced by impeller::DlDispatcherBase::transformFullPerspective(), and impeller::DlDispatcherBase::transformReset().

## ◆ Translate()

void impeller::Canvas::Translate | ( | const Vector3 & | offset | ) |

Definition at line 277 of file canvas.cc.

277 {
278 Concat(Matrix::MakeTranslation(offset));
279 }

References Concat(), and impeller::Matrix::MakeTranslation().

Referenced by impeller::DlDispatcherBase::translate().

## Member Data Documentation

## ◆ kMaxDepth

constexpr uint32_t impeller::Canvas::kMaxDepth = 1 << 24
| static constexpr

Definition at line 120 of file canvas.h.

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

- impeller/display_list/canvas.h
- impeller/display_list/canvas.cc