| Flutter Impeller |

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

`#include <canvas.h>`

## Classes
class | PathBlurShape
class | RRectBlurShape
class | RSuperellipseBlurShape
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 284 of file canvas.cc.

288 : renderer_(renderer),
289 render_target_(render_target),
290 is_onscreen_(is_onscreen),
291 requires_readback_(requires_readback),
292 clip_coverage_stack_(EntityPassClipStack(
293 Rect::MakeSize(render_target.GetRenderTargetSize()))) {
294 Initialize(std::nullopt);
295 SetupRenderPass();
296 }
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 298 of file canvas.cc.

303 : renderer_(renderer),
304 render_target_(render_target),
305 is_onscreen_(is_onscreen),
306 requires_readback_(requires_readback),
307 clip_coverage_stack_(EntityPassClipStack(
308 Rect::MakeSize(render_target.GetRenderTargetSize()))) {
309 Initialize(cull_rect);
310 SetupRenderPass();
311 }

## ◆ 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 313 of file canvas.cc.

318 : renderer_(renderer),
319 render_target_(render_target),
320 is_onscreen_(is_onscreen),
321 requires_readback_(requires_readback),
322 clip_coverage_stack_(EntityPassClipStack(
323 Rect::MakeSize(render_target.GetRenderTargetSize()))) {
324 Initialize(Rect::MakeLTRB(cull_rect.GetLeft(), cull_rect.GetTop(),
325 cull_rect.GetRight(), cull_rect.GetBottom()));
326 SetupRenderPass();
327 }
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 1024 of file canvas.cc.

1026 {
1027 if (IsSkipping()) {
1028 return;
1029 }
1030
1031 // Ideally the clip depth would be greater than the current rendering
1032 // depth because any rendering calls that follow this clip operation will
1033 // pre-increment the depth and then be rendering above our clip depth,
1034 // but that case will be caught by the CHECK in AddRenderEntity above.
1035 // In practice we sometimes have a clip set with no rendering after it
1036 // and in such cases the current depth will equal the clip depth.
1037 // Eventually the DisplayList should optimize these out, but it is hard
1038 // to know if a clip will actually be used in advance of storing it in
1039 // the DisplayList buffer.
1040 // See https://github.com/flutter/flutter/issues/147021
1041 FML_DCHECK(current_depth_ <= transform_stack_.back().clip_depth)
1042 << current_depth_ << " <=? " << transform_stack_.back().clip_depth;
1043 uint32_t clip_depth = transform_stack_.back().clip_depth;
1044
1045 const Matrix clip_transform =
1046 Matrix::MakeTranslation(Vector3(-GetGlobalPassPosition())) *
1047 GetCurrentTransform();
1048
1049 std::optional<Rect> clip_coverage = geometry.GetCoverage(clip_transform);
1050 if (!clip_coverage.has_value()) {
1051 return;
1052 }
1053
1054 ClipContents clip_contents(
1055 clip_coverage.value(),
1056 /*is_axis_aligned_rect=*/geometry.IsAxisAlignedRect() &&
1057 GetCurrentTransform().IsTranslationScaleOnly());
1058 clip_contents.SetClipOperation(clip_op);
1059
1060 EntityPassClipStack::ClipStateResult clip_state_result =
1061 clip_coverage_stack_.RecordClip(
1062 clip_contents, //
1063 /*transform=*/clip_transform, //
1064 /*global_pass_position=*/GetGlobalPassPosition(), //
1065 /*clip_depth=*/clip_depth, //
1066 /*clip_height_floor=*/GetClipHeightFloor(), //
1067 /*is_aa=*/is_aa);
1068
1069 if (clip_state_result.clip_did_change) {
1070 // We only need to update the pass scissor if the clip state has changed.
1071 SetClipScissor(
1072 clip_coverage_stack_.CurrentClipCoverage(),
1073 *render_passes_.back().GetInlinePassContext()->GetRenderPass(),
1074 GetGlobalPassPosition());
1075 }
1076
1077 ++transform_stack_.back().clip_height;
1078 ++transform_stack_.back().num_clips;
1079
1080 if (!clip_state_result.should_render) {
1081 return;
1082 }
1083
1084 // Note: this is a bit of a hack. Its not possible to construct a geometry
1085 // result without begninning the render pass. We should refactor the geometry
1086 // objects so that they only need a reference to the render pass size and/or
1087 // orthographic transform.
1088 Entity entity;
1089 entity.SetTransform(clip_transform);
1090 entity.SetClipDepth(clip_depth);
1091
1092 GeometryResult geometry_result = geometry.GetPositionBuffer(
1093 renderer_, //
1094 entity, //
1095 *render_passes_.back().GetInlinePassContext()->GetRenderPass() //
1096 );
1097 clip_contents.SetGeometry(geometry_result);
1098 clip_coverage_stack_.GetLastReplayResult().clip_contents.SetGeometry(
1099 geometry_result);
1100
1101 clip_contents.Render(
1102 renderer_, *render_passes_.back().GetInlinePassContext()->GetRenderPass(),
1103 clip_depth);
1104 }
impeller::Canvas::GetCurrentTransform
const Matrix & GetCurrentTransform() const
Definition: canvas.cc:358
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 342 of file canvas.cc.

342 {
343 transform_stack_.back().transform = GetCurrentTransform() * transform;
344 }
transform
Matrix transform
Definition: gaussian_blur_filter_contents.cc:312

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 873 of file canvas.cc.

873 {
874 Entity entity;
875 entity.SetTransform(GetCurrentTransform());
876 entity.SetBlendMode(paint.blend_mode);
877
878 if (paint.style == Paint::Style::kFill) {
879 ArcGeometry geom(arc);
880 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
881 return;
882 }
883
884 const Rect& oval_bounds = arc.GetOvalBounds();
885 if (paint.stroke.width > oval_bounds.GetSize().MaxDimension()) {
886 // This is a special case for rendering arcs whose stroke width is so large
887 // you are effectively drawing a sector of a circle.
888 // https://github.com/flutter/flutter/issues/158567
889 Arc expanded_arc(oval_bounds.Expand(Size(paint.stroke.width * 0.5f)),
890 arc.GetStart(), arc.GetSweep(), true);
891
892 ArcGeometry geom(expanded_arc);
893 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
894 return;
895 }
896
897 // IncludeCenter incurs lots of extra work for stroking an arc, including:
898 // - It introduces segments to/from the center point (not too hard).
899 // - It introduces joins on those segments (a bit more complicated).
900 // - Even if the sweep is >=360 degrees, we still draw the segment to
901 // the center and it basically looks like a pie cut into the complete
902 // boundary circle, as if the slice were cut, but not extracted
903 // (hard to express as a continuous kTriangleStrip).
904 if (!arc.IncludeCenter()) {
905 if (arc.IsFullCircle()) {
906 return DrawOval(oval_bounds, paint);
907 }
908
909 // Our fast stroking code only works for circular bounds as it assumes
910 // that the inner and outer radii can be scaled along each angular step
911 // of the arc - which is not true for elliptical arcs where the inner
912 // and outer samples are perpendicular to the traveling direction of the
913 // elliptical curve which may not line up with the center of the bounds.
914 if (oval_bounds.IsSquare()) {
915 ArcGeometry geom(arc, paint.stroke);
916 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
917 return;
918 }
919 }
920
921 ArcStrokeGeometry geom(arc, paint.stroke);
922 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
923 }
impeller::Canvas::DrawOval
void DrawOval(const Rect &rect, const Paint &paint)
Definition: canvas.cc:832
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 1317 of file canvas.cc.

1318 {
1319 atlas_contents->SetAlpha(paint.color.alpha);
1320
1321 Entity entity;
1322 entity.SetTransform(GetCurrentTransform());
1323 entity.SetBlendMode(paint.blend_mode);
1324 entity.SetContents(paint.WithFilters(atlas_contents));
1325
1326 AddRenderEntityToCurrentPass(entity);
1327 }

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 995 of file canvas.cc.

997 {
998 if (IsShadowBlurDrawOperation(paint)) {
999 Rect bounds = Rect::MakeLTRB(center.x - radius, center.y - radius,
1000 center.x + radius, center.y + radius);
1001 RRectBlurShape shape(bounds, radius);
1002 if (AttemptDrawBlur(shape, paint)) {
1003 return;
1004 }
1005 }
1006
1007 if (AttemptDrawAntialiasedCircle(center, radius, paint)) {
1008 return;
1009 }
1010
1011 Entity entity;
1012 entity.SetTransform(GetCurrentTransform());
1013 entity.SetBlendMode(paint.blend_mode);
1014
1015 if (paint.style == Paint::Style::kStroke) {
1016 CircleGeometry geom(center, radius, paint.stroke.width);
1017 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
1018 } else {
1019 CircleGeometry geom(center, radius);
1020 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
1021 }
1022 }
impeller::Paint::Style::kStroke
@ kStroke

References impeller::Paint::blend_mode, GetCurrentTransform(), impeller::Paint::kStroke, impeller::TRect< Scalar >::MakeLTRB(), impeller::Entity::SetBlendMode(), impeller::Entity::SetTransform(), impeller::Paint::stroke, impeller::Paint::style, impeller::StrokeParameters::width, impeller::TPoint< T >::x, and impeller::TPoint< T >::y.

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 785 of file canvas.cc.

789 {
790 // Reasons to defer to regular DrawLine:
791 // - performance for degenerate and "regular line" cases
792 // - length is non-positive - DrawLine will draw appropriate "dot"
793 // - off_length is non-positive - no gaps, DrawLine will draw it solid
794 // - on_length is negative - invalid dashing
795 //
796 // Note that a 0 length "on" dash will draw "dot"s every "off" distance
797 // apart so we proceed with the dashing process in that case.
798 Scalar length = p0.GetDistance(p1);
799 if (length > 0.0f && on_length >= 0.0f && off_length > 0.0f) {
800 Entity entity;
801 entity.SetTransform(GetCurrentTransform());
802 entity.SetBlendMode(paint.blend_mode);
803
804 StrokeDashedLineGeometry geom(p0, p1, on_length, off_length, paint.stroke);
805 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
806 } else {
807 DrawLine(p0, p1, paint);
808 }
809 }
impeller::Canvas::DrawLine
void DrawLine(const Point &p0, const Point &p1, const Paint &paint, bool reuse_depth=false)
Definition: canvas.cc:763
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 957 of file canvas.cc.

959 {
960 Entity entity;
961 entity.SetTransform(GetCurrentTransform());
962 entity.SetBlendMode(paint.blend_mode);
963
964 if (paint.style == Paint::Style::kFill) {
965 FillDiffRoundRectGeometry geom(outer, inner);
966 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
967 } else {
968 StrokeDiffRoundRectGeometry geom(outer, inner, paint.stroke);
969 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
970 }
971 }

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 1124 of file canvas.cc.

1127 {
1128 if (!image) {
1129 return;
1130 }
1131
1132 const Rect source = Rect::MakeSize(image->GetSize());
1133 const Rect dest = source.Shift(offset);
1134
1135 DrawImageRect(image, source, dest, paint, sampler);
1136 }
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:1138
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 1138 of file canvas.cc.

1143 {
1144 if (!image || source.IsEmpty() || dest.IsEmpty()) {
1145 return;
1146 }
1147
1148 ISize size = image->GetSize();
1149 if (size.IsEmpty()) {
1150 return;
1151 }
1152
1153 std::optional<Rect> clipped_source =
1154 source.Intersection(Rect::MakeSize(size));
1155 if (!clipped_source) {
1156 return;
1157 }
1158
1159 if (AttemptColorFilterOptimization(image, source, dest, paint, sampler,
1160 src_rect_constraint)) {
1161 return;
1162 }
1163
1164 if (*clipped_source != source) {
1165 Scalar sx = dest.GetWidth() / source.GetWidth();
1166 Scalar sy = dest.GetHeight() / source.GetHeight();
1167 Scalar tx = dest.GetLeft() - source.GetLeft() * sx;
1168 Scalar ty = dest.GetTop() - source.GetTop() * sy;
1169 Matrix src_to_dest = Matrix::MakeTranslateScale({sx, sy, 1}, {tx, ty, 0});
1170 dest = clipped_source->TransformBounds(src_to_dest);
1171 }
1172
1173 auto texture_contents = TextureContents::MakeRect(dest);
1174 texture_contents->SetTexture(image);
1175 texture_contents->SetSourceRect(*clipped_source);
1176 texture_contents->SetStrictSourceRect(src_rect_constraint ==
1177 SourceRectConstraint::kStrict);
1178 texture_contents->SetSamplerDescriptor(sampler);
1179 texture_contents->SetOpacity(paint.color.alpha);
1180 texture_contents->SetDeferApplyingOpacity(paint.HasColorFilter());
1181
1182 Entity entity;
1183 entity.SetBlendMode(paint.blend_mode);
1184 entity.SetTransform(GetCurrentTransform());
1185
1186 if (!paint.mask_blur_descriptor.has_value()) {
1187 entity.SetContents(paint.WithFilters(std::move(texture_contents)));
1188 AddRenderEntityToCurrentPass(entity);
1189 return;
1190 }
1191
1192 FillRectGeometry out_rect(Rect{});
1193
1194 entity.SetContents(paint.WithFilters(
1195 paint.mask_blur_descriptor->CreateMaskBlur(texture_contents, &out_rect)));
1196 AddRenderEntityToCurrentPass(entity);
1197 }
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 763 of file canvas.cc.

766 {
767 Entity entity;
768 entity.SetTransform(GetCurrentTransform());
769 entity.SetBlendMode(paint.blend_mode);
770
771 auto geometry = std::make_unique<LineGeometry>(p0, p1, paint.stroke);
772
773 if (renderer_.GetContext()->GetFlags().antialiased_lines &&
774 !paint.color_filter && !paint.invert_colors && !paint.image_filter &&
775 !paint.mask_blur_descriptor.has_value() && !paint.color_source) {
776 auto contents = LineContents::Make(std::move(geometry), paint.color);
777 entity.SetContents(std::move(contents));
778 AddRenderEntityToCurrentPass(entity, reuse_depth);
779 } else {
780 AddRenderEntityWithFiltersToCurrentPass(entity, geometry.get(), paint,
781 /*reuse_depth=*/reuse_depth);
782 }
783 }
impeller::ContentContext::GetContext
std::shared_ptr< Context > GetContext() const
Definition: content_context.cc:969
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 832 of file canvas.cc.

832 {
833 // TODO(jonahwilliams): This additional condition avoids an assert in the
834 // stroke circle geometry generator. I need to verify the condition that this
835 // assert prevents.
836 if (rect.IsSquare() && (paint.style == Paint::Style::kFill ||
837 (paint.style == Paint::Style::kStroke &&
838 paint.stroke.width < rect.GetWidth()))) {
839 // Circles have slightly less overhead and can do stroking
840 DrawCircle(rect.GetCenter(), rect.GetWidth() * 0.5f, paint);
841 return;
842 }
843
844 if (IsShadowBlurDrawOperation(paint)) {
845 if (rect.IsSquare()) {
846 // RRectBlurShape takes the corner radii which are half of the
847 // overall width and height of the DrawOval bounds rect.
848 RRectBlurShape shape(rect, rect.GetWidth() * 0.5f);
849 if (AttemptDrawBlur(shape, paint)) {
850 return;
851 }
852 } else {
853 EllipsePathSource source(rect);
854 if (AttemptDrawBlurredPathSource(source, paint)) {
855 return;
856 }
857 }
858 }
859
860 Entity entity;
861 entity.SetTransform(GetCurrentTransform());
862 entity.SetBlendMode(paint.blend_mode);
863
864 if (paint.style == Paint::Style::kStroke) {
865 StrokeEllipseGeometry geom(rect, paint.stroke);
866 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
867 } else {
868 EllipseGeometry geom(rect);
869 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
870 }
871 }
impeller::Canvas::DrawCircle
void DrawCircle(const Point &center, Scalar radius, const Paint &paint)
Definition: canvas.cc:995

References impeller::Paint::blend_mode, DrawCircle(), impeller::TRect< T >::GetCenter(), GetCurrentTransform(), 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 433 of file canvas.cc.

433 {
434 Entity entity;
435 entity.SetTransform(GetCurrentTransform());
436 entity.SetBlendMode(paint.blend_mode);
437
438 CoverGeometry geom;
439 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
440 }

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 413 of file canvas.cc.

413 {
414 if (IsShadowBlurDrawOperation(paint)) {
415 if (AttemptDrawBlurredPathSource(path, paint)) {
416 return;
417 }
418 }
419
420 Entity entity;
421 entity.SetTransform(GetCurrentTransform());
422 entity.SetBlendMode(paint.blend_mode);
423
424 if (paint.style == Paint::Style::kFill) {
425 FillPathGeometry geom(path);
426 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
427 } else {
428 StrokePathGeometry geom(path, paint.stroke);
429 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
430 }
431 }

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 1106 of file canvas.cc.

1110 {
1111 if (radius <= 0) {
1112 return;
1113 }
1114
1115 Entity entity;
1116 entity.SetTransform(GetCurrentTransform());
1117 entity.SetBlendMode(paint.blend_mode);
1118
1119 PointFieldGeometry geom(points, count, radius,
1120 /*round=*/point_style == PointStyle::kRound);
1121 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
1122 }
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 811 of file canvas.cc.

811 {
812 if (IsShadowBlurDrawOperation(paint)) {
813 RRectBlurShape shape(rect, 0.0f);
814 if (AttemptDrawBlur(shape, paint)) {
815 return;
816 }
817 }
818
819 Entity entity;
820 entity.SetTransform(GetCurrentTransform());
821 entity.SetBlendMode(paint.blend_mode);
822
823 if (paint.style == Paint::Style::kStroke) {
824 StrokeRectGeometry geom(rect, paint.stroke);
825 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
826 } else {
827 FillRectGeometry geom(rect);
828 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
829 }
830 }

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 925 of file canvas.cc.

925 {
926 if (IsShadowBlurDrawOperation(paint)) {
927 if (AttemptDrawBlurredRRect(round_rect, paint)) {
928 return;
929 }
930 }
931
932 if (round_rect.GetRadii().AreAllCornersSame() &&
933 paint.style == Paint::Style::kFill) {
934 Entity entity;
935 entity.SetTransform(GetCurrentTransform());
936 entity.SetBlendMode(paint.blend_mode);
937
938 RoundRectGeometry geom(round_rect.GetBounds(),
939 round_rect.GetRadii().top_left);
940 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
941 return;
942 }
943
944 Entity entity;
945 entity.SetTransform(GetCurrentTransform());
946 entity.SetBlendMode(paint.blend_mode);
947
948 if (paint.style == Paint::Style::kFill) {
949 FillRoundRectGeometry geom(round_rect);
950 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
951 } else {
952 StrokeRoundRectGeometry geom(round_rect, paint.stroke);
953 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
954 }
955 }

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

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

## ◆ DrawRoundSuperellipse()

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

Definition at line 973 of file canvas.cc.

974 {
975 if (IsShadowBlurDrawOperation(paint)) {
976 if (AttemptDrawBlurredRSuperellipse(round_superellipse, paint)) {
977 return;
978 }
979 }
980
981 Entity entity;
982 entity.SetTransform(GetCurrentTransform());
983 entity.SetBlendMode(paint.blend_mode);
984
985 if (paint.style == Paint::Style::kFill) {
986 RoundSuperellipseGeometry geom(round_superellipse.GetBounds(),
987 round_superellipse.GetRadii());
988 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
989 } else {
990 StrokeRoundSuperellipseGeometry geom(round_superellipse, paint.stroke);
991 AddRenderEntityWithFiltersToCurrentPass(entity, &geom, paint);
992 }
993 }

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 1869 of file canvas.cc.

1871 {
1872 Scalar max_scale = GetCurrentTransform().GetMaxBasisLengthXY();
1873 if (max_scale * text_frame->GetFont().GetMetrics().point_size >
1874 kMaxTextScale) {
1875 fml::StatusOr<flutter::DlPath> path = text_frame->GetPath();
1876 if (path.ok()) {
1877 Save(1);
1878 Concat(Matrix::MakeTranslation(position));
1879 DrawPath(path.value(), paint);
1880 Restore();
1881 return;
1882 }
1883 }
1884
1885 Entity entity;
1886 entity.SetClipDepth(GetClipHeight());
1887 entity.SetBlendMode(paint.blend_mode);
1888
1889 auto text_contents = std::make_shared<TextContents>();
1890 text_contents->SetTextFrame(text_frame);
1891 text_contents->SetForceTextColor(paint.mask_blur_descriptor.has_value());
1892 text_contents->SetScale(max_scale);
1893 text_contents->SetColor(paint.color);
1894 text_contents->SetOffset(position);
1895 text_contents->SetTextProperties(paint.color,
1896 paint.style == Paint::Style::kStroke
1897 ? std::optional(paint.stroke)
1898 : std::nullopt);
1899
1900 entity.SetTransform(GetCurrentTransform() *
1901 Matrix::MakeTranslation(position));
1902
1903 if (AttemptBlurredTextOptimization(text_frame, text_contents, entity,
1904 paint)) {
1905 return;
1906 }
1907
1908 entity.SetContents(paint.WithFilters(std::move(text_contents)));
1909 AddRenderEntityToCurrentPass(entity, false);
1910 }
impeller::Canvas::Restore
bool Restore()
Definition: canvas.cc:1677
impeller::Canvas::Concat
void Concat(const Matrix &transform)
Definition: canvas.cc:342
impeller::Canvas::DrawPath
void DrawPath(const flutter::DlPath &path, const Paint &paint)
Definition: canvas.cc:413
impeller::Canvas::Save
void Save(uint32_t total_content_depth=kMaxDepth)
Definition: canvas.cc:1385
impeller::kMaxTextScale
static constexpr Scalar kMaxTextScale
Definition: canvas.cc:1867
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 1203 of file canvas.cc.

1205 {
1206 // Override the blend mode with kDestination in order to match the behavior
1207 // of Skia's SK_LEGACY_IGNORE_DRAW_VERTICES_BLEND_WITH_NO_SHADER flag, which
1208 // is enabled when the Flutter engine builds Skia.
1209 if (!paint.color_source) {
1210 blend_mode = BlendMode::kDst;
1211 }
1212
1213 Entity entity;
1214 entity.SetTransform(GetCurrentTransform());
1215 entity.SetBlendMode(paint.blend_mode);
1216
1217 // If there are no vertex colors.
1218 if (UseColorSourceContents(vertices, paint)) {
1219 AddRenderEntityWithFiltersToCurrentPass(entity, vertices.get(), paint);
1220 return;
1221 }
1222
1223 // If the blend mode is destination don't bother to bind or create a texture.
1224 if (blend_mode == BlendMode::kDst) {
1225 auto contents = std::make_shared<VerticesSimpleBlendContents>();
1226 contents->SetBlendMode(blend_mode);
1227 contents->SetAlpha(paint.color.alpha);
1228 contents->SetGeometry(vertices);
1229 entity.SetContents(paint.WithFilters(std::move(contents)));
1230 AddRenderEntityToCurrentPass(entity);
1231 return;
1232 }
1233
1234 // If there is a texture, use this directly. Otherwise render the color
1235 // source to a texture.
1236 if (paint.color_source &&
1237 paint.color_source->type() == flutter::DlColorSourceType::kImage) {
1238 const flutter::DlImageColorSource* image_color_source =
1239 paint.color_source->asImage();
1240 FML_DCHECK(image_color_source &&
1241 image_color_source->image()->impeller_texture());
1242 auto texture = image_color_source->image()->impeller_texture();
1243 auto x_tile_mode = static_cast<Entity::TileMode>(
1244 image_color_source->horizontal_tile_mode());
1245 auto y_tile_mode =
1246 static_cast<Entity::TileMode>(image_color_source->vertical_tile_mode());
1247 auto sampler_descriptor =
1248 skia_conversions::ToSamplerDescriptor(image_color_source->sampling());
1249 auto effect_transform = image_color_source->matrix();
1250
1251 auto contents = std::make_shared<VerticesSimpleBlendContents>();
1252 contents->SetBlendMode(blend_mode);
1253 contents->SetAlpha(paint.color.alpha);
1254 contents->SetGeometry(vertices);
1255 contents->SetEffectTransform(effect_transform);
1256 contents->SetTexture(texture);
1257 contents->SetTileMode(x_tile_mode, y_tile_mode);
1258 contents->SetSamplerDescriptor(sampler_descriptor);
1259
1260 entity.SetContents(paint.WithFilters(std::move(contents)));
1261 AddRenderEntityToCurrentPass(entity);
1262 return;
1263 }
1264
1265 auto src_paint = paint;
1266 src_paint.color = paint.color.WithAlpha(1.0);
1267
1268 std::shared_ptr<ColorSourceContents> src_contents =
1269 src_paint.CreateContents();
1270 src_contents->SetGeometry(vertices.get());
1271
1272 // If the color source has an intrinsic size, then we use that to
1273 // create the src contents as a simplification. Otherwise we use
1274 // the extent of the texture coordinates to determine how large
1275 // the src contents should be. If neither has a value we fall back
1276 // to using the geometry coverage data.
1277 Rect src_coverage;
1278 auto size = src_contents->GetColorSourceSize();
1279 if (size.has_value()) {
1280 src_coverage = Rect::MakeXYWH(0, 0, size->width, size->height);
1281 } else {
1282 auto cvg = vertices->GetCoverage(Matrix{});
1283 FML_CHECK(cvg.has_value());
1284 auto texture_coverage = vertices->GetTextureCoordinateCoverage();
1285 if (texture_coverage.has_value()) {
1286 src_coverage =
1287 Rect::MakeOriginSize(texture_coverage->GetOrigin(),
1288 texture_coverage->GetSize().Max({1, 1}));
1289 } else {
1290 // NOLINTNEXTLINE(bugprone-unchecked-optional-access)
1291 src_coverage = cvg.value();
1292 }
1293 }
1294 src_contents = src_paint.CreateContents();
1295
1296 clip_geometry_.push_back(Geometry::MakeRect(Rect::Round(src_coverage)));
1297 src_contents->SetGeometry(clip_geometry_.back().get());
1298
1299 auto contents = std::make_shared<VerticesSimpleBlendContents>();
1300 contents->SetBlendMode(blend_mode);
1301 contents->SetAlpha(paint.color.alpha);
1302 contents->SetGeometry(vertices);
1303 contents->SetLazyTextureCoverage(src_coverage);
1304 contents->SetLazyTexture(
1305 [src_contents, src_coverage](const ContentContext& renderer) {
1306 // Applying the src coverage as the coverage limit prevents the 1px
1307 // coverage pad from adding a border that is picked up by developer
1308 // specified UVs.
1309 auto snapshot = src_contents->RenderToSnapshot(
1310 renderer, {}, {.coverage_limit = Rect::Round(src_coverage)});
1311 return snapshot.has_value() ? snapshot->texture : nullptr;
1312 });
1313 entity.SetContents(paint.WithFilters(std::move(contents)));
1314 AddRenderEntityToCurrentPass(entity);
1315 }
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 >::MakeOriginSize
constexpr static TRect MakeOriginSize(const TPoint< Type > &origin, const TSize< Type > &size)
Definition: rect.h:144
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 2291 of file canvas.cc.

2291 {
2292 FML_DCHECK(render_passes_.size() == 1u);
2293 render_passes_.back().GetInlinePassContext()->GetRenderPass();
2294 render_passes_.back().GetInlinePassContext()->EndPass(
2295 /*is_onscreen=*/!requires_readback_ && is_onscreen_);
2296 backdrop_data_.clear();
2297
2298 // If requires_readback_ was true, then we rendered to an offscreen texture
2299 // instead of to the onscreen provided in the render target. Now we need to
2300 // draw or blit the offscreen back to the onscreen.
2301 if (requires_readback_) {
2302 BlitToOnscreen(/*is_onscreen_=*/is_onscreen_);
2303 }
2304 if (!EnsureFinalMipmapGeneration()) {
2305 VALIDATION_LOG << "Failed to generate onscreen mipmaps.";
2306 }
2307 if (!renderer_.GetContext()->FlushCommandBuffers()) {
2308 // Not much we can do.
2309 VALIDATION_LOG << "Failed to submit command buffers";
2310 }
2311 render_passes_.clear();
2312 renderer_.GetRenderTargetCache()->End();
2313 clip_geometry_.clear();
2314
2315 Reset();
2316 Initialize(initial_cull_rect_);
2317 }
impeller::Canvas::EnsureFinalMipmapGeneration
bool EnsureFinalMipmapGeneration() const
Definition: canvas.cc:2273
impeller::ContentContext::GetRenderTargetCache
const std::shared_ptr< RenderTargetAllocator > & GetRenderTargetCache() const
Definition: content_context.h:258
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 2273 of file canvas.cc.

2273 {
2274 if (!render_target_.GetRenderTargetTexture()->NeedsMipmapGeneration()) {
2275 return true;
2276 }
2277 std::shared_ptr<CommandBuffer> cmd_buffer =
2278 renderer_.GetContext()->CreateCommandBuffer();
2279 if (!cmd_buffer) {
2280 return false;
2281 }
2282 std::shared_ptr<BlitPass> blit_pass = cmd_buffer->CreateBlitPass();
2283 if (!blit_pass) {
2284 return false;
2285 }
2286 blit_pass->GenerateMipmap(render_target_.GetRenderTargetTexture());
2287 blit_pass->EncodeCommands();
2288 return renderer_.GetContext()->EnqueueCommandBuffer(std::move(cmd_buffer));
2289 }
impeller::RenderTarget::GetRenderTargetTexture
std::shared_ptr< Texture > GetRenderTargetTexture() const
Definition: render_target.cc:176

## ◆ GetCurrentTransform()

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

Definition at line 358 of file canvas.cc.

358 {
359 return transform_stack_.back().transform;
360 }

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 1402 of file canvas.cc.

1402 {
1403 if (!clip_coverage_stack_.HasCoverage()) {
1404 // The current clip is empty. This means the pass texture won't be
1405 // visible, so skip it.
1406 return std::nullopt;
1407 }
1408
1409 std::optional<Rect> maybe_current_clip_coverage =
1410 clip_coverage_stack_.CurrentClipCoverage();
1411 if (!maybe_current_clip_coverage.has_value()) {
1412 return std::nullopt;
1413 }
1414
1415 Rect current_clip_coverage = maybe_current_clip_coverage.value();
1416
1417 FML_CHECK(!render_passes_.empty());
1418 const LazyRenderingConfig& back_render_pass = render_passes_.back();
1419 std::shared_ptr<Texture> back_texture =
1420 back_render_pass.GetInlinePassContext()->GetTexture();
1421 FML_CHECK(back_texture) << "Context is valid:"
1422 << back_render_pass.GetInlinePassContext()->IsValid();
1423
1424 // The maximum coverage of the subpass. Subpasses textures should never
1425 // extend outside the parent pass texture or the current clip coverage.
1426 std::optional<Rect> maybe_coverage_limit =
1427 Rect::MakeOriginSize(GetGlobalPassPosition(),
1428 Size(back_texture->GetSize()))
1429 .Intersection(current_clip_coverage);
1430
1431 if (!maybe_coverage_limit.has_value() || maybe_coverage_limit->IsEmpty()) {
1432 return std::nullopt;
1433 }
1434
1435 return maybe_coverage_limit->Intersection(
1436 Rect::MakeSize(render_target_.GetRenderTargetSize()));
1437 }
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 397 of file canvas.cc.

397 {
398 return transform_stack_.size();
399 }

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

## ◆ PreConcat()

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

Definition at line 346 of file canvas.cc.

346 {
347 transform_stack_.back().transform = transform * GetCurrentTransform();
348 }

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 350 of file canvas.cc.

350 {
351 transform_stack_.back().transform = {};
352 }

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

## ◆ Restore()

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

Definition at line 1677 of file canvas.cc.

1677 {
1678 FML_DCHECK(transform_stack_.size() > 0);
1679 if (transform_stack_.size() == 1) {
1680 return false;
1681 }
1682
1683 // This check is important to make sure we didn't exceed the depth
1684 // that the clips were rendered at while rendering any of the
1685 // rendering ops. It is OK for the current depth to equal the
1686 // outgoing clip depth because that means the clipping would have
1687 // been successful up through the last rendering op, but it cannot
1688 // be greater.
1689 // Also, we bump the current rendering depth to the outgoing clip
1690 // depth so that future rendering operations are not clipped by
1691 // any of the pixels set by the expiring clips. It is OK for the
1692 // estimates used to determine the clip depth in save/saveLayer
1693 // to be overly conservative, but we need to jump the depth to
1694 // the clip depth so that the next rendering op will get a
1695 // larger depth (it will pre-increment the current_depth_ value).
1696 FML_DCHECK(current_depth_ <= transform_stack_.back().clip_depth)
1697 << current_depth_ << " <=? " << transform_stack_.back().clip_depth;
1698 current_depth_ = transform_stack_.back().clip_depth;
1699
1700 if (IsSkipping()) {
1701 transform_stack_.pop_back();
1702 return true;
1703 }
1704
1705 if (transform_stack_.back().rendering_mode ==
1706 Entity::RenderingMode::kSubpassAppendSnapshotTransform ||
1707 transform_stack_.back().rendering_mode ==
1708 Entity::RenderingMode::kSubpassPrependSnapshotTransform) {
1709 auto lazy_render_pass = std::move(render_passes_.back());
1710 render_passes_.pop_back();
1711 // Force the render pass to be constructed if it never was.
1712 lazy_render_pass.GetInlinePassContext()->GetRenderPass();
1713
1714 SaveLayerState save_layer_state = save_layer_state_.back();
1715 save_layer_state_.pop_back();
1716 auto global_pass_position = GetGlobalPassPosition();
1717
1718 std::shared_ptr<Contents> contents = CreateContentsForSubpassTarget(
1719 save_layer_state.paint, //
1720 lazy_render_pass.GetInlinePassContext()->GetTexture(), //
1721 Matrix::MakeTranslation(Vector3{-global_pass_position}) * //
1722 transform_stack_.back().transform //
1723 );
1724
1725 lazy_render_pass.GetInlinePassContext()->EndPass();
1726
1727 // Round the subpass texture position for pixel alignment with the parent
1728 // pass render target. By default, we draw subpass textures with nearest
1729 // sampling, so aligning here is important for avoiding visual nearest
1730 // sampling errors caused by limited floating point precision when
1731 // straddling a half pixel boundary.
1732 Point subpass_texture_position;
1733 if (transform_stack_.back().did_round_out) {
1734 // Subpass coverage was rounded out, origin potentially moved "down" by
1735 // as much as a pixel.
1736 subpass_texture_position =
1737 (save_layer_state.coverage.GetOrigin() - global_pass_position)
1738 .Floor();
1739 } else {
1740 // Subpass coverage was truncated. Pick the closest phyiscal pixel.
1741 subpass_texture_position =
1742 (save_layer_state.coverage.GetOrigin() - global_pass_position)
1743 .Round();
1744 }
1745
1746 Entity element_entity;
1747 element_entity.SetClipDepth(++current_depth_);
1748 element_entity.SetContents(std::move(contents));
1749 element_entity.SetBlendMode(save_layer_state.paint.blend_mode);
1750 element_entity.SetTransform(
1751 Matrix::MakeTranslation(Vector3(subpass_texture_position)));
1752
1753 if (element_entity.GetBlendMode() > Entity::kLastPipelineBlendMode) {
1754 if (renderer_.GetDeviceCapabilities().SupportsFramebufferFetch()) {
1755 ApplyFramebufferBlend(element_entity);
1756 } else {
1757 // End the active pass and flush the buffer before rendering "advanced"
1758 // blends. Advanced blends work by binding the current render target
1759 // texture as an input ("destination"), blending with a second texture
1760 // input ("source"), writing the result to an intermediate texture, and
1761 // finally copying the data from the intermediate texture back to the
1762 // render target texture. And so all of the commands that have written
1763 // to the render target texture so far need to execute before it's bound
1764 // for blending (otherwise the blend pass will end up executing before
1765 // all the previous commands in the active pass).
1766 auto input_texture = FlipBackdrop(GetGlobalPassPosition());
1767 if (!input_texture) {
1768 return false;
1769 }
1770
1771 FilterInput::Vector inputs = {
1772 FilterInput::Make(input_texture,
1773 element_entity.GetTransform().Invert()),
1774 FilterInput::Make(element_entity.GetContents())};
1775 auto contents = ColorFilterContents::MakeBlend(
1776 element_entity.GetBlendMode(), inputs);
1777 contents->SetCoverageHint(element_entity.GetCoverage());
1778 element_entity.SetContents(std::move(contents));
1779 element_entity.SetBlendMode(BlendMode::kSrc);
1780 }
1781 }
1782
1783 element_entity.Render(
1784 renderer_, //
1785 *render_passes_.back().GetInlinePassContext()->GetRenderPass() //
1786 );
1787 clip_coverage_stack_.PopSubpass();
1788 transform_stack_.pop_back();
1789
1790 // We don't need to restore clips if a saveLayer was performed, as the clip
1791 // state is per render target, and no more rendering operations will be
1792 // performed as the render target workloaded is completed in the restore.
1793 return true;
1794 }
1795
1796 size_t num_clips = transform_stack_.back().num_clips;
1797 transform_stack_.pop_back();
1798
1799 if (num_clips > 0) {
1800 EntityPassClipStack::ClipStateResult clip_state_result =
1801 clip_coverage_stack_.RecordRestore(GetGlobalPassPosition(),
1802 GetClipHeight());
1803
1804 // Clip restores are never required with depth based clipping.
1805 FML_DCHECK(!clip_state_result.should_render);
1806 if (clip_state_result.clip_did_change) {
1807 // We only need to update the pass scissor if the clip state has changed.
1808 SetClipScissor(
1809 clip_coverage_stack_.CurrentClipCoverage(), //
1810 *render_passes_.back().GetInlinePassContext()->GetRenderPass(), //
1811 GetGlobalPassPosition() //
1812 );
1813 }
1814 }
1815
1816 return true;
1817 }
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:973
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:425
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 405 of file canvas.cc.

405 {
406 while (GetSaveCount() > count) {
407 if (!Restore()) {
408 return;
409 }
410 }
411 }
impeller::Canvas::GetSaveCount
size_t GetSaveCount() const
Definition: canvas.cc:397

References GetSaveCount(), and Restore().

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

## ◆ Rotate()

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

Definition at line 378 of file canvas.cc.

378 {
379 Concat(Matrix::MakeRotationZ(radians));
380 }
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 1385 of file canvas.cc.

1385 {
1386 if (IsSkipping()) {
1387 return SkipUntilMatchingRestore(total_content_depth);
1388 }
1389
1390 auto entry = CanvasStackEntry{};
1391 entry.transform = transform_stack_.back().transform;
1392 entry.clip_depth = current_depth_ + total_content_depth;
1393 entry.distributed_opacity = transform_stack_.back().distributed_opacity;
1394 FML_DCHECK(entry.clip_depth <= transform_stack_.back().clip_depth)
1395 << entry.clip_depth << " <=? " << transform_stack_.back().clip_depth
1396 << " after allocating " << total_content_depth;
1397 entry.clip_height = transform_stack_.back().clip_height;
1398 entry.rendering_mode = Entity::RenderingMode::kDirect;
1399 transform_stack_.push_back(entry);
1400 }
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 1439 of file canvas.cc.

1445 {
1446 TRACE_EVENT0("flutter", "Canvas::saveLayer");
1447 if (IsSkipping()) {
1448 return SkipUntilMatchingRestore(total_content_depth);
1449 }
1450
1451 auto maybe_coverage_limit = GetLocalCoverageLimit();
1452 if (!maybe_coverage_limit.has_value()) {
1453 return SkipUntilMatchingRestore(total_content_depth);
1454 }
1455 auto coverage_limit = maybe_coverage_limit.value();
1456
1457 if (can_distribute_opacity && !backdrop_filter &&
1458 Paint::CanApplyOpacityPeephole(paint) &&
1459 bounds_promise != ContentBoundsPromise::kMayClipContents) {
1460 Save(total_content_depth);
1461 transform_stack_.back().distributed_opacity *= paint.color.alpha;
1462 return;
1463 }
1464
1465 std::shared_ptr<FilterContents> filter_contents = paint.WithImageFilter(
1466 Rect(), transform_stack_.back().transform,
1467 Entity::RenderingMode::kSubpassPrependSnapshotTransform);
1468
1469 std::optional<Rect> maybe_subpass_coverage = ComputeSaveLayerCoverage(
1470 bounds.value_or(Rect::MakeMaximum()),
1471 transform_stack_.back().transform, //
1472 coverage_limit, //
1473 filter_contents, //
1474 /*flood_output_coverage=*/
1475 Entity::IsBlendModeDestructive(paint.blend_mode), //
1476 /*flood_input_coverage=*/!!backdrop_filter ||
1477 (paint.color_filter &&
1478 paint.color_filter->modifies_transparent_black()) //
1479 );
1480
1481 if (!maybe_subpass_coverage.has_value()) {
1482 return SkipUntilMatchingRestore(total_content_depth);
1483 }
1484
1485 auto subpass_coverage = maybe_subpass_coverage.value();
1486
1487 // When an image filter is present, clamp to avoid flicking due to nearest
1488 // sampled image. For other cases, round out to ensure than any geometry is
1489 // not cut off.
1490 //
1491 // See also this bug: https://github.com/flutter/flutter/issues/144213
1492 //
1493 // TODO(jonahwilliams): this could still round out for filters that use decal
1494 // sampling mode.
1495 ISize subpass_size;
1496 bool did_round_out = false;
1497 Point coverage_origin_adjustment = Point{0, 0};
1498 if (paint.image_filter) {
1499 subpass_size = ISize(subpass_coverage.GetSize());
1500 } else {
1501 did_round_out = true;
1502 subpass_size =
1503 static_cast<ISize>(IRect::RoundOut(subpass_coverage).GetSize());
1504 // If rounding out, adjust the coverage to account for the subpixel shift.
1505 coverage_origin_adjustment =
1506 Point(subpass_coverage.GetLeftTop().x -
1507 std::floor(subpass_coverage.GetLeftTop().x),
1508 subpass_coverage.GetLeftTop().y -
1509 std::floor(subpass_coverage.GetLeftTop().y));
1510 }
1511 if (subpass_size.IsEmpty()) {
1512 return SkipUntilMatchingRestore(total_content_depth);
1513 }
1514
1515 // When there are scaling filters present, these contents may exceed the
1516 // maximum texture size. Perform a clamp here, which may cause rendering
1517 // artifacts.
1518 subpass_size = subpass_size.Min(renderer_.GetContext()
1519 ->GetCapabilities()
1520 ->GetMaximumRenderPassAttachmentSize());
1521
1522 // Backdrop filter state, ignored if there is no BDF.
1523 std::shared_ptr<FilterContents> backdrop_filter_contents;
1524 Point local_position = Point(0, 0);
1525 if (backdrop_filter) {
1526 local_position = subpass_coverage.GetOrigin() - GetGlobalPassPosition();
1527 Canvas::BackdropFilterProc backdrop_filter_proc =
1528 [backdrop_filter = backdrop_filter](
1529 const FilterInput::Ref& input, const Matrix& effect_transform,
1530 Entity::RenderingMode rendering_mode) {
1531 auto filter = WrapInput(backdrop_filter, input);
1532 filter->SetEffectTransform(effect_transform);
1533 filter->SetRenderingMode(rendering_mode);
1534 return filter;
1535 };
1536
1537 std::shared_ptr<Texture> input_texture;
1538
1539 // If the backdrop ID is not nullopt and there is more than one usage
1540 // of it in the current scene, cache the backdrop texture and remove it from
1541 // the current entity pass flip.
1542 bool will_cache_backdrop_texture = false;
1543 BackdropData* backdrop_data = nullptr;
1544 // If we've reached this point, there is at least one backdrop filter. But
1545 // potentially more if there is a backdrop id. We may conditionally set this
1546 // to a higher value in the if block below.
1547 size_t backdrop_count = 1;
1548 if (backdrop_id.has_value()) {
1549 std::unordered_map<int64_t, BackdropData>::iterator backdrop_data_it =
1550 backdrop_data_.find(backdrop_id.value());
1551 if (backdrop_data_it != backdrop_data_.end()) {
1552 backdrop_data = &backdrop_data_it->second;
1553 will_cache_backdrop_texture =
1554 backdrop_data_it->second.backdrop_count > 1;
1555 backdrop_count = backdrop_data_it->second.backdrop_count;
1556 }
1557 }
1558
1559 if (!will_cache_backdrop_texture || !backdrop_data->texture_slot) {
1560 backdrop_count_ -= backdrop_count;
1561
1562 // The onscreen texture can be flipped to if:
1563 // 1. The device supports framebuffer fetch
1564 // 2. There are no more backdrop filters
1565 // 3. The current render pass is for the onscreen pass.
1566 const bool should_use_onscreen =
1567 renderer_.GetDeviceCapabilities().SupportsFramebufferFetch() &&
1568 backdrop_count_ == 0 && render_passes_.size() == 1u;
1569 input_texture = FlipBackdrop(
1570 GetGlobalPassPosition(), //
1571 /*should_remove_texture=*/will_cache_backdrop_texture, //
1572 /*should_use_onscreen=*/should_use_onscreen //
1573 );
1574 if (!input_texture) {
1575 // Validation failures are logged in FlipBackdrop.
1576 return;
1577 }
1578
1579 if (will_cache_backdrop_texture) {
1580 backdrop_data->texture_slot = input_texture;
1581 }
1582 } else {
1583 input_texture = backdrop_data->texture_slot;
1584 }
1585
1586 backdrop_filter_contents = backdrop_filter_proc(
1587 FilterInput::Make(std::move(input_texture)),
1588 transform_stack_.back().transform.Basis(),
1589 // When the subpass has a translation that means the math with
1590 // the snapshot has to be different.
1591 transform_stack_.back().transform.HasTranslation()
1592 ? Entity::RenderingMode::kSubpassPrependSnapshotTransform
1593 : Entity::RenderingMode::kSubpassAppendSnapshotTransform);
1594
1595 if (will_cache_backdrop_texture) {
1596 FML_DCHECK(backdrop_data);
1597 // If all filters on the shared backdrop layer are equal, process the
1598 // layer once.
1599 if (backdrop_data->all_filters_equal &&
1600 !backdrop_data->shared_filter_snapshot.has_value()) {
1601 // TODO(157110): compute minimum input hint.
1602 backdrop_data->shared_filter_snapshot =
1603 backdrop_filter_contents->RenderToSnapshot(renderer_, {}, {});
1604 }
1605
1606 std::optional<Snapshot> maybe_snapshot =
1607 backdrop_data->shared_filter_snapshot;
1608 if (maybe_snapshot.has_value()) {
1609 const Snapshot& snapshot = maybe_snapshot.value();
1610 std::shared_ptr<TextureContents> contents = TextureContents::MakeRect(
1611 subpass_coverage.Shift(-GetGlobalPassPosition()));
1612 auto scaled =
1613 subpass_coverage.TransformBounds(snapshot.transform.Invert());
1614 contents->SetTexture(snapshot.texture);
1615 contents->SetSourceRect(scaled);
1616 contents->SetSamplerDescriptor(snapshot.sampler_descriptor);
1617
1618 // This backdrop entity sets a depth value as it is written to the newly
1619 // flipped backdrop and not into a new saveLayer.
1620 Entity backdrop_entity;
1621 backdrop_entity.SetContents(std::move(contents));
1622 backdrop_entity.SetClipDepth(++current_depth_);
1623 backdrop_entity.SetBlendMode(paint.blend_mode);
1624
1625 backdrop_entity.Render(renderer_, GetCurrentRenderPass());
1626 Save(0);
1627 return;
1628 }
1629 }
1630 }
1631
1632 // When applying a save layer, absorb any pending distributed opacity.
1633 Paint paint_copy = paint;
1634 paint_copy.color.alpha *= transform_stack_.back().distributed_opacity;
1635 transform_stack_.back().distributed_opacity = 1.0;
1636
1637 render_passes_.push_back(
1638 LazyRenderingConfig(renderer_, //
1639 CreateRenderTarget(renderer_, //
1640 subpass_size, //
1641 Color::BlackTransparent() //
1642 )));
1643 save_layer_state_.push_back(SaveLayerState{
1644 paint_copy, subpass_coverage.Shift(-coverage_origin_adjustment)});
1645
1646 CanvasStackEntry entry;
1647 entry.transform = transform_stack_.back().transform;
1648 entry.clip_depth = current_depth_ + total_content_depth;
1649 FML_DCHECK(entry.clip_depth <= transform_stack_.back().clip_depth)
1650 << entry.clip_depth << " <=? " << transform_stack_.back().clip_depth
1651 << " after allocating " << total_content_depth;
1652 entry.clip_height = transform_stack_.back().clip_height;
1653 entry.rendering_mode = Entity::RenderingMode::kSubpassAppendSnapshotTransform;
1654 entry.did_round_out = did_round_out;
1655 transform_stack_.emplace_back(entry);
1656
1657 // Start non-collapsed subpasses with a fresh clip coverage stack limited by
1658 // the subpass coverage. This is important because image filters applied to
1659 // save layers may transform the subpass texture after it's rendered,
1660 // causing parent clip coverage to get misaligned with the actual area that
1661 // the subpass will affect in the parent pass.
1662 clip_coverage_stack_.PushSubpass(subpass_coverage, GetClipHeight());
1663
1664 if (!backdrop_filter_contents) {
1665 return;
1666 }
1667
1668 // Render the backdrop entity.
1669 Entity backdrop_entity;
1670 backdrop_entity.SetContents(std::move(backdrop_filter_contents));
1671 backdrop_entity.SetTransform(
1672 Matrix::MakeTranslation(Vector3(-local_position)));
1673 backdrop_entity.SetClipDepth(std::numeric_limits<uint32_t>::max());
1674 backdrop_entity.Render(renderer_, GetCurrentRenderPass());
1675 }
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:1402
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:295
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 366 of file canvas.cc.

366 {
367 Concat(Matrix::MakeScale(scale));
368 }
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 370 of file canvas.cc.

370 {
371 Concat(Matrix::MakeScale(scale));
372 }

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 2092 of file canvas.cc.

2094 {
2095 backdrop_data_ = std::move(backdrop_data);
2096 backdrop_count_ = backdrop_count;
2097 }

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

## ◆ Skew()

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

Definition at line 374 of file canvas.cc.

374 {
375 Concat(Matrix::MakeSkew(sx, sy));
376 }
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 2215 of file canvas.cc.

2215 {
2216 return renderer_.GetContext()
2217 ->GetCapabilities()
2218 ->SupportsTextureToTextureBlits() &&
2219 renderer_.GetContext()->GetBackendType() ==
2220 Context::BackendType::kMetal;
2221 }
impeller::Context::BackendType::kMetal
@ kMetal

## ◆ Transform()

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

Definition at line 354 of file canvas.cc.

354 {
355 Concat(transform);
356 }

References Concat(), and transform.

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

## ◆ Translate()

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

Definition at line 362 of file canvas.cc.

362 {
363 Concat(Matrix::MakeTranslation(offset));
364 }

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