Flutter Impeller
impeller::Geometry Class Referenceabstract

#include <geometry.h>

Inheritance diagram for impeller::Geometry:
impeller::ArcGeometry impeller::CircleGeometry impeller::CoverGeometry impeller::EllipseGeometry impeller::FillPathSourceGeometry impeller::FillRectGeometry impeller::LineGeometry impeller::PointFieldGeometry impeller::RoundRectGeometry impeller::RoundSuperellipseGeometry impeller::StrokeRectGeometry impeller::StrokeSegmentsGeometry impeller::SuperellipseGeometry impeller::VerticesGeometry

Public Member Functions

virtual ~Geometry ()
 
virtual GeometryResult GetPositionBuffer (const ContentContext &renderer, const Entity &entity, RenderPass &pass) const =0
 
virtual GeometryResult::Mode GetResultMode () const
 
virtual std::optional< RectGetCoverage (const Matrix &transform) const =0
 
virtual bool CoversArea (const Matrix &transform, const Rect &rect) const
 Determines if this geometry, transformed by the given transform, will completely cover all surface area of the given rect. More...
 
virtual bool IsAxisAlignedRect () const
 
virtual bool CanApplyMaskFilter () const
 
virtual Scalar ComputeAlphaCoverage (const Matrix &transform) const
 

Static Public Member Functions

static std::unique_ptr< GeometryMakeFillPath (const flutter::DlPath &path, std::optional< Rect > inner_rect=std::nullopt)
 
static std::unique_ptr< GeometryMakeStrokePath (const flutter::DlPath &path, const StrokeParameters &stroke={})
 
static std::unique_ptr< GeometryMakeCover ()
 
static std::unique_ptr< GeometryMakeRect (const Rect &rect)
 
static std::unique_ptr< GeometryMakeOval (const Rect &rect)
 
static std::unique_ptr< GeometryMakeLine (const Point &p0, const Point &p1, const StrokeParameters &stroke)
 
static std::unique_ptr< GeometryMakeCircle (const Point &center, Scalar radius)
 
static std::unique_ptr< GeometryMakeStrokedCircle (const Point &center, Scalar radius, Scalar stroke_width)
 
static std::unique_ptr< GeometryMakeFilledArc (const Rect &oval_bounds, Degrees start, Degrees sweep, bool include_center)
 
static std::unique_ptr< GeometryMakeStrokedArc (const Rect &oval_bounds, Degrees start, Degrees sweep, const StrokeParameters &stroke)
 
static std::unique_ptr< GeometryMakeRoundRect (const Rect &rect, const Size &radii)
 
static std::unique_ptr< GeometryMakeRoundSuperellipse (const Rect &rect, Scalar corner_radius)
 
static Scalar ComputeStrokeAlphaCoverage (const Matrix &entity, Scalar stroke_width)
 Compute an alpha value to simulate lower coverage of fractional pixel strokes. More...
 
static GeometryResult ComputePositionGeometry (const ContentContext &renderer, const Tessellator::VertexGenerator &generator, const Entity &entity, RenderPass &pass)
 

Detailed Description

Definition at line 50 of file geometry.h.

Constructor & Destructor Documentation

◆ ~Geometry()

virtual impeller::Geometry::~Geometry ( )
inlinevirtual

Definition at line 52 of file geometry.h.

52 {}

Member Function Documentation

◆ CanApplyMaskFilter()

bool impeller::Geometry::CanApplyMaskFilter ( ) const
virtual

Reimplemented in impeller::CoverGeometry, and impeller::DlVerticesGeometry.

Definition at line 144 of file geometry.cc.

144  {
145  return true;
146 }

◆ ComputeAlphaCoverage()

virtual Scalar impeller::Geometry::ComputeAlphaCoverage ( const Matrix transform) const
inlinevirtual

◆ ComputePositionGeometry()

GeometryResult impeller::Geometry::ComputePositionGeometry ( const ContentContext renderer,
const Tessellator::VertexGenerator generator,
const Entity entity,
RenderPass pass 
)
static

Definition at line 26 of file geometry.cc.

30  {
31  using VT = SolidFillVertexShader::PerVertexData;
32 
33  size_t count = generator.GetVertexCount();
34 
35  return GeometryResult{
36  .type = generator.GetTriangleType(),
37  .vertex_buffer =
38  {
39  .vertex_buffer = renderer.GetTransientsBuffer().Emplace(
40  count * sizeof(VT), alignof(VT),
41  [&generator](uint8_t* buffer) {
42  auto vertices = reinterpret_cast<VT*>(buffer);
43  generator.GenerateVertices([&vertices](const Point& p) {
44  *vertices++ = {
45  .position = p,
46  };
47  });
48  FML_DCHECK(vertices == reinterpret_cast<VT*>(buffer) +
49  generator.GetVertexCount());
50  }),
51  .vertex_count = count,
52  .index_type = IndexType::kNone,
53  },
54  .transform = entity.GetShaderTransform(pass),
55  };
56 }
@ kNone
Does not use the index buffer.
TPoint< Scalar > Point
Definition: point.h:327

References impeller::HostBuffer::Emplace(), impeller::Tessellator::VertexGenerator::GenerateVertices(), impeller::Entity::GetShaderTransform(), impeller::ContentContext::GetTransientsBuffer(), impeller::Tessellator::VertexGenerator::GetTriangleType(), impeller::Tessellator::VertexGenerator::GetVertexCount(), impeller::kNone, and impeller::GeometryResult::type.

◆ ComputeStrokeAlphaCoverage()

Scalar impeller::Geometry::ComputeStrokeAlphaCoverage ( const Matrix entity,
Scalar  stroke_width 
)
static

Compute an alpha value to simulate lower coverage of fractional pixel strokes.

Definition at line 149 of file geometry.cc.

150  {
151  Scalar scaled_stroke_width = transform.GetMaxBasisLengthXY() * stroke_width;
152  if (scaled_stroke_width == 0.0 || scaled_stroke_width >= kMinStrokeSize) {
153  return 1.0;
154  }
155  // This scalling is eyeballed from Skia.
156  return std::clamp(scaled_stroke_width * 2.0f, 0.f, 1.f);
157 }
float Scalar
Definition: scalar.h:19
static constexpr Scalar kMinStrokeSize
Definition: geometry.h:19

References impeller::kMinStrokeSize, and transform.

Referenced by impeller::ArcGeometry::ComputeAlphaCoverage(), impeller::CircleGeometry::ComputeAlphaCoverage(), impeller::LineGeometry::ComputeAlphaCoverage(), and impeller::StrokeSegmentsGeometry::ComputeAlphaCoverage().

◆ CoversArea()

bool impeller::Geometry::CoversArea ( const Matrix transform,
const Rect rect 
) const
virtual

Determines if this geometry, transformed by the given transform, will completely cover all surface area of the given rect.

This is a conservative estimate useful for certain optimizations.

Returns
true if the transformed geometry is guaranteed to cover the given rect. May return false in many undetected cases where the transformed geometry does in fact cover the rect.

Reimplemented in impeller::SuperellipseGeometry, impeller::RoundSuperellipseGeometry, impeller::FillRoundRectGeometry, impeller::RoundRectGeometry, impeller::FillRectGeometry, impeller::LineGeometry, impeller::FillPathSourceGeometry, impeller::EllipseGeometry, impeller::CoverGeometry, impeller::CircleGeometry, and impeller::ArcGeometry.

Definition at line 136 of file geometry.cc.

136  {
137  return false;
138 }

Referenced by impeller::SolidColorContents::AsBackgroundColor().

◆ GetCoverage()

◆ GetPositionBuffer()

◆ GetResultMode()

GeometryResult::Mode impeller::Geometry::GetResultMode ( ) const
virtual

Definition at line 58 of file geometry.cc.

58  {
60 }
@ kNormal
The geometry has no overlapping triangles.

References impeller::GeometryResult::kNormal.

Referenced by impeller::ColorSourceContents::DrawGeometry().

◆ IsAxisAlignedRect()

bool impeller::Geometry::IsAxisAlignedRect ( ) const
virtual

◆ MakeCircle()

std::unique_ptr< Geometry > impeller::Geometry::MakeCircle ( const Point center,
Scalar  radius 
)
static

Definition at line 97 of file geometry.cc.

98  {
99  return std::make_unique<CircleGeometry>(center, radius);
100 }

Referenced by impeller::testing::TEST().

◆ MakeCover()

std::unique_ptr< Geometry > impeller::Geometry::MakeCover ( )
static

Definition at line 79 of file geometry.cc.

79  {
80  return std::make_unique<CoverGeometry>();
81 }

Referenced by impeller::testing::TEST_P().

◆ MakeFilledArc()

std::unique_ptr< Geometry > impeller::Geometry::MakeFilledArc ( const Rect oval_bounds,
Degrees  start,
Degrees  sweep,
bool  include_center 
)
static

Definition at line 108 of file geometry.cc.

111  {
112  return std::make_unique<ArcGeometry>(
113  Arc(oval_bounds, start, sweep, include_center));
114 }
const size_t start

References start.

Referenced by impeller::testing::TEST().

◆ MakeFillPath()

std::unique_ptr< Geometry > impeller::Geometry::MakeFillPath ( const flutter::DlPath &  path,
std::optional< Rect inner_rect = std::nullopt 
)
static

Definition at line 62 of file geometry.cc.

64  {
65  return std::make_unique<FillPathGeometry>(path, inner_rect);
66 }

Referenced by impeller::testing::TEST(), and impeller::testing::TEST_P().

◆ MakeLine()

std::unique_ptr< Geometry > impeller::Geometry::MakeLine ( const Point p0,
const Point p1,
const StrokeParameters stroke 
)
static

Definition at line 91 of file geometry.cc.

93  {
94  return std::make_unique<LineGeometry>(p0, p1, stroke);
95 }

Referenced by impeller::testing::TEST().

◆ MakeOval()

std::unique_ptr< Geometry > impeller::Geometry::MakeOval ( const Rect rect)
static

Definition at line 87 of file geometry.cc.

87  {
88  return std::make_unique<EllipseGeometry>(rect);
89 }

◆ MakeRect()

std::unique_ptr< Geometry > impeller::Geometry::MakeRect ( const Rect rect)
static

Definition at line 83 of file geometry.cc.

83  {
84  return std::make_unique<FillRectGeometry>(rect);
85 }

Referenced by impeller::Canvas::DrawVertices(), impeller::testing::TEST(), and impeller::testing::TEST_P().

◆ MakeRoundRect()

std::unique_ptr< Geometry > impeller::Geometry::MakeRoundRect ( const Rect rect,
const Size radii 
)
static

Definition at line 125 of file geometry.cc.

126  {
127  return std::make_unique<RoundRectGeometry>(rect, radii);
128 }

Referenced by impeller::testing::TEST().

◆ MakeRoundSuperellipse()

std::unique_ptr< Geometry > impeller::Geometry::MakeRoundSuperellipse ( const Rect rect,
Scalar  corner_radius 
)
static

Definition at line 130 of file geometry.cc.

132  {
133  return std::make_unique<RoundSuperellipseGeometry>(rect, corner_radius);
134 }

Referenced by impeller::testing::TEST_P().

◆ MakeStrokedArc()

std::unique_ptr< Geometry > impeller::Geometry::MakeStrokedArc ( const Rect oval_bounds,
Degrees  start,
Degrees  sweep,
const StrokeParameters stroke 
)
static

Definition at line 116 of file geometry.cc.

120  {
121  return std::make_unique<ArcGeometry>(Arc(oval_bounds, start, sweep, false),
122  stroke);
123 }

References start.

Referenced by impeller::testing::TEST().

◆ MakeStrokedCircle()

std::unique_ptr< Geometry > impeller::Geometry::MakeStrokedCircle ( const Point center,
Scalar  radius,
Scalar  stroke_width 
)
static

Definition at line 102 of file geometry.cc.

104  {
105  return std::make_unique<CircleGeometry>(center, radius, stroke_width);
106 }

Referenced by impeller::testing::TEST().

◆ MakeStrokePath()

std::unique_ptr< Geometry > impeller::Geometry::MakeStrokePath ( const flutter::DlPath &  path,
const StrokeParameters stroke = {} 
)
static

Definition at line 68 of file geometry.cc.

70  {
71  // Skia behaves like this.
72  StrokeParameters parameters = stroke;
73  if (parameters.miter_limit < 0) {
74  parameters.miter_limit = 4.0;
75  }
76  return std::make_unique<StrokePathGeometry>(path, parameters);
77 }

References impeller::StrokeParameters::miter_limit.

Referenced by impeller::testing::TEST(), and impeller::testing::TEST_P().


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