| Flutter Impeller |

line_geometry.h
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef FLUTTER_IMPELLER_ENTITY_GEOMETRY_LINE_GEOMETRY_H_
6 #define FLUTTER_IMPELLER_ENTITY_GEOMETRY_LINE_GEOMETRY_H_
7
8 #include "impeller/entity/geometry/geometry.h"
9
10 namespace impeller {
11
12 class LineGeometry final : public Geometry {
13 public:
14 explicit LineGeometry(Point p0, Point p1, const StrokeParameters& stroke);
15
16 ~LineGeometry() override;
17
18 static Scalar ComputePixelHalfWidth(const Matrix& transform, Scalar width);
19
20 // |Geometry|
21 bool CoversArea(const Matrix& transform, const Rect& rect) const override;
22
23 // |Geometry|
24 bool IsAxisAlignedRect() const override;
25
26 Scalar ComputeAlphaCoverage(const Matrix& transform) const override;
27
28 // |Geometry|
29 std::optional<Rect> GetCoverage(const Matrix& transform) const override;
30
31 Point GetP0() const { return p0_; }
32 Point GetP1() const { return p1_; }
33 Scalar GetWidth() const { return width_; }
34 Cap GetCap() const { return cap_; }
35
36 static Vector2 ComputeAlongVector(const Matrix& transform,
37 bool allow_zero_length,
38 Point p0,
39 Point p1,
40 Scalar width);
41
42 // Computes the 4 corners of a rectangle that defines the line and
43 // possibly extended endpoints which will be rendered under the given
44 // transform, and returns true if such a rectangle is defined.
45 //
46 // The coordinates will be generated in the original coordinate system
47 // of the line end points and the transform will only be used to determine
48 // the minimum line width.
49 //
50 // For kButt and kSquare end caps the ends should always be exteded as
51 // per that decoration, but for kRound caps the ends might be extended
52 // if the goal is to get a conservative bounds and might not be extended
53 // if the calling code is planning to draw the round caps on the ends.
54 //
55 // @return true if the transform and width were not degenerate
56 static bool ComputeCorners(Point corners[4],
57 const Matrix& transform,
58 bool extend_endpoints,
59 Point p0,
60 Point p1,
61 Scalar width);
62
63 private:
64 // |Geometry|
65 GeometryResult GetPositionBuffer(const ContentContext& renderer,
66 const Entity& entity,
67 RenderPass& pass) const override;
68
69 Point p0_;
70 Point p1_;
71 Scalar width_;
72 Cap cap_;
73
74 LineGeometry(const LineGeometry&) = delete;
75
76 LineGeometry& operator=(const LineGeometry&) = delete;
77 };
78
79 } // namespace impeller
80
81 #endif // FLUTTER_IMPELLER_ENTITY_GEOMETRY_LINE_GEOMETRY_H_
impeller::ContentContext
Definition: content_context.h:122
impeller::Entity
Definition: entity.h:26
impeller::Geometry
Definition: geometry.h:50
impeller::LineGeometry
Definition: line_geometry.h:12
impeller::LineGeometry::~LineGeometry
~LineGeometry() override
impeller::LineGeometry::ComputeAlongVector
static Vector2 ComputeAlongVector(const Matrix &transform, bool allow_zero_length, Point p0, Point p1, Scalar width)
Definition: line_geometry.cc:29
impeller::LineGeometry::GetP1
Point GetP1() const
Definition: line_geometry.h:32
impeller::LineGeometry::ComputePixelHalfWidth
static Scalar ComputePixelHalfWidth(const Matrix &transform, Scalar width)
Definition: line_geometry.cc:18
impeller::LineGeometry::GetWidth
Scalar GetWidth() const
Definition: line_geometry.h:33
impeller::LineGeometry::GetCap
Cap GetCap() const
Definition: line_geometry.h:34
impeller::LineGeometry::LineGeometry
LineGeometry(Point p0, Point p1, const StrokeParameters &stroke)
Definition: line_geometry.cc:11
impeller::LineGeometry::IsAxisAlignedRect
bool IsAxisAlignedRect() const override
Definition: line_geometry.cc:178
impeller::LineGeometry::ComputeAlphaCoverage
Scalar ComputeAlphaCoverage(const Matrix &transform) const override
Definition: line_geometry.cc:77
impeller::LineGeometry::ComputeCorners
static bool ComputeCorners(Point corners[4], const Matrix &transform, bool extend_endpoints, Point p0, Point p1, Scalar width)
Definition: line_geometry.cc:52
impeller::LineGeometry::GetCoverage
std::optional< Rect > GetCoverage(const Matrix &transform) const override
Definition: line_geometry.cc:156
impeller::LineGeometry::GetP0
Point GetP0() const
Definition: line_geometry.h:31
impeller::LineGeometry::CoversArea
bool CoversArea(const Matrix &transform, const Rect &rect) const override
Determines if this geometry, transformed by the given transform, will completely cover all surface ar...
Definition: line_geometry.cc:170
impeller::RenderPass
Render passes encode render commands directed as one specific render target into an underlying comman...
Definition: render_pass.h:30
transform
Matrix transform
Definition: gaussian_blur_filter_contents.cc:312
geometry.h
impeller
Definition: allocation.cc:12
impeller::Scalar
float Scalar
Definition: scalar.h:19
impeller::Cap
Cap
An enum that describes ways to decorate the end of a path contour.
Definition: stroke_parameters.h:13
impeller::GeometryResult
Definition: geometry.h:21
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
impeller::StrokeParameters
A structure to store all of the parameters related to stroking a path or basic geometry object.
Definition: stroke_parameters.h:28
impeller::TPoint< Scalar >
impeller::TRect< Scalar >