| 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 <type_traits>
9 #include "impeller/entity/geometry/geometry.h"
10
11 namespace impeller {
12
13 class LineGeometry final : public Geometry {
14 public:
15 explicit LineGeometry(Point p0, Point p1, Scalar width, Cap cap);
16
17 ~LineGeometry() = default;
18
19 static Scalar ComputePixelHalfWidth(const Matrix& transform, Scalar width);
20
21 // |Geometry|
22 bool CoversArea(const Matrix& transform, const Rect& rect) const override;
23
24 // |Geometry|
25 bool IsAxisAlignedRect() const override;
26
27 private:
28 // Computes the 4 corners of a rectangle that defines the line and
29 // possibly extended endpoints which will be rendered under the given
30 // transform, and returns true if such a rectangle is defined.
31 //
32 // The coordinates will be generated in the original coordinate system
33 // of the line end points and the transform will only be used to determine
34 // the minimum line width.
35 //
36 // For kButt and kSquare end caps the ends should always be exteded as
37 // per that decoration, but for kRound caps the ends might be extended
38 // if the goal is to get a conservative bounds and might not be extended
39 // if the calling code is planning to draw the round caps on the ends.
40 //
41 // @return true if the transform and width were not degenerate
42 bool ComputeCorners(Point corners[4],
43 const Matrix& transform,
44 bool extend_endpoints) const;
45
46 Vector2 ComputeAlongVector(const Matrix& transform,
47 bool allow_zero_length) const;
48
49 // |Geometry|
50 GeometryResult GetPositionBuffer(const ContentContext& renderer,
51 const Entity& entity,
52 RenderPass& pass) const override;
53
54 // |Geometry|
55 std::optional<Rect> GetCoverage(const Matrix& transform) const override;
56
57 Point p0_;
58 Point p1_;
59 Scalar width_;
60 Cap cap_;
61
62 LineGeometry(const LineGeometry&) = delete;
63
64 LineGeometry& operator=(const LineGeometry&) = delete;
65 };
66
67 static_assert(std::is_trivially_destructible<LineGeometry>::value);
68
69 } // namespace impeller
70
71 #endif // FLUTTER_IMPELLER_ENTITY_GEOMETRY_LINE_GEOMETRY_H_
impeller::Scalar
float Scalar
Definition: scalar.h:18
impeller::LineGeometry::LineGeometry
LineGeometry(Point p0, Point p1, Scalar width, Cap cap)
Definition: line_geometry.cc:9
impeller::Entity
Definition: entity.h:20
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:123
transform
Matrix transform
Definition: gaussian_blur_filter_contents.cc:231
impeller::LineGeometry
Definition: line_geometry.h:13
geometry.h
impeller::GeometryResult
Definition: geometry.h:19
impeller::LineGeometry::IsAxisAlignedRect
bool IsAxisAlignedRect() const override
Definition: line_geometry.cc:131
impeller::LineGeometry::ComputePixelHalfWidth
static Scalar ComputePixelHalfWidth(const Matrix &transform, Scalar width)
Definition: line_geometry.cc:14
impeller::RenderPass
Render passes encode render commands directed as one specific render target into an underlying comman...
Definition: render_pass.h:33
impeller::Geometry
Definition: geometry.h:48
impeller::TPoint< Scalar >
impeller::LineGeometry::~LineGeometry
~LineGeometry()=default
impeller
Definition: aiks_blend_unittests.cc:18
impeller::ContentContext
Definition: content_context.h:366
impeller::TRect< Scalar >
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
impeller::Cap
Cap
Definition: path.h:18