| Flutter Impeller |

line_contents_unittests.cc
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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 #include "impeller/entity/contents/line_contents.h"
6
7 #include <algorithm>
8
9 #include "impeller/geometry/geometry_asserts.h"
10 #include "third_party/googletest/googletest/include/gtest/gtest.h"
11
12 namespace impeller {
13 namespace testing {
14
15 namespace {
16 float lookup(Scalar x) {
17 return std::clamp(x, /*lo=*/0.f, /*hi=*/1.f);
18 }
19
20 // This mirrors the function in line.frag.
21 float CalculateLine(const LineVertexShader::PerVertexData& per_vertex,
22 Point position) {
23 Vector3 pos = Vector3(position.x, position.y, 1.0);
24 Scalar d[4] = {pos.Dot(per_vertex.e0), pos.Dot(per_vertex.e1),
25 pos.Dot(per_vertex.e2), pos.Dot(per_vertex.e3)};
26
27 for (int i = 0; i < 4; ++i) {
28 if (d[i] < 0.f) {
29 return 0.0;
30 }
31 }
32
33 return lookup(std::min(d[0], d[2])) * lookup(std::min(d[1], d[3]));
34 }
35 } // namespace
36
37 TEST(LineContents, Create) {
38 Scalar width = 5.0f;
39 auto geometry = std::make_unique<LineGeometry>(
40 /*p0=*/Point{0, 0}, //
41 /*p1=*/Point{100, 100}, //
42 StrokeParameters{
43 .width = width,
44 .cap = Cap::kSquare,
45 });
46 std::unique_ptr<LineContents> contents =
47 LineContents::Make(std::move(geometry), Color(1.f, 0.f, 0.f, 1.f));
48 EXPECT_TRUE(contents);
49 Entity entity;
50 std::optional<Rect> coverage = contents->GetCoverage(entity);
51 EXPECT_TRUE(coverage.has_value());
52 if (coverage.has_value()) {
53 Scalar lip = sqrt((width * width) / 2.f);
54 EXPECT_EQ(*coverage,
55 Rect::MakeXYWH(-lip, -lip, 100 + 2 * lip, 100 + 2 * lip));
56 }
57 }
58
59 TEST(LineContents, CalculatePerVertex) {
60 LineVertexShader::PerVertexData per_vertex[4];
61 auto geometry = std::make_unique<LineGeometry>(
62 /*p0=*/Point{100, 100}, //
63 /*p1=*/Point{200, 100}, //
64 StrokeParameters{
65 .width = 5.f,
66 .cap = Cap::kButt,
67 });
68 Matrix transform;
69
70 fml::StatusOr<LineContents::EffectiveLineParameters> status =
71 LineContents::CalculatePerVertex(per_vertex, geometry.get(), transform);
72 Scalar offset =
73 (LineContents::kSampleRadius * 2.0 + geometry->GetWidth()) / 2.f;
74 ASSERT_TRUE(status.ok());
75 EXPECT_EQ(status.value().width, 5.f);
76 EXPECT_EQ(status.value().radius, LineContents::kSampleRadius);
77 EXPECT_POINT_NEAR(per_vertex[0].position,
78 Point(100 - LineContents::kSampleRadius, 100 + offset));
79 EXPECT_POINT_NEAR(per_vertex[1].position,
80 Point(200 + LineContents::kSampleRadius, 100 + offset));
81 EXPECT_POINT_NEAR(per_vertex[2].position,
82 Point(100 - LineContents::kSampleRadius, 100 - offset));
83 EXPECT_POINT_NEAR(per_vertex[3].position,
84 Point(200 + LineContents::kSampleRadius, 100 - offset));
85
86 for (int i = 1; i < 4; ++i) {
87 EXPECT_VECTOR3_NEAR(per_vertex[0].e0, per_vertex[i].e0) << i;
88 EXPECT_VECTOR3_NEAR(per_vertex[0].e1, per_vertex[i].e1) << i;
89 EXPECT_VECTOR3_NEAR(per_vertex[0].e2, per_vertex[i].e2) << i;
90 EXPECT_VECTOR3_NEAR(per_vertex[0].e3, per_vertex[i].e3) << i;
91 }
92
93 EXPECT_EQ(CalculateLine(per_vertex[0], Point(0, 0)), 0.f);
94 EXPECT_NEAR(CalculateLine(per_vertex[0], Point(150, 100 + offset)), 0.f,
95 kEhCloseEnough);
96 EXPECT_NEAR(CalculateLine(per_vertex[0], Point(150, 100 + offset * 0.5)),
97 0.5f, kEhCloseEnough);
98 EXPECT_NEAR(CalculateLine(per_vertex[0], Point(150, 100)), 1.f,
99 kEhCloseEnough);
100 }
101
102 TEST(LineContents, CreateCurveData) {
103 std::vector<uint8_t> data = LineContents::CreateCurveData(/*width=*/31,
104 /*radius=*/1,
105 /*scale=*/1);
106 EXPECT_EQ(data.size(), 32u);
107 EXPECT_NEAR(data[0] / 255.f, 0.f, kEhCloseEnough);
108 EXPECT_NEAR(data[1] / 255.f, 0.5f, 0.02);
109 EXPECT_NEAR(data[2] / 255.f, 1.f, kEhCloseEnough);
110 EXPECT_NEAR(data[3] / 255.f, 1.f, kEhCloseEnough);
111 }
112
113 TEST(LineContents, CreateCurveDataScaled) {
114 std::vector<uint8_t> data = LineContents::CreateCurveData(/*width=*/15.5,
115 /*radius=*/1,
116 /*scale=*/2);
117 EXPECT_EQ(data.size(), 32u);
118 EXPECT_NEAR(data[0] / 255.f, 0.f, kEhCloseEnough);
119 EXPECT_NEAR(data[1] / 255.f, 0.5f, 0.02);
120 EXPECT_NEAR(data[2] / 255.f, 1.f, kEhCloseEnough);
121 EXPECT_NEAR(data[3] / 255.f, 1.f, kEhCloseEnough);
122 }
123
124 // This scales the line to be less than 1 pixel.
125 TEST(LineContents, CalculatePerVertexLimit) {
126 LineVertexShader::PerVertexData per_vertex[4];
127 Scalar scale = 0.05;
128 auto geometry = std::make_unique<LineGeometry>(
129 /*p0=*/Point{100, 100}, //
130 /*p1=*/Point{200, 100}, //
131 StrokeParameters{
132 .width = 10.f,
133 .cap = Cap::kButt,
134 });
135 Matrix transform = Matrix::MakeTranslation({100, 100, 1.0}) *
136 Matrix::MakeScale({scale, scale, 1.0}) *
137 Matrix::MakeTranslation({-100, -100, 1.0});
138
139 fml::StatusOr<LineContents::EffectiveLineParameters> status =
140 LineContents::CalculatePerVertex(per_vertex, geometry.get(), transform);
141
142 Scalar one_radius_size = std::max(LineContents::kSampleRadius / scale,
143 LineContents::kSampleRadius);
144 Scalar one_px_size = 1.f / scale;
145 Scalar offset = one_px_size / 2.f + one_radius_size;
146 ASSERT_TRUE(status.ok());
147 EXPECT_NEAR(status.value().width, 20.f, kEhCloseEnough);
148 EXPECT_NEAR(status.value().radius, one_px_size * LineContents::kSampleRadius,
149 kEhCloseEnough);
150 EXPECT_POINT_NEAR(per_vertex[0].position,
151 Point(100 - one_radius_size, 100 + offset));
152 EXPECT_POINT_NEAR(per_vertex[1].position,
153 Point(200 + one_radius_size, 100 + offset));
154 EXPECT_POINT_NEAR(per_vertex[2].position,
155 Point(100 - one_radius_size, 100 - offset));
156 EXPECT_POINT_NEAR(per_vertex[3].position,
157 Point(200 + one_radius_size, 100 - offset));
158
159 EXPECT_NEAR(CalculateLine(per_vertex[0], Point(150, 100)), 1.f,
160 kEhCloseEnough);
161 // EXPECT_NEAR(CalculateLine(per_vertex[0], Point(150, 100 +
162 // one_px_size)), 1.f,
163 // kEhCloseEnough);
164 }
165
166 } // namespace testing
167 } // namespace impeller
impeller::Entity
Definition: entity.h:26
impeller::Entity::GetCoverage
std::optional< Rect > GetCoverage() const
Definition: entity.cc:66
impeller::LineContents
Definition: line_contents.h:15
impeller::LineContents::Make
static std::unique_ptr< LineContents > Make(std::unique_ptr< LineGeometry > geometry, Color color)
Definition: line_contents.cc:137
impeller::LineContents::CreateCurveData
static std::vector< uint8_t > CreateCurveData(Scalar width, Scalar radius, Scalar scale)
Definition: line_contents.cc:198
impeller::LineContents::kSampleRadius
static const Scalar kSampleRadius
Definition: line_contents.h:17
impeller::LineContents::CalculatePerVertex
static fml::StatusOr< EffectiveLineParameters > CalculatePerVertex(LineVertexShader::PerVertexData *per_vertex, const LineGeometry *geometry, const Matrix &entity_transform)
Definition: line_contents.cc:227
x
int32_t x
Definition: dl_golden_unittests.cc:458
transform
Matrix transform
Definition: gaussian_blur_filter_contents.cc:214
geometry_asserts.h
EXPECT_VECTOR3_NEAR
#define EXPECT_VECTOR3_NEAR(a, b)
Definition: geometry_asserts.h:206
EXPECT_POINT_NEAR
#define EXPECT_POINT_NEAR(a, b)
Definition: geometry_asserts.h:205
e0
Vector3 e0
Definition: line_contents.cc:106
e3
Vector3 e3
Definition: line_contents.cc:109
e2
Vector3 e2
Definition: line_contents.cc:108
e1
Vector3 e1
Definition: line_contents.cc:107
line_contents.h
impeller::interop::Create
ScopedObject< Object > Create(CtorArgs &&... args)
Definition: object.h:161
impeller::testing::TEST
TEST(AllocationSizeTest, CanCreateTypedAllocations)
Definition: allocation_size_unittests.cc:10
impeller
Definition: allocation.cc:12
impeller::Scalar
float Scalar
Definition: scalar.h:19
impeller::kEhCloseEnough
constexpr float kEhCloseEnough
Definition: constants.h:57
impeller::Point
TPoint< Scalar > Point
Definition: point.h:327
impeller::Cap::kButt
@ kButt
impeller::Cap::kSquare
@ kSquare
impeller::Color
Definition: color.h:124
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
impeller::Matrix::MakeTranslation
static constexpr Matrix MakeTranslation(const Vector3 &t)
Definition: matrix.h:95
impeller::Matrix::MakeScale
static constexpr Matrix MakeScale(const Vector3 &s)
Definition: matrix.h:104
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::StrokeParameters::width
Scalar width
Definition: stroke_parameters.h:29
impeller::TPoint< Scalar >
impeller::TRect< Scalar >::MakeXYWH
constexpr static TRect MakeXYWH(Type x, Type y, Type width, Type height)
Definition: rect.h:136
data
std::shared_ptr< const fml::Mapping > data
Definition: texture_gles.cc:69