Flutter Impeller
skia_conversions.cc
Go to the documentation of this file.
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 
6 #include "display_list/dl_color.h"
7 #include "third_party/skia/modules/skparagraph/include/Paragraph.h"
8 
9 namespace impeller {
10 namespace skia_conversions {
11 
12 Rect ToRect(const SkRect& rect) {
13  return Rect::MakeLTRB(rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
14 }
15 
16 std::optional<Rect> ToRect(const SkRect* rect) {
17  if (rect == nullptr) {
18  return std::nullopt;
19  }
20  return Rect::MakeLTRB(rect->fLeft, rect->fTop, rect->fRight, rect->fBottom);
21 }
22 
23 std::vector<Rect> ToRects(const SkRect tex[], int count) {
24  auto result = std::vector<Rect>();
25  for (int i = 0; i < count; i++) {
26  result.push_back(ToRect(tex[i]));
27  }
28  return result;
29 }
30 
31 std::vector<Point> ToPoints(const SkPoint points[], int count) {
32  std::vector<Point> result(count);
33  for (auto i = 0; i < count; i++) {
34  result[i] = ToPoint(points[i]);
35  }
36  return result;
37 }
38 
40  using Corner = SkRRect::Corner;
42  radii.bottom_left = ToPoint(rrect.radii(Corner::kLowerLeft_Corner));
43  radii.bottom_right = ToPoint(rrect.radii(Corner::kLowerRight_Corner));
44  radii.top_left = ToPoint(rrect.radii(Corner::kUpperLeft_Corner));
45  radii.top_right = ToPoint(rrect.radii(Corner::kUpperRight_Corner));
46  return radii;
47 }
48 
49 Path ToPath(const SkPath& path, Point shift) {
50  auto iterator = SkPath::Iter(path, false);
51 
52  struct PathData {
53  union {
54  SkPoint points[4];
55  };
56  };
57 
58  PathBuilder builder;
59  PathData data;
60  // Reserve a path size with some arbitrarily additional padding.
61  builder.Reserve(path.countPoints() + 8, path.countVerbs() + 8);
62  auto verb = SkPath::Verb::kDone_Verb;
63  do {
64  verb = iterator.next(data.points);
65  switch (verb) {
66  case SkPath::kMove_Verb:
67  builder.MoveTo(ToPoint(data.points[0]));
68  break;
69  case SkPath::kLine_Verb:
70  builder.LineTo(ToPoint(data.points[1]));
71  break;
72  case SkPath::kQuad_Verb:
73  builder.QuadraticCurveTo(ToPoint(data.points[1]),
74  ToPoint(data.points[2]));
75  break;
76  case SkPath::kConic_Verb: {
77  constexpr auto kPow2 = 1; // Only works for sweeps up to 90 degrees.
78  constexpr auto kQuadCount = 1 + (2 * (1 << kPow2));
79  SkPoint points[kQuadCount];
80  const auto curve_count =
81  SkPath::ConvertConicToQuads(data.points[0], //
82  data.points[1], //
83  data.points[2], //
84  iterator.conicWeight(), //
85  points, //
86  kPow2 //
87  );
88 
89  for (int curve_index = 0, point_index = 0; //
90  curve_index < curve_count; //
91  curve_index++, point_index += 2 //
92  ) {
93  builder.QuadraticCurveTo(ToPoint(points[point_index + 1]),
94  ToPoint(points[point_index + 2]));
95  }
96  } break;
97  case SkPath::kCubic_Verb:
98  builder.CubicCurveTo(ToPoint(data.points[1]), ToPoint(data.points[2]),
99  ToPoint(data.points[3]));
100  break;
101  case SkPath::kClose_Verb:
102  builder.Close();
103  break;
104  case SkPath::kDone_Verb:
105  break;
106  }
107  } while (verb != SkPath::Verb::kDone_Verb);
108 
109  FillType fill_type;
110  switch (path.getFillType()) {
111  case SkPathFillType::kWinding:
112  fill_type = FillType::kNonZero;
113  break;
114  case SkPathFillType::kEvenOdd:
115  fill_type = FillType::kOdd;
116  break;
117  case SkPathFillType::kInverseWinding:
118  case SkPathFillType::kInverseEvenOdd:
119  // Flutter doesn't expose these path fill types. These are only visible
120  // via the receiver interface. We should never get here.
121  fill_type = FillType::kNonZero;
122  break;
123  }
124  builder.SetConvexity(path.isConvex() ? Convexity::kConvex
126  builder.Shift(shift);
127  auto sk_bounds = path.getBounds().makeOutset(shift.x, shift.y);
128  builder.SetBounds(ToRect(sk_bounds));
129  return builder.TakePath(fill_type);
130 }
131 
132 Path ToPath(const SkRRect& rrect) {
133  return PathBuilder{}
134  .AddRoundedRect(ToRect(rrect.getBounds()), ToRoundingRadii(rrect))
136  .SetBounds(ToRect(rrect.getBounds()))
137  .TakePath();
138 }
139 
140 Point ToPoint(const SkPoint& point) {
141  return Point::MakeXY(point.fX, point.fY);
142 }
143 
144 Size ToSize(const SkPoint& point) {
145  return Size(point.fX, point.fY);
146 }
147 
148 Color ToColor(const flutter::DlColor& color) {
149  return {
150  static_cast<Scalar>(color.getRedF()), //
151  static_cast<Scalar>(color.getGreenF()), //
152  static_cast<Scalar>(color.getBlueF()), //
153  static_cast<Scalar>(color.getAlphaF()) //
154  };
155 }
156 
157 std::vector<Matrix> ToRSXForms(const SkRSXform xform[], int count) {
158  auto result = std::vector<Matrix>();
159  for (int i = 0; i < count; i++) {
160  auto form = xform[i];
161  // clang-format off
162  auto matrix = Matrix{
163  form.fSCos, form.fSSin, 0, 0,
164  -form.fSSin, form.fSCos, 0, 0,
165  0, 0, 1, 0,
166  form.fTx, form.fTy, 0, 1
167  };
168  // clang-format on
169  result.push_back(matrix);
170  }
171  return result;
172 }
173 
174 Path PathDataFromTextBlob(const sk_sp<SkTextBlob>& blob, Point shift) {
175  if (!blob) {
176  return {};
177  }
178 
179  return ToPath(skia::textlayout::Paragraph::GetPath(blob.get()), shift);
180 }
181 
182 std::optional<impeller::PixelFormat> ToPixelFormat(SkColorType type) {
183  switch (type) {
184  case kRGBA_8888_SkColorType:
186  case kBGRA_8888_SkColorType:
188  case kRGBA_F16_SkColorType:
190  case kBGR_101010x_XR_SkColorType:
192  default:
193  return std::nullopt;
194  }
195  return std::nullopt;
196 }
197 
198 void ConvertStops(const flutter::DlGradientColorSourceBase* gradient,
199  std::vector<Color>& colors,
200  std::vector<float>& stops) {
201  FML_DCHECK(gradient->stop_count() >= 2);
202 
203  auto* dl_colors = gradient->colors();
204  auto* dl_stops = gradient->stops();
205  if (dl_stops[0] != 0.0) {
206  colors.emplace_back(skia_conversions::ToColor(dl_colors[0]));
207  stops.emplace_back(0);
208  }
209  for (auto i = 0; i < gradient->stop_count(); i++) {
210  colors.emplace_back(skia_conversions::ToColor(dl_colors[i]));
211  stops.emplace_back(std::clamp(dl_stops[i], 0.0f, 1.0f));
212  }
213  if (dl_stops[gradient->stop_count() - 1] != 1.0) {
214  colors.emplace_back(colors.back());
215  stops.emplace_back(1.0);
216  }
217  for (auto i = 1; i < gradient->stop_count(); i++) {
218  stops[i] = std::clamp(stops[i], stops[i - 1], stops[i]);
219  }
220 }
221 
222 } // namespace skia_conversions
223 } // namespace impeller
impeller::skia_conversions::PathDataFromTextBlob
Path PathDataFromTextBlob(const sk_sp< SkTextBlob > &blob, Point shift)
Definition: skia_conversions.cc:174
impeller::skia_conversions::ToPoints
std::vector< Point > ToPoints(const SkPoint points[], int count)
Definition: skia_conversions.cc:31
impeller::TPoint::y
Type y
Definition: point.h:31
impeller::Scalar
float Scalar
Definition: scalar.h:18
impeller::skia_conversions::ToPixelFormat
std::optional< impeller::PixelFormat > ToPixelFormat(SkColorType type)
Definition: skia_conversions.cc:182
impeller::skia_conversions::ConvertStops
void ConvertStops(const flutter::DlGradientColorSourceBase *gradient, std::vector< Color > &colors, std::vector< float > &stops)
Convert display list colors + stops into impeller colors and stops, taking care to ensure that the st...
Definition: skia_conversions.cc:198
impeller::FillType::kOdd
@ kOdd
impeller::skia_conversions::ToSize
Size ToSize(const SkPoint &point)
Definition: skia_conversions.cc:144
impeller::Color
Definition: color.h:124
impeller::PathBuilder::SetBounds
PathBuilder & SetBounds(Rect bounds)
Set the bounding box that will be used by Path.GetBoundingBox in place of performing the computation.
Definition: path_builder.cc:453
impeller::PixelFormat::kR8G8B8A8UNormInt
@ kR8G8B8A8UNormInt
impeller::PathBuilder::CubicCurveTo
PathBuilder & CubicCurveTo(Point controlPoint1, Point controlPoint2, Point point, bool relative=false)
Insert a cubic curve from the curren position to point using the control points controlPoint1 and con...
Definition: path_builder.cc:85
impeller::PathBuilder
Definition: path_builder.h:14
impeller::skia_conversions::ToRects
std::vector< Rect > ToRects(const SkRect tex[], int count)
Definition: skia_conversions.cc:23
impeller::skia_conversions::ToColor
Color ToColor(const flutter::DlColor &color)
Definition: skia_conversions.cc:148
impeller::PathBuilder::AddRoundedRect
PathBuilder & AddRoundedRect(Rect rect, RoundingRadii radii)
Definition: path_builder.cc:145
impeller::Size
TSize< Scalar > Size
Definition: size.h:137
impeller::PathBuilder::SetConvexity
PathBuilder & SetConvexity(Convexity value)
Definition: path_builder.cc:80
impeller::PathBuilder::RoundingRadii::bottom_right
Point bottom_right
Definition: path_builder.h:109
impeller::skia_conversions::ToRect
Rect ToRect(const SkRect &rect)
Definition: skia_conversions.cc:12
impeller::PathBuilder::RoundingRadii
Definition: path_builder.h:105
impeller::Convexity::kUnknown
@ kUnknown
impeller::TSize< Scalar >
impeller::skia_conversions::ToRoundingRadii
PathBuilder::RoundingRadii ToRoundingRadii(const SkRRect &rrect)
Definition: skia_conversions.cc:39
impeller::PathBuilder::Shift
PathBuilder & Shift(Point offset)
Transform the existing path segments and contours by the given offset.
Definition: path_builder.cc:442
skia_conversions.h
impeller::PathBuilder::QuadraticCurveTo
PathBuilder & QuadraticCurveTo(Point controlPoint, Point point, bool relative=false)
Insert a quadradic curve from the current position to point using the control point controlPoint.
Definition: path_builder.cc:70
impeller::Path
Paths are lightweight objects that describe a collection of linear, quadratic, or cubic segments....
Definition: path.h:51
impeller::PixelFormat::kB10G10R10XR
@ kB10G10R10XR
impeller::PathBuilder::LineTo
PathBuilder & LineTo(Point point, bool relative=false)
Insert a line from the current position to point.
Definition: path_builder.cc:47
impeller::PathBuilder::RoundingRadii::top_left
Point top_left
Definition: path_builder.h:106
impeller::FillType
FillType
Definition: path.h:29
impeller::PixelFormat::kR16G16B16A16Float
@ kR16G16B16A16Float
impeller::PathBuilder::TakePath
Path TakePath(FillType fill=FillType::kNonZero)
Definition: path_builder.cc:22
impeller::skia_conversions::ToPoint
Point ToPoint(const SkPoint &point)
Definition: skia_conversions.cc:140
impeller::FillType::kNonZero
@ kNonZero
impeller::TPoint::x
Type x
Definition: point.h:30
impeller::PathBuilder::Reserve
void Reserve(size_t point_size, size_t verb_size)
Reserve [point_size] points and [verb_size] verbs in the underlying path buffer.
Definition: path_builder.cc:28
impeller::PathBuilder::Close
PathBuilder & Close()
Definition: path_builder.cc:40
impeller::PathBuilder::RoundingRadii::top_right
Point top_right
Definition: path_builder.h:108
impeller::TPoint
Definition: point.h:27
impeller::PathBuilder::MoveTo
PathBuilder & MoveTo(Point point, bool relative=false)
Definition: path_builder.cc:33
impeller::skia_conversions::ToRSXForms
std::vector< Matrix > ToRSXForms(const SkRSXform xform[], int count)
Definition: skia_conversions.cc:157
impeller::PathBuilder::RoundingRadii::bottom_left
Point bottom_left
Definition: path_builder.h:107
impeller::TRect< Scalar >::MakeLTRB
constexpr static TRect MakeLTRB(Type left, Type top, Type right, Type bottom)
Definition: rect.h:129
impeller::Convexity::kConvex
@ kConvex
impeller::PixelFormat::kB8G8R8A8UNormInt
@ kB8G8R8A8UNormInt
impeller
Definition: aiks_blur_unittests.cc:20
impeller::skia_conversions::ToPath
Path ToPath(const SkPath &path, Point shift)
Definition: skia_conversions.cc:49
impeller::TRect< Scalar >
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
impeller::TPoint< Scalar >::MakeXY
static constexpr TPoint< Type > MakeXY(Type x, Type y)
Definition: point.h:46