Flutter Impeller
paint.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_DISPLAY_LIST_PAINT_H_
6 #define FLUTTER_IMPELLER_DISPLAY_LIST_PAINT_H_
7 
8 #include <memory>
9 
10 #include "display_list/effects/dl_color_filter.h"
11 #include "display_list/effects/dl_color_sources.h"
12 #include "display_list/effects/dl_image_filter.h"
20 #include "impeller/entity/entity.h"
24 
25 namespace impeller {
26 
27 struct Paint {
28  using ImageFilterProc = std::function<std::shared_ptr<FilterContents>(
30  const Matrix& effect_transform,
31  Entity::RenderingMode rendering_mode)>;
32  using MaskFilterProc = std::function<std::shared_ptr<FilterContents>(
34  bool is_solid_color,
35  const Matrix& effect_transform)>;
36  using ColorSourceProc = std::function<std::shared_ptr<ColorSourceContents>()>;
37 
38  /// @brief Whether or not a save layer with the provided paint can perform the
39  /// opacity peephole optimization.
40  static bool CanApplyOpacityPeephole(const Paint& paint) {
41  return paint.blend_mode == BlendMode::kSrcOver &&
42  paint.invert_colors == false &&
43  !paint.mask_blur_descriptor.has_value() &&
44  paint.image_filter == nullptr && paint.color_filter == nullptr;
45  }
46 
47  enum class Style {
48  kFill,
49  kStroke,
50  };
51 
55  /// Text mask blurs need to not apply the CTM to the blur kernel.
56  /// See: https://github.com/flutter/flutter/issues/115112
57  bool respect_ctm = true;
58 
59  std::shared_ptr<FilterContents> CreateMaskBlur(
60  std::shared_ptr<ColorSourceContents> color_source_contents,
61  const flutter::DlColorFilter* color_filter,
62  bool invert_colors,
63  FillRectGeometry* rect_geom) const;
64 
65  std::shared_ptr<FilterContents> CreateMaskBlur(
66  std::shared_ptr<TextureContents> texture_contents,
67  FillRectGeometry* rect_geom) const;
68 
69  std::shared_ptr<FilterContents> CreateMaskBlur(
70  const FilterInput::Ref& input,
71  bool is_solid_color,
72  const Matrix& ctm) const;
73  };
74 
76  const flutter::DlColorSource* color_source = nullptr;
77  const flutter::DlColorFilter* color_filter = nullptr;
78  const flutter::DlImageFilter* image_filter = nullptr;
79 
83  bool invert_colors = false;
84 
85  std::optional<MaskBlurDescriptor> mask_blur_descriptor;
86 
87  /// @brief Wrap this paint's configured filters to the given contents.
88  /// @param[in] input The contents to wrap with paint's filters.
89  /// @return The filter-wrapped contents. If there are no filters that need
90  /// to be wrapped for the current paint configuration, the
91  /// original contents is returned.
92  std::shared_ptr<Contents> WithFilters(std::shared_ptr<Contents> input) const;
93 
94  /// @brief Wrap this paint's configured filters to the given contents of
95  /// subpass target.
96  /// @param[in] input The contents of subpass target to wrap with paint's
97  /// filters.
98  ///
99  /// @return The filter-wrapped contents. If there are no filters that need
100  /// to be wrapped for the current paint configuration, the
101  /// original contents is returned.
102  std::shared_ptr<Contents> WithFiltersForSubpassTarget(
103  std::shared_ptr<Contents> input,
104  const Matrix& effect_transform = Matrix()) const;
105 
106  /// @brief Whether this paint has a color filter that can apply opacity
107  bool HasColorFilter() const;
108 
109  std::shared_ptr<ColorSourceContents> CreateContents() const;
110 
111  std::shared_ptr<Contents> WithMaskBlur(std::shared_ptr<Contents> input,
112  bool is_solid_color,
113  const Matrix& ctm) const;
114 
115  std::shared_ptr<FilterContents> WithImageFilter(
116  const FilterInput::Variant& input,
117  const Matrix& effect_transform,
118  Entity::RenderingMode rendering_mode) const;
119 
120  /// @brief Convert display list colors + stops into impeller colors and
121  /// stops, taking care to ensure that the stops monotonically
122  /// increase from 0.0 to 1.0.
123  ///
124  /// The general process is:
125  /// * Ensure that the first gradient stop value is 0.0. If not, insert a
126  /// new stop with a value of 0.0 and use the first gradient color as this
127  /// new stops color.
128  /// * Ensure the last gradient stop value is 1.0. If not, insert a new stop
129  /// with a value of 1.0 and use the last gradient color as this stops color.
130  /// * Clamp all gradient values between the values of 0.0 and 1.0.
131  /// * For all stop values, ensure that the values are monotonically
132  /// increasing by clamping each value to a minimum of the previous stop
133  /// value and itself. For example, with stop values of 0.0, 0.5, 0.4, 1.0,
134  /// we would clamp such that the values were 0.0, 0.5, 0.5, 1.0.
135  static void ConvertStops(const flutter::DlGradientColorSourceBase* gradient,
136  std::vector<Color>& colors,
137  std::vector<float>& stops);
138 
139  private:
140  std::shared_ptr<Contents> WithColorFilter(
141  std::shared_ptr<Contents> input,
142  ColorFilterContents::AbsorbOpacity absorb_opacity =
144 };
145 
146 } // namespace impeller
147 
148 #endif // FLUTTER_IMPELLER_DISPLAY_LIST_PAINT_H_
std::shared_ptr< FilterInput > Ref
Definition: filter_input.h:32
std::variant< std::shared_ptr< FilterContents >, std::shared_ptr< Contents >, std::shared_ptr< Texture >, Rect > Variant
Definition: filter_input.h:37
BlendMode
Definition: color.h:58
static constexpr Color Black()
Definition: color.h:266
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
FilterContents::BlurStyle style
Definition: paint.h:53
std::shared_ptr< FilterContents > CreateMaskBlur(std::shared_ptr< ColorSourceContents > color_source_contents, const flutter::DlColorFilter *color_filter, bool invert_colors, FillRectGeometry *rect_geom) const
Definition: paint.cc:395
std::shared_ptr< Contents > WithFilters(std::shared_ptr< Contents > input) const
Wrap this paint's configured filters to the given contents.
Definition: paint.cc:278
const flutter::DlColorFilter * color_filter
Definition: paint.h:77
const flutter::DlColorSource * color_source
Definition: paint.h:76
std::function< std::shared_ptr< FilterContents >(FilterInput::Ref, const Matrix &effect_transform, Entity::RenderingMode rendering_mode)> ImageFilterProc
Definition: paint.h:31
static 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: paint.cc:37
const flutter::DlImageFilter * image_filter
Definition: paint.h:78
std::function< std::shared_ptr< ColorSourceContents >()> ColorSourceProc
Definition: paint.h:36
Style style
Definition: paint.h:81
std::shared_ptr< Contents > WithMaskBlur(std::shared_ptr< Contents > input, bool is_solid_color, const Matrix &ctm) const
Definition: paint.cc:302
bool invert_colors
Definition: paint.h:83
static bool CanApplyOpacityPeephole(const Paint &paint)
Whether or not a save layer with the provided paint can perform the opacity peephole optimization.
Definition: paint.h:40
std::optional< MaskBlurDescriptor > mask_blur_descriptor
Definition: paint.h:85
Color color
Definition: paint.h:75
BlendMode blend_mode
Definition: paint.h:82
std::function< std::shared_ptr< FilterContents >(FilterInput::Ref, bool is_solid_color, const Matrix &effect_transform)> MaskFilterProc
Definition: paint.h:35
std::shared_ptr< Contents > WithFiltersForSubpassTarget(std::shared_ptr< Contents > input, const Matrix &effect_transform=Matrix()) const
Wrap this paint's configured filters to the given contents of subpass target.
Definition: paint.cc:289
std::shared_ptr< FilterContents > WithImageFilter(const FilterInput::Variant &input, const Matrix &effect_transform, Entity::RenderingMode rendering_mode) const
Definition: paint.cc:312
StrokeParameters stroke
Definition: paint.h:80
std::shared_ptr< ColorSourceContents > CreateContents() const
Definition: paint.cc:62
bool HasColorFilter() const
Whether this paint has a color filter that can apply opacity.
Definition: paint.cc:469
In filters that use Gaussian distributions, "sigma" is a size of one standard deviation in terms of t...
Definition: sigma.h:32
A structure to store all of the parameters related to stroking a path or basic geometry object.