| Flutter Impeller |

filter_contents.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_CONTENTS_FILTERS_FILTER_CONTENTS_H_
6 #define FLUTTER_IMPELLER_ENTITY_CONTENTS_FILTERS_FILTER_CONTENTS_H_
7
8 #include <memory>
9 #include <optional>
10 #include <variant>
11 #include <vector>
12
13 #include "impeller/core/formats.h"
14 #include "impeller/entity/contents/filters/inputs/filter_input.h"
15 #include "impeller/entity/contents/runtime_effect_contents.h"
16 #include "impeller/entity/entity.h"
17 #include "impeller/entity/geometry/geometry.h"
18 #include "impeller/geometry/matrix.h"
19 #include "impeller/geometry/sigma.h"
20 #include "impeller/runtime_stage/runtime_stage.h"
21
22 namespace impeller {
23
24 class FilterContents : public Contents {
25 public:
26 static const int32_t kBlurFilterRequiredMipCount;
27
28 enum class BlurStyle {
29 /// Blurred inside and outside.
30 kNormal,
31 /// Solid inside, blurred outside.
32 kSolid,
33 /// Nothing inside, blurred outside.
34 kOuter,
35 /// Blurred inside, nothing outside.
36 kInner,
37 };
38
39 enum class MorphType { kDilate, kErode };
40
41 /// Creates a gaussian blur that operates in 2 dimensions.
42 /// See also: `MakeDirectionalGaussianBlur`
43 static std::shared_ptr<FilterContents> MakeGaussianBlur(
44 const FilterInput::Ref& input,
45 Sigma sigma_x,
46 Sigma sigma_y,
47 Entity::TileMode tile_mode = Entity::TileMode::kDecal,
48 BlurStyle mask_blur_style = BlurStyle::kNormal,
49 const Geometry* mask_geometry = nullptr);
50
51 static std::shared_ptr<FilterContents> MakeBorderMaskBlur(
52 FilterInput::Ref input,
53 Sigma sigma_x,
54 Sigma sigma_y,
55 BlurStyle blur_style = BlurStyle::kNormal);
56
57 static std::shared_ptr<FilterContents> MakeDirectionalMorphology(
58 FilterInput::Ref input,
59 Radius radius,
60 Vector2 direction,
61 MorphType morph_type);
62
63 static std::shared_ptr<FilterContents> MakeMorphology(FilterInput::Ref input,
64 Radius radius_x,
65 Radius radius_y,
66 MorphType morph_type);
67
68 static std::shared_ptr<FilterContents> MakeMatrixFilter(
69 FilterInput::Ref input,
70 const Matrix& matrix,
71 const SamplerDescriptor& desc);
72
73 static std::shared_ptr<FilterContents> MakeLocalMatrixFilter(
74 FilterInput::Ref input,
75 const Matrix& matrix);
76
77 static std::shared_ptr<FilterContents> MakeYUVToRGBFilter(
78 std::shared_ptr<Texture> y_texture,
79 std::shared_ptr<Texture> uv_texture,
80 YUVColorSpace yuv_color_space);
81
82 static std::shared_ptr<FilterContents> MakeRuntimeEffect(
83 FilterInput::Ref input,
84 std::shared_ptr<RuntimeStage> runtime_stage,
85 std::shared_ptr<std::vector<uint8_t>> uniforms,
86 std::vector<RuntimeEffectContents::TextureInput> texture_inputs);
87
88 FilterContents();
89
90 ~FilterContents() override;
91
92 /// @brief The input texture sources for this filter. Each input's emitted
93 /// texture is expected to have premultiplied alpha colors.
94 ///
95 /// The number of required or optional textures depends on the
96 /// particular filter's implementation.
97 void SetInputs(FilterInput::Vector inputs);
98
99 /// @brief Sets the transform which gets appended to the effect of this
100 /// filter. Note that this is in addition to the entity's transform.
101 ///
102 /// This is useful for subpass rendering scenarios where it's
103 /// difficult to encode the current transform of the layer into the
104 /// Entity being rendered.
105 void SetEffectTransform(const Matrix& effect_transform);
106
107 /// @brief Create an Entity that renders this filter's output.
108 std::optional<Entity> GetEntity(
109 const ContentContext& renderer,
110 const Entity& entity,
111 const std::optional<Rect>& coverage_hint) const;
112
113 // |Contents|
114 bool Render(const ContentContext& renderer,
115 const Entity& entity,
116 RenderPass& pass) const override;
117
118 // |Contents|
119 std::optional<Rect> GetCoverage(const Entity& entity) const override;
120
121 // |Contents|
122 std::optional<Snapshot> RenderToSnapshot(
123 const ContentContext& renderer,
124 const Entity& entity,
125 std::optional<Rect> coverage_limit = std::nullopt,
126 const std::optional<SamplerDescriptor>& sampler_descriptor = std::nullopt,
127 bool msaa_enabled = true,
128 int32_t mip_count = 1,
129 std::string_view label = "Filter Snapshot") const override;
130
131 /// @brief Determines the coverage of source pixels that will be needed
132 /// to produce results for the specified |output_limit| under the
133 /// specified |effect_transform|. This is essentially a reverse of
134 /// the |GetCoverage| method computing a source coverage from
135 /// an intended |output_limit| coverage.
136 ///
137 /// Both the |output_limit| and the return value are in the
138 /// transformed coordinate space, and so do not need to be
139 /// transformed or inverse transformed by the |effect_transform|
140 /// but individual parameters on the filter might be in the
141 /// untransformed space and should be transformed by the
142 /// |effect_transform| before applying them to the coverages.
143 ///
144 /// The method computes a result such that if the filter is applied
145 /// to a set of pixels filling the computed source coverage, it
146 /// should produce an output that covers the entire specified
147 /// |output_limit|.
148 ///
149 /// This is useful for subpass rendering scenarios where a filter
150 /// will be applied to the output of the subpass and we need to
151 /// determine how large of a render target to allocate in order
152 /// to collect all pixels that might affect the supplied output
153 /// coverage limit. While we might end up clipping the rendering
154 /// of the subpass to its destination, we want to avoid clipping
155 /// out any pixels that contribute to the output limit via the
156 /// filtering operation.
157 ///
158 /// @return The coverage bounds in the transformed space of any source pixel
159 /// that may be needed to produce output for the indicated filter
160 /// that covers the indicated |output_limit|.
161 std::optional<Rect> GetSourceCoverage(const Matrix& effect_transform,
162 const Rect& output_limit) const;
163
164 virtual Matrix GetLocalTransform(const Matrix& parent_transform) const;
165
166 Matrix GetTransform(const Matrix& parent_transform) const;
167
168 /// @brief Marks this filter chain as applying in a subpass scenario.
169 ///
170 /// Subpasses render in screenspace, and this setting informs filters
171 /// that the current transform matrix of the entity is not stored
172 /// in the Entity transform matrix. Instead, the effect transform
173 /// is used in this case.
174 virtual void SetRenderingMode(Entity::RenderingMode rendering_mode);
175
176 private:
177 /// @brief Internal utility method for |GetLocalCoverage| that computes
178 /// the output coverage of this filter across the specified inputs,
179 /// ignoring the coverage hint.
180 virtual std::optional<Rect> GetFilterCoverage(
181 const FilterInput::Vector& inputs,
182 const Entity& entity,
183 const Matrix& effect_transform) const;
184
185 /// @brief Internal utility method for |GetSourceCoverage| that computes
186 /// the inverse effect of this transform on the specified output
187 /// coverage, ignoring the inputs which will be accommodated by
188 /// the caller.
189 virtual std::optional<Rect> GetFilterSourceCoverage(
190 const Matrix& effect_transform,
191 const Rect& output_limit) const = 0;
192
193 /// Applies the specific filter logic to the given inputs and returns an
194 /// Entity representing the filtered result.
195 ///
196 /// This is the primary method that subclasses must implement to define their
197 /// filtering behavior. It takes the results of evaluating the filter inputs
198 /// (as Snapshots) and produces a new Entity containing the filtered output.
199 ///
200 /// @param[in] inputs The evaluated inputs to the filter, typically as
201 /// Snapshots.
202 /// @param[in] renderer The content context providing rendering resources.
203 /// @param[in] entity The entity applying this filter, providing transform,
204 /// blend mode, and other context.
205 /// @param[in] effect_transform An additional transform applied after the
206 /// entity's transform, often used in subpass scenarios.
207 /// @param[in] coverage The calculated coverage area of the filter's output
208 /// in the coordinate space after applying the entity and effect transforms.
209 /// @param[in] coverage_hint An optional hint representing the desired output
210 /// coverage area, which can be used for optimization (e.g., rendering only a
211 /// portion of the input).
212 ///
213 /// @return An optional Entity containing the rendered result of the filter.
214 /// Returns `std::nullopt` if the filter cannot be applied or results in empty
215 /// output.
216 virtual std::optional<Entity> RenderFilter(
217 const FilterInput::Vector& inputs,
218 const ContentContext& renderer,
219 const Entity& entity,
220 const Matrix& effect_transform,
221 const Rect& coverage,
222 const std::optional<Rect>& coverage_hint) const = 0;
223
224 /// @brief Internal utility method to compute the coverage of this
225 /// filter across its internally specified inputs and subject
226 /// to the coverage hint.
227 ///
228 /// Uses |GetFilterCoverage|.
229 std::optional<Rect> GetLocalCoverage(const Entity& local_entity) const;
230
231 FilterInput::Vector inputs_;
232 Matrix effect_transform_ = Matrix();
233
234 FilterContents(const FilterContents&) = delete;
235
236 FilterContents& operator=(const FilterContents&) = delete;
237 };
238
239 } // namespace impeller
240
241 #endif // FLUTTER_IMPELLER_ENTITY_CONTENTS_FILTERS_FILTER_CONTENTS_H_
impeller::ContentContext
Definition: content_context.h:138
impeller::Contents
Definition: contents.h:31
impeller::Entity
Definition: entity.h:26
impeller::Entity::TileMode
TileMode
Definition: entity.h:48
impeller::Entity::TileMode::kDecal
@ kDecal
impeller::Entity::RenderingMode
RenderingMode
Definition: entity.h:33
impeller::FilterContents
Definition: filter_contents.h:24
impeller::FilterContents::kBlurFilterRequiredMipCount
static const int32_t kBlurFilterRequiredMipCount
Definition: filter_contents.h:26
impeller::FilterContents::BlurStyle
BlurStyle
Definition: filter_contents.h:28
impeller::FilterContents::BlurStyle::kNormal
@ kNormal
Blurred inside and outside.
impeller::FilterContents::BlurStyle::kOuter
@ kOuter
Nothing inside, blurred outside.
impeller::FilterContents::BlurStyle::kInner
@ kInner
Blurred inside, nothing outside.
impeller::FilterContents::BlurStyle::kSolid
@ kSolid
Solid inside, blurred outside.
impeller::FilterContents::GetEntity
std::optional< Entity > GetEntity(const ContentContext &renderer, const Entity &entity, const std::optional< Rect > &coverage_hint) const
Create an Entity that renders this filter's output.
Definition: filter_contents.cc:232
impeller::FilterContents::MakeDirectionalMorphology
static std::shared_ptr< FilterContents > MakeDirectionalMorphology(FilterInput::Ref input, Radius radius, Vector2 direction, MorphType morph_type)
Definition: filter_contents.cc:62
impeller::FilterContents::FilterContents
FilterContents()
impeller::FilterContents::GetCoverage
std::optional< Rect > GetCoverage(const Entity &entity) const override
Get the area of the render pass that will be affected when this contents is rendered.
Definition: filter_contents.cc:176
impeller::FilterContents::~FilterContents
~FilterContents() override
impeller::FilterContents::GetTransform
Matrix GetTransform(const Matrix &parent_transform) const
Definition: filter_contents.cc:284
impeller::FilterContents::MorphType
MorphType
Definition: filter_contents.h:39
impeller::FilterContents::MorphType::kErode
@ kErode
impeller::FilterContents::MorphType::kDilate
@ kDilate
impeller::FilterContents::Render
bool Render(const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
Definition: filter_contents.cc:147
impeller::FilterContents::MakeMorphology
static std::shared_ptr< FilterContents > MakeMorphology(FilterInput::Ref input, Radius radius_x, Radius radius_y, MorphType morph_type)
Definition: filter_contents.cc:75
impeller::FilterContents::MakeBorderMaskBlur
static std::shared_ptr< FilterContents > MakeBorderMaskBlur(FilterInput::Ref input, Sigma sigma_x, Sigma sigma_y, BlurStyle blur_style=BlurStyle::kNormal)
Definition: filter_contents.cc:50
impeller::FilterContents::MakeLocalMatrixFilter
static std::shared_ptr< FilterContents > MakeLocalMatrixFilter(FilterInput::Ref input, const Matrix &matrix)
Definition: filter_contents.cc:98
impeller::FilterContents::MakeGaussianBlur
static std::shared_ptr< FilterContents > MakeGaussianBlur(const FilterInput::Ref &input, Sigma sigma_x, Sigma sigma_y, Entity::TileMode tile_mode=Entity::TileMode::kDecal, BlurStyle mask_blur_style=BlurStyle::kNormal, const Geometry *mask_geometry=nullptr)
Definition: filter_contents.cc:37
impeller::FilterContents::SetInputs
void SetInputs(FilterInput::Vector inputs)
The input texture sources for this filter. Each input's emitted texture is expected to have premultip...
Definition: filter_contents.cc:135
impeller::FilterContents::SetRenderingMode
virtual void SetRenderingMode(Entity::RenderingMode rendering_mode)
Marks this filter chain as applying in a subpass scenario.
Definition: filter_contents.cc:288
impeller::FilterContents::GetSourceCoverage
std::optional< Rect > GetSourceCoverage(const Matrix &effect_transform, const Rect &output_limit) const
Determines the coverage of source pixels that will be needed to produce results for the specified |ou...
Definition: filter_contents.cc:210
impeller::FilterContents::SetEffectTransform
void SetEffectTransform(const Matrix &effect_transform)
Sets the transform which gets appended to the effect of this filter. Note that this is in addition to...
Definition: filter_contents.cc:139
impeller::FilterContents::MakeMatrixFilter
static std::shared_ptr< FilterContents > MakeMatrixFilter(FilterInput::Ref input, const Matrix &matrix, const SamplerDescriptor &desc)
Definition: filter_contents.cc:87
impeller::FilterContents::RenderToSnapshot
std::optional< Snapshot > RenderToSnapshot(const ContentContext &renderer, const Entity &entity, std::optional< Rect > coverage_limit=std::nullopt, const std::optional< SamplerDescriptor > &sampler_descriptor=std::nullopt, bool msaa_enabled=true, int32_t mip_count=1, std::string_view label="Filter Snapshot") const override
Render this contents to a snapshot, respecting the entity's transform, path, clip depth,...
Definition: filter_contents.cc:253
impeller::FilterContents::MakeYUVToRGBFilter
static std::shared_ptr< FilterContents > MakeYUVToRGBFilter(std::shared_ptr< Texture > y_texture, std::shared_ptr< Texture > uv_texture, YUVColorSpace yuv_color_space)
Definition: filter_contents.cc:107
impeller::FilterContents::MakeRuntimeEffect
static std::shared_ptr< FilterContents > MakeRuntimeEffect(FilterInput::Ref input, std::shared_ptr< RuntimeStage > runtime_stage, std::shared_ptr< std::vector< uint8_t >> uniforms, std::vector< RuntimeEffectContents::TextureInput > texture_inputs)
Definition: filter_contents.cc:118
impeller::FilterContents::GetLocalTransform
virtual Matrix GetLocalTransform(const Matrix &parent_transform) const
Definition: filter_contents.cc:280
impeller::FilterInput::Ref
std::shared_ptr< FilterInput > Ref
Definition: filter_input.h:32
impeller::FilterInput::Vector
std::vector< FilterInput::Ref > Vector
Definition: filter_input.h:33
impeller::Geometry
Definition: geometry.h:50
impeller::RenderPass
Render passes encode render commands directed as one specific render target into an underlying comman...
Definition: render_pass.h:30
formats.h
entity.h
filter_input.h
geometry.h
matrix.h
impeller
Definition: allocation.cc:12
impeller::YUVColorSpace
YUVColorSpace
Definition: color.h:54
runtime_effect_contents.h
runtime_stage.h
sigma.h
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
impeller::Radius
For convolution filters, the "radius" is the size of the convolution kernel to use on the local space...
Definition: sigma.h:48
impeller::SamplerDescriptor
Definition: sampler_descriptor.h:14
impeller::Sigma
In filters that use Gaussian distributions, "sigma" is a size of one standard deviation in terms of t...
Definition: sigma.h:32
impeller::TPoint< Scalar >
impeller::TRect< Scalar >