| 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/entity.h"
16 #include "impeller/entity/geometry/geometry.h"
17 #include "impeller/geometry/matrix.h"
18 #include "impeller/geometry/sigma.h"
19
20 namespace impeller {
21
22 class FilterContents : public Contents {
23 public:
24 static const int32_t kBlurFilterRequiredMipCount;
25
26 enum class BlurStyle {
27 /// Blurred inside and outside.
28 kNormal,
29 /// Solid inside, blurred outside.
30 kSolid,
31 /// Nothing inside, blurred outside.
32 kOuter,
33 /// Blurred inside, nothing outside.
34 kInner,
35 };
36
37 enum class MorphType { kDilate, kErode };
38
39 /// Creates a gaussian blur that operates in 2 dimensions.
40 /// See also: `MakeDirectionalGaussianBlur`
41 static std::shared_ptr<FilterContents> MakeGaussianBlur(
42 const FilterInput::Ref& input,
43 Sigma sigma_x,
44 Sigma sigma_y,
45 Entity::TileMode tile_mode = Entity::TileMode::kDecal,
46 BlurStyle mask_blur_style = BlurStyle::kNormal,
47 const Geometry* mask_geometry = nullptr);
48
49 static std::shared_ptr<FilterContents> MakeBorderMaskBlur(
50 FilterInput::Ref input,
51 Sigma sigma_x,
52 Sigma sigma_y,
53 BlurStyle blur_style = BlurStyle::kNormal);
54
55 static std::shared_ptr<FilterContents> MakeDirectionalMorphology(
56 FilterInput::Ref input,
57 Radius radius,
58 Vector2 direction,
59 MorphType morph_type);
60
61 static std::shared_ptr<FilterContents> MakeMorphology(FilterInput::Ref input,
62 Radius radius_x,
63 Radius radius_y,
64 MorphType morph_type);
65
66 static std::shared_ptr<FilterContents> MakeMatrixFilter(
67 FilterInput::Ref input,
68 const Matrix& matrix,
69 const SamplerDescriptor& desc);
70
71 static std::shared_ptr<FilterContents> MakeLocalMatrixFilter(
72 FilterInput::Ref input,
73 const Matrix& matrix);
74
75 static std::shared_ptr<FilterContents> MakeYUVToRGBFilter(
76 std::shared_ptr<Texture> y_texture,
77 std::shared_ptr<Texture> uv_texture,
78 YUVColorSpace yuv_color_space);
79
80 FilterContents();
81
82 ~FilterContents() override;
83
84 /// @brief The input texture sources for this filter. Each input's emitted
85 /// texture is expected to have premultiplied alpha colors.
86 ///
87 /// The number of required or optional textures depends on the
88 /// particular filter's implementation.
89 void SetInputs(FilterInput::Vector inputs);
90
91 /// @brief Sets the transform which gets appended to the effect of this
92 /// filter. Note that this is in addition to the entity's transform.
93 ///
94 /// This is useful for subpass rendering scenarios where it's
95 /// difficult to encode the current transform of the layer into the
96 /// Entity being rendered.
97 void SetEffectTransform(const Matrix& effect_transform);
98
99 /// @brief Create an Entity that renders this filter's output.
100 std::optional<Entity> GetEntity(
101 const ContentContext& renderer,
102 const Entity& entity,
103 const std::optional<Rect>& coverage_hint) const;
104
105 // |Contents|
106 bool Render(const ContentContext& renderer,
107 const Entity& entity,
108 RenderPass& pass) const override;
109
110 // |Contents|
111 std::optional<Rect> GetCoverage(const Entity& entity) const override;
112
113 // |Contents|
114 std::optional<Snapshot> RenderToSnapshot(
115 const ContentContext& renderer,
116 const Entity& entity,
117 std::optional<Rect> coverage_limit = std::nullopt,
118 const std::optional<SamplerDescriptor>& sampler_descriptor = std::nullopt,
119 bool msaa_enabled = true,
120 int32_t mip_count = 1,
121 const std::string& label = "Filter Snapshot") const override;
122
123 // |Contents|
124 const FilterContents* AsFilter() const override;
125
126 /// @brief Determines the coverage of source pixels that will be needed
127 /// to produce results for the specified |output_limit| under the
128 /// specified |effect_transform|. This is essentially a reverse of
129 /// the |GetCoverage| method computing a source coverage from
130 /// an intended |output_limit| coverage.
131 ///
132 /// Both the |output_limit| and the return value are in the
133 /// transformed coordinate space, and so do not need to be
134 /// transformed or inverse transformed by the |effect_transform|
135 /// but individual parameters on the filter might be in the
136 /// untransformed space and should be transformed by the
137 /// |effect_transform| before applying them to the coverages.
138 ///
139 /// The method computes a result such that if the filter is applied
140 /// to a set of pixels filling the computed source coverage, it
141 /// should produce an output that covers the entire specified
142 /// |output_limit|.
143 ///
144 /// This is useful for subpass rendering scenarios where a filter
145 /// will be applied to the output of the subpass and we need to
146 /// determine how large of a render target to allocate in order
147 /// to collect all pixels that might affect the supplied output
148 /// coverage limit. While we might end up clipping the rendering
149 /// of the subpass to its destination, we want to avoid clipping
150 /// out any pixels that contribute to the output limit via the
151 /// filtering operation.
152 ///
153 /// @return The coverage bounds in the transformed space of any source pixel
154 /// that may be needed to produce output for the indicated filter
155 /// that covers the indicated |output_limit|.
156 std::optional<Rect> GetSourceCoverage(const Matrix& effect_transform,
157 const Rect& output_limit) const;
158
159 virtual Matrix GetLocalTransform(const Matrix& parent_transform) const;
160
161 Matrix GetTransform(const Matrix& parent_transform) const;
162
163 /// @brief Returns true if this filter graph doesn't perform any basis
164 /// transforms to the filtered content. For example: Rotating,
165 /// scaling, and skewing are all basis transforms, but
166 /// translating is not.
167 ///
168 /// This is useful for determining whether a filtered object's space
169 /// is compatible enough with the parent pass space to perform certain
170 /// subpass clipping optimizations.
171 virtual bool IsTranslationOnly() const;
172
173 /// @brief Returns `true` if this filter does not have any `FilterInput`
174 /// children.
175 bool IsLeaf() const;
176
177 /// @brief Replaces the set of all leaf `FilterContents` with a new set
178 /// of `FilterInput`s.
179 /// @see `FilterContents::IsLeaf`
180 void SetLeafInputs(const FilterInput::Vector& inputs);
181
182 /// @brief Marks this filter chain as applying in a subpass scenario.
183 ///
184 /// Subpasses render in screenspace, and this setting informs filters
185 /// that the current transform matrix of the entity is not stored
186 /// in the Entity transform matrix. Instead, the effect transform
187 /// is used in this case.
188 virtual void SetRenderingMode(Entity::RenderingMode rendering_mode);
189
190 private:
191 /// @brief Internal utility method for |GetLocalCoverage| that computes
192 /// the output coverage of this filter across the specified inputs,
193 /// ignoring the coverage hint.
194 virtual std::optional<Rect> GetFilterCoverage(
195 const FilterInput::Vector& inputs,
196 const Entity& entity,
197 const Matrix& effect_transform) const;
198
199 /// @brief Internal utility method for |GetSourceCoverage| that computes
200 /// the inverse effect of this transform on the specified output
201 /// coverage, ignoring the inputs which will be accommodated by
202 /// the caller.
203 virtual std::optional<Rect> GetFilterSourceCoverage(
204 const Matrix& effect_transform,
205 const Rect& output_limit) const = 0;
206
207 /// @brief Converts zero or more filter inputs into a render instruction.
208 virtual std::optional<Entity> RenderFilter(
209 const FilterInput::Vector& inputs,
210 const ContentContext& renderer,
211 const Entity& entity,
212 const Matrix& effect_transform,
213 const Rect& coverage,
214 const std::optional<Rect>& coverage_hint) const = 0;
215
216 /// @brief Internal utility method to compute the coverage of this
217 /// filter across its internally specified inputs and subject
218 /// to the coverage hint.
219 ///
220 /// Uses |GetFilterCoverage|.
221 std::optional<Rect> GetLocalCoverage(const Entity& local_entity) const;
222
223 FilterInput::Vector inputs_;
224 Matrix effect_transform_ = Matrix();
225
226 FilterContents(const FilterContents&) = delete;
227
228 FilterContents& operator=(const FilterContents&) = delete;
229 };
230
231 } // namespace impeller
232
233 #endif // FLUTTER_IMPELLER_ENTITY_CONTENTS_FILTERS_FILTER_CONTENTS_H_
impeller::FilterContents::IsLeaf
bool IsLeaf() const
Returns true if this filter does not have any FilterInput children.
Definition: filter_contents.cc:280
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:121
impeller::FilterContents::MorphType::kErode
@ kErode
impeller::FilterContents::FilterContents
FilterContents()
geometry.h
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:196
entity.h
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:125
impeller::FilterContents::BlurStyle
BlurStyle
Definition: filter_contents.h:26
impeller::Entity::TileMode::kDecal
@ kDecal
impeller::FilterContents::GetTransform
Matrix GetTransform(const Matrix &parent_transform) const
Definition: filter_contents.cc:268
impeller::FilterInput::Ref
std::shared_ptr< FilterInput > Ref
Definition: filter_input.h:32
formats.h
impeller::FilterContents::BlurStyle::kNormal
@ kNormal
Blurred inside and outside.
impeller::SamplerDescriptor
Definition: sampler_descriptor.h:15
matrix.h
impeller::Entity
Definition: entity.h:20
impeller::FilterContents::Render
bool Render(const ContentContext &renderer, const Entity &entity, RenderPass &pass) const override
Definition: filter_contents.cc:133
sigma.h
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::FilterContents::BlurStyle::kSolid
@ kSolid
Solid inside, blurred outside.
impeller::FilterContents::IsTranslationOnly
virtual bool IsTranslationOnly() const
Returns true if this filter graph doesn't perform any basis transforms to the filtered content....
Definition: filter_contents.cc:271
impeller::FilterContents::MakeDirectionalMorphology
static std::shared_ptr< FilterContents > MakeDirectionalMorphology(FilterInput::Ref input, Radius radius, Vector2 direction, MorphType morph_type)
Definition: filter_contents.cc:61
impeller::Sigma
In filters that use Gaussian distributions, "sigma" is a size of one standard deviation in terms of t...
Definition: sigma.h:32
filter_input.h
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:49
impeller::FilterContents::BlurStyle::kInner
@ kInner
Blurred inside, nothing outside.
impeller::FilterContents::kBlurFilterRequiredMipCount
static const int32_t kBlurFilterRequiredMipCount
Definition: filter_contents.h:24
impeller::Entity::TileMode
TileMode
Definition: entity.h:42
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:106
impeller::RenderPass
Render passes encode render commands directed as one specific render target into an underlying comman...
Definition: render_pass.h:33
impeller::FilterContents::MorphType
MorphType
Definition: filter_contents.h:37
impeller::FilterContents::BlurStyle::kOuter
@ kOuter
Nothing inside, blurred outside.
impeller::Geometry
Definition: geometry.h:55
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:74
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, const std::string &label="Filter Snapshot") const override
Render this contents to a snapshot, respecting the entity's transform, path, clip depth,...
Definition: filter_contents.cc:234
impeller::FilterContents::MorphType::kDilate
@ kDilate
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:162
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:218
impeller::FilterContents::SetLeafInputs
void SetLeafInputs(const FilterInput::Vector &inputs)
Replaces the set of all leaf FilterContents with a new set of FilterInputs.
Definition: filter_contents.cc:289
impeller::TPoint< Scalar >
impeller::FilterContents::MakeMatrixFilter
static std::shared_ptr< FilterContents > MakeMatrixFilter(FilterInput::Ref input, const Matrix &matrix, const SamplerDescriptor &desc)
Definition: filter_contents.cc:86
impeller::YUVColorSpace
YUVColorSpace
Definition: color.h:54
impeller::FilterContents::GetLocalTransform
virtual Matrix GetLocalTransform(const Matrix &parent_transform) const
Definition: filter_contents.cc:264
impeller::FilterContents::SetRenderingMode
virtual void SetRenderingMode(Entity::RenderingMode rendering_mode)
Marks this filter chain as applying in a subpass scenario.
Definition: filter_contents.cc:299
impeller::Entity::RenderingMode
RenderingMode
Definition: entity.h:27
impeller::FilterContents::MakeLocalMatrixFilter
static std::shared_ptr< FilterContents > MakeLocalMatrixFilter(FilterInput::Ref input, const Matrix &matrix)
Definition: filter_contents.cc:97
impeller::FilterInput::Vector
std::vector< FilterInput::Ref > Vector
Definition: filter_input.h:33
impeller::Contents
Definition: contents.h:31
impeller::FilterContents::~FilterContents
~FilterContents() override
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:36
impeller
Definition: allocation.cc:12
impeller::ContentContext
Definition: content_context.h:366
impeller::FilterContents::AsFilter
const FilterContents * AsFilter() const override
Cast to a filter. Returns nullptr if this Contents is not a filter.
Definition: filter_contents.cc:260
impeller::TRect
Definition: rect.h:122
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:37
impeller::FilterContents
Definition: filter_contents.h:22