Flutter Impeller
command.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_RENDERER_COMMAND_H_
6 #define FLUTTER_IMPELLER_RENDERER_COMMAND_H_
7 
8 #include <cstdint>
9 #include <memory>
10 #include <optional>
11 #include <string>
12 
14 #include "impeller/core/formats.h"
16 #include "impeller/core/sampler.h"
18 #include "impeller/core/texture.h"
20 #include "impeller/geometry/rect.h"
22 
23 namespace impeller {
24 
25 #ifdef IMPELLER_DEBUG
26 #define DEBUG_COMMAND_INFO(obj, arg) obj.label = arg;
27 #else
28 #define DEBUG_COMMAND_INFO(obj, arg)
29 #endif // IMPELLER_DEBUG
30 
31 template <class T>
32 struct Resource {
33  using ResourceType = T;
35 
36  Resource() {}
37 
38  Resource(const ShaderMetadata* metadata, ResourceType p_resource)
39  : resource(p_resource), metadata_(metadata) {}
40 
41  Resource(std::shared_ptr<const ShaderMetadata>& metadata,
42  ResourceType p_resource)
43  : resource(p_resource), dynamic_metadata_(metadata) {}
44 
45  const ShaderMetadata* GetMetadata() const {
46  return dynamic_metadata_ ? dynamic_metadata_.get() : metadata_;
47  }
48 
49  private:
50  // Static shader metadata (typically generated by ImpellerC).
51  const ShaderMetadata* metadata_ = nullptr;
52 
53  // Dynamically generated shader metadata.
54  std::shared_ptr<const ShaderMetadata> dynamic_metadata_;
55 };
56 
59 
60 /// @brief combines the texture, sampler and sampler slot information.
64  const std::unique_ptr<const Sampler>& sampler;
65 };
66 
67 /// @brief combines the buffer resource and its uniform slot information.
71 };
72 
73 struct Bindings {
74  std::vector<TextureAndSampler> sampled_images;
75  std::vector<BufferAndUniformSlot> buffers;
76 };
77 
78 //------------------------------------------------------------------------------
79 /// @brief An object used to specify work to the GPU along with references
80 /// to resources the GPU will used when doing said work.
81 ///
82 /// To construct a valid command, follow these steps:
83 /// * Specify a valid pipeline.
84 /// * Specify vertex information via a call `BindVertices`
85 /// * Specify any stage bindings.
86 /// * (Optional) Specify a debug label.
87 ///
88 /// Command can be created frequently and on demand. The resources
89 /// referenced in commands views into buffers managed by other
90 /// allocators and resource managers.
91 ///
92 struct Command : public ResourceBinder {
93  //----------------------------------------------------------------------------
94  /// The pipeline to use for this command.
95  ///
96  std::shared_ptr<Pipeline<PipelineDescriptor>> pipeline;
97  //----------------------------------------------------------------------------
98  /// The buffer, texture, and sampler bindings used by the vertex pipeline
99  /// stage.
100  ///
102  //----------------------------------------------------------------------------
103  /// The buffer, texture, and sampler bindings used by the fragment pipeline
104  /// stage.
105  ///
107 
108 #ifdef IMPELLER_DEBUG
109  //----------------------------------------------------------------------------
110  /// The debugging label to use for the command.
111  ///
112  std::string label;
113 #endif // IMPELLER_DEBUG
114 
115  //----------------------------------------------------------------------------
116  /// The reference value to use in stenciling operations. Stencil configuration
117  /// is part of pipeline setup and can be read from the pipelines descriptor.
118  ///
119  /// @see `Pipeline`
120  /// @see `PipelineDescriptor`
121  ///
122  uint32_t stencil_reference = 0u;
123  //----------------------------------------------------------------------------
124  /// The offset used when indexing into the vertex buffer.
125  ///
126  uint64_t base_vertex = 0u;
127  //----------------------------------------------------------------------------
128  /// The viewport coordinates that the rasterizer linearly maps normalized
129  /// device coordinates to.
130  /// If unset, the viewport is the size of the render target with a zero
131  /// origin, znear=0, and zfar=1.
132  ///
133  std::optional<Viewport> viewport;
134  //----------------------------------------------------------------------------
135  /// The scissor rect to use for clipping writes to the render target. The
136  /// scissor rect must lie entirely within the render target.
137  /// If unset, no scissor is applied.
138  ///
139  std::optional<IRect> scissor;
140  //----------------------------------------------------------------------------
141  /// The number of instances of the given set of vertices to render. Not all
142  /// backends support rendering more than one instance at a time.
143  ///
144  /// @warning Setting this to more than one will limit the availability of
145  /// backends to use with this command.
146  ///
147  size_t instance_count = 1u;
148 
149  //----------------------------------------------------------------------------
150  /// The bound per-vertex data and optional index buffer.
152 
153  //----------------------------------------------------------------------------
154  /// @brief Specify the vertex and index buffer to use for this command.
155  ///
156  /// @param[in] buffer The vertex and index buffer definition. If possible,
157  /// this value should be moved and not copied.
158  ///
159  /// @return returns if the binding was updated.
160  ///
161  bool BindVertices(VertexBuffer buffer);
162 
163  // |ResourceBinder|
164  bool BindResource(ShaderStage stage,
165  DescriptorType type,
166  const ShaderUniformSlot& slot,
167  const ShaderMetadata& metadata,
168  BufferView view) override;
169 
170  bool BindResource(ShaderStage stage,
171  DescriptorType type,
172  const ShaderUniformSlot& slot,
173  const std::shared_ptr<const ShaderMetadata>& metadata,
174  BufferView view);
175 
176  // |ResourceBinder|
177  bool BindResource(ShaderStage stage,
178  DescriptorType type,
179  const SampledImageSlot& slot,
180  const ShaderMetadata& metadata,
181  std::shared_ptr<const Texture> texture,
182  const std::unique_ptr<const Sampler>& sampler) override;
183 
184  bool IsValid() const { return pipeline && pipeline->IsValid(); }
185 
186  private:
187  template <class T>
188  bool DoBindResource(ShaderStage stage,
189  const ShaderUniformSlot& slot,
190  T metadata,
191  BufferView view);
192 };
193 
194 } // namespace impeller
195 
196 #endif // FLUTTER_IMPELLER_RENDERER_COMMAND_H_
impeller::Command
An object used to specify work to the GPU along with references to resources the GPU will used when d...
Definition: command.h:92
pipeline.h
impeller::Command::scissor
std::optional< IRect > scissor
Definition: command.h:139
impeller::ShaderUniformSlot
Metadata required to bind a buffer.
Definition: shader_types.h:81
impeller::Resource::resource
ResourceType resource
Definition: command.h:34
vertex_buffer.h
impeller::Resource::Resource
Resource(const ShaderMetadata *metadata, ResourceType p_resource)
Definition: command.h:38
impeller::ShaderMetadata
Definition: shader_types.h:72
impeller::VertexBuffer
Definition: vertex_buffer.h:13
formats.h
impeller::Command::viewport
std::optional< Viewport > viewport
Definition: command.h:133
impeller::Bindings::sampled_images
std::vector< TextureAndSampler > sampled_images
Definition: command.h:74
impeller::ShaderStage
ShaderStage
Definition: shader_types.h:22
impeller::Command::instance_count
size_t instance_count
Definition: command.h:147
sampler.h
impeller::Command::base_vertex
uint64_t base_vertex
Definition: command.h:126
impeller::Resource
Definition: command.h:32
impeller::Command::vertex_buffer
VertexBuffer vertex_buffer
The bound per-vertex data and optional index buffer.
Definition: command.h:151
impeller::Resource::Resource
Resource(std::shared_ptr< const ShaderMetadata > &metadata, ResourceType p_resource)
Definition: command.h:41
impeller::Command::vertex_bindings
Bindings vertex_bindings
Definition: command.h:101
resource_binder.h
impeller::ResourceBinder
An interface for binding resources. This is implemented by |Command| and |ComputeCommand| to make GPU...
Definition: resource_binder.h:23
impeller::SampledImageSlot
Metadata required to bind a combined texture and sampler.
Definition: shader_types.h:98
impeller::Command::BindVertices
bool BindVertices(VertexBuffer buffer)
Specify the vertex and index buffer to use for this command.
Definition: command.cc:15
impeller::BufferAndUniformSlot::view
BufferResource view
Definition: command.h:70
impeller::TextureAndSampler
combines the texture, sampler and sampler slot information.
Definition: command.h:61
impeller::TextureAndSampler::texture
TextureResource texture
Definition: command.h:63
impeller::BufferAndUniformSlot::slot
ShaderUniformSlot slot
Definition: command.h:69
impeller::Command::BindResource
bool BindResource(ShaderStage stage, DescriptorType type, const ShaderUniformSlot &slot, const ShaderMetadata &metadata, BufferView view) override
Definition: command.cc:25
impeller::Command::stencil_reference
uint32_t stencil_reference
Definition: command.h:122
impeller::TextureAndSampler::slot
SampledImageSlot slot
Definition: command.h:62
impeller::BufferView
Definition: buffer_view.h:15
impeller::Bindings::buffers
std::vector< BufferAndUniformSlot > buffers
Definition: command.h:75
buffer_view.h
impeller::Command::fragment_bindings
Bindings fragment_bindings
Definition: command.h:106
rect.h
texture.h
impeller::TextureAndSampler::sampler
const std::unique_ptr< const Sampler > & sampler
Definition: command.h:64
impeller::Command::pipeline
std::shared_ptr< Pipeline< PipelineDescriptor > > pipeline
Definition: command.h:96
impeller::Resource::GetMetadata
const ShaderMetadata * GetMetadata() const
Definition: command.h:45
shader_types.h
impeller
Definition: aiks_blur_unittests.cc:20
impeller::Command::IsValid
bool IsValid() const
Definition: command.h:184
impeller::BufferAndUniformSlot
combines the buffer resource and its uniform slot information.
Definition: command.h:68
impeller::Bindings
Definition: command.h:73
impeller::DescriptorType
DescriptorType
Definition: shader_types.h:153
impeller::Resource::Resource
Resource()
Definition: command.h:36