| 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
13 #include "impeller/core/buffer_view.h"
14 #include "impeller/core/formats.h"
15 #include "impeller/core/sampler.h"
16 #include "impeller/core/shader_types.h"
17 #include "impeller/core/texture.h"
18 #include "impeller/geometry/rect.h"
19 #include "impeller/renderer/pipeline.h"
20
21 namespace impeller {
22
23 template <class T>
24 class Resource {
25 public:
26 using ResourceType = T;
27 ResourceType resource;
28
29 Resource() {}
30
31 Resource(const ShaderMetadata* metadata, ResourceType p_resource)
32 : resource(std::move(p_resource)), metadata_(metadata) {}
33
34 const ShaderMetadata* GetMetadata() const {
35 return dynamic_metadata_ ? dynamic_metadata_.get() : metadata_;
36 }
37
38 static Resource MakeDynamic(std::unique_ptr<ShaderMetadata> metadata,
39 ResourceType p_resource) {
40 return Resource(std::move(metadata), std::move(p_resource));
41 }
42
43 private:
44 Resource(std::unique_ptr<ShaderMetadata> metadata, ResourceType p_resource)
45 : resource(std::move(p_resource)),
46 dynamic_metadata_(std::move(metadata)) {}
47
48 // Static shader metadata (typically generated by ImpellerC).
49 const ShaderMetadata* metadata_ = nullptr;
50
51 // Dynamically generated shader metadata.
52 std::unique_ptr<const ShaderMetadata> dynamic_metadata_ = nullptr;
53 };
54
55 using BufferResource = Resource<BufferView>;
56 using TextureResource = Resource<std::shared_ptr<const Texture>>;
57
58 /// @brief combines the texture, sampler and sampler slot information.
59 struct TextureAndSampler {
60 SampledImageSlot slot;
61 ShaderStage stage;
62 TextureResource texture;
63 raw_ptr<const Sampler> sampler;
64 };
65
66 //------------------------------------------------------------------------------
67 /// @brief An object used to specify work to the GPU along with references
68 /// to resources the GPU will used when doing said work.
69 ///
70 /// To construct a valid command, follow these steps:
71 /// * Specify a valid pipeline.
72 /// * Specify vertex information via a call `BindVertices`
73 /// * Specify any stage bindings.
74 /// * (Optional) Specify a debug label.
75 ///
76 /// Command can be created frequently and on demand. The resources
77 /// referenced in commands views into buffers managed by other
78 /// allocators and resource managers.
79 ///
80 struct Command {
81 //----------------------------------------------------------------------------
82 /// The pipeline to use for this command.
83 ///
84 PipelineRef pipeline;
85
86 //----------------------------------------------------------------------------
87 /// The index buffer binding used by the vertex shader stage.
88 BufferView index_buffer;
89
90 /// An offset into render pass storage where bound buffers/texture metadata is
91 /// stored.
92 Range bound_buffers = Range{0, 0};
93 Range bound_textures = Range{0, 0};
94
95 //----------------------------------------------------------------------------
96 /// An offset and range of vertex buffers bound for this draw call.
97 ///
98 /// The vertex buffers are stored on the render pass object.
99 Range vertex_buffers;
100
101 //----------------------------------------------------------------------------
102 /// The viewport coordinates that the rasterizer linearly maps normalized
103 /// device coordinates to.
104 /// If unset, the viewport is the size of the render target with a zero
105 /// origin, znear=0, and zfar=1.
106 ///
107 std::optional<Viewport> viewport;
108
109 //----------------------------------------------------------------------------
110 /// The scissor rect to use for clipping writes to the render target. The
111 /// scissor rect must lie entirely within the render target.
112 /// If unset, no scissor is applied.
113 ///
114 std::optional<IRect32> scissor;
115
116 #ifdef IMPELLER_DEBUG
117 //----------------------------------------------------------------------------
118 /// The debugging label to use for the command.
119 ///
120 std::string label;
121 #endif // IMPELLER_DEBUG
122
123 //----------------------------------------------------------------------------
124 /// The offset used when indexing into the vertex buffer.
125 ///
126 uint64_t base_vertex = 0u;
127
128 //----------------------------------------------------------------------------
129 /// The number of elements to draw. When only a vertex buffer is set, this is
130 /// the vertex count. When an index buffer is set, this is the index count.
131 uint32_t element_count = 0u;
132
133 //----------------------------------------------------------------------------
134 /// The number of instances of the given set of vertices to render. Not all
135 /// backends support rendering more than one instance at a time.
136 ///
137 /// @warning Setting this to more than one will limit the availability of
138 /// backends to use with this command.
139 ///
140 uint32_t instance_count = 1u;
141
142 //----------------------------------------------------------------------------
143 /// The reference value to use in stenciling operations. Stencil configuration
144 /// is part of pipeline setup and can be read from the pipelines descriptor.
145 ///
146 /// @see `Pipeline`
147 /// @see `PipelineDescriptor`
148 ///
149 uint32_t stencil_reference = 0u;
150
151 //----------------------------------------------------------------------------
152 /// The type of indices in the index buffer. The indices must be tightly
153 /// packed in the index buffer.
154 IndexType index_type = IndexType::kUnknown;
155
156 bool IsValid() const { return pipeline && pipeline->IsValid(); }
157 };
158
159 } // namespace impeller
160
161 #endif // FLUTTER_IMPELLER_RENDERER_COMMAND_H_
buffer_view.h
impeller::Pipeline::IsValid
virtual bool IsValid() const =0
impeller::Resource
Definition: command.h:24
impeller::Resource::MakeDynamic
static Resource MakeDynamic(std::unique_ptr< ShaderMetadata > metadata, ResourceType p_resource)
Definition: command.h:38
impeller::Resource::ResourceType
T ResourceType
Definition: command.h:26
impeller::Resource::Resource
Resource()
Definition: command.h:29
impeller::Resource::GetMetadata
const ShaderMetadata * GetMetadata() const
Definition: command.h:34
impeller::Resource::Resource
Resource(const ShaderMetadata *metadata, ResourceType p_resource)
Definition: command.h:31
impeller::Resource::resource
ResourceType resource
Definition: command.h:27
impeller::raw_ptr
A wrapper around a raw ptr that adds additional unopt mode only checks.
Definition: raw_ptr.h:15
formats.h
texture.h
impeller
Definition: allocation.cc:12
impeller::IndexType
IndexType
Definition: formats.h:346
impeller::IndexType::kUnknown
@ kUnknown
impeller::ShaderStage
ShaderStage
Definition: shader_types.h:22
std
Definition: comparable.h:95
pipeline.h
rect.h
sampler.h
shader_types.h
impeller::BufferView
Definition: buffer_view.h:19
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:80
impeller::Command::bound_textures
Range bound_textures
Definition: command.h:93
impeller::Command::element_count
uint32_t element_count
Definition: command.h:131
impeller::Command::scissor
std::optional< IRect32 > scissor
Definition: command.h:114
impeller::Command::base_vertex
uint64_t base_vertex
Definition: command.h:126
impeller::Command::stencil_reference
uint32_t stencil_reference
Definition: command.h:149
impeller::Command::index_buffer
BufferView index_buffer
The index buffer binding used by the vertex shader stage.
Definition: command.h:88
impeller::Command::viewport
std::optional< Viewport > viewport
Definition: command.h:107
impeller::Command::instance_count
uint32_t instance_count
Definition: command.h:140
impeller::Command::vertex_buffers
Range vertex_buffers
Definition: command.h:99
impeller::Command::bound_buffers
Range bound_buffers
Definition: command.h:92
impeller::Command::pipeline
PipelineRef pipeline
Definition: command.h:84
impeller::Command::index_type
IndexType index_type
Definition: command.h:154
impeller::Command::IsValid
bool IsValid() const
Definition: command.h:156
impeller::Range
Definition: range.h:13
impeller::SampledImageSlot
Metadata required to bind a combined texture and sampler.
Definition: shader_types.h:98
impeller::ShaderMetadata
Definition: shader_types.h:72
impeller::TextureAndSampler
combines the texture, sampler and sampler slot information.
Definition: command.h:59
impeller::TextureAndSampler::sampler
raw_ptr< const Sampler > sampler
Definition: command.h:63
impeller::TextureAndSampler::slot
SampledImageSlot slot
Definition: command.h:60
impeller::TextureAndSampler::texture
TextureResource texture
Definition: command.h:62
impeller::TextureAndSampler::stage
ShaderStage stage
Definition: command.h:61