| Flutter Impeller |

pipeline_builder.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 #pragma once
6
7 #include "flutter/fml/logging.h"
8 #include "flutter/fml/macros.h"
9 #include "impeller/base/strings.h"
10 #include "impeller/base/validation.h"
11 #include "impeller/core/formats.h"
12 #include "impeller/renderer/context.h"
13 #include "impeller/renderer/pipeline_descriptor.h"
14 #include "impeller/renderer/shader_library.h"
15 #include "impeller/renderer/vertex_descriptor.h"
16
17 namespace impeller {
18
19 //------------------------------------------------------------------------------
20 /// @brief An optional (but highly recommended) utility for creating
21 /// pipelines from reflected shader information.
22 ///
23 /// @tparam VertexShader_ The reflected vertex shader information. Found
24 /// in a generated header file called
25 /// <shader_name>.vert.h.
26 /// @tparam FragmentShader_ The reflected fragment shader information.
27 /// Found in a generated header file called
28 /// <shader_name>.frag.h.
29 ///
30 template <class VertexShader_, class FragmentShader_>
31 struct PipelineBuilder {
32 public:
33 using VertexShader = VertexShader_;
34 using FragmentShader = FragmentShader_;
35
36 static constexpr size_t kVertexBufferIndex =
37 VertexDescriptor::kReservedVertexBufferIndex;
38
39 //----------------------------------------------------------------------------
40 /// @brief Create a default pipeline descriptor using the combination
41 /// reflected shader information. The descriptor can be configured
42 /// further before a pipeline state object is created using it.
43 ///
44 /// @param[in] context The context
45 ///
46 /// @return If the combination of reflected shader information is
47 /// compatible and the requisite functions can be found in the
48 /// context, a pipeline descriptor.
49 ///
50 static std::optional<PipelineDescriptor> MakeDefaultPipelineDescriptor(
51 const Context& context) {
52 PipelineDescriptor desc;
53 if (InitializePipelineDescriptorDefaults(context, desc)) {
54 return {std::move(desc)};
55 }
56 return std::nullopt;
57 }
58
59 [[nodiscard]] static bool InitializePipelineDescriptorDefaults(
60 const Context& context,
61 PipelineDescriptor& desc) {
62 // Setup debug instrumentation.
63 desc.SetLabel(SPrintF("%s Pipeline", FragmentShader::kLabel.data()));
64
65 // Resolve pipeline entrypoints.
66 {
67 auto vertex_function = context.GetShaderLibrary()->GetFunction(
68 VertexShader::kEntrypointName, ShaderStage::kVertex);
69 auto fragment_function = context.GetShaderLibrary()->GetFunction(
70 FragmentShader::kEntrypointName, ShaderStage::kFragment);
71
72 if (!vertex_function || !fragment_function) {
73 VALIDATION_LOG << "Could not resolve pipeline entrypoint(s) '"
74 << VertexShader::kEntrypointName << "' and '"
75 << FragmentShader::kEntrypointName
76 << "' for pipeline named '" << VertexShader::kLabel
77 << "'.";
78 return false;
79 }
80
81 desc.AddStageEntrypoint(std::move(vertex_function));
82 desc.AddStageEntrypoint(std::move(fragment_function));
83 }
84
85 // Setup the vertex descriptor from reflected information.
86 {
87 auto vertex_descriptor = std::make_shared<VertexDescriptor>();
88 vertex_descriptor->SetStageInputs(VertexShader::kAllShaderStageInputs,
89 VertexShader::kInterleavedBufferLayout);
90 vertex_descriptor->RegisterDescriptorSetLayouts(
91 VertexShader::kDescriptorSetLayouts);
92 vertex_descriptor->RegisterDescriptorSetLayouts(
93 FragmentShader::kDescriptorSetLayouts);
94 desc.SetVertexDescriptor(std::move(vertex_descriptor));
95 }
96
97 // Setup fragment shader output descriptions.
98 {
99 // Configure the sole color attachments pixel format. This is by
100 // convention.
101 ColorAttachmentDescriptor color0;
102 color0.format = context.GetCapabilities()->GetDefaultColorFormat();
103 color0.blending_enabled = true;
104 desc.SetColorAttachmentDescriptor(0u, color0);
105 }
106
107 // Setup default stencil buffer descriptions.
108 {
109 StencilAttachmentDescriptor stencil0;
110 stencil0.stencil_compare = CompareFunction::kEqual;
111 desc.SetStencilAttachmentDescriptors(stencil0);
112 desc.SetStencilPixelFormat(
113 context.GetCapabilities()->GetDefaultStencilFormat());
114 }
115
116 return true;
117 }
118 };
119
120 } // namespace impeller
impeller::PipelineDescriptor
Definition: pipeline_descriptor.h:30
impeller::StencilAttachmentDescriptor::stencil_compare
CompareFunction stencil_compare
Definition: formats.h:550
impeller::PipelineDescriptor::SetStencilAttachmentDescriptors
PipelineDescriptor & SetStencilAttachmentDescriptors(std::optional< StencilAttachmentDescriptor > front_and_back)
Definition: pipeline_descriptor.cc:153
impeller::PipelineDescriptor::SetColorAttachmentDescriptor
PipelineDescriptor & SetColorAttachmentDescriptor(size_t index, ColorAttachmentDescriptor desc)
Definition: pipeline_descriptor.cc:106
impeller::PipelineDescriptor::SetStencilPixelFormat
PipelineDescriptor & SetStencilPixelFormat(PixelFormat format)
Definition: pipeline_descriptor.cc:141
impeller::Context::GetCapabilities
virtual const std::shared_ptr< const Capabilities > & GetCapabilities() const =0
Get the capabilities of Impeller context. All optionally supported feature of the platform,...
impeller::Context::GetShaderLibrary
virtual std::shared_ptr< ShaderLibrary > GetShaderLibrary() const =0
Returns the library of shaders used to specify the programmable stages of a pipeline.
shader_library.h
formats.h
impeller::PipelineBuilder::VertexShader
VertexShader_ VertexShader
Definition: pipeline_builder.h:33
validation.h
vertex_descriptor.h
impeller::SPrintF
std::string SPrintF(const char *format,...)
Definition: strings.cc:12
impeller::ColorAttachmentDescriptor::format
PixelFormat format
Definition: formats.h:452
impeller::PipelineBuilder::FragmentShader
FragmentShader_ FragmentShader
Definition: pipeline_builder.h:34
impeller::ShaderStage::kFragment
@ kFragment
strings.h
impeller::PipelineDescriptor::AddStageEntrypoint
PipelineDescriptor & AddStageEntrypoint(std::shared_ptr< const ShaderFunction > function)
Definition: pipeline_descriptor.cc:77
VALIDATION_LOG
#define VALIDATION_LOG
Definition: validation.h:60
impeller::PipelineBuilder::MakeDefaultPipelineDescriptor
static std::optional< PipelineDescriptor > MakeDefaultPipelineDescriptor(const Context &context)
Create a default pipeline descriptor using the combination reflected shader information....
Definition: pipeline_builder.h:50
impeller::VertexDescriptor::kReservedVertexBufferIndex
static constexpr size_t kReservedVertexBufferIndex
Definition: vertex_descriptor.h:25
impeller::Context
To do anything rendering related with Impeller, you need a context.
Definition: context.h:47
impeller::ShaderStage::kVertex
@ kVertex
impeller::StencilAttachmentDescriptor
Definition: formats.h:544
context.h
impeller::CompareFunction::kEqual
@ kEqual
Comparison test passes if new_value == current_value.
pipeline_descriptor.h
impeller::PipelineBuilder
An optional (but highly recommended) utility for creating pipelines from reflected shader information...
Definition: pipeline_builder.h:31
impeller::PipelineDescriptor::SetLabel
PipelineDescriptor & SetLabel(std::string label)
Definition: pipeline_descriptor.cc:67
impeller::PipelineBuilder::kVertexBufferIndex
static constexpr size_t kVertexBufferIndex
Definition: pipeline_builder.h:36
impeller
Definition: aiks_context.cc:10
impeller::ColorAttachmentDescriptor::blending_enabled
bool blending_enabled
Definition: formats.h:453
impeller::PipelineBuilder::InitializePipelineDescriptorDefaults
static bool InitializePipelineDescriptorDefaults(const Context &context, PipelineDescriptor &desc)
Definition: pipeline_builder.h:59
impeller::PipelineDescriptor::SetVertexDescriptor
PipelineDescriptor & SetVertexDescriptor(std::shared_ptr< VertexDescriptor > vertex_descriptor)
Definition: pipeline_descriptor.cc:92
impeller::ColorAttachmentDescriptor
Describe the color attachment that will be used with this pipeline.
Definition: formats.h:451