Flutter Impeller
impeller::PipelineBuilder< VertexShader_, FragmentShader_ > Struct Template Reference

An optional (but highly recommended) utility for creating pipelines from reflected shader information. More...

#include <pipeline_builder.h>

Public Types

using VertexShader = VertexShader_
 
using FragmentShader = FragmentShader_
 

Static Public Member Functions

static std::optional< PipelineDescriptorMakeDefaultPipelineDescriptor (const Context &context, const std::vector< Scalar > &constants={})
 Create a default pipeline descriptor using the combination reflected shader information. The descriptor can be configured further before a pipeline state object is created using it. More...
 
static bool InitializePipelineDescriptorDefaults (const Context &context, PipelineDescriptor &desc)
 

Static Public Attributes

static constexpr size_t kVertexBufferIndex
 

Detailed Description

template<class VertexShader_, class FragmentShader_>
struct impeller::PipelineBuilder< VertexShader_, FragmentShader_ >

An optional (but highly recommended) utility for creating pipelines from reflected shader information.

Template Parameters
VertexShader_The reflected vertex shader information. Found in a generated header file called <shader_name>.vert.h.
FragmentShader_The reflected fragment shader information. Found in a generated header file called <shader_name>.frag.h.

Definition at line 32 of file pipeline_builder.h.

Member Typedef Documentation

◆ FragmentShader

template<class VertexShader_ , class FragmentShader_ >
using impeller::PipelineBuilder< VertexShader_, FragmentShader_ >::FragmentShader = FragmentShader_

Definition at line 35 of file pipeline_builder.h.

◆ VertexShader

template<class VertexShader_ , class FragmentShader_ >
using impeller::PipelineBuilder< VertexShader_, FragmentShader_ >::VertexShader = VertexShader_

Definition at line 34 of file pipeline_builder.h.

Member Function Documentation

◆ InitializePipelineDescriptorDefaults()

template<class VertexShader_ , class FragmentShader_ >
static bool impeller::PipelineBuilder< VertexShader_, FragmentShader_ >::InitializePipelineDescriptorDefaults ( const Context context,
PipelineDescriptor desc 
)
inlinestatic

Definition at line 62 of file pipeline_builder.h.

64  {
65  // Setup debug instrumentation.
66  desc.SetLabel(SPrintF("%s Pipeline", FragmentShader::kLabel.data()));
67 
68  // Resolve pipeline entrypoints.
69  {
70  auto vertex_function = context.GetShaderLibrary()->GetFunction(
71  VertexShader::kEntrypointName, ShaderStage::kVertex);
72  auto fragment_function = context.GetShaderLibrary()->GetFunction(
73  FragmentShader::kEntrypointName, ShaderStage::kFragment);
74 
75  if (!vertex_function || !fragment_function) {
76  VALIDATION_LOG << "Could not resolve pipeline entrypoint(s) '"
77  << VertexShader::kEntrypointName << "' and '"
78  << FragmentShader::kEntrypointName
79  << "' for pipeline named '" << VertexShader::kLabel
80  << "'.";
81  return false;
82  }
83 
84  desc.AddStageEntrypoint(std::move(vertex_function));
85  desc.AddStageEntrypoint(std::move(fragment_function));
86  }
87 
88  // Setup the vertex descriptor from reflected information.
89  {
90  auto vertex_descriptor = std::make_shared<VertexDescriptor>();
91  vertex_descriptor->SetStageInputs(VertexShader::kAllShaderStageInputs,
92  VertexShader::kInterleavedBufferLayout);
93  vertex_descriptor->RegisterDescriptorSetLayouts(
94  VertexShader::kDescriptorSetLayouts);
95  vertex_descriptor->RegisterDescriptorSetLayouts(
96  FragmentShader::kDescriptorSetLayouts);
97  desc.SetVertexDescriptor(std::move(vertex_descriptor));
98  }
99 
100  // Setup fragment shader output descriptions.
101  {
102  // Configure the sole color attachments pixel format. This is by
103  // convention.
104  ColorAttachmentDescriptor color0;
105  color0.format = context.GetCapabilities()->GetDefaultColorFormat();
106  color0.blending_enabled = true;
107  desc.SetColorAttachmentDescriptor(0u, color0);
108  }
109 
110  // Setup default depth buffer descriptions.
111  {
112  DepthAttachmentDescriptor depth0;
113  depth0.depth_compare = CompareFunction::kAlways;
114  desc.SetDepthStencilAttachmentDescriptor(depth0);
115  desc.SetDepthPixelFormat(
116  context.GetCapabilities()->GetDefaultDepthStencilFormat());
117  }
118 
119  // Setup default stencil buffer descriptions.
120  {
121  StencilAttachmentDescriptor stencil0;
122  stencil0.stencil_compare = CompareFunction::kEqual;
123  desc.SetStencilAttachmentDescriptors(stencil0);
124  desc.SetStencilPixelFormat(
125  context.GetCapabilities()->GetDefaultDepthStencilFormat());
126  }
127 
128  return true;
129  }

References impeller::PipelineDescriptor::AddStageEntrypoint(), impeller::ColorAttachmentDescriptor::blending_enabled, impeller::DepthAttachmentDescriptor::depth_compare, impeller::ColorAttachmentDescriptor::format, impeller::Context::GetCapabilities(), impeller::Context::GetShaderLibrary(), impeller::kAlways, impeller::kEqual, impeller::kFragment, impeller::kVertex, impeller::PipelineDescriptor::SetColorAttachmentDescriptor(), impeller::PipelineDescriptor::SetDepthPixelFormat(), impeller::PipelineDescriptor::SetDepthStencilAttachmentDescriptor(), impeller::PipelineDescriptor::SetLabel(), impeller::PipelineDescriptor::SetStencilAttachmentDescriptors(), impeller::PipelineDescriptor::SetStencilPixelFormat(), impeller::PipelineDescriptor::SetVertexDescriptor(), impeller::SPrintF(), impeller::StencilAttachmentDescriptor::stencil_compare, and VALIDATION_LOG.

◆ MakeDefaultPipelineDescriptor()

template<class VertexShader_ , class FragmentShader_ >
static std::optional<PipelineDescriptor> impeller::PipelineBuilder< VertexShader_, FragmentShader_ >::MakeDefaultPipelineDescriptor ( const Context context,
const std::vector< Scalar > &  constants = {} 
)
inlinestatic

Create a default pipeline descriptor using the combination reflected shader information. The descriptor can be configured further before a pipeline state object is created using it.

Parameters
[in]contextThe context
Returns
If the combination of reflected shader information is compatible and the requisite functions can be found in the context, a pipeline descriptor.

Definition at line 51 of file pipeline_builder.h.

53  {}) {
54  PipelineDescriptor desc;
55  desc.SetSpecializationConstants(constants);
56  if (InitializePipelineDescriptorDefaults(context, desc)) {
57  return {std::move(desc)};
58  }
59  return std::nullopt;
60  }

Referenced by impeller::ContentContext::ContentContext(), and impeller::testing::TEST_P().

Member Data Documentation

◆ kVertexBufferIndex

template<class VertexShader_ , class FragmentShader_ >
constexpr size_t impeller::PipelineBuilder< VertexShader_, FragmentShader_ >::kVertexBufferIndex
staticconstexpr
Initial value:

Definition at line 37 of file pipeline_builder.h.


The documentation for this struct was generated from the following file:
impeller::CompareFunction::kEqual
@ kEqual
Comparison test passes if new_value == current_value.
impeller::SPrintF
std::string SPrintF(const char *format,...)
Definition: strings.cc:12
impeller::ShaderStage::kFragment
@ kFragment
impeller::CompareFunction::kAlways
@ kAlways
Comparison test passes always passes.
VALIDATION_LOG
#define VALIDATION_LOG
Definition: validation.h:73
impeller::VertexDescriptor::kReservedVertexBufferIndex
static constexpr size_t kReservedVertexBufferIndex
Definition: vertex_descriptor.h:25
impeller::ShaderStage::kVertex
@ kVertex
impeller::PipelineBuilder::InitializePipelineDescriptorDefaults
static bool InitializePipelineDescriptorDefaults(const Context &context, PipelineDescriptor &desc)
Definition: pipeline_builder.h:62