impeller::CommandBuffer Class Reference

A collection of encoded commands to be submitted to the GPU for execution. A command buffer is obtained from a graphics Context. More...

#include <command_buffer.h>

Inheritance diagram for impeller::CommandBuffer:

Public Types
enum class	Status { kPending , kError , kCompleted }
using	CompletionCallback = std::function< void(Status)>

Public Member Functions
virtual	~CommandBuffer ()
virtual bool	IsValid () const =0
virtual void	SetLabel (const std::string &label) const =0
void	WaitUntilScheduled ()
	Force execution of pending GPU commands.
std::shared_ptr< RenderPass >	CreateRenderPass (const RenderTarget &render_target)
	Create a render pass to record render commands into.
std::shared_ptr< BlitPass >	CreateBlitPass ()
	Create a blit pass to record blit commands into.
std::shared_ptr< ComputePass >	CreateComputePass ()
	Create a compute pass to record compute commands into.

Protected Member Functions
	CommandBuffer (std::weak_ptr< const Context > context)
virtual std::shared_ptr< RenderPass >	OnCreateRenderPass (RenderTarget render_target)=0
virtual std::shared_ptr< BlitPass >	OnCreateBlitPass ()=0
virtual bool	OnSubmitCommands (CompletionCallback callback)=0
virtual void	OnWaitUntilScheduled ()=0
virtual std::shared_ptr< ComputePass >	OnCreateComputePass ()=0

Protected Attributes
std::weak_ptr< const Context >	context_

Friends
class	testing::CommandBufferMock
class	CommandQueue

Detailed Description

A collection of encoded commands to be submitted to the GPU for execution. A command buffer is obtained from a graphics Context.

To submit commands to the GPU, acquire a RenderPass from the command buffer and record Commands into that pass. A RenderPass describes the configuration of the various attachments when the command is submitted.

A command buffer is only meant to be used on a single thread. If a frame workload needs to be encoded from multiple threads, set up and record into multiple command buffers. The order of submission of commands encoded in multiple command buffers can be controlled via either the order in which the command buffers were created, or, using the ReserveSpotInQueue command which allows for encoding commands for submission in an order that is different from the encoding order.

Definition at line 45 of file command_buffer.h.

Member Typedef Documentation

CompletionCallback

using impeller::CommandBuffer::CompletionCallback = std::function<void(Status)>

Definition at line 55 of file command_buffer.h.

Member Enumeration Documentation

Status

enum class impeller::CommandBuffer::Status

strong

Enumerator
kPending
kError
kCompleted

Definition at line 49 of file command_buffer.h.

                    {
    kPending,
    kError,
    kCompleted,
  };

Constructor & Destructor Documentation

~CommandBuffer()

impeller::CommandBuffer::~CommandBuffer ( )

virtualdefault

CommandBuffer()

impeller::CommandBuffer::CommandBuffer ( std::weak_ptr< const Context >  context )

explicitprotected

Definition at line 13 of file command_buffer.cc.

    : context_(std::move(context)) {}

Member Function Documentation

CreateBlitPass()

std::shared_ptr< BlitPass > impeller::CommandBuffer::CreateBlitPass

(

)

Create a blit pass to record blit commands into.

Returns

A valid blit pass or null.

Definition at line 47 of file command_buffer.cc.

                                                      {
  auto pass = OnCreateBlitPass();
  if (pass && pass->IsValid()) {
    pass->SetLabel("BlitPass");
    return pass;
  }
  return nullptr;
}

CreateComputePass()

std::shared_ptr< ComputePass > impeller::CommandBuffer::CreateComputePass

(

)

Create a compute pass to record compute commands into.

Returns

A valid compute pass or null.

Definition at line 56 of file command_buffer.cc.

                                                            {
  if (!IsValid()) {
    return nullptr;
  }
  auto pass = OnCreateComputePass();
  if (pass && pass->IsValid()) {
    pass->SetLabel("ComputePass");
    return pass;
  }
  return nullptr;
}

CreateRenderPass()

std::shared_ptr< RenderPass > impeller::CommandBuffer::CreateRenderPass

(

const RenderTarget &

render_target

)

Create a render pass to record render commands into.

Parameters

[in]

render_target

The description of the render target this pass will target.

Returns

A valid render pass or null.

Definition at line 37 of file command_buffer.cc.

                                       {
  auto pass = OnCreateRenderPass(render_target);
  if (pass && pass->IsValid()) {
    pass->SetLabel("RenderPass");
    return pass;
  }
  return nullptr;
}

IsValid()

virtual bool impeller::CommandBuffer::IsValid ( ) const

pure virtual

Implemented in impeller::CommandBufferGLES, impeller::CommandBufferMTL, and impeller::CommandBufferVK.

OnCreateBlitPass()

virtual std::shared_ptr< BlitPass > impeller::CommandBuffer::OnCreateBlitPass ( )

protectedpure virtual

Implemented in impeller::CommandBufferGLES, impeller::CommandBufferMTL, and impeller::CommandBufferVK.

OnCreateComputePass()

virtual std::shared_ptr< ComputePass > impeller::CommandBuffer::OnCreateComputePass ( )

protectedpure virtual

Implemented in impeller::CommandBufferGLES, impeller::CommandBufferMTL, and impeller::CommandBufferVK.

OnCreateRenderPass()

virtual std::shared_ptr< RenderPass > impeller::CommandBuffer::OnCreateRenderPass ( RenderTarget  render_target )

protectedpure virtual

Implemented in impeller::CommandBufferGLES, impeller::CommandBufferMTL, and impeller::CommandBufferVK.

OnSubmitCommands()

virtual bool impeller::CommandBuffer::OnSubmitCommands ( CompletionCallback  callback )

protectedpure virtual

Implemented in impeller::CommandBufferGLES, impeller::CommandBufferMTL, and impeller::CommandBufferVK.

OnWaitUntilScheduled()

virtual void impeller::CommandBuffer::OnWaitUntilScheduled ( )

protectedpure virtual

Implemented in impeller::CommandBufferGLES, impeller::CommandBufferMTL, and impeller::CommandBufferVK.

SetLabel()

virtual void impeller::CommandBuffer::SetLabel ( const std::string &  label ) const

pure virtual

Implemented in impeller::CommandBufferGLES, impeller::CommandBufferMTL, and impeller::CommandBufferVK.

WaitUntilScheduled()

void impeller::CommandBuffer::WaitUntilScheduled

(

)

Force execution of pending GPU commands.

Definition at line 33 of file command_buffer.cc.

                                       {
  return OnWaitUntilScheduled();
}

Friends And Related Symbol Documentation

CommandQueue

friend class CommandQueue

friend

Definition at line 110 of file command_buffer.h.

testing::CommandBufferMock

friend class testing::CommandBufferMock

friend

Definition at line 46 of file command_buffer.h.

Member Data Documentation

context_

std::weak_ptr<const Context> impeller::CommandBuffer::context_

protected

Definition at line 94 of file command_buffer.h.

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The documentation for this class was generated from the following files:

• impeller/renderer/command_buffer.h
• impeller/renderer/command_buffer.cc