blob: 28158e15561ad9f794fb31ad26c99a873e57c3c4 [file] [log] [blame]
// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#pragma once
#include <functional>
#include <memory>
#include "flutter/fml/macros.h"
#include "impeller/renderer/blit_pass.h"
namespace impeller {
class Context;
class RenderPass;
class RenderTarget;
//------------------------------------------------------------------------------
/// @brief 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 `Command`s 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,
/// setup 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.
///
class CommandBuffer {
public:
enum class Status {
kPending,
kError,
kCompleted,
};
using CompletionCallback = std::function<void(Status)>;
virtual ~CommandBuffer();
virtual bool IsValid() const = 0;
virtual void SetLabel(const std::string& label) const = 0;
//----------------------------------------------------------------------------
/// @brief Schedule the command encoded by render passes within this
/// command buffer on the GPU.
///
/// A command buffer may only be committed once.
///
/// @param[in] callback The completion callback.
///
[[nodiscard]] bool SubmitCommands(CompletionCallback callback);
[[nodiscard]] bool SubmitCommands();
//----------------------------------------------------------------------------
/// @brief Create a render pass to record render commands into.
///
/// @param[in] render_target The description of the render target this pass
/// will target.
///
/// @return A valid render pass or null.
///
std::shared_ptr<RenderPass> CreateRenderPass(
RenderTarget render_target) const;
//----------------------------------------------------------------------------
/// @brief Create a blit pass to record blit commands into.
///
/// @return A valid blit pass or null.
///
std::shared_ptr<BlitPass> CreateBlitPass() const;
protected:
std::weak_ptr<const Context> context_;
explicit CommandBuffer(std::weak_ptr<const Context> context);
virtual std::shared_ptr<RenderPass> OnCreateRenderPass(
RenderTarget render_target) const = 0;
virtual std::shared_ptr<BlitPass> OnCreateBlitPass() const = 0;
[[nodiscard]] virtual bool OnSubmitCommands(CompletionCallback callback) = 0;
private:
FML_DISALLOW_COPY_AND_ASSIGN(CommandBuffer);
};
} // namespace impeller