vertical_sync_win32.hpp

// Copyright Take Vos 2019-2020.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include "vertical_sync.hpp"
#include <span>
#include <thread>
#include <array>
 
namespace tt {
 
class vertical_sync_win32 final : public vertical_sync {
public:
    vertical_sync_win32() noexcept;
    ~vertical_sync_win32() override;
 
    [[nodiscard]] utc_nanoseconds wait() noexcept override;
 
private:
    void *_gdi;
    unsigned int _adapter = 0;
    unsigned int _video_present_source_id;
 
    utc_nanoseconds _previous_frame_time_point;
    std::array<std::chrono::nanoseconds, 15> _frame_duration_data;
    size_t _frame_duration_counter = 0;
 
    void open_adapter() noexcept;
    void close_adapter() noexcept;
 
    [[nodiscard]] std::chrono::nanoseconds average_frame_duration(utc_nanoseconds frameTimestamp) noexcept;
};
 
}