Lime3DS/src/core/perf_stats.h
Yuri Kunde Schlesner fb1979d7e2 Core: Re-write frame limiter
Now based on std::chrono, and also works in terms of emulated time
instead of frames, so we can in the future frame-limit even when the
display is disabled, etc.

The frame limiter can also be enabled along with v-sync now, which
should be useful for those with displays running at more than 60 Hz.
2017-02-26 17:22:04 -08:00

75 lines
2.1 KiB
C++

// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <chrono>
#include <mutex>
#include "common/common_types.h"
namespace Core {
/**
* Class to manage and query performance/timing statistics. All public functions of this class are
* thread-safe unless stated otherwise.
*/
class PerfStats {
public:
using Clock = std::chrono::high_resolution_clock;
struct Results {
/// System FPS (LCD VBlanks) in Hz
double system_fps;
/// Game FPS (GSP frame submissions) in Hz
double game_fps;
/// Walltime per system frame, in seconds, excluding any waits
double frametime;
/// Ratio of walltime / emulated time elapsed
double emulation_speed;
};
void BeginSystemFrame();
void EndSystemFrame();
void EndGameFrame();
Results GetAndResetStats(u64 current_system_time_us);
/**
* Gets the ratio between walltime and the emulated time of the previous system frame. This is
* useful for scaling inputs or outputs moving between the two time domains.
*/
double GetLastFrameTimeScale();
private:
std::mutex object_mutex;
Clock::time_point reset_point = Clock::now();
Clock::time_point frame_begin = reset_point;
Clock::time_point previous_frame_end = reset_point;
Clock::duration accumulated_frametime = Clock::duration::zero();
Clock::duration previous_frame_length = Clock::duration::zero();
u64 reset_point_system_us = 0;
u32 system_frames = 0;
u32 game_frames = 0;
};
class FrameLimiter {
public:
using Clock = std::chrono::high_resolution_clock;
void DoFrameLimiting(u64 current_system_time_us);
private:
/// Emulated system time (in microseconds) at the last limiter invocation
u64 previous_system_time_us = 0;
/// Walltime at the last limiter invocation
Clock::time_point previous_walltime = Clock::now();
/// Accumulated difference between walltime and emulated time
std::chrono::microseconds frame_limiting_delta_err{0};
};
} // namespace Core