From 92c8bd4b1f650438274e50303a6d3f668924d071 Mon Sep 17 00:00:00 2001
From: Yuri Kunde Schlesner <yuriks@yuriks.net>
Date: Sun, 19 Feb 2017 18:18:26 -0800
Subject: [PATCH] PerfStats: Add method to get the instantaneous time ratio

---
 src/core/frontend/emu_window.cpp |  5 ++---
 src/core/perf_stats.cpp          | 14 +++++++++++---
 src/core/perf_stats.h            | 10 +++++++++-
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/core/frontend/emu_window.cpp b/src/core/frontend/emu_window.cpp
index 6b4637741..b65d6ff58 100644
--- a/src/core/frontend/emu_window.cpp
+++ b/src/core/frontend/emu_window.cpp
@@ -5,7 +5,7 @@
 #include <algorithm>
 #include <cmath>
 #include "common/assert.h"
-#include "common/profiler_reporting.h"
+#include "core/core.h"
 #include "core/frontend/emu_window.h"
 #include "core/frontend/key_map.h"
 #include "video_core/video_core.h"
@@ -104,8 +104,7 @@ void EmuWindow::AccelerometerChanged(float x, float y, float z) {
 void EmuWindow::GyroscopeChanged(float x, float y, float z) {
     constexpr float FULL_FPS = 60;
     float coef = GetGyroscopeRawToDpsCoefficient();
-    float stretch =
-        FULL_FPS / Common::Profiling::GetTimingResultsAggregator()->GetAggregatedResults().fps;
+    float stretch = Core::System::GetInstance().perf_stats.Lock()->GetLastFrameTimeScale();
     std::lock_guard<std::mutex> lock(gyro_mutex);
     gyro_x = static_cast<s16>(x * coef * stretch);
     gyro_y = static_cast<s16>(y * coef * stretch);
diff --git a/src/core/perf_stats.cpp b/src/core/perf_stats.cpp
index 6d9e603e4..8d9e521a3 100644
--- a/src/core/perf_stats.cpp
+++ b/src/core/perf_stats.cpp
@@ -6,6 +6,9 @@
 #include "core/hw/gpu.h"
 #include "core/perf_stats.h"
 
+using DoubleSecs = std::chrono::duration<double, std::chrono::seconds::period>;
+using std::chrono::duration_cast;
+
 namespace Core {
 
 void PerfStats::BeginSystemFrame() {
@@ -16,6 +19,9 @@ void PerfStats::EndSystemFrame() {
     auto frame_end = Clock::now();
     accumulated_frametime += frame_end - frame_begin;
     system_frames += 1;
+
+    previous_frame_length = frame_end - previous_frame_end;
+    previous_frame_end = frame_end;
 }
 
 void PerfStats::EndGameFrame() {
@@ -23,9 +29,6 @@ void PerfStats::EndGameFrame() {
 }
 
 PerfStats::Results PerfStats::GetAndResetStats(u64 current_system_time_us) {
-    using DoubleSecs = std::chrono::duration<double, std::chrono::seconds::period>;
-    using std::chrono::duration_cast;
-
     auto now = Clock::now();
     // Walltime elapsed since stats were reset
     auto interval = duration_cast<DoubleSecs>(now - reset_point).count();
@@ -50,4 +53,9 @@ PerfStats::Results PerfStats::GetAndResetStats(u64 current_system_time_us) {
     return results;
 }
 
+double PerfStats::GetLastFrameTimeScale() {
+    constexpr double FRAME_LENGTH = 1.0 / GPU::SCREEN_REFRESH_RATE;
+    return duration_cast<DoubleSecs>(previous_frame_length).count() / FRAME_LENGTH;
+}
+
 } // namespace Core
diff --git a/src/core/perf_stats.h b/src/core/perf_stats.h
index 566a1419a..8a03c511a 100644
--- a/src/core/perf_stats.h
+++ b/src/core/perf_stats.h
@@ -30,11 +30,19 @@ public:
 
     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:
     Clock::time_point reset_point = Clock::now();
 
-    Clock::time_point frame_begin;
+    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;