From 3b2fed472e8306e8745a12e6aca1002e3fe89b63 Mon Sep 17 00:00:00 2001
From: Henrik Rydgard <hrydgard@gmail.com>
Date: Sat, 14 Jun 2014 23:55:16 +0200
Subject: [PATCH] Correct timing on resume, avoids small speed burst when
 resuming gameplay from pause

---
 Core/HLE/sceDisplay.cpp | 17 ++++++++++++-----
 Core/HLE/sceDisplay.h   |  5 ++++-
 Core/SaveState.cpp      |  5 +++++
 UI/MainScreen.cpp       |  2 ++
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/Core/HLE/sceDisplay.cpp b/Core/HLE/sceDisplay.cpp
index f353336fd5..4f55804d8e 100644
--- a/Core/HLE/sceDisplay.cpp
+++ b/Core/HLE/sceDisplay.cpp
@@ -103,6 +103,8 @@ static int brightnessLevel;
 static int mode;
 static int width;
 static int height;
+static int wasPaused;
+
 // Don't include this in the state, time increases regardless of state.
 static double curFrameTime;
 static double nextFrameTime;
@@ -182,6 +184,7 @@ void __DisplayInit() {
 	framebuf.pspFramebufLinesize = 480; // ??
 	lastFlipCycles = 0;
 	lastFlipsTooFrequent = 0;
+	wasPaused = 0;
 
 	enterVblankEvent = CoreTiming::RegisterEvent("EnterVBlank", &hleEnterVblank);
 	leaveVblankEvent = CoreTiming::RegisterEvent("LeaveVBlank", &hleLeaveVblank);
@@ -484,6 +487,10 @@ static float CalculateSmoothTimestep(float lastTimestep) {
 	return summed / (float)ARRAY_SIZE(timestepSmooth);
 }
 
+void __DisplaySetWasPaused() {
+	wasPaused = true;
+}
+
 // Let's collect all the throttling and frameskipping logic here.
 void DoFrameTiming(bool &throttle, bool &skipFrame, float lastTimestep) {
 	float timestep = CalculateSmoothTimestep(lastTimestep);
@@ -496,9 +503,7 @@ void DoFrameTiming(bool &throttle, bool &skipFrame, float lastTimestep) {
 	// Check if the frameskipping code should be enabled. If neither throttling or frameskipping is on,
 	// we have nothing to do here.
 	bool doFrameSkip = g_Config.iFrameSkip != 0;
-
 	
-
 	if (!throttle && g_Config.bFrameSkipUnthrottle) {
 		doFrameSkip = true;
 		skipFrame = true;
@@ -515,14 +520,16 @@ void DoFrameTiming(bool &throttle, bool &skipFrame, float lastTimestep) {
 	time_update();
 	
 	curFrameTime = time_now_d();
-	if (nextFrameTime == 0.0)
+	if (nextFrameTime == 0.0 || wasPaused) {
 		nextFrameTime = time_now_d() + timestep;
+		if (wasPaused)
+			wasPaused = false;
+	}
 	
-	// Argh, we are falling behind! Let's skip a frame and see if we catch up.
-
 	// Auto-frameskip automatically if speed limit is set differently than the default.
 	if (g_Config.bAutoFrameSkip || (g_Config.iFrameSkip == 0 && fpsLimiter == FPS_LIMIT_CUSTOM && g_Config.iFpsLimit > 60)) {
 		// autoframeskip
+		// Argh, we are falling behind! Let's skip a frame and see if we catch up.
 		if (curFrameTime > nextFrameTime && doFrameSkip) {
 			skipFrame = true;
 		}
diff --git a/Core/HLE/sceDisplay.h b/Core/HLE/sceDisplay.h
index 8c7336805c..ae270845bf 100644
--- a/Core/HLE/sceDisplay.h
+++ b/Core/HLE/sceDisplay.h
@@ -40,4 +40,7 @@ void __DisplayGetAveragedFPS(float *out_vps, float *out_fps);
 int __DisplayGetVCount();
 int __DisplayGetFlipCount();
 
-void Register_sceDisplay_driver();
+// Call this when resuming to avoid a small speedup burst
+void __DisplaySetWasPaused();
+
+void Register_sceDisplay_driver();
\ No newline at end of file
diff --git a/Core/SaveState.cpp b/Core/SaveState.cpp
index f288d0a3af..33c438b285 100644
--- a/Core/SaveState.cpp
+++ b/Core/SaveState.cpp
@@ -33,6 +33,7 @@
 #include "Core/FileSystems/MetaFileSystem.h"
 #include "Core/ELF/ParamSFO.h"
 #include "Core/HLE/HLE.h"
+#include "Core/HLE/sceDisplay.h"
 #include "Core/HLE/ReplaceTables.h"
 #include "Core/HLE/sceKernel.h"
 #include "Core/MemMap.h"
@@ -550,6 +551,10 @@ namespace SaveState
 			if (op.callback)
 				op.callback(callbackResult, op.cbUserData);
 		}
+		if (operations.size()) {
+			// Avoid triggering frame skipping due to slowdown
+			__DisplaySetWasPaused();
+		}
 	}
 
 	void Init()
diff --git a/UI/MainScreen.cpp b/UI/MainScreen.cpp
index 1cb1afbe0a..c1b1bacc6c 100644
--- a/UI/MainScreen.cpp
+++ b/UI/MainScreen.cpp
@@ -49,6 +49,7 @@
 #include "GPU/GPUInterface.h"
 #include "i18n/i18n.h"
 
+#include "Core/HLE/sceDisplay.h"
 #include "Core/HLE/sceUmd.h"
 
 #ifdef _WIN32
@@ -984,6 +985,7 @@ GamePauseScreen::~GamePauseScreen() {
 		g_Config.iCurrentStateSlot = saveSlots_->GetSelection();
 		g_Config.Save();
 	}
+	__DisplaySetWasPaused();
 }
 
 void GamePauseScreen::CreateViews() {