Merge pull request #3457 from booto/si-sampling

[RFC] SI: Base SI sampling on VSync & horiz lines

5 files changed, 24 insertions, 33 deletions

diff --git a/Source/Core/Core/HW/SI.cpp b/Source/Core/Core/HW/SI.cpp
index 08539aa63c..e69cb158fb 100644
--- a/Source/Core/Core/HW/SI.cpp
+++ b/Source/Core/Core/HW/SI.cpp
@@ -565,25 +565,9 @@ void RunSIBuffer(u64 userdata, int cyclesLate)
 	}
 }
 
-int GetTicksToNextSIPoll()
+u32 GetPollXLines()
 {
-	// Poll for input at regular intervals (once per frame) when playing or recording a movie
-	if (Movie::IsMovieActive())
-	{
-		if (Movie::IsNetPlayRecording())
-			return SystemTimers::GetTicksPerSecond() / VideoInterface::TargetRefreshRate / 2;
-		else
-			return SystemTimers::GetTicksPerSecond() / VideoInterface::TargetRefreshRate;
-	}
-	if (NetPlay::IsNetPlayRunning())
-		return SystemTimers::GetTicksPerSecond() / VideoInterface::TargetRefreshRate / 2;
-
-	if (!g_Poll.Y && g_Poll.X)
-		return 2 * VideoInterface::GetTicksPerHalfLine() * g_Poll.X;
-	else if (!g_Poll.Y)
-		return SystemTimers::GetTicksPerSecond() / 60;
-
-	return std::min(VideoInterface::GetTicksPerField() / g_Poll.Y, 2 * VideoInterface::GetTicksPerHalfLine() * g_Poll.X);
+	return g_Poll.X;
 }
 
 } // end of namespace SerialInterface
diff --git a/Source/Core/Core/HW/SI.h b/Source/Core/Core/HW/SI.h
index c3078aa72a..e8625b6ffc 100644
--- a/Source/Core/Core/HW/SI.h
+++ b/Source/Core/Core/HW/SI.h
@@ -38,6 +38,6 @@ void ChangeDevice(SIDevices device, int channel);
 
 SIDevices GetDeviceType(int channel);
 
-int GetTicksToNextSIPoll();
+u32 GetPollXLines();
 
 } // end of namespace SerialInterface
diff --git a/Source/Core/Core/HW/SystemTimers.cpp b/Source/Core/Core/HW/SystemTimers.cpp
index e95d207863..38c28aa6ae 100644
--- a/Source/Core/Core/HW/SystemTimers.cpp
+++ b/Source/Core/Core/HW/SystemTimers.cpp
@@ -55,7 +55,6 @@ IPC_HLE_PERIOD: For the Wiimote this is the call schedule:
 #include "Core/HW/AudioInterface.h"
 #include "Core/HW/DSP.h"
 #include "Core/HW/EXI_DeviceIPL.h"
-#include "Core/HW/SI.h"
 #include "Core/HW/SystemTimers.h"
 #include "Core/HW/VideoInterface.h"
 #include "Core/IPC_HLE/WII_IPC_HLE.h"
@@ -69,7 +68,6 @@ namespace SystemTimers
 
 static int et_Dec;
 static int et_VI;
-static int et_SI;
 static int et_CP;
 static int et_AudioDMA;
 static int et_DSP;
@@ -127,12 +125,6 @@ static void VICallback(u64 userdata, int cyclesLate)
 	CoreTiming::ScheduleEvent(VideoInterface::GetTicksPerHalfLine() - cyclesLate, et_VI);
 }
 
-static void SICallback(u64 userdata, int cyclesLate)
-{
-	SerialInterface::UpdateDevices();
-	CoreTiming::ScheduleEvent(SerialInterface::GetTicksToNextSIPoll() - cyclesLate, et_SI);
-}
-
 static void CPCallback(u64 userdata, int cyclesLate)
 {
 	u64 now = CoreTiming::GetTicks();
@@ -248,7 +240,6 @@ void Init()
 
 	et_Dec = CoreTiming::RegisterEvent("DecCallback", DecrementerCallback);
 	et_VI = CoreTiming::RegisterEvent("VICallback", VICallback);
-	et_SI = CoreTiming::RegisterEvent("SICallback", SICallback);
 	if (SConfig::GetInstance().bCPUThread && SConfig::GetInstance().bSyncGPU)
 		et_CP = CoreTiming::RegisterEvent("CPCallback", CPCallback);
 	et_DSP = CoreTiming::RegisterEvent("DSPCallback", DSPCallback);
@@ -259,7 +250,6 @@ void Init()
 
 	CoreTiming::ScheduleEvent(VideoInterface::GetTicksPerHalfLine(), et_VI);
 	CoreTiming::ScheduleEvent(0, et_DSP);
-	CoreTiming::ScheduleEvent(VideoInterface::GetTicksPerField(), et_SI);
 	CoreTiming::ScheduleEvent(s_audio_dma_period, et_AudioDMA);
 	CoreTiming::ScheduleEvent(0, et_Throttle, Common::Timer::GetTimeMs());
 	if (SConfig::GetInstance().bCPUThread && SConfig::GetInstance().bSyncGPU)
diff --git a/Source/Core/Core/HW/VideoInterface.cpp b/Source/Core/Core/HW/VideoInterface.cpp
index c42142df71..3dd8e065e3 100644
--- a/Source/Core/Core/HW/VideoInterface.cpp
+++ b/Source/Core/Core/HW/VideoInterface.cpp
@@ -16,6 +16,7 @@
 #include "Core/HW/Memmap.h"
 #include "Core/HW/MMIO.h"
 #include "Core/HW/ProcessorInterface.h"
+#include "Core/HW/SI.h"
 #include "Core/HW/SystemTimers.h"
 #include "Core/HW/VideoInterface.h"
 #include "Core/PowerPC/PowerPC.h"
@@ -63,7 +64,8 @@ static u32 s_clock_freqs[2] =
 
 static u64 s_ticks_last_line_start;  // number of ticks when the current full scanline started
 static u32 s_half_line_count;  // number of halflines that have occurred for this full frame
-
+static u32 s_half_line_of_next_si_poll; // halfline when next SI poll results should be available
+static constexpr u32 num_half_lines_for_si_poll = (7 * 2) + 1; // this is how long an SI poll takes
 
 static FieldType s_current_field;
 
@@ -100,6 +102,7 @@ void DoState(PointerWrap &p)
 	p.Do(TargetRefreshRate);
 	p.Do(s_ticks_last_line_start);
 	p.Do(s_half_line_count);
+	p.Do(s_half_line_of_next_si_poll);
 	p.Do(s_current_field);
 	p.Do(s_even_field_first_hl);
 	p.Do(s_odd_field_first_hl);
@@ -158,6 +161,7 @@ void Preset(bool _bNTSC)
 
 	s_ticks_last_line_start = 0;
 	s_half_line_count = 1;
+	s_half_line_of_next_si_poll = num_half_lines_for_si_poll; // first sampling starts at vsync
 	s_current_field = FIELD_ODD;
 
 	UpdateParameters();
@@ -661,6 +665,11 @@ static void EndField()
 // Run when: When a frame is scanned (progressive/interlace)
 void Update()
 {
+	if (s_half_line_of_next_si_poll == s_half_line_count)
+	{
+		SerialInterface::UpdateDevices();
+		s_half_line_of_next_si_poll += SerialInterface::GetPollXLines();
+	}
 	if (s_half_line_count == s_even_field_first_hl)
 	{
 		BeginField(FIELD_EVEN);
@@ -688,11 +697,19 @@ void Update()
 
 	s_half_line_count++;
 
-	if (s_half_line_count > GetHalfLinesPerEvenField() + GetHalfLinesPerOddField()) {
+	if (s_half_line_count > GetHalfLinesPerEvenField() + GetHalfLinesPerOddField())
+	{
 		s_half_line_count = 1;
+		s_half_line_of_next_si_poll = num_half_lines_for_si_poll; // first results start at vsync
 	}
 
-	if (s_half_line_count & 1) {
+	if (s_half_line_count == GetHalfLinesPerEvenField())
+	{
+		s_half_line_of_next_si_poll = GetHalfLinesPerEvenField() + num_half_lines_for_si_poll;
+	}
+
+	if (s_half_line_count & 1)
+	{
 		s_ticks_last_line_start = CoreTiming::GetTicks();
 	}
 
diff --git a/Source/Core/Core/State.cpp b/Source/Core/Core/State.cpp
index f1fd56cf7c..ec6c9d8759 100644
--- a/Source/Core/Core/State.cpp
+++ b/Source/Core/Core/State.cpp
@@ -71,7 +71,7 @@ static Common::Event g_compressAndDumpStateSyncEvent;
 static std::thread g_save_thread;
 
 // Don't forget to increase this after doing changes on the savestate system
-static const u32 STATE_VERSION = 49; // Last changed in PR 2149
+static const u32 STATE_VERSION = 50; // Last changed in PR 3457
 
 // Maps savestate versions to Dolphin versions.
 // Versions after 42 don't need to be added to this list,