From 589557be9c912668f5b04519cfe5a6a89c75e70a Mon Sep 17 00:00:00 2001
From: Emil Lenngren <emil.lenngren@gmail.com>
Date: Fri, 29 Apr 2022 22:17:07 +0200
Subject: [PATCH] Reduce input lag by one frame by reading the controller at
 the correct place

---
 libultraship/libultraship/Window.cpp | 5 ++++-
 libultraship/libultraship/Window.h   | 1 +
 soh/soh/GbiWrap.cpp                  | 1 +
 soh/soh/OTRGlobals.cpp               | 4 ++++
 soh/soh/OTRGlobals.h                 | 1 +
 soh/src/code/graph.c                 | 1 +
 6 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/libultraship/libultraship/Window.cpp b/libultraship/libultraship/Window.cpp
index 2b57c547e..0feb7229f 100644
--- a/libultraship/libultraship/Window.cpp
+++ b/libultraship/libultraship/Window.cpp
@@ -275,8 +275,11 @@ namespace Ship {
         WmApi->set_keyboard_callbacks(Window::KeyDown, Window::KeyUp, Window::AllKeysUp);
     }
 
-    void Window::RunCommands(Gfx* Commands) {
+    void Window::StartFrame() {
         gfx_start_frame();
+    }
+
+    void Window::RunCommands(Gfx* Commands) {
         gfx_run(Commands);
         gfx_end_frame();
     }
diff --git a/libultraship/libultraship/Window.h b/libultraship/libultraship/Window.h
index 0d12211b0..b075e496f 100644
--- a/libultraship/libultraship/Window.h
+++ b/libultraship/libultraship/Window.h
@@ -18,6 +18,7 @@ namespace Ship {
 			~Window();
 			void MainLoop(void (*MainFunction)(void));
 			void Init();
+			void StartFrame();
 			void RunCommands(Gfx* Commands);
 			void SetFrameDivisor(int divisor);
 			void GetPixelDepthPrepare(float x, float y);
diff --git a/soh/soh/GbiWrap.cpp b/soh/soh/GbiWrap.cpp
index c7f69f1a9..9f71f1717 100644
--- a/soh/soh/GbiWrap.cpp
+++ b/soh/soh/GbiWrap.cpp
@@ -5,6 +5,7 @@
 extern "C" {
 void InitOTR();
 void Graph_ProcessFrame(void (*run_one_game_iter)(void));
+void Graph_StartFrame();
 void Graph_ProcessGfxCommands(Gfx* commands);
 void OTRLogString(const char* src);
 void OTRGfxPrint(const char* str, void* printer, void (*printImpl)(void*, char));
diff --git a/soh/soh/OTRGlobals.cpp b/soh/soh/OTRGlobals.cpp
index 69917e8ac..d2bc941cf 100644
--- a/soh/soh/OTRGlobals.cpp
+++ b/soh/soh/OTRGlobals.cpp
@@ -92,6 +92,10 @@ extern "C" void Graph_ProcessFrame(void (*run_one_game_iter)(void)) {
     OTRGlobals::Instance->context->GetWindow()->MainLoop(run_one_game_iter);
 }
 
+extern "C" void Graph_StartFrame() {
+    OTRGlobals::Instance->context->GetWindow()->StartFrame();
+}
+
 // C->C++ Bridge
 extern "C" void Graph_ProcessGfxCommands(Gfx* commands) {
     OTRGlobals::Instance->context->GetWindow()->SetFrameDivisor(R_UPDATE_RATE);
diff --git a/soh/soh/OTRGlobals.h b/soh/soh/OTRGlobals.h
index dfb235712..7ce08649a 100644
--- a/soh/soh/OTRGlobals.h
+++ b/soh/soh/OTRGlobals.h
@@ -21,6 +21,7 @@ private:
 #ifndef __cplusplus
 void InitOTR();
 void Graph_ProcessFrame(void (*run_one_game_iter)(void));
+void Graph_StartFrame();
 void Graph_ProcessGfxCommands(Gfx* commands);
 void OTRLogString(const char* src);
 void OTRGfxPrint(const char* str, void* printer, void (*printImpl)(void*, char));
diff --git a/soh/src/code/graph.c b/soh/src/code/graph.c
index 10293fa5f..5d0495961 100644
--- a/soh/src/code/graph.c
+++ b/soh/src/code/graph.c
@@ -472,6 +472,7 @@ static void RunFrame()
             uint64_t ticksA, ticksB;
             ticksA = GetPerfCounter();
             
+            Graph_StartFrame();
 
             PadMgr_ThreadEntry(&gPadMgr);