From bea796fb2df6d65c9ce588303882b9a224052aad Mon Sep 17 00:00:00 2001
From: zeromus <zeromus@users.noreply.github.com>
Date: Sat, 15 Aug 2020 23:13:17 -0400
Subject: [PATCH] experimental "Frame Inch" designed to make quick presses of
 frame advance always do something (concerning #2303).

---
 src/BizHawk.Client.Common/config/Binding.cs   |  1 +
 src/BizHawk.Client.EmuHawk/MainForm.Hotkey.cs |  4 ++++
 src/BizHawk.Client.EmuHawk/MainForm.cs        | 20 ++++++++++++++++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/BizHawk.Client.Common/config/Binding.cs b/src/BizHawk.Client.Common/config/Binding.cs
index 4ce4fc919d..b02abf9562 100644
--- a/src/BizHawk.Client.Common/config/Binding.cs
+++ b/src/BizHawk.Client.Common/config/Binding.cs
@@ -145,6 +145,7 @@ namespace BizHawk.Client.Common
 						Bind("General", "Screen Client to Clipboard", "Ctrl+Shift+C"),
 						Bind("General", "Toggle Skip Lag Frame"),
 						Bind("General", "Toggle Key Priority"),
+						Bind("General", "Frame Inch"),
 
 						Bind("Save States", "Save State 0", "Shift+F10"),
 						Bind("Save States", "Save State 1", "Shift+F1"),
diff --git a/src/BizHawk.Client.EmuHawk/MainForm.Hotkey.cs b/src/BizHawk.Client.EmuHawk/MainForm.Hotkey.cs
index 4a12f40fac..cd8ad4525f 100644
--- a/src/BizHawk.Client.EmuHawk/MainForm.Hotkey.cs
+++ b/src/BizHawk.Client.EmuHawk/MainForm.Hotkey.cs
@@ -19,6 +19,10 @@ namespace BizHawk.Client.EmuHawk
 				case "Pause":
 					TogglePause();
 					break;
+				case "Frame Inch":
+					//special! allow this key to get handled as Frame Advance, too
+					FrameInch = true;
+					return false;
 				case "Toggle Throttle":
 					_unthrottled ^= true;
 					ThrottleMessage();
diff --git a/src/BizHawk.Client.EmuHawk/MainForm.cs b/src/BizHawk.Client.EmuHawk/MainForm.cs
index 187d94b1a2..00ffc816ea 100644
--- a/src/BizHawk.Client.EmuHawk/MainForm.cs
+++ b/src/BizHawk.Client.EmuHawk/MainForm.cs
@@ -771,6 +771,7 @@ namespace BizHawk.Client.EmuHawk
 		public LoadRomArgs CurrentlyOpenRomArgs { get; private set; }
 		public bool PauseAvi { get; set; }
 		public bool PressFrameAdvance { get; set; }
+		public bool FrameInch { get; set; }
 		public bool HoldFrameAdvance { get; set; } // necessary for tastudio > button
 		public bool PressRewind { get; set; } // necessary for tastudio < button
 		public bool FastForward { get; set; }
@@ -2802,8 +2803,25 @@ namespace BizHawk.Client.EmuHawk
 				runFrame = true;
 			}
 
-			if (InputManager.ClientControls["Frame Advance"] || PressFrameAdvance || HoldFrameAdvance)
+
+			bool oldFrameAdvanceCondition = InputManager.ClientControls["Frame Advance"] || PressFrameAdvance || HoldFrameAdvance;
+			if (FrameInch)
 			{
+				FrameInch = false;
+				if (EmulatorPaused || oldFrameAdvanceCondition)
+				{
+					oldFrameAdvanceCondition = true;
+				}
+				else
+				{
+					PauseEmulator();
+					oldFrameAdvanceCondition = false;
+				}
+			}
+
+			if (oldFrameAdvanceCondition || FrameInch)
+			{
+				FrameInch = false;
 				_runloopFrameAdvance = true;
 
 				// handle the initial trigger of a frame advance