From 71e855a822b5fbd08fbdd02a78cdb0ea85398ea4 Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Sun, 13 Feb 2022 10:22:59 -0800
Subject: [PATCH] GE Debugger: Track last gstate on stepping.

---
 GPU/Debugger/Stepping.cpp | 36 ++++++++++++++++++++++++++----------
 GPU/Debugger/Stepping.h   |  3 +++
 2 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/GPU/Debugger/Stepping.cpp b/GPU/Debugger/Stepping.cpp
index ea3ce03715..2b750235a7 100644
--- a/GPU/Debugger/Stepping.cpp
+++ b/GPU/Debugger/Stepping.cpp
@@ -65,6 +65,8 @@ static GPUDebugBuffer bufferClut;
 static int bufferLevel;
 static u32 pauseSetCmdValue;
 
+static GPUgstate lastGState;
+
 static void SetPauseAction(PauseAction act, bool waitComplete = true) {
 	pauseLock.lock();
 	std::unique_lock<std::mutex> guard(actionLock);
@@ -133,6 +135,22 @@ static void RunPauseAction() {
 	pauseAction = PAUSE_BREAK;
 }
 
+static void StartStepping() {
+	if (lastGState.cmdmem[1] == 0) {
+		lastGState = gstate;
+		// Play it safe so we don't keep resetting.
+		lastGState.cmdmem[1] |= 0x01000000;
+	}
+	gpuDebug->NotifySteppingEnter();
+	isStepping = true;
+}
+
+static void StopStepping() {
+	gpuDebug->NotifySteppingExit();
+	lastGState = gstate;
+	isStepping = false;
+}
+
 bool SingleStep() {
 	std::unique_lock<std::mutex> guard(pauseLock);
 	if (coreState != CORE_RUNNING && coreState != CORE_NEXTFRAME && coreState != CORE_STEPPING) {
@@ -147,13 +165,9 @@ bool SingleStep() {
 		return false;
 	}
 
-	gpuDebug->NotifySteppingEnter();
-	isStepping = true;
-
+	StartStepping();
 	RunPauseAction();
-
-	gpuDebug->NotifySteppingExit();
-	isStepping = false;
+	StopStepping();
 	return true;
 }
 
@@ -171,13 +185,12 @@ bool EnterStepping() {
 		return false;
 	}
 
-	gpuDebug->NotifySteppingEnter();
+	StartStepping();
 
 	// Just to be sure.
 	if (pauseAction == PAUSE_CONTINUE) {
 		pauseAction = PAUSE_BREAK;
 	}
-	isStepping = true;
 	stepCounter++;
 
 	do {
@@ -185,8 +198,7 @@ bool EnterStepping() {
 		pauseWait.wait(guard);
 	} while (pauseAction != PAUSE_CONTINUE);
 
-	gpuDebug->NotifySteppingExit();
-	isStepping = false;
+	StopStepping();
 	return true;
 }
 
@@ -263,4 +275,8 @@ void ForceUnpause() {
 	actionWait.notify_all();
 }
 
+GPUgstate LastState() {
+	return lastGState;
+}
+
 }  // namespace
diff --git a/GPU/Debugger/Stepping.h b/GPU/Debugger/Stepping.h
index af93743eb3..35409c03b9 100644
--- a/GPU/Debugger/Stepping.h
+++ b/GPU/Debugger/Stepping.h
@@ -22,6 +22,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/Core.h"
 #include "GPU/Common/GPUDebugInterface.h"
+#include "GPU/GPUState.h"
 
 namespace GPUStepping {
 	// Should be called from the emu thread.
@@ -42,4 +43,6 @@ namespace GPUStepping {
 
 	void ResumeFromStepping();
 	void ForceUnpause();
+
+	GPUgstate LastState();
 };