From bde81380c38c601e70fa2a4708762d96aa02b2ce Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Thu, 13 Apr 2023 23:49:25 +1000
Subject: [PATCH] GS/SW: Stop C rasterizer crashing with AA1

---
 pcsx2/GS/Renderers/SW/GSDrawScanline.cpp      | 21 ++++++++-----------
 pcsx2/GS/Renderers/SW/GSDrawScanline.h        |  1 +
 .../SW/GSDrawScanlineCodeGenerator.cpp        |  3 ++-
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/pcsx2/GS/Renderers/SW/GSDrawScanline.cpp b/pcsx2/GS/Renderers/SW/GSDrawScanline.cpp
index 1aec5522b9..fede8e4827 100644
--- a/pcsx2/GS/Renderers/SW/GSDrawScanline.cpp
+++ b/pcsx2/GS/Renderers/SW/GSDrawScanline.cpp
@@ -451,10 +451,14 @@ __ri static void WritePixel(const T& src, int addr, int i, u32 psm, const GSScan
 }
 
 void GSDrawScanline::CDrawScanline(int pixels, int left, int top, const GSVertexSW& scan, GSScanlineLocalData& local)
+{
+	CDrawScanline(pixels, left, top, scan, local, GlobalFromLocal(local).sel);
+}
+
+__ri void GSDrawScanline::CDrawScanline(int pixels, int left, int top, const GSVertexSW& scan, GSScanlineLocalData& local, GSScanlineSelector sel)
 {
 	const GSScanlineGlobalData& global = GlobalFromLocal(local);
 
-	GSScanlineSelector sel = global.sel;
 	constexpr int vlen = sizeof(VectorF) / sizeof(float);
 
 #if _M_SSE < 0x501
@@ -1729,17 +1733,10 @@ void GSDrawScanline::CDrawScanline(int pixels, int left, int top, const GSVertex
 
 void GSDrawScanline::CDrawEdge(int pixels, int left, int top, const GSVertexSW& scan, GSScanlineLocalData& local)
 {
-	// This sucks. But so does not jitting!
-	const GSScanlineGlobalData* old_gd = local.gd;
-	GSScanlineGlobalData gd;
-	std::memcpy(&gd, &local.gd, sizeof(gd));
-	gd.sel.zwrite = 0;
-	gd.sel.edge = 1;
-	local.gd = &gd;
-
-	CDrawScanline(pixels, left, top, scan, local);
-
-	local.gd = old_gd;
+	GSScanlineSelector sel = local.gd->sel;
+	sel.zwrite = 0;
+	sel.edge = 1;
+	CDrawScanline(pixels, left, top, scan, local, sel);
 }
 
 template <class T, bool masked>
diff --git a/pcsx2/GS/Renderers/SW/GSDrawScanline.h b/pcsx2/GS/Renderers/SW/GSDrawScanline.h
index 3814e625ff..41c8d779de 100644
--- a/pcsx2/GS/Renderers/SW/GSDrawScanline.h
+++ b/pcsx2/GS/Renderers/SW/GSDrawScanline.h
@@ -63,6 +63,7 @@ private:
 	static void CSetupPrim(const GSVertexSW* vertex, const u16* index, const GSVertexSW& dscan, GSScanlineLocalData& local);
 	static void CDrawScanline(int pixels, int left, int top, const GSVertexSW& scan, GSScanlineLocalData& local);
 	static void CDrawEdge(int pixels, int left, int top, const GSVertexSW& scan, GSScanlineLocalData& local);
+	__ri static void CDrawScanline(int pixels, int left, int top, const GSVertexSW& scan, GSScanlineLocalData& local, GSScanlineSelector sel);
 };
 
 MULTI_ISA_UNSHARED_END
diff --git a/pcsx2/GS/Renderers/SW/GSDrawScanlineCodeGenerator.cpp b/pcsx2/GS/Renderers/SW/GSDrawScanlineCodeGenerator.cpp
index 212b61131b..22e36a52f0 100644
--- a/pcsx2/GS/Renderers/SW/GSDrawScanlineCodeGenerator.cpp
+++ b/pcsx2/GS/Renderers/SW/GSDrawScanlineCodeGenerator.cpp
@@ -91,7 +91,8 @@ GSDrawScanlineCodeGenerator::GSDrawScanlineCodeGenerator(u64 key, void* code, si
 
 	if (shouldUseCDrawScanline(key))
 	{
-		jmp(reinterpret_cast<const void*>(&GSDrawScanline::CDrawScanline));
+		jmp(reinterpret_cast<const void*>(static_cast<void (*)(int, int, int, const GSVertexSW&, GSScanlineLocalData&)>(
+			&GSDrawScanline::CDrawScanline)));
 		return;
 	}