From ed756a6d31f390921f050811bd48ecc58e1a3545 Mon Sep 17 00:00:00 2001
From: Toni Wilen <twilen@winuae.net>
Date: Wed, 27 Mar 2024 20:58:54 +0200
Subject: [PATCH] Make sure weird vblank where vblank starts after vsync end is
 visible, only if extreme or ultra extreme overscan.

---
 custom.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/custom.cpp b/custom.cpp
index 2ebe4d20..f1c4c90e 100644
--- a/custom.cpp
+++ b/custom.cpp
@@ -7351,6 +7351,13 @@ static void init_beamcon0(bool fakehz)
 		if (vsstrt > 0 && vsstrt < maxvpos / 2) {
 			maxvpos_display_vsync += vsstrt - 1;
 		}
+		// if (weird mode where) vblank starts after vsync start+3: minfirstline = vsstrt+3
+		if (currprefs.gfx_overscanmode >= OVERSCANMODE_EXTREME && firstblankedline >= vsstrt + 3 && minfirstline > vsstrt + 3 && firstblankedline < minfirstline) {
+			minfirstline = vsstrt + 3;
+			if (minfirstline_hw > minfirstline) {
+				minfirstline_hw = minfirstline;
+			}
+		}
 	} else {
 		firstblankedline = maxvpos + 1;
 	}
-- 
2.47.3