From 80b36379e7ba0adf55289c7f1de3b0cc604932f3 Mon Sep 17 00:00:00 2001
From: mjbudd77 <mjbudd77@gmail.com>
Date: Sat, 9 Oct 2021 18:31:20 -0400
Subject: [PATCH] Mouse screen coordinates calculation fix for NTSC 2X video
 scaler. Fixes issue #409 for the Qt GUI.

---
 src/drivers/Qt/sdl-video.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/drivers/Qt/sdl-video.cpp b/src/drivers/Qt/sdl-video.cpp
index 99818979..6496ed45 100644
--- a/src/drivers/Qt/sdl-video.cpp
+++ b/src/drivers/Qt/sdl-video.cpp
@@ -494,8 +494,17 @@ void FCEUI_AviVideoUpdate(const unsigned char* buffer)
 uint32 PtoV(double nx, double ny)
 {
 	int x, y;
+
 	y = (int)( ny * (double)nes_shm->video.nrow );
-	x = (int)( nx * (double)nes_shm->video.ncol );
+
+	if ( nes_shm->video.preScaler == 3 )
+	{
+		x = (int)( nx * (double)nes_shm->video.ncol * (256.0/301.0) );
+	}
+	else
+	{
+		x = (int)( nx * (double)nes_shm->video.ncol );
+	}
 
 	//printf("Scaled (%i,%i) \n", x, y);