From db01fa04f29c9e1a2f1fa5ca0da8cca8cd11a2df Mon Sep 17 00:00:00 2001
From: Lephenixnoir <sebastien.michelland@protonmail.com>
Date: Wed, 4 Aug 2021 15:11:03 +0200
Subject: [PATCH] Set a black frame when not using direct-DD access

---
 cgdoom/cgdoom.c  | 7 ++++++-
 cgdoom/i_video.c | 7 +++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/cgdoom/cgdoom.c b/cgdoom/cgdoom.c
index 6793980..c5cc2c7 100644
--- a/cgdoom/cgdoom.c
+++ b/cgdoom/cgdoom.c
@@ -609,6 +609,8 @@ int main(void){
 #else 
 	EnableColor(1);
 	EnableStatusArea(3);
+	Bdisp_FrameAndColor(3, 16);
+	Bdisp_FrameAndColor(1, 0);
 
 	WADFileInfo wads[16];
 	int wad_count = FindWADs(wads, 16);
@@ -689,9 +691,12 @@ int main(void){
 		}
 	}
 
-	memset(VRAM,0,WIDTH*HEIGHT*2);
+	memset(VRAM, 0, WIDTH*HEIGHT*2);
 	D_DoomMain();
 
+	Bdisp_FrameAndColor(3, 16);
+	Bdisp_FrameAndColor(1, 0);
+
 	if(gWADfd >= 0)
 		Bfile_CloseFile_OS(gWADfd);
 
diff --git a/cgdoom/i_video.c b/cgdoom/i_video.c
index 4f2f49f..b636bae 100644
--- a/cgdoom/i_video.c
+++ b/cgdoom/i_video.c
@@ -159,6 +159,13 @@ void I_ShutdownGraphics(void)
 
 void I_Flip (void)
 {
+  /* Set a black frame if the current one is white */
+  if ((Bdisp_FrameAndColor(0, 0) & 1) == 0)
+  {
+    Bdisp_FrameAndColor(3, 17);
+    Bdisp_FrameAndColor(1, 0);
+  }
+
   int x,y;
   for(y=0;y<SCREENHEIGHT;y++)
   {