From cb6e9b90fb99eb1bca219d9b7e70a0e5fecfac95 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Sat, 7 Aug 2010 03:57:22 +0000
Subject: [PATCH] - Added r_clearbuffer cvar. Valid values are:   * 0. Do not
 clear. This is the standard behavior.   * 1. Clear to black.   * 2. Clear to
 white.   * 3. Alternate between black and white every 128 ms.   * 4. Step
 through the palette one color at a time every 32 ms.   * 5. Epileptic seizure
 inducing random colors every frame.

SVN r2491 (trunk)
---
 src/r_main.cpp | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/src/r_main.cpp b/src/r_main.cpp
index 93131b149..e3008862f 100644
--- a/src/r_main.cpp
+++ b/src/r_main.cpp
@@ -100,6 +100,7 @@ static float CurrentVisibility = 8.f;
 static fixed_t MaxVisForWall;
 static fixed_t MaxVisForFloor;
 static FRandom pr_torchflicker ("TorchFlicker");
+static FRandom pr_hom ("HOM-Flasher");
 static TArray<InterpolationViewer> PastViewers;
 static int centerxwide;
 static bool polyclipped;
@@ -111,6 +112,7 @@ bool r_dontmaplines;
 CVAR (String, r_viewsize, "", CVAR_NOSET)
 CVAR (Int, r_polymost, 0, 0)
 CVAR (Bool, r_deathcamera, false, CVAR_ARCHIVE)
+CVAR (Int, r_clearbuffer, 0, 0)
 
 fixed_t			r_BaseVisibility;
 fixed_t			r_WallVisibility;
@@ -1270,6 +1272,34 @@ void R_SetupFrame (AActor *actor)
 	{
 		polyclipped = RP_SetupFrame (false);
 	}
+
+	if (RenderTarget == screen && r_clearbuffer != 0)
+	{
+		int color;
+		int hom = r_clearbuffer;
+
+		if (hom == 3)
+		{
+			hom = ((I_FPSTime() / 128) & 1) + 1;
+		}
+		if (hom == 1)
+		{
+			color = GPalette.BlackIndex;
+		}
+		else if (hom == 2)
+		{
+			color = GPalette.WhiteIndex;
+		}
+		else if (hom == 4)
+		{
+			color = (I_FPSTime() / 32) & 255;
+		}
+		else
+		{
+			color = pr_hom();
+		}
+		memset(RenderTarget->GetBuffer(), color, RenderTarget->GetPitch() * RenderTarget->GetHeight());
+	}
 }
 
 //==========================================================================