From 87939a668fdad500844657853f4a17cb4bf02ab8 Mon Sep 17 00:00:00 2001
From: Dimitris Panokostas <midwan@gmail.com>
Date: Sat, 30 Jan 2021 12:47:06 +0100
Subject: [PATCH] Improve blacker than black function to reduce overexposure

---
 src/gfxutil.cpp | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/src/gfxutil.cpp b/src/gfxutil.cpp
index 0b000b9b4..b042d73b5 100644
--- a/src/gfxutil.cpp
+++ b/src/gfxutil.cpp
@@ -381,15 +381,9 @@ void alloc_colors64k(int monid, int rw, int gw, int bw, int rs, int gs, int bs,
 		int b = ((i & 0xf) << 4) | (i & 0x0f);
 
 		if (currprefs.gfx_blackerthanblack) {
-			r += 10;
-			g += 10;
-			b += 10;
-			if (r > 255)
-				r = 255;
-			if (g > 255)
-				g = 255;
-			if (b > 255)
-				b = 255;
+			r = (r * (255 - 10) / 255) + 10;
+			g = (g * (255 - 10) / 255) + 10;
+			b = (g * (255 - 10) / 255) + 10;
 		}
 		
 		r = uae_gamma[r + j][0];