From: Toni Wilen <twilen@winuae.net>
Date: Sun, 8 Mar 2026 18:43:08 +0000 (+0200)
Subject: Black level calibration update
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=dfbe93e9f34f6daf21e8db4e271de3de4bb9a896;p=francis%2Fwinuae.git

Black level calibration update
---

diff --git a/drawing.cpp b/drawing.cpp
index 9617632c..7dd044c3 100644
--- a/drawing.cpp
+++ b/drawing.cpp
@@ -5471,6 +5471,7 @@ void end_draw_denise(void)
 static uae_u8 blc_prev[3];
 static void emulate_black_level_calibration(uae_u32 *b1, uae_u32 *b2, uae_u32 *db, int dtotal, int cstart, int clen)
 {
+	bool useb2 = b1 != b2 && b2;
 	int shift = hresolution + 1;
 	int off = cstart << shift;
 
@@ -5493,8 +5494,11 @@ static void emulate_black_level_calibration(uae_u32 *b1, uae_u32 *b2, uae_u32 *d
 		}
 	}
 	if (!cnt) {
+		memcpy(b1, db, (dtotal * sizeof(uae_u32)) << shift);
+		if (useb2) {
+			memcpy(b2, db, (dtotal * sizeof(uae_u32)) << shift);
+		}
 		return;
-
 	}
 
 #if 1
@@ -5513,7 +5517,6 @@ static void emulate_black_level_calibration(uae_u32 *b1, uae_u32 *b2, uae_u32 *d
 //	if (outc[0] > 10 || outc[1] > 10 || outc[2] > 10)
 //		write_log("%02x %02x %02x\n", outc[0], outc[1], outc[2]);
 
-	bool useb2 = b1 != b2 && b2;
 	if (outc[0] <= 3 && outc[1] <= 3 && outc[2] <= 3) {
 		memcpy(b1, db, (dtotal * sizeof(uae_u32)) << shift);
 		if (useb2) {
@@ -5532,10 +5535,7 @@ static void emulate_black_level_calibration(uae_u32 *b1, uae_u32 *b2, uae_u32 *d
 						if (c[j] <= outc[j]) {
 							c[j] = 0;
 						} else {
-							int cc = c[j] + outc[j];
-							if (cc >= 256) {
-								cc = 255;
-							}
+							uae_u8 cc = c[j] - outc[j];
 							c[j] = cc;
 						}
 					}
@@ -5567,7 +5567,6 @@ static uae_u32 filter_pixel(uae_u32 p1, uae_u32 p2)
 // ultra extreme debug pixel patterns
 static uint32_t decode_denise_specials_debug(uint32_t v, int inc)
 {
-	*buf_d++ = v;
 	if (decode_specials_debug > 1) {
 		int t = ((inc >> 1) + this_line->linear_vpos + 1) & 3;
 		if (denise_blank_active2) {
@@ -5605,6 +5604,7 @@ static uint32_t decode_denise_specials_debug(uint32_t v, int inc)
 			}
 		}
 	}
+	*buf_d++ = v;
 	return v;
 }