From: Toni Wilen <twilen@winuae.net>
Date: Sun, 26 Oct 2025 14:30:38 +0000 (+0200)
Subject: Switch to normal emulation if BPLDAT1 is written to even if line is blanked.
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=0a371dd6db9aa28096e2f9ea70dfe8331de82e5a;p=francis%2Fwinuae.git

Switch to normal emulation if BPLDAT1 is written to even if line is blanked.
---

diff --git a/drawing.cpp b/drawing.cpp
index 9a365eed..533c16d3 100644
--- a/drawing.cpp
+++ b/drawing.cpp
@@ -517,6 +517,7 @@ static int internal_pixel_cnt, internal_pixel_start_cnt;
 static bool no_denise_lol, denise_strlong_seen;
 #define STRLONG_SEEN_DELAY 2
 static int denise_strlong_seen_delay;
+static bool denise_vsync_bpl_detect;
 
 void set_inhibit_frame(int monid, int bit)
 {
@@ -3738,6 +3739,7 @@ static void expand_drga_early(struct denise_rga *rd)
 				aga_unalign1 += 2;
 			}
 		}
+		denise_vsync_bpl_detect = false;
 		break;
 	}
 
@@ -5507,6 +5509,7 @@ static void draw_denise_vsync(int erase)
 		center_y_erase = false;
 		resetfulllinestate();
 	}
+	denise_vsync_bpl_detect = true;
 }
 
 static void denise_draw_update(void)
@@ -5712,15 +5715,23 @@ static void draw_denise_line(int gfx_ypos, enum nln_how how, uae_u32 linecnt, in
 	bool blankedline = (this_line->linear_vpos >= denise_vblank_extra_bottom || this_line->linear_vpos < denise_vblank_extra_top) && currprefs.gfx_overscanmode < OVERSCANMODE_EXTREME && !programmedmode;
 	bool line_is_blanked = false;
 
-	if (denise_pixtotal_max == -0x7fffffff || blankedline || blanked) {
+	if ((denise_pixtotal_max == -0x7fffffff && denise_vsync_bpl_detect) || blankedline || blanked) {
 
 		// don't draw vertical blanking if not ultra extreme overscan
 		internal_pixel_cnt = -1;
 		line_is_blanked = true;
 		while (denise_cck < denise_endcycle) {
+			// start drawing normally if BPLDAT1 gets written to, even if line is blanked
+			if (!denise_vsync_bpl_detect) {
+				while (denise_cck < denise_endcycle) {
+					lts();
+					lts_changed = false;
+				}
+				break;
+			}
 			while (denise_cck < denise_endcycle) {
 				do_denise_cck(denise_linecnt, denise_startpos, denise_cck);
-				if (lts_changed) {
+				if (lts_changed || !denise_vsync_bpl_detect) {
 					break;
 				}
 				if (aga_mode) {
@@ -5753,6 +5764,7 @@ static void draw_denise_line(int gfx_ypos, enum nln_how how, uae_u32 linecnt, in
 						*debug_dma_dhpos_odd = denise_hcounter;
 #endif
 						denise_hcounter_cmp++;
+						denise_hcounter &= 511;
 						denise_hcounter++;
 						denise_hcounter &= 511;
 						denise_hcounter_next++;