From: Toni Wilen <twilen@winuae.net>
Date: Thu, 4 Apr 2024 16:58:21 +0000 (+0300)
Subject: Denise strobe vblank update
X-Git-Tag: 5300~46
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=b2ddc1d1bd1082830f787135174ffcf89df8b816;p=francis%2Fwinuae.git

Denise strobe vblank update
---

diff --git a/custom.cpp b/custom.cpp
index 39d0cae3..a5c917e9 100644
--- a/custom.cpp
+++ b/custom.cpp
@@ -382,7 +382,7 @@ static uae_u32 refmask;
 static int refresh_handled_slot;
 static bool refptr_preupdated;
 static bool hstrobe_conflict;
-static uae_u16 last_hstrobe;
+static uae_u16 strobe_vblank;
 static bool vhposw_modified;
 static int line_disabled;
 static bool custom_disabled;
@@ -6306,11 +6306,14 @@ static void reset_decisions_hsync_start(void)
 	} else if (ecs_agnus) {
 		// Visible vblank end is delayed by 1 line
 		thisline_decision.vb = vb_start_line >= 2 + vblank_extraline || vb_end_next_line ? 0 : VB_NOVB;
-		if (hstrobe_conflict && last_hstrobe == 0x3a && thisline_decision.vb) {
+		if (hstrobe_conflict && strobe_vblank && thisline_decision.vb) {
 			thisline_decision.vb = VB_XBLANK;
 		}
 	} else {
 		thisline_decision.vb = vb_start_line >= 2 + vblank_extraline || vb_end_next_line ? 0 : VB_NOVB;
+		if (hstrobe_conflict && strobe_vblank && thisline_decision.vb) {
+			thisline_decision.vb = VB_XBLANK;
+		}
 	}
 
 	// if programmed vblank
@@ -14160,7 +14163,13 @@ static void hsync_handler_post(bool onvsync)
 		uae_u16 strobe = get_strobe_reg(i);
 		if (i == 0) {
 			if (!hstrobe_conflict) {
-				last_hstrobe = strobe;
+				if (strobe == 0x38 || (strobe == 0x3a && ecs_denise)) {
+					// OCS: only STREQU enables vblank. STREQU and STRVBL if ECS Denise.
+					strobe_vblank = 1;
+				} else if (strobe == 0x3c) {
+					// STRHOR disables vblank
+					strobe_vblank = 0;
+				}
 			}
 		}
 		alloc_cycle(hp, strobe != 0x1fe ? CYCLE_STROBE : CYCLE_REFRESH);
@@ -14544,7 +14553,7 @@ void custom_reset(bool hardreset, bool keyboardreset)
 	hdiwstate_blank = diw_states::DIW_waiting_start;
 	maxvpos_display_vsync_next = false;
 	hstrobe_conflict = false;
-	last_hstrobe = 0;
+	strobe_vblank = 0;
 
 	irq_forced_delay = 0;
 	irq_forced = 0;
@@ -15181,9 +15190,17 @@ static int REGPARAM2 custom_wput_1 (int hpos, uaecptr addr, uae_u32 value, int n
 #endif
 	case 0x034: POTGO(value); break;
 
-	case 0x038: last_hstrobe = 0x38; break;
-	case 0x03a: last_hstrobe = 0x3a; break;
-	case 0x03c: last_hstrobe = 0x3c; break;
+	case 0x038:
+		strobe_vblank = 1;
+		break;
+	case 0x03a:
+		if (ecs_denise) {
+			strobe_vblank = 1;
+		}
+		break;
+	case 0x03c:
+		strobe_vblank = 0;
+		break;
 
 	case 0x040: BLTCON0(hpos, value); break;
 	case 0x042: BLTCON1(hpos, value); break;