From: Toni Wilen <twilen@winuae.net>
Date: Fri, 10 Mar 2023 18:20:11 +0000 (+0200)
Subject: VPOSW mid screen change updates
X-Git-Tag: 5.0.0~122
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=841cf7ec5647776f3ce11ab5cfcb7e37a0896ae7;p=francis%2Fwinuae.git

VPOSW mid screen change updates
---

diff --git a/custom.cpp b/custom.cpp
index 42fd3e9f..553c47d4 100644
--- a/custom.cpp
+++ b/custom.cpp
@@ -7470,7 +7470,6 @@ static void VPOSW(uae_u16 v)
 		lol = 0;
 	}
 	if (lof_changing) {
-		bool newlof = (v & 0x8000) != 0;
 		return;
 	}
 	vpos &= 0x00ff;
@@ -7492,6 +7491,7 @@ static void VPOSW(uae_u16 v)
 static void VHPOSW(uae_u16 v)
 {
 	int oldvpos = vpos;
+	int newvpos = vpos;
 #if 0
 	if (M68K_GETPC < 0xf00000 || 1)
 		write_log (_T("VHPOSW %04X PC=%08x\n"), v, M68K_GETPC);
@@ -7512,22 +7512,32 @@ static void VHPOSW(uae_u16 v)
 	int hnew = v & 0xff;
 	int hdiff = hnew - hpos;
 	if (copper_access && (hdiff & 1)) {
-		write_log("VHPOSW write with odd horizontal change. Possible copper confusion possible.\n");
+		write_log("VHPOSW write %04X. New horizontal value is odd. Copper confusion possible.\n", v);
 	}
 	modify_eventcounter(-(hdiff - 2));
 
 	v >>= 8;
-	vpos &= 0xff00;
-	vpos |= v;
-	if (vpos != oldvpos) {
-		cia_adjust_eclock_phase((vpos - oldvpos) * maxhpos);
+	newvpos &= 0xff00;
+	newvpos |= v;
+	if (newvpos != oldvpos) {
+		cia_adjust_eclock_phase((newvpos - oldvpos) * maxhpos);
 		vposw_change++;
+#ifdef DEBUGGER
+		record_dma_hsync(hpos + 2);
+		if (debug_dma) {
+			int vp = vpos;
+			vpos = newvpos;
+			record_dma_hsync(maxhpos);
+			vpos = vp;
+		}
+#endif
 	}
-	if (vpos < oldvpos) {
-		vpos = oldvpos;
-	} else if (vpos < minfirstline && oldvpos < minfirstline) {
-		vpos = oldvpos;
+	if (newvpos < oldvpos) {
+		newvpos = oldvpos;
+	} else if (newvpos < minfirstline && oldvpos < minfirstline) {
+		newvpos = oldvpos;
 	}
+	vpos = newvpos;
 	vb_check();
 #if 0
 	if (vpos < oldvpos)
diff --git a/events.cpp b/events.cpp
index c5184993..3f1f1d21 100644
--- a/events.cpp
+++ b/events.cpp
@@ -467,14 +467,18 @@ int current_hpos(void)
 // emulate VPOSHW writes changing cycle counter
 void modify_eventcounter(int diff)
 {
+	if (diff == 0) {
+		return;
+	}
 
 	int hpos = current_hpos();
 
-	if (hpos + diff < 0) {
-		return;
-	}
+	// fake >HTOTAL change delays
 	if (hpos + diff >= maxhpos) {
-		return;
+		int dd = maxhpos - (hpos + diff);
+		diff += dd;
+	} else if (hpos + diff < 0) {
+		diff = (maxhpos - (0x100 - hpos + diff));
 	}
 
 	int cdiff = diff * CYCLE_UNIT;
@@ -489,8 +493,6 @@ void modify_eventcounter(int diff)
 		currcycle += cdiff;
 	}
 
-	int hp1 = current_hpos();
-
 	cia_adjust_eclock_phase(diff);
 
 	// adjust all existing timers
@@ -505,8 +507,6 @@ void modify_eventcounter(int diff)
 		eventtab2[i].evtime += cdiff;
 	}
 
-	int hp2 = current_hpos();
-
 	events_schedule();
 }