From 4b3c344825402e5384e8b3b734c6cd349282e737 Mon Sep 17 00:00:00 2001
From: tinkeros <76139882+tinkeros@users.noreply.github.com>
Date: Sat, 25 Feb 2023 19:41:54 -0600
Subject: [PATCH] Skip partial updates when updating entire screen (#90)

---
 src/System/Gr/GrScreen.ZC | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/System/Gr/GrScreen.ZC b/src/System/Gr/GrScreen.ZC
index dcfd93a9..d3166177 100755
--- a/src/System/Gr/GrScreen.ZC
+++ b/src/System/Gr/GrScreen.ZC
@@ -395,10 +395,16 @@ U0 GrUpdateScreen32()
 	while (src < size) //draw 2 pixels at a time
 		*dst++ = gr_palette[*src++ & 0xFF] | gr_palette[*src++ & 0xFF] << 32;
 
-	GrCalcScreenUpdates;
-
 	if (LBtr(&sys_semas[SEMA_FLUSH_VBE_IMAGE], 0))
+	{
 		MemCopy(text.fb_alias, text.raw_screen, text.buffer_size);
+		src -= GR_WIDTH * GR_HEIGHT; // Reset src ptr
+		MemCopy(gr.screen_cache, src, GR_WIDTH * GR_HEIGHT);
+	}
+	else
+	{
+		GrCalcScreenUpdates;
+	}
 }
 
 U0 GrUpdateScreen()