From 263fc54d03495c3863f353283842b2dd2734f3d6 Mon Sep 17 00:00:00 2001
From: bkleiner <benedikt.kleiner@gmail.com>
Date: Sun, 12 Jan 2025 01:55:41 +0100
Subject: [PATCH] osd: add rolling refresh for hd systems

---
 src/driver/osd/osd.c | 12 ++++++++++++
 src/driver/osd/osd.h |  1 +
 src/osd/render.c     |  2 ++
 3 files changed, 15 insertions(+)

diff --git a/src/driver/osd/osd.c b/src/driver/osd/osd.c
index 55d8815ff..d63c0c136 100644
--- a/src/driver/osd/osd.c
+++ b/src/driver/osd/osd.c
@@ -79,6 +79,18 @@ void osd_clear() {
     ;
 }
 
+void osd_mark_row_dirty() {
+  static uint8_t row = 0;
+
+  const uint16_t offset = row * cols;
+  for (uint32_t i = 0; i < cols; i++) {
+    display[offset + i].dirty = display[offset + i].val != ' ';
+  }
+  display_dirty = display_row_dirty[row] = true;
+
+  row = (row + 1) % rows;
+}
+
 uint8_t osd_clear_async() {
   static uint8_t state = 0;
 
diff --git a/src/driver/osd/osd.h b/src/driver/osd/osd.h
index f95f00efb..ff995bda4 100644
--- a/src/driver/osd/osd.h
+++ b/src/driver/osd/osd.h
@@ -60,6 +60,7 @@ bool osd_is_ready();
 bool osd_update();
 
 void osd_clear();
+void osd_mark_row_dirty();
 uint8_t osd_clear_async();
 
 void osd_display_refresh();
diff --git a/src/osd/render.c b/src/osd/render.c
index dc6a04bf1..08cfc71a1 100644
--- a/src/osd/render.c
+++ b/src/osd/render.c
@@ -531,6 +531,8 @@ static void osd_display_regular() {
       // display warning if we can not detect a camera
       osd_start(OSD_ATTR_BLINK, 7, 7);
       osd_write_str("NO CAMERA SIGNAL");
+    } else if (osd_system == OSD_SYS_HD) {
+      osd_mark_row_dirty();
     }
     osd_state.element = 0;
     break;