From 37cc5f52eb1ad0f86c9459285e44726a5bdb0950 Mon Sep 17 00:00:00 2001
From: Witold Filipczyk <witekfl@poczta.onet.pl>
Date: Sun, 11 Dec 2022 16:22:41 +0100
Subject: [PATCH] [terminal] Periodically refresh screen

DISPLAY_TIME_REFRESH 50ms (No more than 20fps).
It is still using too much CPU for refreshing screen.
---
 src/main/select.c | 11 ++++++++++-
 src/setup.h       |  1 +
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/main/select.c b/src/main/select.c
index cf638965..77c14f15 100644
--- a/src/main/select.c
+++ b/src/main/select.c
@@ -489,6 +489,15 @@ set_handlers(int fd, select_handler_T read_func, select_handler_T write_func,
 	}
 }
 
+static timer_id_T periodic_redraw_timer = TIMER_ID_UNDEF;
+
+static void
+periodic_redraw_all_terminals(void *data)
+{
+	redraw_all_terminals();
+	install_timer(&periodic_redraw_timer, DISPLAY_TIME_REFRESH, periodic_redraw_all_terminals, NULL);
+}
+
 void
 select_loop(void (*init)(void))
 {
@@ -515,12 +524,12 @@ select_loop(void (*init)(void))
 	}
 #endif
 	if (event_enabled) {
+		periodic_redraw_all_terminals(NULL);
 		while (!program.terminate) {
 			check_signals();
 			if (1 /*(!F)*/) {
 				do_event_loop(EVLOOP_NONBLOCK);
 				check_signals();
-				redraw_all_terminals();
 			}
 			if (program.terminate) break;
 			do_event_loop(EVLOOP_ONCE);
diff --git a/src/setup.h b/src/setup.h
index 589ff064..161cf8dc 100644
--- a/src/setup.h
+++ b/src/setup.h
@@ -61,6 +61,7 @@
 
 #define DISPLAY_TIME_MIN		((milliseconds_T) 200)
 #define DISPLAY_TIME			20
+#define DISPLAY_TIME_REFRESH	((milliseconds_T) 50)
 
 #define HTML_LEFT_MARGIN		3
 #define HTML_MAX_TABLE_LEVEL		10