Fix occasional lag when switching animations

2 files changed, 10 insertions, 4 deletions

diff --git a/src/display.cc b/src/display.cc
index f06b5e3..98b394a 100644
--- a/src/display.cc
+++ b/src/display.cc
@@ -45,8 +45,6 @@ void Display::enable()
 
 void Display::multiplex()
 {
-	static uint8_t scroll;
-
 	/*
 	 * To avoid flickering, do not put any code (or expensive index
 	 * calculations) between the following three lines.
@@ -57,8 +55,8 @@ void Display::multiplex()
 
 	if (++active_col == 8) {
 		active_col = 0;
-		if (++scroll == current_anim->speed) {
-			scroll = 0;
+		if (++update_cnt == current_anim->speed) {
+			update_cnt = 0;
 			need_update = 1;
 		}
 	}
@@ -170,6 +168,7 @@ void Display::reset()
 {
 	for (uint8_t i = 0; i < 8; i++)
 		disp_buf[i] = 0xff;
+	update_cnt = 0;
 	str_pos = 0;
 	str_chunk = 0;
 	char_pos = -1;
diff --git a/src/display.h b/src/display.h
index fd91994..1bf5758 100644
--- a/src/display.h
+++ b/src/display.h
@@ -88,6 +88,13 @@ class Display {
 		animation_t *current_anim;
 
 		/**
+		 * Internal display update counter. Incremented by multiplex().
+		 * update() is called (and the counter reset) whenever
+		 * update_cnt == need_update.
+		 */
+		uint8_t update_cnt;
+
+		/**
 		 * Set to a true value by multiplex() if an update (that is,
 		 * a scroll step or a new frame) is needed. Checked and reset to
 		 * false by update().