From 2c508afc6e3a42478264272d5c6c8e70159f8e3f Mon Sep 17 00:00:00 2001
From: Curtis McEnroe <june@causal.agency>
Date: Tue, 6 Aug 2019 14:50:24 -0400
Subject: Factor out scrolling

---
 term.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/term.c b/term.c
index dff09f4..18eeb66 100644
--- a/term.c
+++ b/term.c
@@ -74,6 +74,22 @@ static void move(struct Cell *dst, struct Cell *src, uint len) {
 	memmove(dst, src, sizeof(*dst) * len);
 }
 
+static void scrollUp(uint n) {
+	move(
+		cell(scroll.top, 0), cell(scroll.top + n, 0),
+		cols * (scroll.bot - scroll.top - (n - 1))
+	);
+	clear(cell(scroll.bot - (n - 1), 0), cell(scroll.bot, cols - 1));
+}
+
+static void scrollDown(uint n) {
+	move(
+		cell(scroll.top + n, 0), cell(scroll.top, 0),
+		cols * (scroll.bot - scroll.top - (n - 1))
+	);
+	clear(cell(scroll.top, 0), cell(scroll.top + (n - 1), cols - 1));
+}
+
 static char updateNUL(wchar_t ch) {
 	switch (ch) {
 		break; case ESC: return ESC;
@@ -83,11 +99,7 @@ static char updateNUL(wchar_t ch) {
 
 		break; case NL: {
 			if (y == scroll.bot) {
-				move(
-					cell(scroll.top, 0), cell(scroll.top + 1, 0),
-					cols * (scroll.bot - scroll.top)
-				);
-				clear(cell(scroll.bot, 0), cell(scroll.bot, cols - 1));
+				scrollUp(1);
 			} else {
 				y = MIN(y + 1, rows - 1);
 			}
@@ -133,13 +145,7 @@ static char updateESC(wchar_t ch) {
 		break; case CSI: return CSI;
 		break; case OSC: return OSC;
 
-		break; case RI: {
-			move(
-				cell(scroll.top + 1, 0), cell(scroll.top, 0),
-				cols * (scroll.bot - scroll.top)
-			);
-			clear(cell(scroll.top, 0), cell(scroll.top, cols - 1));
-		}
+		break; case RI: scrollDown(1);
 
 		break; case '(': discard = true; return ESC;
 		break; case '=': // ignore
-- 
cgit 1.4.1