From 1d7423d8867a802f442b18143824a4cffa8fb9d0 Mon Sep 17 00:00:00 2001
From: Henrik Hautakoski <henrik.hautakoski@gmail.com>
Date: Mon, 15 Sep 2025 08:06:02 +0200
Subject: [PATCH] feat(grid): add MoveRowDown()

---
 game/grid.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/game/grid.go b/game/grid.go
index ffbafee..d59e7ea 100644
--- a/game/grid.go
+++ b/game/grid.go
@@ -40,6 +40,14 @@ func (g *Grid) IsRowFull(y byte) bool {
 	return true
 }
 
+func (g *Grid) MoveRowDown(y, num_rows byte) {
+	w := uint16(g.Width())
+	src := uint16(y) * w
+	dst := uint16(y+num_rows) * w
+	copy(g[dst:dst+w], g[src:src+w])
+	clear(g[src : src+w])
+}
+
 func (g *Grid) ClearRow(y byte) {
 	w := uint16(g.Width())
 	n := uint16(y) * w