From 7457b40a4528e98f6fba3a6c17bba1c93418b679 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Wed, 15 Nov 2023 09:53:51 -0800
Subject: [PATCH] renderer/metal: handle preedit wider than our screen

---
 src/renderer/Metal.zig | 3 +--
 src/renderer/State.zig | 8 ++++++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/renderer/Metal.zig b/src/renderer/Metal.zig
index 8e8cc0e97..5bc0520eb 100644
--- a/src/renderer/Metal.zig
+++ b/src/renderer/Metal.zig
@@ -1101,10 +1101,9 @@ fn rebuildCells(
         y: usize,
         x: [2]usize,
     } = if (preedit) |preedit_v| preedit: {
-        var x = screen.cursor.x;
         break :preedit .{
             .y = screen.cursor.y,
-            .x = .{ x, x + preedit_v.width() },
+            .x = preedit_v.range(screen.cursor.x, screen.cols - 1),
         };
     } else null;
 
diff --git a/src/renderer/State.zig b/src/renderer/State.zig
index efe29ecb9..57b54365d 100644
--- a/src/renderer/State.zig
+++ b/src/renderer/State.zig
@@ -48,4 +48,12 @@ pub const Preedit = struct {
 
         return result;
     }
+
+    pub fn range(self: *const Preedit, start: usize, max: usize) [2]usize {
+        // If our preedit goes off the end of the screen, we adjust it so
+        // that it shifts left.
+        const end = start + self.width();
+        const offset = if (end > max) end - max else 0;
+        return .{ start -| offset, end -| offset };
+    }
 };