chore: update vendored libghostty-vt

refs #276

1 files changed, 85 insertions, 0 deletions

diff --git a/vendor/libghostty-vt/src/terminal/c/unicode.zig b/vendor/libghostty-vt/src/terminal/c/unicode.zig
new file mode 100644
index 00000000..14451338
--- /dev/null
+++ b/vendor/libghostty-vt/src/terminal/c/unicode.zig
@@ -0,0 +1,85 @@
+const std = @import("std");
+const lib = @import("../lib.zig");
+const unicode_pkg = @import("../../unicode/main.zig");
+
+pub fn codepoint_width(cp: u32) callconv(lib.calling_conv) u8 {
+    if (cp > 0x10FFFF) return 1;
+    return unicode_pkg.codepointWidth(@intCast(cp));
+}
+
+pub fn grapheme_width(
+    cps: ?[*]const u32,
+    len: usize,
+    width: ?*u8,
+) callconv(lib.calling_conv) usize {
+    if (len == 0) {
+        if (width) |ptr| ptr.* = 0;
+        return 0;
+    }
+
+    const ptr = cps orelse {
+        if (width) |out| out.* = 0;
+        return 0;
+    };
+    const result = unicode_pkg.graphemeWidth(u32, ptr[0..len]);
+    if (width) |out| out.* = result.width;
+    return result.len;
+}
+
+test "codepoint_width narrow" {
+    const testing = std.testing;
+    try testing.expectEqual(1, codepoint_width('a'));
+}
+
+test "codepoint_width wide" {
+    const testing = std.testing;
+    try testing.expectEqual(2, codepoint_width(0x4E00));
+}
+
+test "codepoint_width zero" {
+    const testing = std.testing;
+    try testing.expectEqual(0, codepoint_width(0x0301));
+}
+
+test "codepoint_width out of range" {
+    const testing = std.testing;
+    try testing.expectEqual(1, codepoint_width(0x110000));
+    try testing.expectEqual(1, codepoint_width(std.math.maxInt(u32)));
+}
+
+test "grapheme_width empty" {
+    const testing = std.testing;
+
+    var width: u8 = 42;
+    try testing.expectEqual(@as(usize, 0), grapheme_width(null, 0, &width));
+    try testing.expectEqual(@as(u8, 0), width);
+}
+
+test "grapheme_width null width" {
+    const testing = std.testing;
+
+    const cps = [_]u32{ 0x2764, 0xFE0F };
+    try testing.expectEqual(@as(usize, 2), grapheme_width(cps[0..].ptr, cps.len, null));
+}
+
+test "grapheme_width out of range" {
+    const testing = std.testing;
+
+    var width: u8 = 0;
+    const invalid_first = [_]u32{ 0x110000, 0x0301 };
+    try testing.expectEqual(@as(usize, 1), grapheme_width(invalid_first[0..].ptr, invalid_first.len, &width));
+    try testing.expectEqual(@as(u8, 1), width);
+
+    const invalid_second = [_]u32{ 'a', 0x110000 };
+    try testing.expectEqual(@as(usize, 1), grapheme_width(invalid_second[0..].ptr, invalid_second.len, &width));
+    try testing.expectEqual(@as(u8, 1), width);
+}
+
+test "grapheme_width emoji sequence" {
+    const testing = std.testing;
+
+    var width: u8 = 0;
+    const cps = [_]u32{ 0x1F468, 0x200D, 0x1F469, 0x200D, 0x1F467 };
+    try testing.expectEqual(@as(usize, cps.len), grapheme_width(cps[0..].ptr, cps.len, &width));
+    try testing.expectEqual(@as(u8, 2), width);
+}