From 939e6e7a65e3ef40b53f81799401e6c17498121a Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sun, 2 Oct 2022 11:05:40 -0700
Subject: [PATCH] pkg/harfbuzz: add coretext compilation on macOS

---
 build.zig                 |  7 ++++++-
 pkg/harfbuzz/build.zig    | 16 +++++++++++++++-
 pkg/harfbuzz/c.zig        |  3 +++
 pkg/harfbuzz/coretext.zig | 30 ++++++++++++++++++++++++++++++
 pkg/harfbuzz/freetype.zig |  2 ++
 pkg/harfbuzz/main.zig     |  1 +
 6 files changed, 57 insertions(+), 2 deletions(-)
 create mode 100644 pkg/harfbuzz/coretext.zig

diff --git a/build.zig b/build.zig
index 57bae6254..b090cf49a 100644
--- a/build.zig
+++ b/build.zig
@@ -258,13 +258,18 @@ fn addDeps(
         });
 
         // Harfbuzz
-        _ = try harfbuzz.link(b, step, .{
+        const harfbuzz_step = try harfbuzz.link(b, step, .{
             .freetype = .{
                 .enabled = true,
                 .step = freetype_step,
                 .include = &freetype.include_paths,
             },
+
+            .coretext = .{
+                .enabled = enable_coretext,
+            },
         });
+        system_sdk.include(b, harfbuzz_step, .{});
 
         // Libuv
         const libuv_step = try libuv.link(b, step);
diff --git a/pkg/harfbuzz/build.zig b/pkg/harfbuzz/build.zig
index b32792609..0ca97c598 100644
--- a/pkg/harfbuzz/build.zig
+++ b/pkg/harfbuzz/build.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const freetypepkg = @import("../freetype/build.zig");
+const macospkg = @import("../macos/build.zig");
 
 /// Directories with our includes.
 const root = thisDir() ++ "../../../vendor/harfbuzz/";
@@ -10,7 +11,7 @@ pub const include_paths = .{include_path};
 pub const pkg = std.build.Pkg{
     .name = "harfbuzz",
     .source = .{ .path = thisDir() ++ "/main.zig" },
-    .dependencies = &.{freetypepkg.pkg},
+    .dependencies = &.{ freetypepkg.pkg, macospkg.pkg },
 };
 
 fn thisDir() []const u8 {
@@ -19,12 +20,17 @@ fn thisDir() []const u8 {
 
 pub const Options = struct {
     freetype: Freetype = .{},
+    coretext: CoreText = .{},
 
     pub const Freetype = struct {
         enabled: bool = false,
         step: ?*std.build.LibExeObjStep = null,
         include: ?[]const []const u8 = null,
     };
+
+    pub const CoreText = struct {
+        enabled: bool = false,
+    };
 };
 
 pub fn link(
@@ -85,6 +91,14 @@ pub fn buildHarfbuzz(
         "-DHAVE_FT_GET_TRANSFORM=1",
     });
 
+    if (opt.coretext.enabled) {
+        try flags.appendSlice(&.{
+            "-DHAVE_CORETEXT=1",
+        });
+
+        lib.linkFramework("ApplicationServices");
+    }
+
     // C files
     lib.addCSourceFiles(srcs, flags.items);
 
diff --git a/pkg/harfbuzz/c.zig b/pkg/harfbuzz/c.zig
index 958e398ea..9f8790fe5 100644
--- a/pkg/harfbuzz/c.zig
+++ b/pkg/harfbuzz/c.zig
@@ -1,4 +1,7 @@
+const builtin = @import("builtin");
+
 pub usingnamespace @cImport({
     @cInclude("hb.h");
     @cInclude("hb-ft.h");
+    if (builtin.os.tag == .macos) @cInclude("hb-coretext.h");
 });
diff --git a/pkg/harfbuzz/coretext.zig b/pkg/harfbuzz/coretext.zig
new file mode 100644
index 000000000..4253feddb
--- /dev/null
+++ b/pkg/harfbuzz/coretext.zig
@@ -0,0 +1,30 @@
+const macos = @import("macos");
+const std = @import("std");
+const c = @import("c.zig");
+const Face = @import("face.zig").Face;
+const Font = @import("font.zig").Font;
+const Error = @import("errors.zig").Error;
+
+// Use custom extern functions so that the proper CoreText structs are used
+// without a ptrcast.
+extern fn hb_coretext_font_create(ct_face: *macos.text.Font) ?*c.hb_font_t;
+
+/// Creates an hb_font_t font object from the specified CTFontRef.
+pub fn createFont(face: *macos.text.Font) Error!Font {
+    const handle = hb_coretext_font_create(face) orelse return Error.HarfbuzzFailed;
+    return Font{ .handle = handle };
+}
+
+test {
+    if (!@hasDecl(c, "hb_coretext_font_create")) return error.SkipZigTest;
+
+    const name = try macos.foundation.String.createWithBytes("Monaco", .utf8, false);
+    defer name.release();
+    const desc = try macos.text.FontDescriptor.createWithNameAndSize(name, 12);
+    defer desc.release();
+    const font = try macos.text.Font.createWithFontDescriptor(desc, 12);
+    defer font.release();
+
+    var hb_font = try createFont(font);
+    defer hb_font.destroy();
+}
diff --git a/pkg/harfbuzz/freetype.zig b/pkg/harfbuzz/freetype.zig
index 6147fcb5e..c7d96b6b7 100644
--- a/pkg/harfbuzz/freetype.zig
+++ b/pkg/harfbuzz/freetype.zig
@@ -47,6 +47,8 @@ pub fn setFontFuncs(font: Font) void {
 }
 
 test {
+    if (!@hasDecl(c, "hb_ft_font_create_referenced")) return error.SkipZigTest;
+
     const testing = std.testing;
     const testFont = freetype.testing.font_regular;
     const ftc = freetype.c;
diff --git a/pkg/harfbuzz/main.zig b/pkg/harfbuzz/main.zig
index 27195090f..6cbb1b2c3 100644
--- a/pkg/harfbuzz/main.zig
+++ b/pkg/harfbuzz/main.zig
@@ -8,6 +8,7 @@ pub usingnamespace @import("font.zig");
 pub usingnamespace @import("shape.zig");
 pub usingnamespace @import("version.zig");
 pub const freetype = @import("freetype.zig");
+pub const coretext = @import("coretext.zig");
 
 test {
     @import("std").testing.refAllDecls(@This());