font: coretext face presentation

pkg/macos/text/font.zig

@@ -89,6 +89,12 @@ pub const Font = opaque {
             @ptrToInt(c.CTFontCopyDisplayName(@ptrCast(c.CTFontRef, self))),
         );
     }
+
+    pub fn getSymbolicTraits(self: *Font) text.FontSymbolicTraits {
+        return @bitCast(text.FontSymbolicTraits, c.CTFontGetSymbolicTraits(
+            @ptrCast(c.CTFontRef, self),
+        ));
+    }
 };
 
 pub const FontOrientation = enum(c_uint) {
@@ -108,6 +114,12 @@ test {
     const font = try Font.createWithFontDescriptor(desc, 12);
     defer font.release();
 
+    // Traits
+    {
+        const traits = font.getSymbolicTraits();
+        try testing.expect(!traits.color_glyphs);
+    }
+
     var glyphs = [1]graphics.Glyph{0};
     try testing.expect(font.getGlyphsForCharacters(
         &[_]u16{'A'},

src/font/DeferredFace.zig

@@ -111,7 +111,13 @@ pub fn load(
         },
 
         .coretext => {
-            try self.loadCoreText(lib, size);
+            // It is possible to use CoreText with Freetype so we support
+            // both here.
+            switch (font.Face) {
+                font.face.freetype.Face => try self.loadCoreTextFreetype(lib, size),
+                else => unreachable,
+            }
+
             return;
         },
 
@@ -136,7 +142,7 @@ fn loadFontconfig(
     self.face = try Face.initFile(lib, filename, face_index, size);
 }
 
-fn loadCoreText(
+fn loadCoreTextFreetype(
     self: *DeferredFace,
     lib: Library,
     size: font.face.DesiredSize,

src/font/face.zig

@@ -1,7 +1,7 @@
 const builtin = @import("builtin");
 const options = @import("main.zig").options;
-const freetype = @import("face/freetype.zig");
-const coretext = @import("face/coretext.zig");
+pub const freetype = @import("face/freetype.zig");
+pub const coretext = @import("face/coretext.zig");
 
 /// Face implementation for the compile options.
 pub const Face = switch (options.backend) {

src/font/face/coretext.zig

@@ -1,3 +1,4 @@
+const std = @import("std");
 const macos = @import("macos");
 const harfbuzz = @import("harfbuzz");
 const font = @import("../main.zig");
@@ -9,6 +10,9 @@ pub const Face = struct {
     /// Harfbuzz font corresponding to this face.
     hb_font: harfbuzz.Font,
 
+    /// The presentation for this font.
+    presentation: font.Presentation,
+
     /// Initialize a CoreText-based face from another initialized font face
     /// but with a new size. This is often how CoreText fonts are initialized
     /// because the font is loaded at a default size during discovery, and then
@@ -21,9 +25,12 @@ pub const Face = struct {
         const hb_font = try harfbuzz.coretext.createFont(ct_font);
         errdefer hb_font.destroy();
 
+        const traits = ct_font.getSymbolicTraits();
+
         return Face{
             .font = ct_font,
             .hb_font = hb_font,
+            .presentation = if (traits.color_glyphs) .emoji else .text,
         };
     }
 
@@ -35,6 +42,8 @@ pub const Face = struct {
 };
 
 test {
+    const testing = std.testing;
+
     const name = try macos.foundation.String.createWithBytes("Monaco", .utf8, false);
     defer name.release();
     const desc = try macos.text.FontDescriptor.createWithNameAndSize(name, 12);
@@ -44,4 +53,22 @@ test {
 
     var face = try Face.initFontCopy(ct_font, .{ .points = 18 });
     defer face.deinit();
+
+    try testing.expectEqual(font.Presentation.text, face.presentation);
+}
+
+test "emoji" {
+    const testing = std.testing;
+
+    const name = try macos.foundation.String.createWithBytes("Apple Color Emoji", .utf8, false);
+    defer name.release();
+    const desc = try macos.text.FontDescriptor.createWithNameAndSize(name, 12);
+    defer desc.release();
+    const ct_font = try macos.text.Font.createWithFontDescriptor(desc, 12);
+    defer ct_font.release();
+
+    var face = try Face.initFontCopy(ct_font, .{ .points = 18 });
+    defer face.deinit();
+
+    try testing.expectEqual(font.Presentation.emoji, face.presentation);
 }