font/coretext: score discovered fonts

pkg/macos/foundation/array.zig

@@ -63,7 +63,7 @@ pub const MutableArray = opaque {
             a: *const Elem,
             b: *const Elem,
             context: ?*Context,
-        ) ComparisonResult,
+        ) callconv(.C) ComparisonResult,
     ) void {
         CFArraySortValues(
             self,
@@ -122,7 +122,7 @@ test "array sorting" {
         void,
         null,
         struct {
-            fn compare(a: *const u8, b: *const u8, _: ?*void) ComparisonResult {
+            fn compare(a: *const u8, b: *const u8, _: ?*void) callconv(.C) ComparisonResult {
                 if (a.* > b.*) return .greater;
                 if (a.* == b.*) return .equal;
                 return .less;

pkg/macos/text/font_descriptor.zig

@@ -46,18 +46,22 @@ pub const FontDescriptor = opaque {
         ) orelse Allocator.Error.OutOfMemory;
     }
 
+    pub fn retain(self: *FontDescriptor) void {
+        _ = c.CFRetain(self);
+    }
+
     pub fn release(self: *FontDescriptor) void {
         c.CFRelease(self);
     }
 
-    pub fn copyAttribute(self: *FontDescriptor, comptime attr: FontAttribute) attr.Value() {
+    pub fn copyAttribute(self: *const FontDescriptor, comptime attr: FontAttribute) attr.Value() {
         return @ptrFromInt(@intFromPtr(c.CTFontDescriptorCopyAttribute(
             @ptrCast(self),
             @ptrCast(attr.key()),
         )));
     }
 
-    pub fn copyAttributes(self: *FontDescriptor) *foundation.Dictionary {
+    pub fn copyAttributes(self: *const FontDescriptor) *foundation.Dictionary {
         return @ptrFromInt(@intFromPtr(c.CTFontDescriptorCopyAttributes(
             @ptrCast(self),
         )));

src/Surface.zig

@@ -246,7 +246,7 @@ pub fn init(
             var name_buf: [256]u8 = undefined;
 
             if (config.@"font-family") |family| {
-                var disco_it = try disco.discover(.{
+                var disco_it = try disco.discover(alloc, .{
                     .family = family,
                     .style = config.@"font-style".nameValue(),
                     .size = font_size.points,
@@ -259,7 +259,7 @@ pub fn init(
                 } else log.warn("font-family not found: {s}", .{family});
             }
             if (config.@"font-family-bold") |family| {
-                var disco_it = try disco.discover(.{
+                var disco_it = try disco.discover(alloc, .{
                     .family = family,
                     .style = config.@"font-style-bold".nameValue(),
                     .size = font_size.points,
@@ -273,7 +273,7 @@ pub fn init(
                 } else log.warn("font-family-bold not found: {s}", .{family});
             }
             if (config.@"font-family-italic") |family| {
-                var disco_it = try disco.discover(.{
+                var disco_it = try disco.discover(alloc, .{
                     .family = family,
                     .style = config.@"font-style-italic".nameValue(),
                     .size = font_size.points,
@@ -287,7 +287,7 @@ pub fn init(
                 } else log.warn("font-family-italic not found: {s}", .{family});
             }
             if (config.@"font-family-bold-italic") |family| {
-                var disco_it = try disco.discover(.{
+                var disco_it = try disco.discover(alloc, .{
                     .family = family,
                     .style = config.@"font-style-bold-italic".nameValue(),
                     .size = font_size.points,

src/cli/list_fonts.zig

@@ -85,7 +85,7 @@ fn runArgs(alloc_gpa: Allocator, argsIter: anytype) !u8 {
     // Look up all available fonts
     var disco = font.Discover.init();
     defer disco.deinit();
-    var disco_it = try disco.discover(.{
+    var disco_it = try disco.discover(alloc, .{
         .family = config.family,
         .style = config.style,
         .bold = config.bold,

src/font/DeferredFace.zig

@@ -408,6 +408,7 @@ test "coretext" {
 
     const discovery = @import("main.zig").discovery;
     const testing = std.testing;
+    const alloc = testing.allocator;
 
     // Load freetype
     var lib = try Library.init();
@@ -416,7 +417,7 @@ test "coretext" {
     // Get a deferred face from fontconfig
     var def = def: {
         var fc = discovery.CoreText.init();
-        var it = try fc.discover(.{ .family = "Monaco", .size = 12 });
+        var it = try fc.discover(alloc, .{ .family = "Monaco", .size = 12 });
         defer it.deinit();
         break :def (try it.next()).?;
     };

src/font/Group.zig

@@ -313,7 +313,7 @@ pub fn indexForCodepoint(
     // If we are regular, try looking for a fallback using discovery.
     if (style == .regular and font.Discover != void) {
         if (self.discover) |disco| discover: {
-            var disco_it = disco.discover(.{
+            var disco_it = disco.discover(self.alloc, .{
                 .codepoint = cp,
                 .size = self.size.points,
                 .bold = style == .bold or style == .bold_italic,
@@ -382,7 +382,7 @@ fn indexForCodepointOverride(self: *Group, cp: u32) !?FontIndex {
     const idx_: ?FontIndex = self.descriptor_cache.get(desc) orelse idx: {
         // Slow path: we have to find this descriptor and load the font
         const discover = self.discover orelse return null;
-        var disco_it = try discover.discover(desc);
+        var disco_it = try discover.discover(self.alloc, desc);
         defer disco_it.deinit();
 
         const face = (try disco_it.next()) orelse {

src/font/discovery.zig

@@ -1,5 +1,6 @@
 const std = @import("std");
 const builtin = @import("builtin");
+const Allocator = std.mem.Allocator;
 const assert = std.debug.assert;
 const fontconfig = @import("fontconfig");
 const macos = @import("macos");
@@ -307,7 +308,7 @@ pub const CoreText = struct {
 
     /// Discover fonts from a descriptor. This returns an iterator that can
     /// be used to build up the deferred fonts.
-    pub fn discover(self: *const CoreText, desc: Descriptor) !DiscoverIterator {
+    pub fn discover(self: *const CoreText, alloc: Allocator, desc: Descriptor) !DiscoverIterator {
         _ = self;
 
         // Build our pattern that we'll search for
@@ -323,25 +324,104 @@ pub const CoreText = struct {
         const set = try macos.text.FontCollection.createWithFontDescriptors(desc_arr);
         defer set.release();
         const list = set.createMatchingFontDescriptors();
-        errdefer list.release();
+        defer list.release();
+
+        // Sort our descriptors
+        const zig_list = try copyMatchingDescriptors(alloc, list);
+        errdefer alloc.free(zig_list);
+        sortMatchingDescriptors(&desc, zig_list);
 
         return DiscoverIterator{
-            .list = list,
+            .alloc = alloc,
+            .list = zig_list,
             .i = 0,
         };
     }
 
-    pub const DiscoverIterator = struct {
+    fn copyMatchingDescriptors(
+        alloc: Allocator,
         list: *macos.foundation.Array,
+    ) ![]*macos.text.FontDescriptor {
+        var result = try alloc.alloc(*macos.text.FontDescriptor, list.getCount());
+        errdefer alloc.free(result);
+        for (0..result.len) |i| {
+            result[i] = list.getValueAtIndex(macos.text.FontDescriptor, i);
+
+            // We need to retain becauseonce the list is freed it will
+            // release all its members.
+            result[i].retain();
+        }
+        return result;
+    }
+
+    fn sortMatchingDescriptors(
+        desc: *const Descriptor,
+        list: []*macos.text.FontDescriptor,
+    ) void {
+        var desc_mut = desc.*;
+        if (desc_mut.style == null) {
+            // If there is no explicit style set, we set a preferred
+            // based on the style bool attributes.
+            //
+            // TODO: doesn't handle i18n font names well, we should have
+            // another mechanism that uses the weight attribute if it exists.
+            // Wait for this to be a real problem.
+            desc_mut.style = if (desc_mut.bold and desc_mut.italic)
+                "Bold Italic"
+            else if (desc_mut.bold)
+                "Bold"
+            else if (desc_mut.italic)
+                "Italic"
+            else
+                null;
+        }
+
+        std.mem.sortUnstable(*macos.text.FontDescriptor, list, &desc_mut, struct {
+            fn lessThan(
+                desc_inner: *const Descriptor,
+                lhs: *macos.text.FontDescriptor,
+                rhs: *macos.text.FontDescriptor,
+            ) bool {
+                const lhs_score = score(desc_inner, lhs);
+                const rhs_score = score(desc_inner, rhs);
+                // Higher score is "less" (earlier)
+                return lhs_score > rhs_score;
+            }
+        }.lessThan);
+    }
+
+    fn score(desc: *const Descriptor, ct_desc: *const macos.text.FontDescriptor) i32 {
+        var score_acc: i32 = 0;
+
+        score_acc += if (desc.style) |desired_style| style: {
+            const style = ct_desc.copyAttribute(.style_name);
+            defer style.release();
+            var buf: [128]u8 = undefined;
+            const style_str = style.cstring(&buf, .utf8) orelse break :style 0;
+
+            // Matching style string gets highest score
+            if (std.mem.eql(u8, desired_style, style_str)) break :style 100;
+
+            // Otherwise the score is based on the length of the style string.
+            // Shorter styles are scored higher.
+            break :style -1 * @as(i32, @intCast(style_str.len));
+        } else 0;
+
+        return score_acc;
+    }
+
+    pub const DiscoverIterator = struct {
+        alloc: Allocator,
+        list: []const *macos.text.FontDescriptor,
         i: usize,
 
         pub fn deinit(self: *DiscoverIterator) void {
-            self.list.release();
+            self.alloc.free(self.list);
             self.* = undefined;
         }
 
         pub fn next(self: *DiscoverIterator) !?DeferredFace {
-            if (self.i >= self.list.getCount()) return null;
+            if (self.i >= self.list.len) return null;
 
             // Get our descriptor. We need to remove the character set
             // limitation because we may have used that to filter but we
@@ -349,7 +429,7 @@ pub const CoreText = struct {
             // available.
             //const desc = self.list.getValueAtIndex(macos.text.FontDescriptor, self.i);
             const desc = desc: {
-                const original = self.list.getValueAtIndex(macos.text.FontDescriptor, self.i);
+                const original = self.list[self.i];
 
                 // For some reason simply copying the attributes and recreating
                 // the descriptor removes the charset restriction. This is tested.
@@ -392,8 +472,11 @@ test "descriptor hash familiy names" {
 test "fontconfig" {
     if (options.backend != .fontconfig_freetype) return error.SkipZigTest;
 
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
     var fc = Fontconfig.init();
-    var it = try fc.discover(.{ .family = "monospace", .size = 12 });
+    var it = try fc.discover(alloc, .{ .family = "monospace", .size = 12 });
     defer it.deinit();
 }
 
@@ -401,9 +484,10 @@ test "fontconfig codepoint" {
     if (options.backend != .fontconfig_freetype) return error.SkipZigTest;
 
     const testing = std.testing;
+    const alloc = testing.allocator;
 
     var fc = Fontconfig.init();
-    var it = try fc.discover(.{ .codepoint = 'A', .size = 12 });
+    var it = try fc.discover(alloc, .{ .codepoint = 'A', .size = 12 });
     defer it.deinit();
 
     // The first result should have the codepoint. Later ones may not
@@ -420,10 +504,11 @@ test "coretext" {
         return error.SkipZigTest;
 
     const testing = std.testing;
+    const alloc = testing.allocator;
 
     var ct = CoreText.init();
     defer ct.deinit();
-    var it = try ct.discover(.{ .family = "Monaco", .size = 12 });
+    var it = try ct.discover(alloc, .{ .family = "Monaco", .size = 12 });
     defer it.deinit();
     var count: usize = 0;
     while (try it.next()) |_| {
@@ -437,10 +522,11 @@ test "coretext codepoint" {
         return error.SkipZigTest;
 
     const testing = std.testing;
+    const alloc = testing.allocator;
 
     var ct = CoreText.init();
     defer ct.deinit();
-    var it = try ct.discover(.{ .codepoint = 'A', .size = 12 });
+    var it = try ct.discover(alloc, .{ .codepoint = 'A', .size = 12 });
     defer it.deinit();
 
     // The first result should have the codepoint. Later ones may not

src/font/shaper/harfbuzz.zig

@@ -908,7 +908,7 @@ fn testShaper(alloc: Allocator) !TestShaper {
         // On CoreText we want to load Apple Emoji, we should have it.
         var disco = font.Discover.init();
         defer disco.deinit();
-        var disco_it = try disco.discover(.{
+        var disco_it = try disco.discover(alloc, .{
             .family = "Apple Color Emoji",
             .size = 12,
             .monospace = false,