font: set "backend" enum vs booleans

src/font/DeferredFace.zig

@@ -19,10 +19,12 @@ const Presentation = @import("main.zig").Presentation;
 face: ?Face = null,
 
 /// Fontconfig
-fc: if (options.fontconfig) ?Fontconfig else void = if (options.fontconfig) null else {},
+fc: if (options.backend == .fontconfig_freetype) ?Fontconfig else void =
+    if (options.backend == .fontconfig_freetype) null else {},
 
 /// CoreText
-ct: if (options.coretext) ?CoreText else void = if (options.coretext) null else {},
+ct: if (options.backend == .coretext) ?CoreText else void =
+    if (options.backend == .coretext) null else {},
 
 /// Fontconfig specific data. This is only present if building with fontconfig.
 pub const Fontconfig = struct {
@@ -61,8 +63,11 @@ pub fn initLoaded(face: Face) DeferredFace {
 
 pub fn deinit(self: *DeferredFace) void {
     if (self.face) |*face| face.deinit();
-    if (options.fontconfig) if (self.fc) |*fc| fc.deinit();
-    if (options.coretext) if (self.ct) |*ct| ct.deinit();
+    switch (options.backend) {
+        .fontconfig_freetype => if (self.fc) |*fc| fc.deinit(),
+        .coretext => if (self.ct) |*ct| ct.deinit(),
+        .freetype => {},
+    }
     self.* = undefined;
 }
 
@@ -74,16 +79,16 @@ pub inline fn loaded(self: DeferredFace) bool {
 /// Returns the name of this face. The memory is always owned by the
 /// face so it doesn't have to be freed.
 pub fn name(self: DeferredFace) ![:0]const u8 {
-    if (options.fontconfig) {
-        if (self.fc) |fc|
-            return (try fc.pattern.get(.fullname, 0)).string;
-    }
+    switch (options.backend) {
+        .fontconfig_freetype => if (self.fc) |fc|
+            return (try fc.pattern.get(.fullname, 0)).string,
 
-    if (options.coretext) {
-        if (self.ct) |ct| {
+        .coretext => if (self.ct) |ct| {
             const display_name = ct.font.copyDisplayName();
             return display_name.cstringPtr(.utf8) orelse "<unsupported internal encoding>";
-        }
+        },
+
+        .freetype => {},
     }
 
     return "TODO: built-in font names";
@@ -98,19 +103,21 @@ pub fn load(
     // No-op if we already loaded
     if (self.face != null) return;
 
-    if (options.fontconfig) {
+    switch (options.backend) {
+        .fontconfig_freetype => {
             try self.loadFontconfig(lib, size);
             return;
-    }
+        },
 
-    if (options.coretext) {
+        .coretext => {
             try self.loadCoreText(lib, size);
             return;
-    }
+        },
 
         // Unreachable because we must be already loaded or have the
         // proper configuration for one of the other deferred mechanisms.
-    unreachable;
+        .freetype => unreachable,
+    }
 }
 
 fn loadFontconfig(
@@ -181,9 +188,10 @@ pub fn hasCodepoint(self: DeferredFace, cp: u32, p: ?Presentation) bool {
         return face.glyphIndex(cp) != null;
     }
 
+    switch (options.backend) {
+        .fontconfig_freetype => {
             // If we are using fontconfig, use the fontconfig metadata to
             // avoid loading the face.
-    if (options.fontconfig) {
             if (self.fc) |fc| {
                 // Check if char exists
                 if (!fc.charset.hasChar(cp)) return false;
@@ -201,10 +209,10 @@ pub fn hasCodepoint(self: DeferredFace, cp: u32, p: ?Presentation) bool {
 
                 return true;
             }
-    }
+        },
 
+        .coretext => {
             // If we are using coretext, we check the loaded CT font.
-    if (options.coretext) {
             if (self.ct) |ct| {
                 // Turn UTF-32 into UTF-16 for CT API
                 var unichars: [2]u16 = undefined;
@@ -215,6 +223,9 @@ pub fn hasCodepoint(self: DeferredFace, cp: u32, p: ?Presentation) bool {
                 var glyphs = [2]macos.graphics.Glyph{ 0, 0 };
                 return ct.font.getGlyphsForCharacters(unichars[0..len], glyphs[0..len]);
             }
+        },
+
+        .freetype => {},
     }
 
     // This is unreachable because discovery mechanisms terminate, and
@@ -239,7 +250,7 @@ test "preloaded" {
 }
 
 test "fontconfig" {
-    if (!options.fontconfig) return error.SkipZigTest;
+    if (options.backend != .fontconfig_freetype) return error.SkipZigTest;
 
     const discovery = @import("main.zig").discovery;
     const testing = std.testing;
@@ -269,7 +280,7 @@ test "fontconfig" {
 }
 
 test "coretext" {
-    if (!options.coretext) return error.SkipZigTest;
+    if (options.backend != .coretext) return error.SkipZigTest;
 
     const discovery = @import("main.zig").discovery;
     const testing = std.testing;

src/font/Group.zig

@@ -224,7 +224,7 @@ test {
 }
 
 test {
-    if (!options.fontconfig) return error.SkipZigTest;
+    if (options.backend != .fontconfig_freetype) return error.SkipZigTest;
 
     const testing = std.testing;
     const alloc = testing.allocator;

src/font/discovery.zig

@@ -9,12 +9,11 @@ const DeferredFace = @import("main.zig").DeferredFace;
 const log = std.log.named(.discovery);
 
 /// Discover implementation for the compile options.
-pub const Discover = if (options.fontconfig)
-    Fontconfig
-else if (options.coretext)
-    CoreText
-else
-    void;
+pub const Discover = switch (options.backend) {
+    .fontconfig_freetype => Fontconfig,
+    .coretext => CoreText,
+    else => void,
+};
 
 /// Descriptor is used to search for fonts. The only required field
 /// is "family". The rest are ignored unless they're set to a non-zero
@@ -273,7 +272,7 @@ pub const CoreText = struct {
 };
 
 test "fontconfig" {
-    if (!options.fontconfig) return error.SkipZigTest;
+    if (options.backend != .fontconfig_freetype) return error.SkipZigTest;
 
     const testing = std.testing;
 
@@ -286,7 +285,7 @@ test "fontconfig" {
 }
 
 test "core text" {
-    if (!options.coretext) return error.SkipZigTest;
+    if (options.backend != .coretext) return error.SkipZigTest;
 
     const testing = std.testing;
 

src/font/main.zig

@@ -14,11 +14,25 @@ pub const Discover = discovery.Discover;
 
 /// Build options
 pub const options: struct {
-    coretext: bool = false,
-    fontconfig: bool = false,
+    backend: Backend,
 } = .{
-    .coretext = build_options.coretext,
-    .fontconfig = build_options.fontconfig,
+    .backend = if (build_options.coretext)
+        .coretext
+    else if (build_options.fontconfig)
+        .fontconfig_freetype
+    else
+        .freetype,
+};
+
+pub const Backend = enum {
+    /// FreeType for font rendering with no font discovery enabled.
+    freetype,
+
+    /// Fontconfig for font discovery and FreeType for font rendering.
+    fontconfig_freetype,
+
+    /// CoreText for both font discovery and rendering (macOS).
+    coretext,
 };
 
 /// The styles that a family can take.