can now use -Dfont-backend to choose the font backend to use

build.zig

@@ -21,6 +21,7 @@ const utf8proc = @import("pkg/utf8proc/build.zig");
 const zlib = @import("pkg/zlib/build.zig");
 const tracylib = @import("pkg/tracy/build.zig");
 const system_sdk = @import("vendor/mach/libs/glfw/system_sdk.zig");
+const font = @import("src/font/main.zig");
 const WasmTarget = @import("src/os/wasm/target.zig").Target;
 const LibtoolStep = @import("src/build/LibtoolStep.zig");
 const LipoStep = @import("src/build/LipoStep.zig");
@@ -44,10 +45,9 @@ comptime {
 
 // Build options, see the build options help for more info.
 var tracy: bool = false;
-var enable_coretext: bool = false;
-var enable_fontconfig: bool = false;
 var flatpak: bool = false;
 var app_runtime: apprt.Runtime = .none;
+var font_backend: font.Backend = .freetype;
 
 pub fn build(b: *std.build.Builder) !void {
     const optimize = b.standardOptimizeOption(.{});
@@ -62,6 +62,8 @@ pub fn build(b: *std.build.Builder) !void {
         break :target result;
     };
 
+    const wasm_target: WasmTarget = .browser;
+
     tracy = b.option(
         bool,
         "tracy",
@@ -74,17 +76,11 @@ pub fn build(b: *std.build.Builder) !void {
         "Build for Flatpak (integrates with Flatpak APIs). Only has an effect targeting Linux.",
     ) orelse false;
 
-    enable_coretext = b.option(
-        bool,
-        "coretext",
-        "Enable coretext for font discovery (default true on macOS)",
-    ) orelse target.isDarwin();
-
-    enable_fontconfig = b.option(
-        bool,
-        "fontconfig",
-        "Enable fontconfig for font discovery (default true on Linux)",
-    ) orelse target.isLinux();
+    font_backend = b.option(
+        font.Backend,
+        "font-backend",
+        "The font backend to use for discovery and rasterization.",
+    ) orelse font.Backend.default(target, wasm_target);
 
     app_runtime = b.option(
         apprt.Runtime,
@@ -131,9 +127,8 @@ pub fn build(b: *std.build.Builder) !void {
     const exe_options = b.addOptions();
     exe_options.addOption(bool, "tracy_enabled", tracy);
     exe_options.addOption(bool, "flatpak", flatpak);
-    exe_options.addOption(bool, "coretext", enable_coretext);
-    exe_options.addOption(bool, "fontconfig", enable_fontconfig);
     exe_options.addOption(apprt.Runtime, "app_runtime", app_runtime);
+    exe_options.addOption(font.Backend, "font_backend", font_backend);
 
     // Exe
     {
@@ -263,7 +258,7 @@ pub fn build(b: *std.build.Builder) !void {
     // wasm
     {
         // Build our Wasm target.
-        const wasm_target: std.zig.CrossTarget = .{
+        const wasm_crosstarget: std.zig.CrossTarget = .{
             .cpu_arch = .wasm32,
             .os_tag = .freestanding,
             .cpu_model = .{ .explicit = &std.Target.wasm.cpu.mvp },
@@ -286,13 +281,12 @@ pub fn build(b: *std.build.Builder) !void {
 
         // We want to support alternate wasm targets in the future (i.e.
         // server side) so we have this now although its hardcoded.
-        const wasm_specific_target: WasmTarget = .browser;
-        exe_options.addOption(WasmTarget, "wasm_target", wasm_specific_target);
+        exe_options.addOption(WasmTarget, "wasm_target", wasm_target);
 
         const wasm = b.addSharedLibrary(.{
             .name = "ghostty-wasm",
             .root_source_file = .{ .path = "src/main_wasm.zig" },
-            .target = wasm_target,
+            .target = wasm_crosstarget,
             .optimize = optimize,
         });
         wasm.setOutputDir("zig-out");
@@ -320,7 +314,7 @@ pub fn build(b: *std.build.Builder) !void {
         const main_test = b.addTest(.{
             .name = "wasm-test",
             .root_source_file = .{ .path = "src/main_wasm.zig" },
-            .target = wasm_target,
+            .target = wasm_crosstarget,
         });
         main_test.addOptions("build_options", exe_options);
         _ = try addDeps(b, main_test, true);
@@ -456,7 +450,7 @@ fn addDeps(
     // We always need the Zig packages
     // TODO: This can't be the right way to use the new Zig modules system,
     // so take a closer look at this again later.
-    if (enable_fontconfig) step.addModule("fontconfig", fontconfig.module(b));
+    if (font_backend.hasFontconfig()) step.addModule("fontconfig", fontconfig.module(b));
     const mod_freetype = freetype.module(b);
     const mod_macos = macos.module(b);
     step.addModule("freetype", mod_freetype);
@@ -512,7 +506,7 @@ fn addDeps(
         step.linkSystemLibrary("pixman-1");
         step.linkSystemLibrary("zlib");
 
-        if (enable_fontconfig) step.linkSystemLibrary("fontconfig");
+        if (font_backend.hasFontconfig()) step.linkSystemLibrary("fontconfig");
     }
 
     // Other dependencies, we may dynamically link
@@ -553,7 +547,7 @@ fn addDeps(
             },
 
             .coretext = .{
-                .enabled = enable_coretext,
+                .enabled = font_backend.hasCoretext(),
             },
         });
         system_sdk.include(b, harfbuzz_step, .{});
@@ -564,7 +558,7 @@ fn addDeps(
         try static_libs.append(.{ .generated = &pixman_step.output_path_source });
 
         // Only Linux gets fontconfig
-        if (enable_fontconfig) {
+        if (font_backend.hasFontconfig()) {
             // Libxml2
             const libxml2_lib = try libxml2.create(
                 b,

src/build_config.zig

@@ -7,6 +7,7 @@ const builtin = @import("builtin");
 const options = @import("build_options");
 const assert = std.debug.assert;
 const apprt = @import("apprt.zig");
+const font = @import("font/main.zig");
 
 /// The artifact we're producing. This can be used to determine if we're
 /// building a standalone exe, an embedded lib, etc.
@@ -18,6 +19,12 @@ pub const app_runtime: apprt.Runtime = switch (artifact) {
     else => std.meta.stringToEnum(apprt.Runtime, std.meta.tagName(options.app_runtime)).?,
 };
 
+/// The font backend desired for the build.
+pub const font_backend: font.Backend = std.meta.stringToEnum(
+    font.Backend,
+    std.meta.tagName(options.font_backend),
+).?;
+
 /// Whether our devmode UI is enabled or not. This requires imgui to be
 /// compiled.
 pub const devmode_enabled = artifact == .exe and app_runtime == .glfw;

src/font/main.zig

@@ -1,6 +1,6 @@
 const std = @import("std");
 const builtin = @import("builtin");
-const build_options = @import("build_options");
+const build_config = @import("../build_config.zig");
 
 pub const Atlas = @import("Atlas.zig");
 pub const discovery = @import("discovery.zig");
@@ -32,10 +32,12 @@ pub usingnamespace if (builtin.target.isWasm()) struct {
 pub const options: struct {
     backend: Backend,
 } = .{
-    .backend = Backend.default(),
+    .backend = build_config.font_backend,
 };
 
 pub const Backend = enum {
+    const WasmTarget = @import("../os/wasm/target.zig").Target;
+
     /// FreeType for font rendering with no font discovery enabled.
     freetype,
 
@@ -54,32 +56,62 @@ pub const Backend = enum {
     web_canvas,
 
     /// Returns the default backend for a build environment. This is
-    /// meant to be called at comptime.
-    pub fn default() Backend {
-        const wasm_target = @import("../os/wasm/target.zig");
-        if (wasm_target.target) |target| return switch (target) {
-            .browser => .web_canvas,
-        };
+    /// meant to be called at comptime by the build.zig script. To get the
+    /// backend look at build_options.
+    pub fn default(
+        target: std.zig.CrossTarget,
+        wasm_target: WasmTarget,
+    ) Backend {
+        if (target.getCpuArch() == .wasm32) {
+            return switch (wasm_target) {
+                .browser => .web_canvas,
+            };
+        }
 
-        return if (build_options.coretext)
-            .coretext_freetype
-        else if (build_options.fontconfig)
-            .fontconfig_freetype
-        else
-            .freetype;
+        return if (target.isDarwin()) darwin: {
+            // On macOS right now, the coretext renderer is still pretty buggy
+            // so we default to coretext for font discovery and freetype for
+            // rasterization.
+            break :darwin .coretext_freetype;
+        } else .fontconfig_freetype;
     }
 
-    /// Helper that just returns true if we should be using freetype. This
-    /// is used for tests.
-    pub fn freetype(self: Backend) bool {
+    // All the functions below can be called at comptime or runtime to
+    // determine if we have a certain dependency.
+
+    pub fn hasFreetype(self: Backend) bool {
         return switch (self) {
-            .freetype, .fontconfig_freetype => true,
+            .freetype,
+            .fontconfig_freetype,
+            .coretext_freetype,
+            => true,
             .coretext, .web_canvas => false,
         };
     }
 
-    test "default can run at comptime" {
-        _ = comptime default();
+    pub fn hasCoretext(self: Backend) bool {
+        return switch (self) {
+            .coretext,
+            .coretext_freetype,
+            => true,
+
+            .freetype,
+            .fontconfig_freetype,
+            .web_canvas,
+            => false,
+        };
+    }
+
+    pub fn hasFontconfig(self: Backend) bool {
+        return switch (self) {
+            .fontconfig_freetype => true,
+
+            .freetype,
+            .coretext,
+            .coretext_freetype,
+            .web_canvas,
+            => false,
+        };
     }
 };
 

src/main.zig

@@ -129,8 +129,9 @@ pub const GlobalState = struct {
     pub fn init(self: *GlobalState) void {
         // Output some debug information right away
         std.log.info("runtime={}", .{build_config.app_runtime});
+        std.log.info("font_backend={}", .{build_config.font_backend});
         std.log.info("dependency harfbuzz={s}", .{harfbuzz.versionString()});
-        if (options.fontconfig) {
+        if (comptime build_config.font_backend.hasFontconfig()) {
             std.log.info("dependency fontconfig={d}", .{fontconfig.version()});
         }
         std.log.info("renderer={}", .{renderer.Renderer});