From 3cb5dae9d86c680aaada3be22b9cbdefad505cc6 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sun, 3 Apr 2022 20:08:29 -0700
Subject: [PATCH] fontconfig example

---
 build.zig        |  1 +
 nix/devshell.nix |  2 ++
 src/fonts.zig    | 39 +++++++++++++++++++++++++++++++++++++++
 src/main.zig     |  4 ++++
 4 files changed, 46 insertions(+)
 create mode 100644 src/fonts.zig

diff --git a/build.zig b/build.zig
index d1e5fee69..d79e98b3e 100644
--- a/build.zig
+++ b/build.zig
@@ -21,6 +21,7 @@ pub fn build(b: *std.build.Builder) !void {
     ftlib.link(exe);
 
     exe.linkSystemLibrary("epoxy");
+    exe.linkSystemLibrary("fontconfig");
 
     const run_cmd = exe.run();
     run_cmd.step.dependOn(b.getInstallStep());
diff --git a/nix/devshell.nix b/nix/devshell.nix
index cabde9da8..3dd0a9828 100644
--- a/nix/devshell.nix
+++ b/nix/devshell.nix
@@ -8,6 +8,7 @@
 , vttest
 , zig
 
+, fontconfig
 , libepoxy
 , libGL
 , libX11
@@ -32,6 +33,7 @@
   buildInputs = [
     # TODO: non-linux
   ] ++ lib.optionals stdenv.isLinux [
+    fontconfig
     libepoxy
     libGL
 
diff --git a/src/fonts.zig b/src/fonts.zig
new file mode 100644
index 000000000..bd951d7a8
--- /dev/null
+++ b/src/fonts.zig
@@ -0,0 +1,39 @@
+const std = @import("std");
+const fc = @cImport({
+    @cInclude("fontconfig/fontconfig.h");
+});
+
+// Set to true when FontConfig is initialized.
+var initialized: bool = false;
+
+pub fn list() !void {
+    if (!initialized) {
+        if (fc.FcInit() != fc.FcTrue) {
+            return error.InitializionFailed;
+        }
+    }
+
+    const pat = fc.FcPatternCreate();
+    defer fc.FcPatternDestroy(pat);
+
+    const key = fc.FC_FULLNAME;
+    const os = fc.FcObjectSetBuild(
+        key,
+        @as([*c]const u8, 0), // @as required Zig #1481
+    );
+    defer fc.FcObjectSetDestroy(os);
+
+    const fs = fc.FcFontList(null, pat, os);
+    defer fc.FcFontSetDestroy(fs);
+
+    var i: usize = 0;
+    while (i <= fs.*.nfont) : (i += 1) {
+        const fpat = fs.*.fonts[i];
+        var str: [*c]fc.FcChar8 = undefined;
+        if (fc.FcPatternGetString(fpat, key, 0, &str) == fc.FcResultMatch) {
+            std.log.info("FONT: {s}", .{
+                @ptrCast([*:0]u8, str),
+            });
+        }
+    }
+}
diff --git a/src/main.zig b/src/main.zig
index f5f4b6ebf..b5d17e50e 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -2,8 +2,12 @@ const std = @import("std");
 const glfw = @import("glfw");
 const gl = @import("opengl.zig");
 const stb = @import("stb.zig");
+const fonts = @import("fonts.zig");
 
 pub fn main() !void {
+    // List our fonts
+    try fonts.list();
+
     try glfw.init(.{});
     defer glfw.terminate();