Fonts: bundle Liberation Sans and register it with fontconfig

- ship assets/LiberationSans-Regular.ttf (+ OFL license/README)
- at startup, resolve the .so path via dladdr, add assets/...ttf to the
  current fontconfig config with FcConfigAppFontAddFile, and fall back to
  the system Liberation path if the asset is missing
- font creation tries Liberation Sans, then DejaVu Sans/Noto/Tahoma/Verdana/
  Arial, so the overlay still renders on installs without the bundled font

4 files changed, 180 insertions, 10 deletions

diff --git a/assets/LiberationSans-Regular.ttf b/assets/LiberationSans-Regular.ttf
new file mode 100644
index 0000000..adb8947
--- /dev/null
+++ b/assets/LiberationSans-Regular.ttf
diff --git a/assets/OFL.txt b/assets/OFL.txt
new file mode 100644
index 0000000..445c414
--- /dev/null
+++ b/assets/OFL.txt
@@ -0,0 +1,94 @@
+Digitized data copyright (c) 2010 Google Corporation
+        with Reserved Font Arimo, Tinos and Cousine.
+Copyright (c) 2012 Red Hat, Inc.
+        with Reserved Font Name Liberation.
+
+This Font Software is licensed under the SIL Open Font License,
+Version 1.1.
+
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+
+PREAMBLE The goals of the Open Font License (OFL) are to stimulate
+worldwide development of collaborative font projects, to support the font
+creation efforts of academic and linguistic communities, and to provide
+a free and open framework in which fonts may be shared and improved in
+partnership with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves.
+The fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works.  The fonts and derivatives,
+however, cannot be released under any other type of license.  The
+requirement for fonts to remain under this license does not apply to
+any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such.
+This may include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components
+as distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting ? in part or in whole ?
+any of the components of the Original Version, by changing formats or
+by porting the Font Software to a new environment.
+
+"Author" refers to any designer, engineer, programmer, technical writer
+or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,in
+   Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+   redistributed and/or sold with any software, provided that each copy
+   contains the above copyright notice and this license. These can be
+   included either as stand-alone text files, human-readable headers or
+   in the appropriate machine-readable metadata fields within text or
+   binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+   Name(s) unless explicit written permission is granted by the
+   corresponding Copyright Holder. This restriction only applies to the
+   primary font name as presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+   Software shall not be used to promote, endorse or advertise any
+   Modified Version, except to acknowledge the contribution(s) of the
+   Copyright Holder(s) and the Author(s) or with their explicit written
+   permission.
+
+5) The Font Software, modified or unmodified, in part or in whole, must
+   be distributed entirely under this license, and must not be distributed
+   under any other license. The requirement for fonts to remain under
+   this license does not apply to any document created using the Font
+   Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT.  IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM OTHER
+DEALINGS IN THE FONT SOFTWARE.
diff --git a/assets/README.md b/assets/README.md
new file mode 100644
index 0000000..a4afd45
--- /dev/null
+++ b/assets/README.md
@@ -0,0 +1,9 @@
+# Bundled font
+
+`LiberationSans-Regular.ttf` is the Liberation Sans regular face from the
+Liberation Fonts project (https://github.com/liberationfonts/liberation-fonts).
+
+Licensed under the SIL Open Font License 1.1; see `OFL.txt`.
+
+`hl2hake` registers this file with fontconfig at startup so the VGUI overlay
+does not depend on the host/game install having Liberation Sans installed.
diff --git a/src/menu.cpp b/src/menu.cpp
index 9537e05..1ef8638 100644
--- a/src/menu.cpp
+++ b/src/menu.cpp
@@ -4,7 +4,9 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
+#include <dlfcn.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 // ---------------------------------------------------------------------------
 // ConMsg (tier0 console printer — prints to in-game console)
@@ -217,6 +219,63 @@ static std::string config_path() {
   return dir + "/config";
 }
 
+// Register the bundled Liberation Sans with fontconfig so the VGUI overlay
+// does not depend on the host/game install having it. The font file lives in
+// assets/ next to the .so (or the system path as a fallback).
+void register_bundled_font() {
+  static bool done = false;
+  if (done)
+    return;
+  done = true;
+
+  std::string path;
+  Dl_info info;
+  if (dladdr((void *)&register_bundled_font, &info) && info.dli_fname) {
+    char resolved[4096];
+    const char *lib = realpath(info.dli_fname, resolved);
+    std::string p = lib ? resolved : info.dli_fname;
+    size_t slash = p.find_last_of('/');
+    if (slash != std::string::npos)
+      p.resize(slash + 1);
+    else
+      p = "./";
+    p += "assets/LiberationSans-Regular.ttf";
+    if (access(p.c_str(), R_OK) == 0)
+      path = p;
+  }
+  if (path.empty()) {
+    const char *sys = "/usr/share/fonts/liberation/LiberationSans-Regular.ttf";
+    if (access(sys, R_OK) == 0)
+      path = sys;
+  }
+  if (path.empty()) {
+    logf("font: bundled LiberationSans-Regular.ttf not found");
+    return;
+  }
+
+  void *fc = dlopen("libfontconfig.so.1", RTLD_LAZY | RTLD_GLOBAL);
+  if (!fc) {
+    logf("font: libfontconfig.so.1 not available");
+    return;
+  }
+  using InitFn = int (*)();
+  using GetCurrentFn = void *(*)();
+  using AddFileFn = int (*)(void *, const char *);
+  auto init = (InitFn)dlsym(fc, "FcInit");
+  auto get = (GetCurrentFn)dlsym(fc, "FcConfigGetCurrent");
+  auto add = (AddFileFn)dlsym(fc, "FcConfigAppFontAddFile");
+  if (!init || !get || !add) {
+    logf("font: fontconfig symbols missing");
+    return;
+  }
+  init();
+  void *cfg = get();
+  if (cfg && add(cfg, path.c_str()))
+    logf("font: registered %s", path.c_str());
+  else
+    logf("font: failed to register %s", path.c_str());
+}
+
 static void config_save() {
   FILE *f = fopen(config_path().c_str(), "w");
   if (!f)
@@ -671,17 +730,24 @@ void outer_draw() {
   if (!g_surface || (!g_menu_open && !draw_test && !esp_on))
     return;
   if (!g_font) {
-    g_font = surf_create_font();
-    if (!g_font) {
-      logf("outer_draw: CreateFont failed");
-      return;
+    static const char *families[] = {
+        "Liberation Sans", "DejaVu Sans", "Noto Sans", "Tahoma",
+        "Verdana",         "Arial",      nullptr};
+    bool font_ok = false;
+    for (int fi = 0; families[fi] && !font_ok; fi++) {
+      g_font = surf_create_font();
+      if (!g_font)
+        continue;
+      if (surf_set_font_glyph_set(g_font, families[fi], 16, 400, 0, 0, 0x400,
+                                  0x20, 0xFF)) {
+        logf("outer_draw: font family %s", families[fi]);
+        font_ok = true;
+      } else {
+        g_font = 0;
+      }
     }
-    // FONTFLAG_CUSTOM only; Liberation Sans is an installed real TTF (Verdana
-    // substitutes to Noto). Raw glyphs, ASCII range pinned.
-    if (!surf_set_font_glyph_set(g_font, "Liberation Sans", 16, 400, 0, 0,
-                                 0x400, 0x20, 0xFF)) {
-      logf("outer_draw: SetFontGlyphSet failed");
-      g_font = 0;
+    if (!font_ok) {
+      logf("outer_draw: no usable font");
       return;
     }
   }
@@ -789,6 +855,7 @@ static ISurface *find_surface_interface() {
 
 void install_menu() {
   build_tree();
+  register_bundled_font();
   logf("config: %s", config_path().c_str());
   config_load();
   // resolve ISurface once (used by the DrawPrintText hook in hl2h.cpp and