Add Atkinson Hyperlegible Mono font support

PiperOrigin-RevId: 937799904
Change-Id: I89e4652cc45afdd9a55b3042395c4a56c70289fb

cmake/third_party_deps/atkinson_hyperlegible_mono.cmake

@@ -0,0 +1,28 @@
+# Copyright 2026 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set(MUJOCO_DEP_VERSION_atkinson_hyperlegible_mono
+    154d50362016cc3e873eb21d242cd0772384c8f9
+    CACHE STRING "Tag/version of `atkinson_hyperlegible_mono` to be fetched."
+)
+mark_as_advanced(MUJOCO_DEP_VERSION_atkinson_hyperlegible_mono)
+
+include(FindOrFetch)
+
+fetchpackage(
+    PACKAGE_NAME  atkinson_hyperlegible_mono
+    GIT_REPO      https://github.com/googlefonts/atkinson-hyperlegible-next-mono.git
+    GIT_TAG       ${MUJOCO_DEP_VERSION_atkinson_hyperlegible_mono}
+    CUSTOM_CMAKE  "${CMAKE_SOURCE_DIR}/cmake/third_party_deps/atkinson_hyperlegible_mono/CMakeLists.txt"
+)

cmake/third_party_deps/atkinson_hyperlegible_mono/CMakeLists.txt

@@ -0,0 +1,15 @@
+# Copyright 2026 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Data-only package.

src/experimental/platform/hal/window.cc

@@ -84,6 +84,13 @@ static void InitImGui(SDL_Window* window, float content_scale,
     constexpr ImWchar icon_ranges[] = {0xf000, 0xf3ff, 0x000};
     io.Fonts->AddFontFromMemoryTTF(data, size, 13.f, &icon_cfg, icon_ranges);
 
+    ImFontConfig mono_cfg;
+    mono_cfg.FontDataOwnedByAtlas = false;
+    font = mju_openResource("", "font:AtkinsonHyperlegibleMono-Regular.ttf", nullptr,
+                            nullptr, 0);
+    size = mju_readResource(font, const_cast<const void**>(&data));
+    io.Fonts->AddFontFromMemoryTTF(data, size, 14.f, &mono_cfg);
+
     // Note: we purposefully do not "close" the font resources as ImGui may
     // need them again to resize fonts.
   }

src/experimental/studio/CMakeLists.txt

@@ -17,6 +17,7 @@ cmake_minimum_required(VERSION 3.16)
 include(third_party_deps/dear_imgui)
 include(third_party_deps/implot)
 include(third_party_deps/atkinson_hyperlegible_next)
+include(third_party_deps/atkinson_hyperlegible_mono)
 include(third_party_deps/font_awesome)
 
 # Common configuration shared between mujoco_studio and mujoco_live.
@@ -81,6 +82,16 @@ function(configure_studio_target TARGET_NAME)
                 ${STUDIO_ASSETS_DIR}
         COMMENT "Copying fontawesome-webfont.ttf to build directory"
     )
+    add_custom_command(
+        TARGET ${TARGET_NAME}
+        POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E make_directory ${STUDIO_ASSETS_DIR}
+        COMMAND ${CMAKE_COMMAND}
+            -E copy
+                "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/../_deps/atkinson_hyperlegible_mono-src/fonts/ttf/AtkinsonHyperlegibleMono-Regular.ttf"
+                ${STUDIO_ASSETS_DIR}/AtkinsonHyperlegibleMono-Regular.ttf
+        COMMENT "Copying AtkinsonHyperlegibleMono-Regular font to build directory"
+    )
 
     # Filament backend requires additional files to be copied into an "assets" folder.
     if(MUJOCO_USE_FILAMENT)

src/experimental/studio/live.js

@@ -143,6 +143,7 @@ var Module = {
       "assets/fontawesome-webfont.ttf",
       "assets/ibl.ktx",
       "assets/AtkinsonHyperlegibleNext[wght].ttf",
+      "assets/AtkinsonHyperlegibleMono-Regular.ttf",
       "assets/pbr.filamat",
       "assets/pbr_transparent.filamat",
       "assets/pbr_packed.filamat",