Move resource provider registration into a separate library.

PiperOrigin-RevId: 956506812
Change-Id: I9acde018e282171f41e0f8c756cd02b39c35dc67

src/experimental/platform/CMakeLists.txt

@@ -22,6 +22,8 @@ target_sources(${MUJOCO_PLATFORM_TARGET_NAME}
     PUBLIC
         helpers.cc
         helpers.h
+        resources.cc
+        resources.h
         sys_utils.cc
         sys_utils.h
         hal/egl_utils.cc

src/experimental/platform/resources.cc

@@ -0,0 +1,108 @@
+// 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.
+
+#include "experimental/platform/resources.h"
+
+#include <filesystem>  // NOLINT(build/c++17)
+#include <fstream>
+#include <ios>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include <mujoco/mujoco.h>
+#include "experimental/platform/sys_utils.h"
+
+namespace mujoco::platform {
+
+namespace {
+
+std::string Resolve(std::string_view path) {
+  std::string_view subpath = path.substr(path.find(':') + 1);
+  std::filesystem::path exe_dir = mujoco::platform::GetModuleDir((void*)&Resolve);
+  if (exe_dir.empty()) {
+    return std::string("assets/") + std::string(subpath);
+  }
+  std::filesystem::path resources_dir = exe_dir.parent_path() / "Resources";
+  if (std::filesystem::exists(resources_dir / "assets")) {
+    return (resources_dir / "assets" / subpath).string();
+  }
+  return (exe_dir / "assets" / subpath).string();
+}
+
+class FileResource {
+ public:
+  explicit FileResource(const std::string& path)
+      : file_(path, std::ios::binary | std::ios::ate) {
+    if (!file_.is_open()) {
+      mju_warning("Cannot open file %s", path.c_str());
+      return;
+    }
+
+    size_ = file_.tellg();
+    file_.seekg(0, std::ios::beg);
+  }
+
+  int Read(const void** buffer) {
+    buffer_.resize(size_);
+    if (!file_.read(reinterpret_cast<char*>(buffer_.data()), size_)) {
+      return 0;
+    }
+    *buffer = buffer_.data();
+    return size_;
+  }
+
+  int Size() const { return size_; }
+
+  FileResource(const FileResource&) = delete;
+  FileResource& operator=(const FileResource&) = delete;
+
+ private:
+  std::ifstream file_;
+  std::vector<char> buffer_;
+  int size_ = 0;
+};
+
+}  // namespace
+
+void RegisterResourceProviders() {
+  mjpResourceProvider resource_provider;
+  mjp_defaultResourceProvider(&resource_provider);
+
+  resource_provider.open = [](mjResource* resource) {
+    const std::string resolved_path = Resolve(resource->name);
+    FileResource* f = new FileResource(resolved_path);
+    if (f->Size() == 0) {
+      delete f;
+      return 0;
+    }
+    resource->data = f;
+    return f->Size();
+  };
+  resource_provider.read = [](mjResource* resource, const void** buffer) {
+    FileResource* f = static_cast<FileResource*>(resource->data);
+    return f->Read(buffer);
+  };
+  resource_provider.close = [](mjResource* resource) {
+    delete static_cast<FileResource*>(resource->data);
+    resource->data = nullptr;
+  };
+
+  resource_provider.prefix = "font";
+  mjp_registerResourceProvider(&resource_provider);
+  resource_provider.prefix = "filament";
+  mjp_registerResourceProvider(&resource_provider);
+}
+
+}  // namespace mujoco::platform

src/experimental/platform/resources.h

@@ -0,0 +1,25 @@
+// 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.
+
+#ifndef MUJOCO_SRC_EXPERIMENTAL_PLATFORM_RESOURCES_H_
+#define MUJOCO_SRC_EXPERIMENTAL_PLATFORM_RESOURCES_H_
+
+namespace mujoco::platform {
+
+// Registers MuJoCo resource providers for font and filament assets.
+void RegisterResourceProviders();
+
+}  // namespace mujoco::platform
+
+#endif  // MUJOCO_SRC_EXPERIMENTAL_PLATFORM_RESOURCES_H_

src/experimental/studio/launcher.cc

@@ -16,99 +16,21 @@
 
 #include <cstdlib>
 #include <cstring>
-#include <filesystem>  // NOLINT(build/c++17)
-#include <fstream>
-#include <ios>
 #include <string>
 #include <string_view>
-#include <vector>
 
 #include <mujoco/mujoco.h>
 #include "experimental/platform/hal/graphics_mode.h"
-#include "experimental/platform/sys_utils.h"
+#include "experimental/platform/resources.h"
 #include "experimental/studio/app.h"
 
 namespace mujoco::studio {
-namespace {
-
-std::string Resolve(std::string_view path) {
-  std::string_view subpath = path.substr(path.find(':') + 1);
-  std::filesystem::path exe_dir = mujoco::platform::GetModuleDir((void*)&Resolve);
-  if (exe_dir.empty()) {
-    return std::string("assets/") + std::string(subpath);
-  }
-  std::filesystem::path resources_dir = exe_dir.parent_path() / "Resources";
-  if (std::filesystem::exists(resources_dir / "assets")) {
-    return (resources_dir / "assets" / subpath).string();
-  }
-  return (exe_dir / "assets" / subpath).string();
-}
-
-class FileResource {
- public:
-  explicit FileResource(const std::string& path)
-      : file_(path, std::ios::binary | std::ios::ate) {
-    if (!file_.is_open()) {
-      mju_warning("Cannot open file %s", path.c_str());
-      return;
-    }
-
-    size_ = file_.tellg();
-    file_.seekg(0, std::ios::beg);
-  }
-
-  int Read(const void** buffer) {
-    buffer_.resize(size_);
-    if (!file_.read(reinterpret_cast<char*>(buffer_.data()), size_)) {
-      return 0;
-    }
-    *buffer = buffer_.data();
-    return size_;
-  }
-
-  int Size() const { return size_; }
-
-  FileResource(const FileResource&) = delete;
-  FileResource& operator=(const FileResource&) = delete;
-
- private:
-  std::ifstream file_;
-  std::vector<char> buffer_;
-  int size_ = 0;
-};
-
-}  // namespace
 
 int LaunchStudio(int argc, char** argv, LauncherConfig config) {
   const char* home = std::getenv("HOME");
   const std::string ini_path = std::string(home ? home : ".") + "/.mujoco.ini";
 
-  mjpResourceProvider resource_provider;
+  mujoco::platform::RegisterResourceProviders();
-  mjp_defaultResourceProvider(&resource_provider);
-
-  resource_provider.open = [](mjResource* resource) {
-    const std::string resolved_path = Resolve(resource->name);
-    FileResource* f = new FileResource(resolved_path);
-    if (f->Size() == 0) {
-      delete f;
-      return 0;
-    }
-    resource->data = f;
-    return f->Size();
-  };
-  resource_provider.read = [](mjResource* resource, const void** buffer) {
-    FileResource* f = static_cast<FileResource*>(resource->data);
-    return f->Read(buffer);
-  };
-  resource_provider.close = [](mjResource* resource) {
-    delete static_cast<FileResource*>(resource->data);
-    resource->data = nullptr;
-  };
-
-  resource_provider.prefix = "font";
-  mjp_registerResourceProvider(&resource_provider);
-  resource_provider.prefix = "filament";
-  mjp_registerResourceProvider(&resource_provider);
 
   if (config.gfx_mode.empty()) {
     const char* display = std::getenv("DISPLAY");