Initial implementation of toolbox-based "Studio" app.

PiperOrigin-RevId: 809966748
Change-Id: Ic6333259ca1d112a2e42d47ccc44326bfcea3bdd

src/experimental/studio/app.h

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+// Copyright 2025 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
+//
+//     http://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_STUDIO_APP_H_
+#define MUJOCO_SRC_EXPERIMENTAL_STUDIO_APP_H_
+
+#include <chrono>
+#include <cstdint>
+#include <memory>
+#include <ratio>
+#include <string>
+#include <string_view>
+#include <unordered_map>
+#include <vector>
+
+#include <mujoco/mujoco.h>
+#include "experimental/toolbox/helpers.h"
+#include "experimental/toolbox/physics.h"
+#include "experimental/toolbox/renderer.h"
+#include "experimental/toolbox/window.h"
+
+namespace mujoco::studio {
+
+// Owns, updates, and renders a MuJoCo simulation.
+class App {
+ public:
+  using Clock = std::chrono::steady_clock;
+  using TimePoint = std::chrono::time_point<Clock>;
+  using Seconds = std::chrono::duration<double>;
+  using Milliseconds = std::chrono::duration<double, std::milli>;
+
+  App(int width, int height, std::string ini_path,
+      const toolbox::LoadAssetFn& load_asset_fn);
+
+  // Loads a model into the simulation.
+  void LoadModel(std::string model_file);
+
+  // Processes window events and advances the state of the simulation.
+  bool Update();
+
+  // Syncs the state of the simulation with the renderer.
+  void Sync();
+
+  // Builds the GUI. We do this after Sync() to ensure we have the latest data
+  // for building the GUI.
+  void BuildGui();
+
+  // Renders everything (e.g. the simulation and the GUI).
+  void Render();
+
+ private:
+  static int LoadAssetCallback(const char* path, void* user_data,
+                               unsigned char** out, std::uint64_t* out_size);
+
+  // UI state that is persisted across application runs
+  struct UiState {
+    bool classic_ui = true;
+
+    char watch_field[1000] = "qpos";
+    int watch_index = 0;
+    int camera_idx = 0;
+    int key_idx = 0;
+    int scrub_idx = 0;
+    bool dark_mode = true;
+
+    // UI visibility.
+    bool simulation = false;
+    bool physics = false;
+    bool rendering = false;
+    bool watch = false;
+    bool visualization = false;
+    bool groups = false;
+    bool joints = false;
+    bool controls = false;
+    bool profiler = false;
+    bool sensor = false;
+
+    using Dict = std::unordered_map<std::string, std::string>;
+    Dict ToDict() const;
+    void FromDict(const Dict& dict);
+  };
+
+  // UI state that is transient and only needed while the application runs
+  // TODO(matijak): Combine this with UiState and identify the list of transient
+  // variables with a comment
+  struct UiTempState {
+    // bool paused = false;  // Application starts with the simulation running.
+    bool help = false;
+    bool info = false;
+    bool modal_open = false;
+    bool load_popup = false;
+    bool save_xml_popup = false;
+    bool save_mjb_popup = false;
+    bool save_screenshot_popup = false;
+    bool print_model_popup = false;
+    bool print_data_popup = false;
+    bool should_exit = false;
+    // bool should_reload = false;
+    bool style_editor = false;
+    bool imgui_demo = false;
+    bool perturb_active = false;
+
+    int speed_index = 0;
+
+    // Visibility, position and size of the left and right UI panels
+    bool show_ui_lhs = true;
+    bool show_ui_rhs = true;
+    float pos_ui_lhs[2];
+    float pos_ui_rhs[2];
+    float size_ui_lhs[2];
+    float size_ui_rhs[2];
+
+    char filename[1000] = "";
+  };
+
+  void OnModelLoaded(std::string_view model_file);
+
+  void LoadSettings();
+  void SaveSettings();
+
+  void SetCamera(int idx);
+
+  void ChangeSpeed(int delta);
+
+  void HandleMouseEvents();
+  void HandleKeyboardEvents();
+
+  void ClearProfilerData();
+  void UpdateProfilerData();
+
+  void BuildGuiWithWindows();
+  void BuildGuiWithSections();
+
+  void InfoGui();
+  void HelpGui();
+  void MainMenuGui();
+  void FileDialogGui();
+  void SimulationGui();
+  void PhysicsGui();
+  void RenderingGui();
+  void VisualizationGui();
+  void GroupsGui();
+  void WatchGui();
+  void SensorGui();
+  void ProfilerGui();
+  void JointsGui();
+  void ControlsGui();
+
+  mjModel* Model() { return physics_->GetModel(); };
+  mjData* Data() { return physics_->GetData(); };
+
+  std::string ini_path_;
+  std::string model_file_;
+
+  std::unique_ptr<toolbox::Window> window_;
+  std::unique_ptr<toolbox::Renderer> renderer_;
+  std::unique_ptr<toolbox::Physics> physics_;
+  toolbox::LoadAssetFn load_asset_fn_;
+
+  mjvCamera camera_;
+  mjvPerturb perturb_;
+  mjvOption vis_options_;
+
+  // profiler data
+  std::vector<float> cpu_total_;
+  std::vector<float> cpu_collision_;
+  std::vector<float> cpu_prepare_;
+  std::vector<float> cpu_solve_;
+  std::vector<float> cpu_other_;
+  std::vector<float> dim_dof_;
+  std::vector<float> dim_body_;
+  std::vector<float> dim_constraint_;
+  std::vector<float> dim_sqrt_nnz_;
+  std::vector<float> dim_contact_;
+  std::vector<float> dim_iteration_;
+
+  UiState ui_;
+  UiTempState tmp_;
+};
+
+}  // namespace mujoco::studio
+
+#endif  // MUJOCO_SRC_EXPERIMENTAL_STUDIO_APP_H_

src/experimental/studio/main.cc

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+// Copyright 2025 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
+//
+//     http://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.
+
+// Main entry point for the Filament-based MuJoCo renderer.
+
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <fstream>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include "third_party/absl/flags/flag.h"
+#include "third_party/mujoco/google/runfiles/runfiles.h"
+#include "experimental/studio/app.h"
+
+ABSL_FLAG(int, window_width, 1400, "Window width");
+ABSL_FLAG(int, window_height, 700, "Window height");
+ABSL_FLAG(std::string, model_file, "", "MuJoCo model file.");
+
+constexpr char kDataPath[] = "third_party/mujoco/google/filament/assets/data/";
+
+static std::vector<std::byte> LoadAsset(std::string_view path) {
+  std::ifstream file(path, std::ios::binary | std::ios::ate);
+  if (!file.is_open()) {
+    return {};
+  }
+  std::streampos file_size = file.tellg();
+  file.seekg(0, std::ios::beg);
+  std::vector<std::byte> buffer(file_size);
+  if (!file.read(reinterpret_cast<char*>(buffer.data()), file_size)) {
+    return {};
+  }
+  return buffer;
+}
+
+int main(int argc, char** argv, char** envp) {
+
+  const int width = absl::GetFlag(FLAGS_window_width);
+  const int height = absl::GetFlag(FLAGS_window_height);
+  const std::string ini_path = file::JoinPath(getenv("HOME"), ".mujoco.ini");
+  mujoco::studio::App app(width, height, ini_path, LoadAsset);
+
+  // If the model file is not specified, try to load it from the first argument
+  std::string model_file = absl::GetFlag(FLAGS_model_file);
+  if (model_file.empty() && argc > 1 && argv[1][0] != '-') model_file = argv[1];
+  app.LoadModel(model_file);
+  while (app.Update()) {
+    app.Sync();
+    app.BuildGui();
+    app.Render();
+  }
+  return 0;
+}