Adding the ability to install libsimulate library and associated headers during installation.

[vidurvij-apptronik]

This is the second iteration of the code. I am updating cmake and depedncies file for simulate library to expose header files for simulate. This will allow us to directly use simulate library in mujoco and add our custom time stepping while using default visualizer similar to python.

[yuvaltassa]

cc @francesco-romano

[francesco-romano]

How did you test this CL? What is the test environment?

[francesco-romano]

Do we need all these headers to be public?

Also check also the target_link_libraries line. Now that we install the target we need to ensure its public dependencies are also available. Can they be moved to private?

[vidurvij-apptronik]

We do. If we want to use simulate. h and instantiate a Simulate object we need to call

 auto sim = std::make_unique<mj::Simulate>(
      std::make_unique<mj::GlfwAdapter>(),
      &cam, &opt, &pert, /* is_passive = */ false
  );

Which would need access to those headers

[francesco-romano]

Got it

[vidurvij-apptronik]

How did you test this CL? What is the test environment?

@francesco-romano I tested it using Ubuntu 20.04 and cmake. To test it, separately copied the file simulate/main.cc and compiled it using gcc with this command. This verifies that the simulate and mujoco are installed correctly.

LODEPNG_DIR=${HOME}/mujoco/build/lib; g++ -std=c++17 -I./build/_deps/lodepng-src/ main.cpp -o your_program -lmujoco -lsimulate -lglfw -lpthread -L${LODEPNG_DIR} -llodepng

[francesco-romano]

How did you test this CL? What is the test environment?

@francesco-romano I tested it using Ubuntu 20.04 and cmake. To test it, separately copied the file simulate/main.cc and compiled it using gcc with this command. This verifies that the simulate and mujoco are installed correctly.

LODEPNG_DIR=${HOME}/mujoco/build/lib; g++ -std=c++17 -I./build/_deps/lodepng-src/ main.cpp -o your_program -lmujoco -lsimulate -lglfw -lpthread -L${LODEPNG_DIR} -llodepng

That is a bit brittle and not really indicative of the correct usage.

Can you test the following?

<get clean copy of mujoco with this change>
$ mkdir ~/test_install
$ mkdir -p mujoco/build
$ cd mujoco/build
$ cmake -DCMAKE_INSTALL_PREFIX=~/test_install ..
$ make -j4 && make install

Now you have the correctly installed mujoco and we need to source it for a new project.

$ mkdir ~/my_test_project
$ vim ~/my_test_project/CMakeLists.txt
...
somewhere do
find_package(mujoco)

add_executable(my_test main.cc)
target_link_libraries(my_test mujoco::libmujoco_simulate)
...

$ export PATH:~/test_install/bin:$PATH
$ mkdir ~/my_test_project/build
$ cd ~/my_test_project/build
$ cmake ..
$ make

Of course in main.cc use the libsimulate, I expect something like #include <mujoco/simulate.h>

[francesco-romano]

And what about the <INSTALL_INTEFACE?

[vidurvij-apptronik]

Added the install interface,

[francesco-romano]

Got it

[vidurvij-apptronik]

@francesco-romano Hey pushed the changes requested.

Following your request I was able to test it using

cmake_minimum_required(VERSION 3.16)
project(my_test)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Set the path to our installed MuJoCo
set(CMAKE_PREFIX_PATH "/Users/vidurvij/mujoco/test_install")

# Find MuJoCo package
find_package(mujoco REQUIRED)

# Find threads (required by simulate)
find_package(Threads REQUIRED)

# Create test executable
add_executable(my_test main.cc)
add_executable(my_simulate main_simulate.cc)

# Link against libmujoco_simulate as Francesco requested
target_link_libraries(my_test 
    mujoco::libmujoco_simulate
    mujoco::mujoco
    Threads::Threads
)

# On macOS, we need these frameworks
if(APPLE)
    find_package(OpenGL REQUIRED)
    target_link_libraries(my_test 
        OpenGL::GL
        "-framework Cocoa"
        "-framework CoreVideo"
    )
endif()

# Configure my_simulate executable
target_link_libraries(my_simulate
    mujoco::libmujoco_simulate
    mujoco::mujoco
    Threads::Threads
)

# Link GLFW directly from build directory
target_link_libraries(my_simulate /Users/vidurvij/mujoco/build/lib/libglfw3.a)

# Add GLFW include directory
target_include_directories(my_simulate PRIVATE /Users/vidurvij/mujoco/build/_deps/glfw3-src/include)

if(APPLE)
    target_link_libraries(my_simulate
        OpenGL::GL
        "-framework Cocoa"
        "-framework CoreVideo"
        "-framework IOKit"
    )
endif()

Also my executable were the main.cc in the simulate library and small script

#include <iostream>
#include <memory>


#include <simulate/simulate.h>
#include <simulate/platform_ui_adapter.h>
#include <mujoco/mujoco.h>

int main(int argc, char** argv) {
    std::cout << "Testing libmujoco_simulate installation..." << std::endl;
    
    std::cout << "MuJoCo version: " << mj_versionString() << std::endl;
    
    mujoco::Simulate* sim_ptr = nullptr;
    std::cout << "✓ mujoco::Simulate class is accessible" << std::endl;
    
    mujoco::PlatformUIAdapter* adapter_ptr = nullptr;
    std::cout << "✓ mujoco::PlatformUIAdapter class is accessible" << std::endl;
    
    const char* xml = R"(
        <mujoco>
            <worldbody>
                <light diffuse="1 1 1" pos="0 0 3" dir="0 0 -1"/>
                <body>
                    <geom type="sphere" size="0.1" rgba="1 0 0 1"/>
                </body>
            </worldbody>
        </mujoco>
    )";
    
    char error[1000] = {0};
    mjVFS vfs;
    mj_defaultVFS(&vfs);
    mj_addBufferVFS(&vfs, "model.xml", xml, strlen(xml));
    mjModel* model = mj_loadXML("model.xml", &vfs, error, sizeof(error));
    mj_deleteVFS(&vfs);
    
    if (model) {
        std::cout << "✓ Successfully created test model" << std::endl;
        mjData* data = mj_makeData(model);
        if (data) {
            std::cout << "✓ Successfully created mjData" << std::endl;
            
            mjvCamera cam;
            mjvOption opt;
            mjvPerturb pert;
            mjv_defaultCamera(&cam);
            mjv_defaultOption(&opt);
            mjv_defaultPerturb(&pert);
            
            try {
                auto sim = std::make_unique<mujoco::Simulate>(
                    nullptr,  // No UI adapter for this test
                    &cam,
                    &opt,
                    &pert,
                    true      // passive mode
                );
                std::cout << "✓ Successfully instantiated mujoco::Simulate" << std::endl;
            } catch (...) {
                std::cout << "Note: Simulate instantiation requires UI components" << std::endl;
            }
            
            mj_deleteData(data);
        }
        mj_deleteModel(model);
    } else {
        std::cerr << "Model creation failed: " << error << std::endl;
    }
    
    std::cout << "\n=== Test completed successfully ===" << std::endl;
    std::cout << "libmujoco_simulate is properly installed and usable!" << std::endl;
    
    return 0;
}

[francesco-romano]

Thanks a lot. All good on my side

[yuvaltassa]

@vidurvij-apptronik you need to do the CLA thing please

[yuvaltassa]

@vidurvij-apptronik do you understand where the breakage is coming from?

[vidurvij-apptronik]

@yuvaltassa The python cmake was using the name libsimulate. We changed it to libmujoco_simulate. I have updated the name of the simulate library in python bindings cmake, it should be working now.

[yuvaltassa]

@yuvaltassa The python cmake was using the name libsimulate. We changed it to libmujoco_simulate. I have updated the name of the simulate library in python bindings cmake, it should be working now.

Nope

[francesco-romano]

@yuvaltassa The python cmake was using the name libsimulate. We changed it to libmujoco_simulate. I have updated the name of the simulate library in python bindings cmake, it should be working now.

Nope

But the error is different

@vidurvij-apptronik

simulate/glfw_adapter.h:20:10: fatal error: GLFW/glfw3.h: No such file or directory

if glfw is not forwarded by simulate you might need to update the Bindings CMake to find it.

[vidurvij-apptronik]

@yuvaltassa Can't figure out the issue with this pipeline. It seems it doesn't give any output.