SpatialOS C++ Blank project
This is a SpatialOS project which can serve as a template for building SpatialOS workers using the C++ SDK. It uses CMake as the build system. If you're new to SpatialOS, have a look at Introduction to the C++ worker SDK.
About managed and external workers
Have a look at the Glossary entry for Workers for a complete discussion and examples.
Quick start
The build scripts for each project:
- Generate C++ code from schema
- Download the C++ worker SDK
- Create a
cmake_build
directory in the worker directory - Invoke
cmake
with arguments depending on the target platform
To build and launch a local deployment execute the following commands. The
target platform is one of windows
, linux
or macos
. Set it based on your
development environment:
spatial worker build --target=<platform>
spatial local launch
To connect a new instance of the external C++ worker:
spatial local worker launch External local
What the project does
It's a blank project so the short answer is - not much. The snapshot file in
this project contains a single entity with an ACL which matches the Managed
worker attributes. When you launch a deployment, a single instance of the
Managed
worker will be started as configured in default_launch.json
.
After connecting successfully both the Managed
and External
workers log a
message to SpatialOS which should be displayed in the output of spatial local launch
as it's running. Then they just spin in a loop processing the Ops list.
When SpatialOS disconnects a worker, a message is written to the console output of the worker and it exits with an error status.
Instances of the External
worker won't have any entities added to their view
because they don't have write access to anything in the snapshot.
Project structure
The CMake project hierarchy doesn't exactly match the directory structure of
the project. For example the projects for workers add as subdirectories the
schema
and dependencies
projects.
This is how projects are structured in the directory:
+-- schema/CMakeLists.txt
+-- dependencies/CMakeLists.txt
+-- workers
|-- External/
| |-- External/CMakeLists.txt
| |-- CMakeLists.txt
| |-- build.json
|-- Managed/
|-- Managed/CMakeLists.txt
|-- CMakeLists.txt
|-- build.json
This enables you to keep the worker directories free of CMake files for schema and dependencies while not needing a CMake file at the root of the project.
The schema
directory contains a sample empty component called blank
. It is
not used by the workers directly so feel free to delete it but it's there to
show how sources generated from the schema could be linked in the worker
binary. See schema/CMakeLists.txt
which creates a library with all generated
sources.
The worker project
The following applies to both the Managed
and External
worker projects but examples will only be about Managed
.
After running spatial build
the generated project by CMake will be in
workers/Managed/cmake_build
. Exactly what it contains will depend on the
generator you use. A worker project includes 3 subdirectories in its
CMakeLists.txt
- dependencies
, schema
and Managed
. The first two are
not true subdirectories of workers/Managed
in the file structure but their
binary directories are set as if they were.
Attaching a debugger
If you use a Visual Studio generator with CMake, the generated solution contains several projects to match the build targets. You can start a worker from Visual Studio by setting the project matching the worker name as the startup project for the solution and navigating to Properties > Configuration properties > Debugging
to set the command arguments. Using receptionist localhost 7777 DebugWorker
as the command arguments for example will connect a new instance of the worker named DebugWorker
via the receptionist to a local running deployment. You can do this for both worker types that come with this project. Make sure you are starting the project using a local debugger (e.g. Local Windows Debugger).
Cloud deployment
As usual set the project_name
field in spatialos.json
to match your SpatialOS project name. Then upload and launch:
spatial cloud upload <AssemblyName>
spatial cloud launch <AssemblyName> default_launch.json <deploymentname>
See spatial cloud connect external
if you want to connect to a cloud deployment. In
addition, the External
worker has a second external launch configuration
called cloud
which could be used to connect provided that you know the
deployment name and have a login token:
spatial local worker launch External cloud <deployment-name> <login-token>
Integrating with an existing project
If you have an existing project, to add a new C++ worker to it:
- Decide whether the worker you're adding will be used as a managed or external worker.
- Copy the corresponding directory (e.g.
workers/Managed
) into the workers directory of your existing project. - In the worker project
CMakeLists.txt
setSCHEMA_SOURCE_DIR
andWORKER_SDK_DIR
to point to the CMake projects in your project that generate the corresponding targets and if the targets have different names fromSchema
andWorkerSdk
also rename those. - Add it to the
workers
definition in your SpatialOS launch configuration (e.g.default_launch.json
)
If you don't want to follow the steps manually, use
worker_create.sh
which will copy and rename the required
files. Feel free to modify this script to suit your needs.
Release notes
The following are versions of SpatialOS with the changes to this project listed.
12.0.0
- Use
worker::ComponentRegistry
where required. - Add
worker_create.sh
to make it easier to create C++ workers in other projects from these templates. - Set
is_connected
flag based on connection state.
11.0.1
Initial release.