score-back/openwiki/quickstart.md

Cloud Point RPC — Quickstart

What is this?

Cloud Point RPC is a C++20 JSON-RPC 2.0 server and client implementation designed to bridge a C++ backend with a Unity Scene over TCP. The server exposes RPC methods that retrieve camera intrinsic/extrinsic parameters and point cloud data. A C API (server_api.h) allows Unity (or other C consumers) to embed the server, register custom RPC handlers, and manage the server lifecycle from native code.

The project is a work in progress: the server side with C-API is implemented, while the client side with OpenCV integration is still planned (see README TODO).

Repository layout

Path	Purpose
include/cloud_point_rpc/	C++ public headers: TCP server/client, RPC server/client, config, serialization, service, coder
include/server_api.h	C API for embedding the server in Unity/native consumers
include/test_api.h	C API for test-driven method registration and scheduled calls
include/export.h	Cross-platform shared-library export macros (CRPC_EXPORT)
src/	Implementation files and executable entrypoints
tests/	GTest/GMock unit and integration tests (single unit_tests executable)
rpc/	Git submodule — json-rpc-cxx providing jsonrpccxx headers
subprojects/	Meson wrap dependencies (asio, nlohmann_json, glog, yaml-cpp, base64, gtest)
docs/	PlantUML communication model diagram
config.yml	Sample server configuration (IP and port)
Dockerfile	Container image for the CLI client
.gitea/workflows/test.yaml	CI pipeline (build + test on push to master)

Build and run

git submodule init && git submodule update
meson setup build
meson compile -C build

Start the test server (uses mock camera data from config.yml):

./build/src/cloud_point_rpc_server config.yaml

Run the interactive CLI client:

./build/src/cloud_point_rpc_cli config.yaml

Run all tests:

meson test -C build -v

For Windows build instructions and Docker usage, see Build & Testing.

Documentation sections

• Architecture — Layered design, TCP framing, threading model, communication flow
• RPC Protocol — JSON-RPC 2.0 methods, request/response format, error codes, Base64 encoding
• C API — C interface for Unity integration, rpc_string memory management, test API
• Build & Testing — Meson build system, dependencies, config, Docker, CI, test suite overview

Key concepts

• Namespace: All C++ code lives in score (renamed from cloud_point_rpc early in development).
• Wire framing: Every TCP message is prefixed with an 8-byte little-endian uint64_t payload size, then the JSON-RPC payload follows. See Architecture → Wire framing.
• Two server entrypoints: server_main.cpp is a standalone executable with mock data; server_api.cpp provides the embeddable C API that Unity uses to start the server and register callbacks.
• Base64: Camera parameter arrays and point cloud data are Base64-encoded for ASCII-safe transport over JSON. Encoding/decoding is done on the Unity side per API.md.