http

apps/RenderCadenceCompositor/README.md

@@ -47,6 +47,8 @@ Included now:
 - small JSON writer for future HTTP/WebSocket payloads
 - JSON serialization for cadence telemetry snapshots
 - background logging with `log`, `warning`, and `error` levels
+- local HTTP control server matching the OpenAPI route surface
+- startup config provider for `config/runtime-host.json`
 - compact telemetry
 - non-GL frame-exchange tests
 
@@ -101,12 +103,53 @@ build\vs2022-x64-debug\Debug\RenderCadenceCompositor.exe --shader solid-color
 
 Use `--no-shader` to keep the simple motion fallback only.
 
+## Startup Config
+
+On startup the app loads `config/runtime-host.json` through `AppConfigProvider`, then applies explicit CLI overrides.
+
+Currently consumed fields:
+
+- `serverPort`
+- `shaderLibrary`
+- `oscBindAddress`
+- `oscPort`
+- `oscSmoothing`
+- `inputVideoFormat`
+- `inputFrameRate`
+- `outputVideoFormat`
+- `outputFrameRate`
+- `autoReload`
+- `maxTemporalHistoryFrames`
+- `previewFps`
+- `enableExternalKeying`
+
+The loaded config is treated as a read-only startup snapshot. Subsystems that need config should receive this snapshot or a narrowed config struct from app orchestration; they should not reload files independently.
+
+Supported CLI overrides:
+
+- `--shader <shader-id>`
+- `--no-shader`
+- `--port <port>`
+
 ## Expected Telemetry
 
 Startup, shutdown, shader-build, and render-thread event messages are written through the app logger. Telemetry is intentionally separate and remains a compact once-per-second cadence line.
 
 The logger writes to the console, `OutputDebugStringA`, and `logs/render-cadence-compositor.log` by default. Render-thread log calls use the non-blocking path so diagnostics do not become cadence blockers.
 
+## HTTP Control Server
+
+The app starts a local HTTP control server on `http://127.0.0.1:8080` by default, searching nearby ports if that one is busy.
+
+Current endpoints:
+
+- `GET /api/state`: returns an OpenAPI-shaped state scaffold with cadence telemetry under `performance.cadence`
+- `GET /docs/openapi.yaml` and `GET /openapi.yaml`: serves the OpenAPI document
+- `GET /docs`: serves Swagger UI
+- OpenAPI POST routes are present but return `{ "ok": false, "error": "Endpoint is not implemented in RenderCadenceCompositor yet." }`
+
+The HTTP server runs on its own thread. It samples/copies telemetry through callbacks and does not call render work or DeckLink scheduling.
+
 The app prints one line per second:
 
 ```text
@@ -191,10 +234,12 @@ This app keeps the same core behavior but splits it into modules that can grow:
 - `frames/`: system-memory handoff
 - `platform/`: COM/Win32/hidden GL context support
 - `render/`: cadence, simple rendering, PBO readback
+- `control/`: local HTTP API edge
 - `json/`: compact JSON serialization helpers
 - `video/`: DeckLink output wrapper and scheduling thread
 - `telemetry/`: cadence telemetry
 - `app/`: startup/shutdown orchestration
+- `app/AppConfigProvider`: startup config loading and CLI overrides
 
 ## Next Porting Steps