acdream/src/AcDream.App/Rendering/RenderFramePreparationController.cs

namespace AcDream.App.Rendering;

internal interface IRenderWeatherFramePhase
{
    void Tick(double deltaSeconds);
}

/// <summary>
/// Optional per-frame developer-presentation hook. Its one production
/// implementation (the ImGui developer-tools frontend) was removed at
/// Campaign V slice V11; the interface survives as the seam a follow-up
/// re-homing Settings/Debug onto the retained UI will implement, and every
/// current caller already treats it as optional (<c>null</c>-conditional).
/// </summary>
internal interface IDevToolsFrameLifecycle : IRenderFrameFailureRecovery
{
    void BeginFrame(float deltaSeconds);

    void Render(double deltaSeconds, int viewportWidth, int viewportHeight);
}

/// <summary>
/// Preserves the accepted pre-world order after the GPU/resource transaction:
/// begin optional developer UI, advance render-time weather, then hand the
/// completed preparation to the world phase.
/// </summary>
internal sealed class RenderFramePreparationController : IRenderFrameResourcePhase
{
    private readonly IRenderFrameResourcePhase _resources;
    private readonly IDevToolsFrameLifecycle? _devTools;
    private readonly IRenderWeatherFramePhase _weather;

    public RenderFramePreparationController(
        IRenderFrameResourcePhase resources,
        IDevToolsFrameLifecycle? devTools,
        IRenderWeatherFramePhase weather)
    {
        _resources = resources ?? throw new ArgumentNullException(nameof(resources));
        _devTools = devTools;
        _weather = weather ?? throw new ArgumentNullException(nameof(weather));
    }

    public void Prepare(RenderFrameInput input)
    {
        _resources.Prepare(input);
        _devTools?.BeginFrame((float)input.DeltaSeconds);
        _weather.Tick(input.DeltaSeconds);
    }
}