/// <summary>
/// Starts the engine's main loop.
/// </summary>
/// <param name="cancelToken"></param>
/// <returns></returns>
internal Task Start(CancellationToken cancelToken)
{
if (_runningTask != null)
{
throw new SeeingSharpGraphicsException("Unable to start engine's main loop: Loop has already started!");
}
_runningTask = Task.Factory.StartNew(async() =>
{
var renderStopWatch = new Stopwatch();
renderStopWatch.Start();
var renderingRenderLoops = new List <RenderLoop>(16);
var scenesToRender = new List <Scene>(16);
var camerasToUpdate = new List <Camera3DBase>(16);
var devicesInUse = new List <EngineDevice>(16);
var inputFrames = new List <InputFrame>(16);
var updateState = new UpdateState(TimeSpan.Zero, null);
while (!cancelToken.IsCancellationRequested)
{
var exceptionOccurred = false;
try
{
using (_host.BeginMeasureActivityDuration(SeeingSharpConstants.PERF_GLOBAL_PER_FRAME))
{
// Wait some time before doing anything..
var lastRenderMilliseconds = renderStopWatch.GetTrueElapsedMilliseconds();
var delayTime = SeeingSharpConstants.MINIMUM_FRAME_TIME_MS - lastRenderMilliseconds;
if (delayTime < SeeingSharpConstants.MINIMUM_DELAY_TIME_MS)
{
delayTime = SeeingSharpConstants.MINIMUM_DELAY_TIME_MS;
}
using (_host.BeginMeasureActivityDuration(SeeingSharpConstants.PERF_GLOBAL_WAIT_TIME))
{
SeeingSharpUtil.MaximumDelay(delayTime);
}
// Get all render loops
renderingRenderLoops.Clear();
lock (_registeredRenderLoopsLock)
{
renderingRenderLoops.AddRange(_registeredRenderLoops);
}
// Queries for devices / scenes in use
QueryForScenesAndCameras(renderingRenderLoops, scenesToRender, camerasToUpdate);
QueryForDevicesInUse(renderingRenderLoops, devicesInUse);
var deviceInUseCount = devicesInUse.Count;
// Handle device lost events
for (var loop = 0; loop < deviceInUseCount; loop++)
{
var actDevice = devicesInUse[loop];
if (!actDevice.IsLost)
{
continue;
}
actDevice.RecreateAfterDeviceLost();
}
// Cleanup device resources
for (var loop = 0; loop < deviceInUseCount; loop++)
{
var actDevice = devicesInUse[loop];
actDevice.CleanupDeviceResourceCollection();
}
// Get all input frames
_host.InputGatherer !.QueryForCurrentFrames(inputFrames);
// Build new UpdateState object
var updateTime = renderStopWatch.Elapsed;
if (updateTime.TotalMilliseconds > 100.0)
{
updateTime = TimeSpan.FromMilliseconds(100.0);
}
updateState.Reset(updateTime, inputFrames);
// Restart the stopwatch
renderStopWatch.Restart();
// First global pass: Update scene and prepare rendering
_logicUpdateAndPrepareRendering.SetPassParameters(renderingRenderLoops, scenesToRender, devicesInUse, updateState);
await _logicUpdateAndPrepareRendering.ExecutePassAsync()
.ConfigureAwait(false);
// Update all cameras
foreach (var actCamera in camerasToUpdate)
{
actCamera.AnimationHandler.Update(updateState);
}
// Queries for devices / scenes in use (may have changed during prepare)
QueryForScenesAndCameras(renderingRenderLoops, scenesToRender, camerasToUpdate);
QueryForDevicesInUse(renderingRenderLoops, devicesInUse);
// Second global pass: Render scene(s) and update beside
_logicRenderAndUpdateBeside.SetPassParameters(renderingRenderLoops, scenesToRender, devicesInUse, updateState);
_logicRenderAndUpdateBeside.ExecutePass();
// Raise generic input event (if registered)
_cachedInputEventArgs.NotifyNewPass(inputFrames);
try
{
this.GenericInput?.Raise(this, _cachedInputEventArgs);
}
catch (Exception ex)
{
GraphicsCore.PublishInternalExceptionInfo(ex, InternalExceptionLocation.EngineMainLoop_GenericInputEvent);
}
// Clear unreferenced Scenes finally
lock (_scenesForUnloadLock)
{
foreach (var actScene in _scenesForUnload)
{
actScene.UnloadResources();
actScene.Clear(true);
}
_scenesForUnload.Clear();
}
// Unload all Direct2D resources which are not needed anymore
while (_drawing2DResourcesToUnload.TryDequeue(out var act2DResourceToUnload))
{
var deviceCount = _host.DeviceCount;
for (var loop = 0; loop < deviceCount; loop++)
{
act2DResourceToUnload.UnloadResources(_host.Devices[loop]);
}
}
}
}
catch (Exception ex)
{
exceptionOccurred = true;
// Publish exception info
GraphicsCore.PublishInternalExceptionInfo(ex, InternalExceptionLocation.EngineMainLoop_Loop);
}
// Execute global awaitors
var prevCount = _globalLoopAwaitors.Count;
var currentIndex = 0;
while (currentIndex < prevCount)
{
currentIndex++;
if (_globalLoopAwaitors.TryDequeue(out var currentAction))
{
currentAction();
}
}
if (exceptionOccurred)
{
// Wait some time and try rendering again
await Task.Delay(1000);
}
// Handle suspend / resume
var suspendWaiter = _suspendWaiter;
if (suspendWaiter != null)
{
_suspendCallWaiterSource !.TrySetResult(null);
// Wait for resuming
await suspendWaiter;
}
// Trigger calculation of performance values
_host.PerformanceAnalyzer !.CalculateResults();
}
});
return(_runningTask);
}