// Schedule all the jobs for the simulation step.
// Enqueued callbacks can choose to inject additional jobs at defined sync points.
// threadCountHint defines which simulation type will be called:
// - threadCountHint > 0 will result in default multithreaded simulation
// - threadCountHint <=0 will result in a very small number of jobs (1 per physics step phase) that are scheduled sequentially
// Behavior doesn't change regardless of the threadCountHint provided.
public unsafe SimulationJobHandles ScheduleStepJobs(SimulationStepInput input, SimulationCallbacks callbacksIn, JobHandle inputDeps, int threadCountHint = 0)
{
SafetyChecks.CheckFiniteAndPositiveAndThrow(input.TimeStep, nameof(input.TimeStep));
SafetyChecks.CheckInRangeAndThrow(input.NumSolverIterations, new int2(1, int.MaxValue), nameof(input.NumSolverIterations));
bool singleThreadedSim = (threadCountHint <= 0);
// Dispose and reallocate input velocity buffer, if dynamic body count has increased.
// Dispose previous collision and trigger event data streams.
// New event streams are reallocated later when the work item count is known.
JobHandle handle = SimulationContext.ScheduleReset(input, inputDeps, false);
SimulationContext.TimeStep = input.TimeStep;
StepContext = new StepContext();
if (input.World.NumDynamicBodies == 0)
{
// No need to do anything, since nothing can move
m_StepHandles = new SimulationJobHandles(handle);
return(m_StepHandles);
}
SimulationCallbacks callbacks = callbacksIn ?? new SimulationCallbacks();
// Find all body pairs that overlap in the broadphase
var handles = input.World.CollisionWorld.ScheduleFindOverlapsJobs(
out NativeStream dynamicVsDynamicBodyPairs, out NativeStream dynamicVsStaticBodyPairs, handle, threadCountHint);
handle = handles.FinalExecutionHandle;
var disposeHandle1 = handles.FinalDisposeHandle;
var postOverlapsHandle = handle;
// Sort all overlapping and jointed body pairs into phases
handles = m_Scheduler.ScheduleCreatePhasedDispatchPairsJob(
ref input.World, ref dynamicVsDynamicBodyPairs, ref dynamicVsStaticBodyPairs, handle,
ref StepContext.PhasedDispatchPairs, out StepContext.SolverSchedulerInfo, threadCountHint);
handle = handles.FinalExecutionHandle;
var disposeHandle2 = handles.FinalDisposeHandle;
// Apply gravity and copy input velocities at this point (in parallel with the scheduler, but before the callbacks)
var applyGravityAndCopyInputVelocitiesHandle = Solver.ScheduleApplyGravityAndCopyInputVelocitiesJob(
input.World.DynamicsWorld.MotionVelocities, SimulationContext.InputVelocities,
input.TimeStep * input.Gravity, singleThreadedSim ? handle : postOverlapsHandle, threadCountHint);
handle = JobHandle.CombineDependencies(handle, applyGravityAndCopyInputVelocitiesHandle);
handle = callbacks.Execute(SimulationCallbacks.Phase.PostCreateDispatchPairs, this, ref input.World, handle);
// Create contact points & joint Jacobians
handles = NarrowPhase.ScheduleCreateContactsJobs(ref input.World, input.TimeStep,
ref StepContext.Contacts, ref StepContext.Jacobians, ref StepContext.PhasedDispatchPairs, handle,
ref StepContext.SolverSchedulerInfo, threadCountHint);
handle = handles.FinalExecutionHandle;
var disposeHandle3 = handles.FinalDisposeHandle;
handle = callbacks.Execute(SimulationCallbacks.Phase.PostCreateContacts, this, ref input.World, handle);
// Create contact Jacobians
handles = Solver.ScheduleBuildJacobiansJobs(ref input.World, input.TimeStep, input.Gravity, input.NumSolverIterations,
handle, ref StepContext.PhasedDispatchPairs, ref StepContext.SolverSchedulerInfo,
ref StepContext.Contacts, ref StepContext.Jacobians, threadCountHint);
handle = handles.FinalExecutionHandle;
var disposeHandle4 = handles.FinalDisposeHandle;
handle = callbacks.Execute(SimulationCallbacks.Phase.PostCreateContactJacobians, this, ref input.World, handle);
// Solve all Jacobians
Solver.StabilizationData solverStabilizationData = new Solver.StabilizationData(input, SimulationContext);
handles = Solver.ScheduleSolveJacobiansJobs(ref input.World.DynamicsWorld, input.TimeStep, input.NumSolverIterations,
ref StepContext.Jacobians, ref SimulationContext.CollisionEventDataStream, ref SimulationContext.TriggerEventDataStream,
ref StepContext.SolverSchedulerInfo, solverStabilizationData, handle, threadCountHint);
handle = handles.FinalExecutionHandle;
var disposeHandle5 = handles.FinalDisposeHandle;
handle = callbacks.Execute(SimulationCallbacks.Phase.PostSolveJacobians, this, ref input.World, handle);
// Integrate motions
handle = Integrator.ScheduleIntegrateJobs(ref input.World.DynamicsWorld, input.TimeStep, handle, threadCountHint);
// Synchronize the collision world
if (input.SynchronizeCollisionWorld)
{
handle = input.World.CollisionWorld.ScheduleUpdateDynamicTree(ref input.World, input.TimeStep, input.Gravity, handle, threadCountHint); // TODO: timeStep = 0?
}
// Return the final simulation handle
m_StepHandles.FinalExecutionHandle = handle;
// Different dispose logic for single threaded simulation compared to "standard" threading (multi threaded)
if (singleThreadedSim)
{
handle = dynamicVsDynamicBodyPairs.Dispose(handle);
handle = dynamicVsStaticBodyPairs.Dispose(handle);
handle = StepContext.PhasedDispatchPairs.Dispose(handle);
handle = StepContext.Contacts.Dispose(handle);
handle = StepContext.Jacobians.Dispose(handle);
handle = StepContext.SolverSchedulerInfo.ScheduleDisposeJob(handle);
m_StepHandles.FinalDisposeHandle = handle;
}
else
{
// Return the final handle, which includes disposing temporary arrays
JobHandle *deps = stackalloc JobHandle[5]
{
disposeHandle1,
disposeHandle2,
disposeHandle3,
disposeHandle4,
disposeHandle5
};
m_StepHandles.FinalDisposeHandle = JobHandleUnsafeUtility.CombineDependencies(deps, 5);
}
return(m_StepHandles);
}
// Steps the simulation immediately on a single thread without spawning any jobs.
public static void StepImmediate(SimulationStepInput input, ref SimulationContext simulationContext)
{
SafetyChecks.CheckFiniteAndPositiveAndThrow(input.TimeStep, nameof(input.TimeStep));
SafetyChecks.CheckInRangeAndThrow(input.NumSolverIterations, new int2(1, int.MaxValue), nameof(input.NumSolverIterations));
if (input.World.NumDynamicBodies == 0)
{
// No need to do anything, since nothing can move
return;
}
// Inform the context of the timeStep
simulationContext.TimeStep = input.TimeStep;
// Find all body pairs that overlap in the broadphase
var dynamicVsDynamicBodyPairs = new NativeStream(1, Allocator.Temp);
var dynamicVsStaticBodyPairs = new NativeStream(1, Allocator.Temp);
{
var dynamicVsDynamicBodyPairsWriter = dynamicVsDynamicBodyPairs.AsWriter();
var dynamicVsStaticBodyPairsWriter = dynamicVsStaticBodyPairs.AsWriter();
input.World.CollisionWorld.FindOverlaps(ref dynamicVsDynamicBodyPairsWriter, ref dynamicVsStaticBodyPairsWriter);
}
// Create dispatch pairs
var dispatchPairs = new NativeList <DispatchPairSequencer.DispatchPair>(Allocator.Temp);
DispatchPairSequencer.CreateDispatchPairs(ref dynamicVsDynamicBodyPairs, ref dynamicVsStaticBodyPairs,
input.World.NumDynamicBodies, input.World.Joints, ref dispatchPairs);
// Apply gravity and copy input velocities
Solver.ApplyGravityAndCopyInputVelocities(input.World.DynamicsWorld.MotionVelocities,
simulationContext.InputVelocities, input.TimeStep * input.Gravity);
// Narrow phase
var contacts = new NativeStream(1, Allocator.Temp);
{
var contactsWriter = contacts.AsWriter();
NarrowPhase.CreateContacts(ref input.World, dispatchPairs.AsArray(), input.TimeStep, ref contactsWriter);
}
// Build Jacobians
var jacobians = new NativeStream(1, Allocator.Temp);
{
var contactsReader = contacts.AsReader();
var jacobiansWriter = jacobians.AsWriter();
Solver.BuildJacobians(ref input.World, input.TimeStep, input.Gravity, input.NumSolverIterations,
dispatchPairs.AsArray(), ref contactsReader, ref jacobiansWriter);
}
// Solve Jacobians
{
var jacobiansReader = jacobians.AsReader();
var collisionEventsWriter = simulationContext.CollisionEventDataStream.AsWriter();
var triggerEventsWriter = simulationContext.TriggerEventDataStream.AsWriter();
Solver.StabilizationData solverStabilizationData = new Solver.StabilizationData(input, simulationContext);
Solver.SolveJacobians(ref jacobiansReader, input.World.DynamicsWorld.MotionVelocities,
input.TimeStep, input.NumSolverIterations, ref collisionEventsWriter, ref triggerEventsWriter, solverStabilizationData);
}
// Integrate motions
Integrator.Integrate(input.World.DynamicsWorld.MotionDatas, input.World.DynamicsWorld.MotionVelocities, input.TimeStep);
// Synchronize the collision world if asked for
if (input.SynchronizeCollisionWorld)
{
input.World.CollisionWorld.UpdateDynamicTree(ref input.World, input.TimeStep, input.Gravity);
}
}
