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o3de/Gems/Terrain/Code/Source/TerrainSystem/TerrainSystem.h

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29 KiB
C++

/*
* Copyright (c) Contributors to the Open 3D Engine Project.
* For complete copyright and license terms please see the LICENSE at the root of this distribution.
*
* SPDX-License-Identifier: Apache-2.0 OR MIT
*
*/
#pragma once
#include <AzCore/std/containers/fixed_vector.h>
#include <AzCore/Math/Vector3.h>
#include <AzCore/std/algorithm.h>
#include <AzCore/std/smart_ptr/make_shared.h>
#include <AzCore/std/parallel/condition_variable.h>
#include <AzCore/std/parallel/shared_mutex.h>
#include <AzCore/std/containers/map.h>
#include <AzCore/std/containers/span.h>
#include <AzCore/Math/Color.h>
#include <AzCore/Math/Aabb.h>
#include <AzCore/Component/TickBus.h>
#include <AzCore/Jobs/JobManagerBus.h>
#include <AzCore/Jobs/JobFunction.h>
#include <AzFramework/Terrain/TerrainDataRequestBus.h>
#include <TerrainRaycast/TerrainRaycastContext.h>
#include <TerrainSystem/TerrainSystemBus.h>
namespace Terrain
{
struct TerrainLayerPriorityComparator
{
bool operator()(const AZ::EntityId& layer1id, const AZ::EntityId& layer2id) const;
};
class TerrainSystem
: public AzFramework::Terrain::TerrainDataRequestBus::Handler
, private Terrain::TerrainSystemServiceRequestBus::Handler
, private AZ::TickBus::Handler
{
public:
TerrainSystem();
~TerrainSystem();
///////////////////////////////////////////
// TerrainSystemServiceRequestBus::Handler Impl
void Activate() override;
void Deactivate() override;
void RegisterArea(AZ::EntityId areaId) override;
void UnregisterArea(AZ::EntityId areaId) override;
void RefreshArea(
AZ::EntityId areaId, AzFramework::Terrain::TerrainDataNotifications::TerrainDataChangedMask changeMask) override;
///////////////////////////////////////////
// TerrainDataRequestBus::Handler Impl
float GetTerrainHeightQueryResolution() const override;
void SetTerrainHeightQueryResolution(float queryResolution) override;
AZ::Aabb GetTerrainAabb() const override;
void SetTerrainAabb(const AZ::Aabb& worldBounds) override;
//! Returns terrains height in meters at location x,y.
//! @terrainExistsPtr: Can be nullptr. If != nullptr then, if there's no terrain at location x,y or location x,y is inside a terrain
//! HOLE then *terrainExistsPtr will become false,
//! otherwise *terrainExistsPtr will become true.
float GetHeight(const AZ::Vector3& position, Sampler sampler = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
float GetHeightFromVector2(const AZ::Vector2& position, Sampler sampler = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
float GetHeightFromFloats(float x, float y, Sampler sampler = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
//! Given an XY coordinate, return the max surface type and weight.
//! @terrainExists: Can be nullptr. If != nullptr then, if there's no terrain at location x,y or location x,y is inside a terrain
//! HOLE then *terrainExistsPtr will be set to false,
//! otherwise *terrainExistsPtr will be set to true.
AzFramework::SurfaceData::SurfaceTagWeight GetMaxSurfaceWeight(
const AZ::Vector3& position, Sampler sampleFilter = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
AzFramework::SurfaceData::SurfaceTagWeight GetMaxSurfaceWeightFromVector2(
const AZ::Vector2& inPosition, Sampler sampleFilter = Sampler::DEFAULT, bool* terrainExistsPtr = nullptr) const override;
AzFramework::SurfaceData::SurfaceTagWeight GetMaxSurfaceWeightFromFloats(
const float x, const float y, Sampler sampleFilter = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
void GetSurfaceWeights(
const AZ::Vector3& inPosition,
AzFramework::SurfaceData::SurfaceTagWeightList& outSurfaceWeights,
Sampler sampleFilter = Sampler::DEFAULT,
bool* terrainExistsPtr = nullptr) const override;
void GetSurfaceWeightsFromVector2(
const AZ::Vector2& inPosition,
AzFramework::SurfaceData::SurfaceTagWeightList& outSurfaceWeights,
Sampler sampleFilter = Sampler::DEFAULT,
bool* terrainExistsPtr = nullptr) const override;
void GetSurfaceWeightsFromFloats(
float x,
float y,
AzFramework::SurfaceData::SurfaceTagWeightList& outSurfaceWeights,
Sampler sampleFilter = Sampler::DEFAULT,
bool* terrainExistsPtr = nullptr) const override;
//! Convenience function for low level systems that can't do a reverse lookup from Crc to string. Everyone else should use
//! GetMaxSurfaceWeight or GetMaxSurfaceWeightFromFloats. Not available in the behavior context. Returns nullptr if the position is
//! inside a hole or outside of the terrain boundaries.
const char* GetMaxSurfaceName(
const AZ::Vector3& position, Sampler sampleFilter = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
//! Returns true if there's a hole at location x,y.
//! Also returns true if there's no terrain data at location x,y.
bool GetIsHole(const AZ::Vector3& position, Sampler sampleFilter = Sampler::BILINEAR) const override;
bool GetIsHoleFromVector2(const AZ::Vector2& position, Sampler sampleFilter = Sampler::BILINEAR) const override;
bool GetIsHoleFromFloats(float x, float y, Sampler sampleFilter = Sampler::BILINEAR) const override;
// Given an XY coordinate, return the surface normal.
//! @terrainExists: Can be nullptr. If != nullptr then, if there's no terrain at location x,y or location x,y is inside a terrain
//! HOLE then *terrainExistsPtr will be set to false,
//! otherwise *terrainExistsPtr will be set to true.
AZ::Vector3 GetNormal(
const AZ::Vector3& position, Sampler sampleFilter = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
AZ::Vector3 GetNormalFromVector2(
const AZ::Vector2& position, Sampler sampleFilter = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
AZ::Vector3 GetNormalFromFloats(
float x, float y, Sampler sampleFilter = Sampler::BILINEAR, bool* terrainExistsPtr = nullptr) const override;
void GetSurfacePoint(
const AZ::Vector3& inPosition,
AzFramework::SurfaceData::SurfacePoint& outSurfacePoint,
Sampler sampleFilter = Sampler::DEFAULT,
bool* terrainExistsPtr = nullptr) const override;
void GetSurfacePointFromVector2(
const AZ::Vector2& inPosition,
AzFramework::SurfaceData::SurfacePoint& outSurfacePoint,
Sampler sampleFilter = Sampler::DEFAULT,
bool* terrainExistsPtr = nullptr) const override;
void GetSurfacePointFromFloats(
float x,
float y,
AzFramework::SurfaceData::SurfacePoint& outSurfacePoint,
Sampler sampleFilter = Sampler::DEFAULT,
bool* terrainExistsPtr = nullptr) const override;
//! Given a list of XY coordinates, call the provided callback function with surface data corresponding to each
//! XY coordinate in the list.
virtual void ProcessHeightsFromList(const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessNormalsFromList(const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessSurfaceWeightsFromList(const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessSurfacePointsFromList(const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessHeightsFromListOfVector2(const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessNormalsFromListOfVector2(const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessSurfaceWeightsFromListOfVector2(const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessSurfacePointsFromListOfVector2(const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
//! Returns the number of samples for a given region and step size. The first and second
//! elements of the pair correspond to the X and Y sample counts respectively.
virtual AZStd::pair<size_t, size_t> GetNumSamplesFromRegion(const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize) const override;
//! Given a region(aabb) and a step size, call the provided callback function with surface data corresponding to the
//! coordinates in the region.
virtual void ProcessHeightsFromRegion(const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessNormalsFromRegion(const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessSurfaceWeightsFromRegion(const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
virtual void ProcessSurfacePointsFromRegion(const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT) const override;
AzFramework::EntityContextId GetTerrainRaycastEntityContextId() const override;
AzFramework::RenderGeometry::RayResult GetClosestIntersection(
const AzFramework::RenderGeometry::RayRequest& ray) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessHeightsFromListAsync(
const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessNormalsFromListAsync(
const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessSurfaceWeightsFromListAsync(
const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessSurfacePointsFromListAsync(
const AZStd::span<const AZ::Vector3>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessHeightsFromListOfVector2Async(
const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessNormalsFromListOfVector2Async(
const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessSurfaceWeightsFromListOfVector2Async(
const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessSurfacePointsFromListOfVector2Async(
const AZStd::span<const AZ::Vector2>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessHeightsFromRegionAsync(
const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessNormalsFromRegionAsync(
const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessSurfaceWeightsFromRegionAsync(
const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
AZStd::shared_ptr<TerrainJobContext> ProcessSurfacePointsFromRegionAsync(
const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const override;
private:
template<typename SynchronousFunctionType, typename VectorType>
AZStd::shared_ptr<TerrainJobContext> ProcessFromListAsync(
SynchronousFunctionType synchronousFunction,
const AZStd::span<const VectorType>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const;
template<typename SynchronousFunctionType>
AZStd::shared_ptr<TerrainJobContext> ProcessFromRegionAsync(
SynchronousFunctionType synchronousFunction,
const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter = Sampler::DEFAULT,
AZStd::shared_ptr<ProcessAsyncParams> params = nullptr) const;
void ClampPosition(float x, float y, AZ::Vector2& outPosition, AZ::Vector2& normalizedDelta) const;
bool InWorldBounds(float x, float y) const;
AZ::EntityId FindBestAreaEntityAtPosition(float x, float y, AZ::Aabb& bounds) const;
void GetOrderedSurfaceWeights(
const float x,
const float y,
Sampler sampler,
AzFramework::SurfaceData::SurfaceTagWeightList& outSurfaceWeights,
bool* terrainExistsPtr) const;
float GetHeightSynchronous(float x, float y, Sampler sampler, bool* terrainExistsPtr) const;
float GetTerrainAreaHeight(float x, float y, bool& terrainExists) const;
AZ::Vector3 GetNormalSynchronous(float x, float y, Sampler sampler, bool* terrainExistsPtr) const;
typedef AZStd::function<void(
const AZStd::span<const AZ::Vector3> inPositions,
AZStd::span<AZ::Vector3> outPositions,
AZStd::span<bool> outTerrainExists,
AZStd::span<AzFramework::SurfaceData::SurfaceTagWeightList> outSurfaceWeights,
AZ::EntityId areaId)> BulkQueriesCallback;
void GetHeightsSynchronous(
const AZStd::span<const AZ::Vector3>& inPositions,
Sampler sampler, AZStd::span<float> heights,
AZStd::span<bool> terrainExists) const;
void GetNormalsSynchronous(
const AZStd::span<const AZ::Vector3>& inPositions,
Sampler sampler, AZStd::span<AZ::Vector3> normals,
AZStd::span<bool> terrainExists) const;
void GetOrderedSurfaceWeightsFromList(
const AZStd::span<const AZ::Vector3>& inPositions, Sampler sampler,
AZStd::span<AzFramework::SurfaceData::SurfaceTagWeightList> outSurfaceWeightsList,
AZStd::span<bool> terrainExists) const;
void MakeBulkQueries(
const AZStd::span<const AZ::Vector3> inPositions,
AZStd::span<AZ::Vector3> outPositions,
AZStd::span<bool> outTerrainExists,
AZStd::span<AzFramework::SurfaceData::SurfaceTagWeightList> outSurfaceWieghts,
BulkQueriesCallback queryCallback) const;
void GenerateQueryPositions(const AZStd::span<const AZ::Vector3>& inPositions,
AZStd::vector<AZ::Vector3>& outPositions,
Sampler sampler) const;
AZStd::vector<AZ::Vector3> GenerateInputPositionsFromRegion(
const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize) const;
AZStd::vector<AZ::Vector3> GenerateInputPositionsFromListOfVector2(
const AZStd::span<AZ::Vector2>& inPositionsVec2) const;
// AZ::TickBus::Handler overrides ...
void OnTick(float deltaTime, AZ::ScriptTimePoint time) override;
struct TerrainSystemSettings
{
AZ::Aabb m_worldBounds;
float m_heightQueryResolution{ 1.0f };
bool m_systemActive{ false };
};
TerrainSystemSettings m_currentSettings;
TerrainSystemSettings m_requestedSettings;
bool m_terrainSettingsDirty = true;
bool m_terrainHeightDirty = false;
bool m_terrainSurfacesDirty = false;
AZ::Aabb m_dirtyRegion;
// Cached data for each terrain area to use when looking up terrain data.
struct TerrainAreaData
{
AZ::Aabb m_areaBounds{ AZ::Aabb::CreateNull() };
bool m_useGroundPlane{ false };
};
mutable AZStd::shared_mutex m_areaMutex;
AZStd::map<AZ::EntityId, TerrainAreaData, TerrainLayerPriorityComparator> m_registeredAreas;
mutable TerrainRaycastContext m_terrainRaycastContext;
AZ::JobManager* m_terrainJobManager = nullptr;
mutable AZStd::mutex m_activeTerrainJobContextMutex;
mutable AZStd::condition_variable m_activeTerrainJobContextMutexConditionVariable;
mutable AZStd::deque<AZStd::shared_ptr<TerrainJobContext>> m_activeTerrainJobContexts;
};
template<typename SynchronousFunctionType, typename VectorType>
inline AZStd::shared_ptr<AzFramework::Terrain::TerrainDataRequests::TerrainJobContext> TerrainSystem::ProcessFromListAsync(
SynchronousFunctionType synchronousFunction,
const AZStd::span<const VectorType>& inPositions,
AzFramework::Terrain::SurfacePointListFillCallback perPositionCallback,
Sampler sampleFilter,
AZStd::shared_ptr<ProcessAsyncParams> params) const
{
// Determine the number of jobs to split the work into based on:
// 1. The number of available worker threads.
// 2. The desired number of jobs as passed in.
// 3. The number of positions being processed.
const int32_t numWorkerThreads = m_terrainJobManager->GetNumWorkerThreads();
const int32_t numJobsDesired = params ? params->m_desiredNumberOfJobs : ProcessAsyncParams::NumJobsDefault;
const int32_t numJobsMax = (numJobsDesired > 0) ? AZStd::min(numWorkerThreads, numJobsDesired) : numWorkerThreads;
const int32_t numPositionsToProcess = static_cast<int32_t>(inPositions.size());
const int32_t minPositionsPerJob = params && (params->m_desiredNumberOfJobs > 0) ? params->m_desiredNumberOfJobs : ProcessAsyncParams::MinPositionsPerJobDefault;
const int32_t numJobs = AZStd::min(numJobsMax, numPositionsToProcess / minPositionsPerJob);
if (numJobs <= 0)
{
AZ_Warning("TerrainSystem", false, "No positions to process.");
return nullptr;
}
// Create a terrain job context, track it, and split the work across multiple jobs.
AZStd::shared_ptr<TerrainJobContext> jobContext = AZStd::make_shared<TerrainJobContext>(*m_terrainJobManager, numJobs);
{
AZStd::unique_lock<AZStd::mutex> lock(m_activeTerrainJobContextMutex);
m_activeTerrainJobContexts.push_back(jobContext);
}
const int32_t numPositionsPerJob = numPositionsToProcess / numJobs;
for (int32_t i = 0; i < numJobs; ++i)
{
// If the number of positions can't be divided evenly by the number of jobs,
// ensure we still process the remaining positions along with the final job.
const size_t subSpanOffset = i * numPositionsPerJob;
const size_t subSpanCount = (i < numJobs - 1) ? numPositionsPerJob : AZStd::dynamic_extent;
// Define the job function using the sub span of positions to process.
const AZStd::span<const VectorType>& positionsToProcess = inPositions.subspan(subSpanOffset, subSpanCount);
auto jobFunction = [this, synchronousFunction, positionsToProcess, perPositionCallback, sampleFilter, jobContext, params]()
{
// Process the sub span of positions, unless the associated job context has been cancelled.
if (!jobContext->IsCancelled())
{
synchronousFunction(positionsToProcess, perPositionCallback, sampleFilter);
}
// Decrement the number of completions remaining, invoke the completion callback if this happens
// to be the final job completed, and remove this TerrainJobContext from the list of active ones.
const bool wasLastJobCompleted = jobContext->OnJobCompleted();
if (wasLastJobCompleted)
{
if (params && params->m_completionCallback)
{
params->m_completionCallback(jobContext);
}
{
AZStd::unique_lock<AZStd::mutex> lock(m_activeTerrainJobContextMutex);
m_activeTerrainJobContexts.erase(AZStd::find(m_activeTerrainJobContexts.begin(),
m_activeTerrainJobContexts.end(),
jobContext));
m_activeTerrainJobContextMutexConditionVariable.notify_one();
}
}
};
// Create the job and start it immediately.
AZ::Job* processJob = AZ::CreateJobFunction(jobFunction, true, jobContext.get());
processJob->Start();
}
return jobContext;
}
template<typename SynchronousFunctionType>
inline AZStd::shared_ptr<AzFramework::Terrain::TerrainDataRequests::TerrainJobContext> TerrainSystem::ProcessFromRegionAsync(
SynchronousFunctionType synchronousFunction,
const AZ::Aabb& inRegion,
const AZ::Vector2& stepSize,
AzFramework::Terrain::SurfacePointRegionFillCallback perPositionCallback,
Sampler sampleFilter,
AZStd::shared_ptr<ProcessAsyncParams> params) const
{
// ToDo: Determine the number of jobs to split the work into based on:
// 1. The number of available worker threads.
// 2. The desired number of jobs as passed in.
// 3. The size of the area being processed.
//
// Note: We are currently restricting the number of worker threads to one
// because splitting the work over multiple threads causes contention when
// locking various mutexes, resulting in slower overall wall time for async
// requests split over multiple threads vs one where all the work is done on
// a single thread. The latter is still preferable over a regular synchronous
// call because it is just as quick and prevents the main thread from blocking.
// Once the mutex contention issues have been addressed, we should come up with
// an algorithm to break up 'inRegion' into sub-regions (or lists of positions?)
// so that async calls automatically split the work between available job manager
// worker threads, unless the ProcessAsyncParams specifiy a desired number of jobs.
const int32_t numWorkerThreads = m_terrainJobManager->GetNumWorkerThreads();
const int32_t numJobsDesired = params ? params->m_desiredNumberOfJobs : ProcessAsyncParams::NumJobsDefault;
int32_t numJobs = (numJobsDesired > 0) ? AZStd::min(numWorkerThreads, numJobsDesired) : numWorkerThreads;
if (numJobs != 1)
{
// Temp until we figure out how to break up the region.
AZ_Warning("TerrainSystem", false, "We don't yet support breaking up regions.");
numJobs = 1;
}
// Create a terrain job context and split the work across multiple jobs.
AZStd::shared_ptr<TerrainJobContext> jobContext = AZStd::make_shared<TerrainJobContext>(*m_terrainJobManager, numJobs);
{
AZStd::unique_lock<AZStd::mutex> lock(m_activeTerrainJobContextMutex);
m_activeTerrainJobContexts.push_back(jobContext);
}
for (int32_t i = 0; i < numJobs; ++i)
{
// Define the job function using the sub region of positions to process.
const AZ::Aabb& subRegion = inRegion; // ToDo: Figure out how to break up the region.
auto jobFunction = [this, synchronousFunction, subRegion, stepSize, perPositionCallback, sampleFilter, jobContext, params]()
{
// Process the sub region of positions, unless the associated job context has been cancelled.
if (!jobContext->IsCancelled())
{
synchronousFunction(subRegion, stepSize, perPositionCallback, sampleFilter);
}
// Decrement the number of completions remaining, invoke the completion callback if this happens
// to be the final job completed, and remove this TerrainJobContext from the list of active ones.
const bool wasLastJobCompleted = jobContext->OnJobCompleted();
if (wasLastJobCompleted)
{
if (params && params->m_completionCallback)
{
params->m_completionCallback(jobContext);
}
{
AZStd::unique_lock<AZStd::mutex> lock(m_activeTerrainJobContextMutex);
m_activeTerrainJobContexts.erase(AZStd::find(m_activeTerrainJobContexts.begin(),
m_activeTerrainJobContexts.end(),
jobContext));
m_activeTerrainJobContextMutexConditionVariable.notify_one();
}
}
};
// Create the job and start it immediately.
AZ::Job* processJob = AZ::CreateJobFunction(jobFunction, true, jobContext.get());
processJob->Start();
}
return jobContext;
}
} // namespace Terrain