JoltPhysics/Samples/Tests/General/ChangeMotionTypeTest.cpp

// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
// SPDX-License-Identifier: MIT

#include <TestFramework.h>

#include <Tests/General/ChangeMotionTypeTest.h>
#include <Jolt/Physics/Collision/Shape/BoxShape.h>
#include <Jolt/Physics/Collision/Shape/SphereShape.h>
#include <Jolt/Physics/Body/BodyCreationSettings.h>
#include <Layers.h>

JPH_IMPLEMENT_RTTI_VIRTUAL(ChangeMotionTypeTest)
{
	JPH_ADD_BASE_CLASS(ChangeMotionTypeTest, Test)
}

void ChangeMotionTypeTest::Initialize()
{
	// Floor
	CreateFloor();

	// Create body as static, but allow to become dynamic
	BodyCreationSettings settings;
	settings.SetShape(new BoxShape(Vec3(0.5f, 1.0f, 2.0f)));
	settings.mPosition = RVec3(0, 10, 0);
	settings.mMotionType = EMotionType::Static;
	settings.mObjectLayer = Layers::MOVING; // Put in moving layer, this will result in some overhead when the body is static
	settings.mAllowDynamicOrKinematic = true;
	mBody = mBodyInterface->CreateBody(settings);
	mBodyInterface->AddBody(mBody->GetID(), EActivation::Activate);

	UpdateMotionType();
}

void ChangeMotionTypeTest::UpdateMotionType()
{
	static const EMotionType cycle[] = { EMotionType::Dynamic, EMotionType::Kinematic, EMotionType::Static, EMotionType::Kinematic, EMotionType::Dynamic, EMotionType::Static };
	static const char *label[] = { "Dynamic", "Kinematic", "Static", "Kinematic", "Dynamic", "Static" };

	// Calculate desired motion type
	int idx = int(mTime) % size(cycle);
	EMotionType motion_type = cycle[idx];

	// Update motion type and reactivate the body
	if (motion_type != mBody->GetMotionType())
	{
		mBodyInterface->SetMotionType(mBody->GetID(), motion_type, EActivation::Activate);
		SetBodyLabel(mBody->GetID(), label[idx]);
	}
}

void ChangeMotionTypeTest::PrePhysicsUpdate(const PreUpdateParams &inParams)
{
	// Increment time
	mTime += inParams.mDeltaTime;

	UpdateMotionType();

	// Provide kinematic body a target
	if (mBody->IsKinematic())
		mBody->MoveKinematic(RVec3(Sin(mTime), 10, 0), Quat::sRotation(Vec3::sAxisX(), Cos(mTime)), inParams.mDeltaTime);
}

void ChangeMotionTypeTest::SaveState(StateRecorder &inStream) const
{
	inStream.Write(mTime);
}

void ChangeMotionTypeTest::RestoreState(StateRecorder &inStream)
{
	inStream.Read(mTime);

	UpdateMotionType();
}