JoltPhysics/Samples/Tests/SoftBody/SoftBodyContactListenerTest.cpp

// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2024 Jorrit Rouwe
// SPDX-License-Identifier: MIT

#include <TestFramework.h>

#include <Tests/SoftBody/SoftBodyContactListenerTest.h>
#include <Jolt/Physics/Body/BodyCreationSettings.h>
#include <Jolt/Physics/SoftBody/SoftBodyCreationSettings.h>
#include <Jolt/Physics/SoftBody/SoftBodyManifold.h>
#include <Jolt/Physics/Collision/Shape/SphereShape.h>
#include <Utils/SoftBodyCreator.h>
#include <Renderer/DebugRendererImp.h>
#include <Layers.h>

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

void SoftBodyContactListenerTest::Initialize()
{
	// Install contact listener for soft bodies
	mPhysicsSystem->SetSoftBodyContactListener(this);

	// Floor
	CreateFloor();

	// Start the 1st cycle
	StartCycle();
}

void SoftBodyContactListenerTest::PrePhysicsUpdate(const PreUpdateParams &inParams)
{
	mTime += inParams.mDeltaTime;
	if (mTime > 2.5f)
	{
		// Next cycle
		mCycle = (mCycle + 1) % 7;
		mTime = 0.0f;

		// Remove the old scene
		mBodyInterface->RemoveBody(mOtherBodyID);
		mBodyInterface->DestroyBody(mOtherBodyID);
		mBodyInterface->RemoveBody(mSoftBodyID);
		mBodyInterface->DestroyBody(mSoftBodyID);

		// Start the new
		StartCycle();
	}

	// Draw current state
	const char *cycle_names[] = { "Accept contact", "Sphere 10x mass", "Cloth 10x mass", "Sphere infinite mass", "Cloth infinite mass", "Sensor contact", "Reject contact" };
	mDebugRenderer->DrawText3D(mBodyInterface->GetPosition(mOtherBodyID), cycle_names[mCycle], Color::sWhite, 1.0f);
}

void SoftBodyContactListenerTest::StartCycle()
{
	// Create the cloth
	Ref<SoftBodySharedSettings> cloth_settings = SoftBodyCreator::CreateClothWithFixatedCorners(15, 15, 0.75f);

	// Create cloth that's fixated at the corners
	SoftBodyCreationSettings cloth(cloth_settings, RVec3(0, 5, 0), Quat::sRotation(Vec3::sAxisY(), 0.25f * JPH_PI), Layers::MOVING);
	cloth.mUpdatePosition = false; // Don't update the position of the cloth as it is fixed to the world
	cloth.mMakeRotationIdentity = false; // Test explicitly checks if soft bodies with a rotation collide with shapes properly
	mSoftBodyID = mBodyInterface->CreateAndAddSoftBody(cloth, EActivation::Activate);

	// Create sphere
	BodyCreationSettings bcs(new SphereShape(1.0f), RVec3(0, 7, 0), Quat::sIdentity(), EMotionType::Dynamic, Layers::MOVING);
	bcs.mOverrideMassProperties = EOverrideMassProperties::CalculateInertia;
	bcs.mMassPropertiesOverride.mMass = 100.0f;
	mOtherBodyID = mBodyInterface->CreateAndAddBody(bcs, EActivation::Activate);
}

SoftBodyValidateResult SoftBodyContactListenerTest::OnSoftBodyContactValidate(const Body &inSoftBody, const Body &inOtherBody, SoftBodyContactSettings &ioSettings)
{
	switch (mCycle)
	{
	case 0:
		// Normal
		return SoftBodyValidateResult::AcceptContact;

	case 1:
		// Makes the sphere 10x as heavy
		ioSettings.mInvMassScale2 = 0.1f;
		ioSettings.mInvInertiaScale2 = 0.1f;
		return SoftBodyValidateResult::AcceptContact;

	case 2:
		// Makes the cloth 10x as heavy
		ioSettings.mInvMassScale1 = 0.1f;
		return SoftBodyValidateResult::AcceptContact;

	case 3:
		// Makes the sphere have infinite mass
		ioSettings.mInvMassScale2 = 0.0f;
		ioSettings.mInvInertiaScale2 = 0.0f;
		return SoftBodyValidateResult::AcceptContact;

	case 4:
		// Makes the cloth have infinite mass
		ioSettings.mInvMassScale1 = 0.0f;
		return SoftBodyValidateResult::AcceptContact;

	case 5:
		// Sensor contact
		ioSettings.mIsSensor = true;
		return SoftBodyValidateResult::AcceptContact;

	default:
		// No contacts
		return SoftBodyValidateResult::RejectContact;
	}
}

void SoftBodyContactListenerTest::OnSoftBodyContactAdded(const Body &inSoftBody, const SoftBodyManifold &inManifold)
{
	// Draw contacts
	RMat44 com = inSoftBody.GetCenterOfMassTransform();
	for (const SoftBodyVertex &vertex : inManifold.GetVertices())
		if (inManifold.HasContact(vertex))
		{
			RVec3 position = com * inManifold.GetLocalContactPoint(vertex);
			Vec3 normal = inManifold.GetContactNormal(vertex);
			mDebugRenderer->DrawMarker(position, Color::sRed, 0.1f);
			mDebugRenderer->DrawArrow(position, position + normal, Color::sGreen, 0.1f);
		}
}