Created 2D example (#378)

Samples/Samples.cmake

@@ -123,6 +123,8 @@ set(SAMPLES_SRC_FILES
 	${SAMPLES_ROOT}/Tests/General/SimpleTest.h
 	${SAMPLES_ROOT}/Tests/General/StackTest.cpp
 	${SAMPLES_ROOT}/Tests/General/StackTest.h
+	${SAMPLES_ROOT}/Tests/General/TwoDFunnelTest.cpp
+	${SAMPLES_ROOT}/Tests/General/TwoDFunnelTest.h
 	${SAMPLES_ROOT}/Tests/General/WallTest.cpp
 	${SAMPLES_ROOT}/Tests/General/WallTest.h
 	${SAMPLES_ROOT}/Tests/General/ActivateDuringUpdateTest.cpp

Samples/SamplesApp.cpp

@@ -90,6 +90,7 @@ JPH_DECLARE_RTTI_FOR_FACTORY(ContactListenerTest)
 JPH_DECLARE_RTTI_FOR_FACTORY(ActivateDuringUpdateTest)
 JPH_DECLARE_RTTI_FOR_FACTORY(SensorTest)
 JPH_DECLARE_RTTI_FOR_FACTORY(DynamicMeshTest)
+JPH_DECLARE_RTTI_FOR_FACTORY(TwoDFunnelTest)
 
 static TestNameAndRTTI sGeneralTests[] =
 {
@@ -98,6 +99,7 @@ static TestNameAndRTTI sGeneralTests[] =
 	{ "Wall",								JPH_RTTI(WallTest) },
 	{ "Island",								JPH_RTTI(IslandTest) },
 	{ "Funnel",								JPH_RTTI(FunnelTest) },
+	{ "2D Funnel",							JPH_RTTI(TwoDFunnelTest) },
 	{ "Friction",							JPH_RTTI(FrictionTest) },
 	{ "Friction (Per Triangle)",			JPH_RTTI(FrictionPerTriangleTest) },
 	{ "Gravity Factor",						JPH_RTTI(GravityFactorTest) },

Samples/Tests/General/TwoDFunnelTest.cpp

@@ -0,0 +1,65 @@
+// SPDX-FileCopyrightText: 2022 Jorrit Rouwe
+// SPDX-License-Identifier: MIT
+
+#include <TestFramework.h>
+
+#include <Tests/General/TwoDFunnelTest.h>
+#include <Jolt/Physics/Collision/Shape/BoxShape.h>
+#include <Jolt/Physics/Collision/Shape/SphereShape.h>
+#include <Jolt/Physics/Collision/Shape/CapsuleShape.h>
+#include <Jolt/Physics/Constraints/SixDOFConstraint.h>
+#include <Jolt/Physics/Body/BodyCreationSettings.h>
+#include <Layers.h>
+
+JPH_IMPLEMENT_RTTI_VIRTUAL(TwoDFunnelTest) 
+{ 
+	JPH_ADD_BASE_CLASS(TwoDFunnelTest, Test) 
+}
+
+void TwoDFunnelTest::Initialize()
+{
+	// Floor
+	CreateFloor();
+
+	// 2D funnel
+	RefConst<Shape> wall = new BoxShape(Vec3(0.1f, 10, 1));
+	mBodyInterface->CreateAndAddBody(BodyCreationSettings(wall, RVec3(-12, 8, 0), Quat::sRotation(Vec3::sAxisZ(), 0.2f * JPH_PI), EMotionType::Static, Layers::NON_MOVING), EActivation::DontActivate);
+	mBodyInterface->CreateAndAddBody(BodyCreationSettings(wall, RVec3(12, 8, 0), Quat::sRotation(Vec3::sAxisZ(), -0.2f * JPH_PI), EMotionType::Static, Layers::NON_MOVING), EActivation::DontActivate);
+
+	// Shapes falling in 2D funnel
+	Ref<Shape> shapes[] = {
+		new SphereShape(0.5f),
+		new BoxShape(Vec3::sReplicate(0.5f)),
+		new CapsuleShape(0.2f, 0.3f)
+	};
+
+	// Constraint to limit motion in XY plane
+	SixDOFConstraintSettings constraint_settings;
+	constraint_settings.MakeFreeAxis(SixDOFConstraintSettings::EAxis::RotationX); // Don't limit, we use inertia tensor to limit rotation
+	constraint_settings.MakeFreeAxis(SixDOFConstraintSettings::EAxis::RotationY); // Don't limit, we use inertia tensor to limit rotation
+	constraint_settings.MakeFreeAxis(SixDOFConstraintSettings::EAxis::RotationZ);
+	constraint_settings.MakeFreeAxis(SixDOFConstraintSettings::EAxis::TranslationX);
+	constraint_settings.MakeFreeAxis(SixDOFConstraintSettings::EAxis::TranslationY);
+	constraint_settings.MakeFixedAxis(SixDOFConstraintSettings::EAxis::TranslationZ); // Don't allow movement in Z direction
+
+	BodyCreationSettings bcs(shapes[0], RVec3::sZero(), Quat::sIdentity(), EMotionType::Dynamic, Layers::MOVING);
+	for (int x = 0; x < 20; ++x)
+		for (int y = 0; y < 10; ++y)
+		{
+			// Create body
+			bcs.SetShape(shapes[(x * y) % size(shapes)]);
+			bcs.mPosition = RVec3(-10.0_r + x, 10.0_r + y, 0);
+			Body &body = *mBodyInterface->CreateBody(bcs);			
+			mBodyInterface->AddBody(body.GetID(), EActivation::Activate);
+
+			// Constraint the body to the XY plane
+			TwoBodyConstraint *constraint = constraint_settings.Create(Body::sFixedToWorld, body);
+			mPhysicsSystem->AddConstraint(constraint);
+
+			// Update the mass properties for this body to make it rotate only around Z
+			MassProperties mass_properties = bcs.GetShape()->GetMassProperties();
+			MotionProperties *mp = body.GetMotionProperties();
+			mp->SetInverseMass(1.0f / mass_properties.mMass);
+			mp->SetInverseInertia(Vec3(0, 0, 1.0f / mass_properties.mInertia.GetAxisZ().Length()), Quat::sIdentity());
+		}
+}

Samples/Tests/General/TwoDFunnelTest.h

@@ -0,0 +1,16 @@
+// SPDX-FileCopyrightText: 2022 Jorrit Rouwe
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include <Tests/Test.h>
+
+// This is a test that shows how to create a 2D simulation
+class TwoDFunnelTest : public Test
+{
+public:
+	JPH_DECLARE_RTTI_VIRTUAL(TwoDFunnelTest)
+
+	// See: Test
+	virtual void		Initialize() override;
+};