JoltPhysics/Samples/Tests/Tools/LoadSnapshotTest.cpp

// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
// SPDX-License-Identifier: MIT

#include <TestFramework.h>

#include <Tests/Tools/LoadSnapshotTest.h>
#include <Jolt/Physics/PhysicsScene.h>
#include <Jolt/Core/StreamWrapper.h>
#include <Application/DebugUI.h>
#include <Utils/Log.h>
#include <Layers.h>
#include <fstream>

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

void LoadSnapshotTest::Initialize()
{
	ifstream stream("snapshot.bin", ifstream::in | ifstream::binary);
	if (!stream.is_open()) 
		FatalError("Unable to open 'snapshot.bin'");

	StreamInWrapper wrapper(stream);
	PhysicsScene::PhysicsSceneResult result = PhysicsScene::sRestoreFromBinaryState(wrapper);
	if (result.HasError())
		FatalError(result.GetError().c_str());
	Ref<PhysicsScene> scene = result.Get();

	// Determine quaternion that rotates the world so that up is Y
	Quat up_rotation;
	switch (sUpAxis)
	{
	case 0:		up_rotation = Quat::sRotation(Vec3::sAxisZ(), 0.5f * JPH_PI);	break;
	case 2:		up_rotation = Quat::sRotation(Vec3::sAxisX(), -0.5f * JPH_PI);	break;
	default:	up_rotation = Quat::sIdentity();								break;
	}

	for (BodyCreationSettings &settings : scene->GetBodies())
	{
		if (sOverrideLayers)
		{
			// Override the layer so that all static objects are in the non-moving layer and everything else is in the moving layer
			if (settings.mMotionType == EMotionType::Static)
				settings.mObjectLayer = Layers::NON_MOVING;
			else
				settings.mObjectLayer = Layers::MOVING;
		}

		// Rotate the body so that it matches Y is up
		settings.mPosition = up_rotation * settings.mPosition;
		settings.mRotation = up_rotation * settings.mRotation;
	}

	scene->CreateBodies(mPhysicsSystem);
}

void LoadSnapshotTest::CreateSettingsMenu(DebugUI *inUI, UIElement *inSubMenu)
{
	inUI->CreateComboBox(inSubMenu, "Up Axis", { "X", "Y", "Z" }, sUpAxis, [](int inItem) { sUpAxis = inItem; });
	inUI->CreateCheckBox(inSubMenu, "Override Object Layers", sOverrideLayers, [](UICheckBox::EState inState) { sOverrideLayers = inState == UICheckBox::STATE_CHECKED; });
	inUI->CreateTextButton(inSubMenu, "Accept Changes", [=]() { RestartTest(); });
}