JoltPhysics/PerformanceTest/Layers.h

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

#pragma once

#include <Jolt/Physics/Collision/ObjectLayer.h>
#include <Jolt/Physics/Collision/BroadPhase/BroadPhaseLayer.h>

/// Layer that objects can be in, determines which other objects it can collide with
namespace Layers
{
	static constexpr uint8 NON_MOVING = 0;
	static constexpr uint8 MOVING = 1;
	static constexpr uint8 NUM_LAYERS = 2;
};

/// Function that determines if two object layers can collide
inline bool ObjectCanCollide(ObjectLayer inObject1, ObjectLayer inObject2)
{
	switch (inObject1)
	{
	case Layers::NON_MOVING:
		return inObject2 == Layers::MOVING; // Non moving only collides with moving
	case Layers::MOVING:
		return true; // Moving collides with everything
	default:
		JPH_ASSERT(false);
		return false;
	}
};

/// Broadphase layers
namespace BroadPhaseLayers
{
	static constexpr BroadPhaseLayer NON_MOVING(0);
	static constexpr BroadPhaseLayer MOVING(1);
	static constexpr uint NUM_LAYERS(2);
};

/// BroadPhaseLayerInterface implementation
class BPLayerInterfaceImpl final : public BroadPhaseLayerInterface
{
public:
									BPLayerInterfaceImpl()
	{
		// Create a mapping table from object to broad phase layer
		mObjectToBroadPhase[Layers::NON_MOVING] = BroadPhaseLayers::NON_MOVING;
		mObjectToBroadPhase[Layers::MOVING] = BroadPhaseLayers::MOVING;
	}

	virtual uint					GetNumBroadPhaseLayers() const override
	{
		return BroadPhaseLayers::NUM_LAYERS;
	}

	virtual BroadPhaseLayer			GetBroadPhaseLayer(ObjectLayer inLayer) const override
	{
		JPH_ASSERT(inLayer < Layers::NUM_LAYERS);
		return mObjectToBroadPhase[inLayer];
	}

#if defined(JPH_EXTERNAL_PROFILE) || defined(JPH_PROFILE_ENABLED)
	virtual const char *			GetBroadPhaseLayerName(BroadPhaseLayer inLayer) const override
	{
		switch ((BroadPhaseLayer::Type)inLayer)
		{
		case (BroadPhaseLayer::Type)BroadPhaseLayers::NON_MOVING:	return "NON_MOVING";
		case (BroadPhaseLayer::Type)BroadPhaseLayers::MOVING:		return "MOVING";
		default:													JPH_ASSERT(false); return "INVALID";
		}
	}
#endif // JPH_EXTERNAL_PROFILE || JPH_PROFILE_ENABLED

private:
	BroadPhaseLayer					mObjectToBroadPhase[Layers::NUM_LAYERS];
};

/// Function that determines if two broadphase layers can collide
inline bool BroadPhaseCanCollide(ObjectLayer inLayer1, BroadPhaseLayer inLayer2)
{
	switch (inLayer1)
	{
	case Layers::NON_MOVING:
		return inLayer2 == BroadPhaseLayers::MOVING;
	case Layers::MOVING:
		return true;	
	default:
		JPH_ASSERT(false);
		return false;
	}
}