// Copyright (C) 2009-2022, Panagiotis Christopoulos Charitos and contributors.
// All rights reserved.
// Code licensed under the BSD License.
// http://www.anki3d.org/LICENSE

#include <AnKi/Scene/Components/ReflectionProbeComponent.h>
#include <AnKi/Scene/Components/MoveComponent.h>
#include <AnKi/Scene/SceneGraph.h>
#include <AnKi/Scene/SceneNode.h>
#include <AnKi/Core/ConfigSet.h>

namespace anki {

ReflectionProbeComponent::ReflectionProbeComponent(SceneNode* node)
	: SceneComponent(node, getStaticClassId())
	, m_uuid(node->getSceneGraph().getNewUuid())
	, m_spatial(this)
{
	m_worldPos = node->getWorldTransform().getOrigin().xyz();

	for(U32 i = 0; i < 6; ++i)
	{
		m_frustums[i].init(FrustumType::kPerspective, &node->getMemoryPool());
		m_frustums[i].setPerspective(kClusterObjectFrustumNearPlane, 100.0f, kPi / 2.0f, kPi / 2.0f);
		m_frustums[i].setWorldTransform(
			Transform(m_worldPos.xyz0(), Frustum::getOmnidirectionalFrustumRotations()[i], 1.0f));
		m_frustums[i].setShadowCascadeCount(1);
		m_frustums[i].update();
	}
}

ReflectionProbeComponent::~ReflectionProbeComponent()
{
}

Error ReflectionProbeComponent::update(SceneComponentUpdateInfo& info, Bool& updated)
{
	const Bool moved = info.m_node->movedThisFrame();
	const Bool shapeUpdated = m_dirty;
	m_dirty = false;
	updated = moved || shapeUpdated;

	if(moved) [[unlikely]]
	{
		m_worldPos = info.m_node->getWorldTransform().getOrigin().xyz();

		for(U32 i = 0; i < 6; ++i)
		{
			m_frustums[i].setWorldTransform(
				Transform(m_worldPos.xyz0(), Frustum::getOmnidirectionalFrustumRotations()[i], 1.0f));
		}
	}

	if(shapeUpdated) [[unlikely]]
	{
		F32 effectiveDistance = max(m_halfSize.x(), m_halfSize.y());
		effectiveDistance = max(effectiveDistance, m_halfSize.z());
		effectiveDistance =
			max(effectiveDistance, getExternalSubsystems(*info.m_node).m_config->getSceneProbeEffectiveDistance());

		const F32 shadowCascadeDistance = min(
			effectiveDistance, getExternalSubsystems(*info.m_node).m_config->getSceneProbeShadowEffectiveDistance());

		for(U32 i = 0; i < 6; ++i)
		{
			m_frustums[i].setFar(effectiveDistance);
			m_frustums[i].setShadowCascadeDistance(0, shadowCascadeDistance);

			// Add something really far to force LOD 0 to be used. The importing tools create LODs with holes some times
			// and that causes the sky to bleed to GI rendering
			m_frustums[i].setLodDistances({effectiveDistance - 3.0f * kEpsilonf, effectiveDistance - 2.0f * kEpsilonf,
										   effectiveDistance - 1.0f * kEpsilonf});
		}
	}

	if(updated) [[unlikely]]
	{
		// Set a new UUID to force the renderer to update the probe
		m_uuid = info.m_node->getSceneGraph().getNewUuid();

		for(U32 i = 0; i < 6; ++i)
		{
			m_frustums[i].update();
		}

		Aabb aabbWorld(-m_halfSize + m_worldPos, m_halfSize + m_worldPos);
		m_spatial.setBoundingShape(aabbWorld);
		m_spatial.update(info.m_node->getSceneGraph().getOctree());
	}

	return Error::kNone;
}

} // end namespace anki