UnrealEngineUWP/Engine/Source/Editor/AnimGraph/Private/EditModes/TwoBoneIKEditMode.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include "EditModes/TwoBoneIKEditMode.h"
#include "SceneManagement.h"
#include "EngineUtils.h"
#include "IPersonaPreviewScene.h"
#include "Animation/DebugSkelMeshComponent.h"

struct HTwoBoneIKProxy : public HHitProxy
{
	DECLARE_HIT_PROXY();

	HTwoBoneIKProxy(FTwoBoneIKEditMode::BoneSelectModeType InBoneSelectMode)
		: HHitProxy(HPP_Wireframe)
		, BoneSelectMode(InBoneSelectMode)
	{}

	virtual EMouseCursor::Type GetMouseCursor() override
	{
		return EMouseCursor::Crosshairs;
	}

	FTwoBoneIKEditMode::BoneSelectModeType BoneSelectMode;
};

IMPLEMENT_HIT_PROXY(HTwoBoneIKProxy, HHitProxy);

FTwoBoneIKEditMode::FTwoBoneIKEditMode()
	: TwoBoneIKRuntimeNode(nullptr)
	, TwoBoneIKGraphNode(nullptr)
	, BoneSelectMode(BSM_EndEffector)
	, PreviousBoneSpace(BCS_BoneSpace)
{
}

void FTwoBoneIKEditMode::EnterMode(UAnimGraphNode_Base* InEditorNode, FAnimNode_Base* InRuntimeNode)
{
	TwoBoneIKRuntimeNode = static_cast<FAnimNode_TwoBoneIK*>(InRuntimeNode);
	TwoBoneIKGraphNode = CastChecked<UAnimGraphNode_TwoBoneIK>(InEditorNode);

	NodePropertyDelegateHandle = TwoBoneIKGraphNode->OnNodePropertyChanged().AddSP(this, &FTwoBoneIKEditMode::OnExternalNodePropertyChange);
	PreviousBoneSpace = TwoBoneIKGraphNode->Node.EffectorLocationSpace;

	FAnimNodeEditMode::EnterMode(InEditorNode, InRuntimeNode);
}

void FTwoBoneIKEditMode::ExitMode()
{
	TwoBoneIKGraphNode->OnNodePropertyChanged().Remove(NodePropertyDelegateHandle);

	TwoBoneIKGraphNode = nullptr;
	TwoBoneIKRuntimeNode = nullptr;

	FAnimNodeEditMode::ExitMode();
}

void FTwoBoneIKEditMode::Render(const FSceneView* View, FViewport* Viewport, FPrimitiveDrawInterface* PDI)
{
	USkeletalMeshComponent* SkelMeshComp = GetAnimPreviewScene().GetPreviewMeshComponent();
	if (SkelMeshComp && SkelMeshComp->SkeletalMesh && SkelMeshComp->SkeletalMesh->GetSkeleton())
	{
		USkeleton* Skeleton = SkelMeshComp->SkeletalMesh->GetSkeleton();

		PDI->SetHitProxy(new HTwoBoneIKProxy(BSM_EndEffector));
		DrawTargetLocation(PDI, BSM_EndEffector, FColor(255, 128, 128), FColor(180, 128, 128));
		PDI->SetHitProxy(new HTwoBoneIKProxy(BSM_JointTarget));
		DrawTargetLocation(PDI, BSM_JointTarget, FColor(128, 255, 128), FColor(128, 180, 128));
		PDI->SetHitProxy(nullptr);
	}

	FAnimNodeEditMode::Render(View, Viewport, PDI);
}

void FTwoBoneIKEditMode::DrawTargetLocation(FPrimitiveDrawInterface* PDI, BoneSelectModeType InBoneSelectMode, const FColor& TargetColor, const FColor& BoneColor) const
{
	EBoneControlSpace SpaceBase;
	if (InBoneSelectMode == BSM_EndEffector)
	{
		SpaceBase = TwoBoneIKRuntimeNode->EffectorLocationSpace;
	}
	else // BSM_JointTarget
	{
		SpaceBase = TwoBoneIKRuntimeNode->JointTargetLocationSpace;
	}

	const bool bInBoneSpace = (SpaceBase == BCS_ParentBoneSpace) || (SpaceBase == BCS_BoneSpace);
	FVector Location = GetWidgetLocation(InBoneSelectMode);
	FMatrix Matrix = FTransform(Location).ToMatrixNoScale();

	DrawCoordinateSystem( PDI, Location, FRotator::ZeroRotator, 20.f, SDPG_Foreground );
	DrawWireDiamond( PDI, Matrix, 4.f, bInBoneSpace ? BoneColor : TargetColor, SDPG_Foreground );
}

FVector FTwoBoneIKEditMode::GetWidgetLocation(BoneSelectModeType InBoneSelectMode) const
{
	EBoneControlSpace Space;
	FVector Location;
	FBoneSocketTarget Target;

	if (InBoneSelectMode == BSM_EndEffector)
	{
		Space = TwoBoneIKRuntimeNode->EffectorLocationSpace;
		Location = TwoBoneIKRuntimeNode->EffectorLocation;
		Target = TwoBoneIKRuntimeNode->EffectorTarget;
	}
	else // BSM_JointTarget
	{
		Space = TwoBoneIKRuntimeNode->JointTargetLocationSpace;
		Location = TwoBoneIKRuntimeNode->JointTargetLocation;
		Target = TwoBoneIKRuntimeNode->JointTarget;
	}

	USkeletalMeshComponent* SkelComp = GetAnimPreviewScene().GetPreviewMeshComponent();

	// Make sure Node has had a chance to evaluate and cache a pose.
	if (TwoBoneIKRuntimeNode->ForwardedPose.GetPose().GetNumBones() > 0)
	{
		return ConvertWidgetLocation(SkelComp, TwoBoneIKRuntimeNode->ForwardedPose, Target, Location, Space);
	}
	else
	{
		return SkelComp->GetComponentTransform().GetLocation();
	}
}

FVector FTwoBoneIKEditMode::GetWidgetLocation() const
{
	return GetWidgetLocation(BoneSelectMode);
}

UE::Widget::EWidgetMode FTwoBoneIKEditMode::GetWidgetMode() const
{
	int32 BoneIndex = GetAnimPreviewScene().GetPreviewMeshComponent()->GetBoneIndex(TwoBoneIKGraphNode->Node.IKBone.BoneName);
	// Two bone IK node uses only Translate
	if (BoneIndex != INDEX_NONE)
	{
		return UE::Widget::WM_Translate;
	}

	return UE::Widget::WM_None;
}

FBoneSocketTarget FTwoBoneIKEditMode::GetSelectedTarget() const
{
	// should return mesh bone index
	if (BoneSelectMode == BSM_EndEffector)
	{
		if (TwoBoneIKRuntimeNode->EffectorLocationSpace == EBoneControlSpace::BCS_BoneSpace ||
			TwoBoneIKRuntimeNode->EffectorLocationSpace == EBoneControlSpace::BCS_ParentBoneSpace)
		{
			return TwoBoneIKRuntimeNode->EffectorTarget;
		}

	}
	else if (BoneSelectMode == BSM_JointTarget)
	{
		if (TwoBoneIKRuntimeNode->JointTargetLocationSpace == EBoneControlSpace::BCS_BoneSpace ||
			TwoBoneIKRuntimeNode->JointTargetLocationSpace == EBoneControlSpace::BCS_ParentBoneSpace)
		{
			return TwoBoneIKRuntimeNode->JointTarget;
		}
	}

	return FBoneSocketTarget();
}

bool FTwoBoneIKEditMode::HandleClick(FEditorViewportClient* InViewportClient, HHitProxy* HitProxy, const FViewportClick& Click)
{
	bool bResult = FAnimNodeEditMode::HandleClick(InViewportClient, HitProxy, Click);

	if (HitProxy != nullptr && HitProxy->IsA(HTwoBoneIKProxy::StaticGetType()))
	{
		HTwoBoneIKProxy* TwoBoneIKHitProxy = static_cast<HTwoBoneIKProxy*>(HitProxy);
		BoneSelectMode = TwoBoneIKHitProxy->BoneSelectMode;
		bResult = true;
	}

	return bResult;
}

void FTwoBoneIKEditMode::Tick(FEditorViewportClient* ViewportClient, float DeltaTime)
{
	FAnimNodeEditMode::Tick(ViewportClient, DeltaTime);

	// Cache the current bone space
	PreviousBoneSpace = TwoBoneIKGraphNode->Node.EffectorLocationSpace;
}

void FTwoBoneIKEditMode::OnExternalNodePropertyChange(FPropertyChangedEvent& InPropertyEvent)
{
	USkeletalMeshComponent* SkelComponent = GetAnimPreviewScene().GetPreviewMeshComponent();

	if(!SkelComponent)
	{
		// Can't do anything below without the component
		return;
	}

	// @todo: talk to tom s about this - to do discuss
	// this code doesn't really work great unless you have very specific order of operation is happening
	// 
/*
	FProperty* Property = InPropertyEvent.Property;
	FProperty* InnerProperty = InPropertyEvent.MemberProperty;
	
	if(InnerProperty && InnerProperty->GetFName() == GET_MEMBER_NAME_CHECKED(UAnimGraphNode_TwoBoneIK, Node))
	{
		if(Property && Property->GetFName() == GET_MEMBER_NAME_CHECKED(FAnimNode_TwoBoneIK, EffectorLocationSpace))
		{
			if(TwoBoneIKGraphNode->Node.EffectorLocationSpace == BCS_BoneSpace || TwoBoneIKGraphNode->Node.EffectorLocationSpace == BCS_ParentBoneSpace)
			{
				// Moving to bone space, to actually do this we would need the transform at the node before the
				// one we're editing... We can't do that so just reset the transform.
				TwoBoneIKRuntimeNode->EffectorLocationSpace = TwoBoneIKGraphNode->Node.EffectorLocationSpace;
				TwoBoneIKRuntimeNode->EffectorLocation = FVector::ZeroVector;
				TwoBoneIKGraphNode->SetDefaultValue(GET_MEMBER_NAME_STRING_CHECKED(FAnimNode_TwoBoneIK, EffectorLocation), TwoBoneIKRuntimeNode->EffectorLocation);
			}
			else
			{
				// Need to convert our transform into world/component space
				FTransform CurrentTransform = FTransform(GetWidgetLocation());
				FTransform NewBSTransform;

				ConvertToBoneSpaceTransform(SkelComponent, CurrentTransform, NewBSTransform, TwoBoneIKGraphNode->Node.EffectorTarget, TwoBoneIKGraphNode->Node.EffectorLocationSpace);

				TwoBoneIKRuntimeNode->EffectorLocationSpace = TwoBoneIKGraphNode->Node.EffectorLocationSpace;
				TwoBoneIKRuntimeNode->EffectorLocation = NewBSTransform.GetLocation();

				TwoBoneIKGraphNode->SetDefaultValue(GET_MEMBER_NAME_STRING_CHECKED(FAnimNode_TwoBoneIK, EffectorLocation), TwoBoneIKRuntimeNode->EffectorLocation);
			}
		}
	}*/
}

void FTwoBoneIKEditMode::DoTranslation(FVector& InTranslation)
{
	USkeletalMeshComponent* SkelComp = GetAnimPreviewScene().GetPreviewMeshComponent();

	if (BoneSelectMode == BSM_EndEffector)
	{
		FVector Offset = ConvertCSVectorToBoneSpace(SkelComp, InTranslation, TwoBoneIKRuntimeNode->ForwardedPose, GetSelectedTarget(), TwoBoneIKGraphNode->Node.EffectorLocationSpace);

		TwoBoneIKRuntimeNode->EffectorLocation += Offset;
		TwoBoneIKGraphNode->Node.EffectorLocation = TwoBoneIKRuntimeNode->EffectorLocation;
		TwoBoneIKGraphNode->SetDefaultValue(GET_MEMBER_NAME_STRING_CHECKED(FAnimNode_TwoBoneIK, EffectorLocation), TwoBoneIKRuntimeNode->EffectorLocation);
	}
	else if (BoneSelectMode == BSM_JointTarget)
	{
		FVector Offset = ConvertCSVectorToBoneSpace(SkelComp, InTranslation, TwoBoneIKRuntimeNode->ForwardedPose, GetSelectedTarget(), TwoBoneIKGraphNode->Node.JointTargetLocationSpace);

		TwoBoneIKRuntimeNode->JointTargetLocation += Offset;
		TwoBoneIKGraphNode->Node.JointTargetLocation = TwoBoneIKRuntimeNode->JointTargetLocation;
		TwoBoneIKGraphNode->SetDefaultValue(GET_MEMBER_NAME_STRING_CHECKED(FAnimNode_TwoBoneIK, JointTargetLocation), TwoBoneIKRuntimeNode->JointTargetLocation);
	}
}