UnrealEngineUWP/Engine/Source/Editor/CurveEditor/Private/SCurveEditorView.cpp

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

#include "SCurveEditorView.h"

#include "Containers/Map.h"
#include "CurveDataAbstraction.h"
#include "CurveDrawInfo.h"
#include "CurveEditor.h"
#include "CurveEditorHelpers.h"
#include "CurveEditorScreenSpace.h"
#include "CurveEditorSelection.h"
#include "CurveEditorSettings.h"
#include "CurveModel.h"
#include "Curves/KeyHandle.h"
#include "Curves/RichCurve.h"
#include "HAL/PlatformCrt.h"
#include "ICurveEditorBounds.h"
#include "Layout/Geometry.h"
#include "Math/Color.h"
#include "Misc/AssertionMacros.h"
#include "SCurveEditorPanel.h"
#include "Slate/SRetainerWidget.h"
#include "Templates/Tuple.h"
#include "Templates/UnrealTemplate.h"

TAutoConsoleVariable<bool> CVarUseCurveCache(TEXT("CurveEditor.UseCurveCache"), true, TEXT("When true we cache curve values, when false we always regenerate."));

SCurveEditorView::SCurveEditorView()
	: bPinned(0)
	, bInteractive(1)
	, bFixedOutputBounds(0)
	, bAutoSize(1)
	, bAllowEmpty(0)
{
	CurveCacheFlags = ECurveCacheFlags::All;
	CachedValues.CachedActiveCurvesSerialNumber = 0xFFFFFFFF;
	CachedValues.CachedSelectionSerialNumber = 0xFFFFFFFF;
	CachedValues.CachedGeometrySize.X = -1.;
	CachedValues.CachedGeometrySize.Y = -1;
}

FVector2D SCurveEditorView::ComputeDesiredSize(float LayoutScaleMultiplier) const
{
	FVector2D ContentDesiredSize = SCompoundWidget::ComputeDesiredSize(LayoutScaleMultiplier);
	return FVector2D(ContentDesiredSize.X, FixedHeight.Get(ContentDesiredSize.Y));
}

void SCurveEditorView::GetInputBounds(double& OutInputMin, double& OutInputMax) const
{
	TSharedPtr<FCurveEditor> CurveEditor = WeakCurveEditor.Pin();
	if (CurveEditor)
	{
		CurveEditor->GetBounds().GetInputBounds(OutInputMin, OutInputMax);

		// This code assumes no scaling between the container and the view (which is a pretty safe assumption to make)
		const FGeometry& ViewGeometry      = GetCachedGeometry();
		const FGeometry ContainerGeometry = CurveEditor->GetPanel().IsValid() ? CurveEditor->GetPanel()->GetViewContainerGeometry() : ViewGeometry;

		const float ContainerWidth = ContainerGeometry.GetLocalSize().X;
		const float ViewWidth      = ViewGeometry.GetLocalSize().X;

		if (ViewWidth > 0.f)
		{
			const float LeftPixelCrop = ViewGeometry.LocalToAbsolute(FVector2D(0.f, 0.f)).X - ContainerGeometry.LocalToAbsolute(FVector2D(0.f, 0.f)).X;
			const float RightPixelCrop = ContainerGeometry.LocalToAbsolute(FVector2D(ContainerWidth, 0.f)).X - ViewGeometry.LocalToAbsolute(FVector2D(ViewWidth, 0.f)).X;

			const double ContainerInputPerPixel = (OutInputMax - OutInputMin) / ContainerWidth;

			// Offset by the total range first
			OutInputMin += ContainerInputPerPixel * LeftPixelCrop;
			OutInputMax -= ContainerInputPerPixel * RightPixelCrop;
		}
	}
}

FCurveEditorScreenSpace SCurveEditorView::GetViewSpace() const
{
	double InputMin = 0.0, InputMax = 1.0;
	GetInputBounds(InputMin, InputMax);

	return FCurveEditorScreenSpace(GetCachedGeometry().GetLocalSize(), InputMin, InputMax, OutputMin, OutputMax);
}

void SCurveEditorView::AddCurve(FCurveModelID CurveID)
{
	CurveInfoByID.Add(CurveID, FCurveInfo{CurveInfoByID.Num()});
	OnCurveListChanged();
}

void SCurveEditorView::RemoveCurve(FCurveModelID CurveID)
{
	if (FCurveInfo* InfoToRemove = CurveInfoByID.Find(CurveID))
	{
		const int32 CurveIndex = InfoToRemove->CurveIndex;
		InfoToRemove = nullptr;

		CurveInfoByID.Remove(CurveID);

		for (TTuple<FCurveModelID, FCurveInfo>& Info : CurveInfoByID)
		{
			if (Info.Value.CurveIndex > CurveIndex)
			{
				--Info.Value.CurveIndex;
			}
		}

		OnCurveListChanged();
	}
}

void SCurveEditorView::SetOutputBounds(double InOutputMin, double InOutputMax)
{
	if (!bFixedOutputBounds)
	{
		OutputMin = InOutputMin;
		OutputMax = InOutputMax;
	}
}

void SCurveEditorView::Zoom(const FVector2D& Amount)
{
	FCurveEditorScreenSpace ViewSpace = GetViewSpace();

	const double InputOrigin  = (ViewSpace.GetInputMax()  - ViewSpace.GetInputMin())  * 0.5;
	const double OutputOrigin = (ViewSpace.GetOutputMax() - ViewSpace.GetOutputMin()) * 0.5;

	ZoomAround(Amount, InputOrigin, OutputOrigin);
}

void SCurveEditorView::ZoomAround(const FVector2D& Amount, double InputOrigin, double OutputOrigin)
{
	TSharedPtr<FCurveEditor> CurveEditor = WeakCurveEditor.Pin();
	check(CurveEditor.IsValid());

	if (Amount.X != 0.f && CurveEditor.IsValid())
	{
		double InputMin = 0.0, InputMax = 1.0;
		CurveEditor->GetBounds().GetInputBounds(InputMin, InputMax);

		InputMin = InputOrigin - (InputOrigin - InputMin) * Amount.X;
		InputMax = InputOrigin + (InputMax - InputOrigin) * Amount.X;

		CurveEditor->GetBounds().SetInputBounds(InputMin, InputMax);
	}

	if (Amount.Y != 0.f)
	{
		OutputMin = OutputOrigin - (OutputOrigin - OutputMin) * Amount.Y;
		OutputMax = OutputOrigin + (OutputMax - OutputOrigin) * Amount.Y;
	}
}

void SCurveEditorView::GetCurveDrawParams(TArray<FCurveDrawParams>& OutDrawParams) const
{
	TSharedPtr<FCurveEditor> CurveEditor = WeakCurveEditor.Pin();
	if (!CurveEditor)
	{
		return;
	}

	// Get the Min/Max values on the X axis, for Time
	double InputMin = 0, InputMax = 1;
	GetInputBounds(InputMin, InputMax);

	OutDrawParams.Reset(CurveInfoByID.Num());

	for (const TTuple<FCurveModelID, FCurveInfo>& Pair : CurveInfoByID)
	{
		FCurveDrawParams Params(Pair.Key);

		FCurveModel* CurveModel = CurveEditor->FindCurve(Pair.Key);
		if (!ensureAlways(CurveModel))
		{
			continue;
		}

		GetCurveDrawParam(CurveEditor, Pair.Key, CurveModel,InputMin, InputMax, Params);
		OutDrawParams.Add(MoveTemp(Params));
	}
}

void SCurveEditorView::GetCurveDrawParam(TSharedPtr<FCurveEditor>& CurveEditor,const FCurveModelID& ModelID, FCurveModel* CurveModel, 
	double InputMin, double InputMax, FCurveDrawParams& Params) const
{

	FCurveEditorScreenSpace CurveSpace = GetCurveSpace(ModelID);
	const float DisplayRatio = (CurveSpace.PixelsPerOutput() / CurveSpace.PixelsPerInput());

	const FKeyHandleSet* SelectedKeys = CurveEditor->GetSelection().GetAll().Find(ModelID);

	// Create a new set of Curve Drawing Parameters to represent this particular Curve
	Params.Color = CurveModel->GetColor();
	Params.bKeyDrawEnabled = CurveModel->IsKeyDrawEnabled();

	// Gather the display metrics to use for each key type. This allows a Curve Model to override
	// whether or not the curve supports Keys, Arrive/Leave Tangents, etc. If the Curve Model doesn't
	// support a particular capability we can skip drawing them.
	CurveModel->GetKeyDrawInfo(ECurvePointType::ArriveTangent, FKeyHandle::Invalid(), Params.ArriveTangentDrawInfo);
	CurveModel->GetKeyDrawInfo(ECurvePointType::LeaveTangent, FKeyHandle::Invalid(), Params.LeaveTangentDrawInfo);

	// Gather the interpolating points in input/output space
	TArray<TTuple<double, double>> InterpolatingPoints;

	CurveModel->DrawCurve(*CurveEditor, CurveSpace, InterpolatingPoints);
	Params.InterpolatingPoints.Reset(InterpolatingPoints.Num());

	// An Input Offset allows for a fixed offset to all keys, such as displaying them in the middle of a frame instead of at the start.
	double InputOffset = CurveModel->GetInputDisplayOffset();

	// Convert the interpolating points to screen space
	for (TTuple<double, double> Point : InterpolatingPoints)
	{
		Params.InterpolatingPoints.Add(
			FVector2D(
				CurveSpace.SecondsToScreen(Point.Get<0>() + InputOffset),
				CurveSpace.ValueToScreen(Point.Get<1>())
			)
		);
	}

	TArray<FKeyHandle> VisibleKeys;
	CurveModel->GetKeys(*CurveEditor, InputMin, InputMax, TNumericLimits<double>::Lowest(), TNumericLimits<double>::Max(), VisibleKeys);

	if (VisibleKeys.Num())
	{
		ECurveEditorTangentVisibility TangentVisibility = CurveEditor->GetSettings()->GetTangentVisibility();

		TArray<FKeyPosition> AllKeyPositions;
		TArray<FKeyAttributes> AllKeyAttributes;

		AllKeyPositions.SetNum(VisibleKeys.Num());
		AllKeyAttributes.SetNum(VisibleKeys.Num());
		Params.Points.Reset(VisibleKeys.Num());

		CurveModel->GetKeyPositions(VisibleKeys, AllKeyPositions);
		CurveModel->GetKeyAttributes(VisibleKeys, AllKeyAttributes);
		for (int32 Index = 0; Index < VisibleKeys.Num(); ++Index)
		{
			const FKeyHandle      KeyHandle = VisibleKeys[Index];
			const FKeyPosition& KeyPosition = AllKeyPositions[Index];
			const FKeyAttributes& Attributes = AllKeyAttributes[Index];

			bool bShowTangents = TangentVisibility == ECurveEditorTangentVisibility::AllTangents ||
				(TangentVisibility == ECurveEditorTangentVisibility::SelectedKeys && SelectedKeys &&
					(SelectedKeys->Contains(VisibleKeys[Index], ECurvePointType::Any)));

			float TimeScreenPos = CurveSpace.SecondsToScreen(KeyPosition.InputValue + InputOffset);
			float ValueScreenPos = CurveSpace.ValueToScreen(KeyPosition.OutputValue);

			// Add this key
			FCurvePointInfo Key(KeyHandle);
			Key.ScreenPosition = FVector2D(TimeScreenPos, ValueScreenPos);
			Key.LayerBias = 2;

			// Add draw info for the specific key
			CurveModel->GetKeyDrawInfo(ECurvePointType::Key, KeyHandle, /*Out*/ Key.DrawInfo);
			Params.Points.Add(Key);

			if (bShowTangents && Attributes.HasArriveTangent())
			{
				float ArriveTangent = Attributes.GetArriveTangent();

				FCurvePointInfo ArriveTangentPoint(KeyHandle);
				ArriveTangentPoint.Type = ECurvePointType::ArriveTangent;


				if (Attributes.HasTangentWeightMode() && Attributes.HasArriveTangentWeight() &&
					(Attributes.GetTangentWeightMode() == RCTWM_WeightedBoth || Attributes.GetTangentWeightMode() == RCTWM_WeightedArrive))
				{
					FVector2D TangentOffset = CurveEditor::ComputeScreenSpaceTangentOffset(CurveSpace, ArriveTangent, -Attributes.GetArriveTangentWeight());
					ArriveTangentPoint.ScreenPosition = Key.ScreenPosition + TangentOffset;
				}
				else
				{
					float PixelLength = 60.0f;
					ArriveTangentPoint.ScreenPosition = Key.ScreenPosition + CurveEditor::GetVectorFromSlopeAndLength(ArriveTangent * -DisplayRatio, -PixelLength);
				}
				ArriveTangentPoint.LineDelta = Key.ScreenPosition - ArriveTangentPoint.ScreenPosition;
				ArriveTangentPoint.LayerBias = 1;

				// Add draw info for the specific tangent
				FKeyDrawInfo TangentDrawInfo;
				CurveModel->GetKeyDrawInfo(ECurvePointType::ArriveTangent, KeyHandle, /*Out*/ ArriveTangentPoint.DrawInfo);

				Params.Points.Add(ArriveTangentPoint);
			}

			if (bShowTangents && Attributes.HasLeaveTangent())
			{
				float LeaveTangent = Attributes.GetLeaveTangent();

				FCurvePointInfo LeaveTangentPoint(KeyHandle);
				LeaveTangentPoint.Type = ECurvePointType::LeaveTangent;

				if (Attributes.HasTangentWeightMode() && Attributes.HasLeaveTangentWeight() &&
					(Attributes.GetTangentWeightMode() == RCTWM_WeightedBoth || Attributes.GetTangentWeightMode() == RCTWM_WeightedLeave))
				{
					FVector2D TangentOffset = CurveEditor::ComputeScreenSpaceTangentOffset(CurveSpace, LeaveTangent, Attributes.GetLeaveTangentWeight());

					LeaveTangentPoint.ScreenPosition = Key.ScreenPosition + TangentOffset;
				}
				else
				{
					float PixelLength = 60.0f;
					LeaveTangentPoint.ScreenPosition = Key.ScreenPosition + CurveEditor::GetVectorFromSlopeAndLength(LeaveTangent * -DisplayRatio, PixelLength);

				}

				LeaveTangentPoint.LineDelta = Key.ScreenPosition - LeaveTangentPoint.ScreenPosition;
				LeaveTangentPoint.LayerBias = 1;

				// Add draw info for the specific tangent
				FKeyDrawInfo TangentDrawInfo;
				CurveModel->GetKeyDrawInfo(ECurvePointType::LeaveTangent, KeyHandle, /*Out*/ LeaveTangentPoint.DrawInfo);

				Params.Points.Add(LeaveTangentPoint);
			}
		}
	}
}

void SCurveEditorView::RefreshRetainer()
{
	if (RetainerWidget)
	{
		RetainerWidget->RequestRender();
	}
}

void SCurveEditorView::CheckCacheAndInvalidateIfNeeded()
{
	TSharedPtr<FCurveEditor> CurveEditor = WeakCurveEditor.Pin();
	if (CurveEditor.IsValid() == false)
	{
		return;
	}
	const bool bUseCurveCache = CVarUseCurveCache.GetValueOnGameThread();

	if (bUseCurveCache)
	{
		//if number of curves have changed, just redo all
		if (CurveEditor->GetActiveCurvesSerialNumber() != CachedValues.CachedActiveCurvesSerialNumber)
		{
			CachedValues.CachedActiveCurvesSerialNumber = CurveEditor->GetActiveCurvesSerialNumber();
			CurveCacheFlags = ECurveCacheFlags::All;
		}
		if (CachedValues.CachedTangentVisibility != CurveEditor->GetSettings()->GetTangentVisibility())
		{
			CachedValues.CachedTangentVisibility = CurveEditor->GetSettings()->GetTangentVisibility();
			CurveCacheFlags = ECurveCacheFlags::All;
		}
		if (CachedValues.CachedSelectionSerialNumber != CurveEditor->GetSelection().GetSerialNumber())
		{
			CachedValues.CachedSelectionSerialNumber = CurveEditor->GetSelection().GetSerialNumber();
			CurveCacheFlags = ECurveCacheFlags::All;
		}

		//Only get view values if we need to since we will reset them every time we get all
		if (CurveCacheFlags != ECurveCacheFlags::All)
		{
			if (OutputMin != CachedValues.CachedOutputMin || OutputMax != CachedValues.CachedOutputMax)
			{
				CurveCacheFlags = ECurveCacheFlags::All;
			}
			else if (CachedValues.CachedGeometrySize != GetCachedGeometry().GetLocalSize())
			{
				CurveCacheFlags = ECurveCacheFlags::All;
			}
			else
			{
				double InputMin = 0, InputMax = 1;
				GetInputBounds(InputMin, InputMax);
				if (InputMin != CachedValues.CachedInputMin || InputMax != CachedValues.CachedInputMax)
				{
					CurveCacheFlags = ECurveCacheFlags::All;
				}
			}
		}
		if (CurveCacheFlags == ECurveCacheFlags::All)
		{
			CachedValues.CachedOutputMin = OutputMin;
			CachedValues.CachedOutputMax = OutputMax;
			GetInputBounds(CachedValues.CachedInputMin, CachedValues.CachedInputMax);
			CachedValues.CachedGeometrySize = GetCachedGeometry().GetLocalSize();

			CachedDrawParams.Reset();
			GetCurveDrawParams(CachedDrawParams);
			CurveCacheFlags = ECurveCacheFlags::CheckCurves;
			RefreshRetainer();
		}
		else if (CurveCacheFlags == ECurveCacheFlags::CheckCurves)
		{
			bool bSomethingChanged = false;
			for (FCurveDrawParams& Params : CachedDrawParams)
			{
				FCurveModel* CurveModel = CurveEditor->FindCurve(Params.GetID());
				if (CurveModel->HasChangedAndResetTest())
				{
					bSomethingChanged = true;
					GetCurveDrawParam(CurveEditor, Params.GetID(), CurveModel, CachedValues.CachedInputMin, CachedValues.CachedInputMax, Params);
				}
			}
			if (bSomethingChanged)
			{
				RefreshRetainer();
			}
		}
	}
	else
	{
		CachedValues.CachedOutputMin = OutputMin;
		CachedValues.CachedOutputMax = OutputMax;
		GetInputBounds(CachedValues.CachedInputMin, CachedValues.CachedInputMax);
		CachedValues.CachedGeometrySize = GetCachedGeometry().GetLocalSize();

		CachedDrawParams.Reset();
		GetCurveDrawParams(CachedDrawParams);

		RefreshRetainer();
	}
}