void USplineComponent::UpdateSpline()
{
const int32 NumPoints = SplineInfo.Points.Num();
check(!bClosedLoop || NumPoints == 0 || (NumPoints >= 2 && SplineInfo.Points[0].OutVal == SplineInfo.Points[NumPoints - 1].OutVal));
// Automatically set the tangents on any CurveAuto keys
SplineInfo.AutoSetTangents(0.0f, bStationaryEndpoints);
// Nothing else to do if less than 2 points
if (NumPoints < 2)
{
return;
}
// Adjust auto tangents for first and last keys to take into account the looping
if (bClosedLoop)
{
auto& FirstPoint = SplineInfo.Points[0];
auto& LastPoint = SplineInfo.Points[NumPoints - 1];
const auto& SecondPoint = SplineInfo.Points[1];
const auto& PenultimatePoint = SplineInfo.Points[NumPoints - 2];
if (FirstPoint.InterpMode == CIM_CurveAuto || FirstPoint.InterpMode == CIM_CurveAutoClamped)
{
FVector Tangent;
ComputeCurveTangent(
PenultimatePoint.InVal - LastPoint.InVal, PenultimatePoint.OutVal,
FirstPoint.InVal, FirstPoint.OutVal,
SecondPoint.InVal, SecondPoint.OutVal,
0.0f,
FirstPoint.InterpMode == CIM_CurveAutoClamped,
Tangent);
FirstPoint.LeaveTangent = Tangent;
FirstPoint.ArriveTangent = Tangent;
LastPoint.LeaveTangent = Tangent;
LastPoint.ArriveTangent = Tangent;
}
}
const int32 NumSegments = NumPoints - 1;
// Start by clearing it
SplineReparamTable.Points.Reset(NumSegments * ReparamStepsPerSegment + 1);
float AccumulatedLength = 0.0f;
for (int32 SegmentIndex = 0; SegmentIndex < NumSegments; ++SegmentIndex)
{
for (int32 Step = 0; Step < ReparamStepsPerSegment; ++Step)
{
const float Param = static_cast<float>(Step) / ReparamStepsPerSegment;
const float SegmentLength = (Step == 0) ? 0.0f : GetSegmentLength(SegmentIndex, Param);
SplineReparamTable.AddPoint(SegmentLength + AccumulatedLength, SegmentIndex + Param);
}
AccumulatedLength += GetSegmentLength(SegmentIndex, 1.0f);
}
SplineReparamTable.AddPoint(AccumulatedLength, static_cast<float>(NumSegments));
}
void FRichCurve::AutoSetTangents(float Tension)
{
// Iterate over all points in this InterpCurve
for(int32 KeyIndex=0; KeyIndex<Keys.Num(); KeyIndex++)
{
FRichCurveKey& Key = Keys[KeyIndex];
float ArriveTangent = Key.ArriveTangent;
float LeaveTangent = Key.LeaveTangent;
if(KeyIndex == 0)
{
if(KeyIndex < Keys.Num()-1) // Start point
{
// If first section is not a curve, or is a curve and first point has manual tangent setting.
if( Key.TangentMode == RCTM_Auto )
{
LeaveTangent = 0.0f;
}
}
}
else
{
if(KeyIndex < Keys.Num()-1) // Inner point
{
FRichCurveKey& PrevKey = Keys[KeyIndex-1];
if( Key.InterpMode == RCIM_Cubic && (Key.TangentMode == RCTM_Auto ))
{
FRichCurveKey& NextKey = Keys[KeyIndex+1];
ComputeCurveTangent(
Keys[ KeyIndex - 1 ].Time, // Previous time
Keys[ KeyIndex - 1 ].Value, // Previous point
Keys[ KeyIndex ].Time, // Current time
Keys[ KeyIndex ].Value, // Current point
Keys[ KeyIndex + 1 ].Time, // Next time
Keys[ KeyIndex + 1 ].Value, // Next point
Tension, // Tension
false, // Want clamping?
ArriveTangent ); // Out
// In 'auto' mode, arrive and leave tangents are always the same
LeaveTangent = ArriveTangent;
}
else if( PrevKey.InterpMode == RCIM_Constant || Key.InterpMode == RCIM_Constant )
{
if(Keys[ KeyIndex - 1 ].InterpMode != RCIM_Cubic)
{
ArriveTangent = 0.0f;
}
LeaveTangent = 0.0f;
}
}
else // End point
{
// If last section is not a curve, or is a curve and final point has manual tangent setting.
if( Key.InterpMode == RCIM_Cubic && Key.TangentMode == RCTM_Auto)
{
ArriveTangent = 0.0f;
}
}
}
Key.ArriveTangent = ArriveTangent;
Key.LeaveTangent = LeaveTangent;
}
}
