godot-module-template/engine/thirdparty/jolt_physics/Jolt/Physics/Constraints/PulleyConstraint.cpp

254 lines
8.5 KiB
C++

// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2022 Jorrit Rouwe
// SPDX-License-Identifier: MIT
#include <Jolt/Jolt.h>
#include <Jolt/Physics/Constraints/PulleyConstraint.h>
#include <Jolt/Physics/Body/Body.h>
#include <Jolt/ObjectStream/TypeDeclarations.h>
#include <Jolt/Core/StreamIn.h>
#include <Jolt/Core/StreamOut.h>
#ifdef JPH_DEBUG_RENDERER
#include <Jolt/Renderer/DebugRenderer.h>
#endif // JPH_DEBUG_RENDERER
JPH_NAMESPACE_BEGIN
using namespace literals;
JPH_IMPLEMENT_SERIALIZABLE_VIRTUAL(PulleyConstraintSettings)
{
JPH_ADD_BASE_CLASS(PulleyConstraintSettings, TwoBodyConstraintSettings)
JPH_ADD_ENUM_ATTRIBUTE(PulleyConstraintSettings, mSpace)
JPH_ADD_ATTRIBUTE(PulleyConstraintSettings, mBodyPoint1)
JPH_ADD_ATTRIBUTE(PulleyConstraintSettings, mFixedPoint1)
JPH_ADD_ATTRIBUTE(PulleyConstraintSettings, mBodyPoint2)
JPH_ADD_ATTRIBUTE(PulleyConstraintSettings, mFixedPoint2)
JPH_ADD_ATTRIBUTE(PulleyConstraintSettings, mRatio)
JPH_ADD_ATTRIBUTE(PulleyConstraintSettings, mMinLength)
JPH_ADD_ATTRIBUTE(PulleyConstraintSettings, mMaxLength)
}
void PulleyConstraintSettings::SaveBinaryState(StreamOut &inStream) const
{
ConstraintSettings::SaveBinaryState(inStream);
inStream.Write(mSpace);
inStream.Write(mBodyPoint1);
inStream.Write(mFixedPoint1);
inStream.Write(mBodyPoint2);
inStream.Write(mFixedPoint2);
inStream.Write(mRatio);
inStream.Write(mMinLength);
inStream.Write(mMaxLength);
}
void PulleyConstraintSettings::RestoreBinaryState(StreamIn &inStream)
{
ConstraintSettings::RestoreBinaryState(inStream);
inStream.Read(mSpace);
inStream.Read(mBodyPoint1);
inStream.Read(mFixedPoint1);
inStream.Read(mBodyPoint2);
inStream.Read(mFixedPoint2);
inStream.Read(mRatio);
inStream.Read(mMinLength);
inStream.Read(mMaxLength);
}
TwoBodyConstraint *PulleyConstraintSettings::Create(Body &inBody1, Body &inBody2) const
{
return new PulleyConstraint(inBody1, inBody2, *this);
}
PulleyConstraint::PulleyConstraint(Body &inBody1, Body &inBody2, const PulleyConstraintSettings &inSettings) :
TwoBodyConstraint(inBody1, inBody2, inSettings),
mFixedPosition1(inSettings.mFixedPoint1),
mFixedPosition2(inSettings.mFixedPoint2),
mRatio(inSettings.mRatio),
mMinLength(inSettings.mMinLength),
mMaxLength(inSettings.mMaxLength)
{
if (inSettings.mSpace == EConstraintSpace::WorldSpace)
{
// If all properties were specified in world space, take them to local space now
mLocalSpacePosition1 = Vec3(inBody1.GetInverseCenterOfMassTransform() * inSettings.mBodyPoint1);
mLocalSpacePosition2 = Vec3(inBody2.GetInverseCenterOfMassTransform() * inSettings.mBodyPoint2);
mWorldSpacePosition1 = inSettings.mBodyPoint1;
mWorldSpacePosition2 = inSettings.mBodyPoint2;
}
else
{
// If properties were specified in local space, we need to calculate world space positions
mLocalSpacePosition1 = Vec3(inSettings.mBodyPoint1);
mLocalSpacePosition2 = Vec3(inSettings.mBodyPoint2);
mWorldSpacePosition1 = inBody1.GetCenterOfMassTransform() * inSettings.mBodyPoint1;
mWorldSpacePosition2 = inBody2.GetCenterOfMassTransform() * inSettings.mBodyPoint2;
}
// Calculate min/max length if it was not provided
float current_length = GetCurrentLength();
if (mMinLength < 0.0f)
mMinLength = current_length;
if (mMaxLength < 0.0f)
mMaxLength = current_length;
// Initialize the normals to a likely valid axis in case the fixed points overlap with the attachment points (most likely the fixed points are above both bodies)
mWorldSpaceNormal1 = mWorldSpaceNormal2 = -Vec3::sAxisY();
}
void PulleyConstraint::NotifyShapeChanged(const BodyID &inBodyID, Vec3Arg inDeltaCOM)
{
if (mBody1->GetID() == inBodyID)
mLocalSpacePosition1 -= inDeltaCOM;
else if (mBody2->GetID() == inBodyID)
mLocalSpacePosition2 -= inDeltaCOM;
}
float PulleyConstraint::CalculatePositionsNormalsAndLength()
{
// Update world space positions (the bodies may have moved)
mWorldSpacePosition1 = mBody1->GetCenterOfMassTransform() * mLocalSpacePosition1;
mWorldSpacePosition2 = mBody2->GetCenterOfMassTransform() * mLocalSpacePosition2;
// Calculate world space normals
Vec3 delta1 = Vec3(mWorldSpacePosition1 - mFixedPosition1);
float delta1_len = delta1.Length();
if (delta1_len > 0.0f)
mWorldSpaceNormal1 = delta1 / delta1_len;
Vec3 delta2 = Vec3(mWorldSpacePosition2 - mFixedPosition2);
float delta2_len = delta2.Length();
if (delta2_len > 0.0f)
mWorldSpaceNormal2 = delta2 / delta2_len;
// Calculate length
return delta1_len + mRatio * delta2_len;
}
void PulleyConstraint::CalculateConstraintProperties()
{
// Calculate attachment points relative to COM
Vec3 r1 = Vec3(mWorldSpacePosition1 - mBody1->GetCenterOfMassPosition());
Vec3 r2 = Vec3(mWorldSpacePosition2 - mBody2->GetCenterOfMassPosition());
mIndependentAxisConstraintPart.CalculateConstraintProperties(*mBody1, *mBody2, r1, mWorldSpaceNormal1, r2, mWorldSpaceNormal2, mRatio);
}
void PulleyConstraint::SetupVelocityConstraint(float inDeltaTime)
{
// Determine if the constraint is active
float current_length = CalculatePositionsNormalsAndLength();
bool min_length_violation = current_length <= mMinLength;
bool max_length_violation = current_length >= mMaxLength;
if (min_length_violation || max_length_violation)
{
// Determine max lambda based on if the length is too big or small
mMinLambda = max_length_violation? -FLT_MAX : 0.0f;
mMaxLambda = min_length_violation? FLT_MAX : 0.0f;
CalculateConstraintProperties();
}
else
mIndependentAxisConstraintPart.Deactivate();
}
void PulleyConstraint::ResetWarmStart()
{
mIndependentAxisConstraintPart.Deactivate();
}
void PulleyConstraint::WarmStartVelocityConstraint(float inWarmStartImpulseRatio)
{
mIndependentAxisConstraintPart.WarmStart(*mBody1, *mBody2, mWorldSpaceNormal1, mWorldSpaceNormal2, mRatio, inWarmStartImpulseRatio);
}
bool PulleyConstraint::SolveVelocityConstraint(float inDeltaTime)
{
if (mIndependentAxisConstraintPart.IsActive())
return mIndependentAxisConstraintPart.SolveVelocityConstraint(*mBody1, *mBody2, mWorldSpaceNormal1, mWorldSpaceNormal2, mRatio, mMinLambda, mMaxLambda);
else
return false;
}
bool PulleyConstraint::SolvePositionConstraint(float inDeltaTime, float inBaumgarte)
{
// Calculate new length (bodies may have changed)
float current_length = CalculatePositionsNormalsAndLength();
float position_error = 0.0f;
if (current_length < mMinLength)
position_error = current_length - mMinLength;
else if (current_length > mMaxLength)
position_error = current_length - mMaxLength;
if (position_error != 0.0f)
{
// Update constraint properties (bodies may have moved)
CalculateConstraintProperties();
return mIndependentAxisConstraintPart.SolvePositionConstraint(*mBody1, *mBody2, mWorldSpaceNormal1, mWorldSpaceNormal2, mRatio, position_error, inBaumgarte);
}
return false;
}
#ifdef JPH_DEBUG_RENDERER
void PulleyConstraint::DrawConstraint(DebugRenderer *inRenderer) const
{
// Color according to length vs min/max length
float current_length = GetCurrentLength();
Color color = Color::sGreen;
if (current_length < mMinLength)
color = Color::sYellow;
else if (current_length > mMaxLength)
color = Color::sRed;
// Draw constraint
inRenderer->DrawLine(mWorldSpacePosition1, mFixedPosition1, color);
inRenderer->DrawLine(mFixedPosition1, mFixedPosition2, color);
inRenderer->DrawLine(mFixedPosition2, mWorldSpacePosition2, color);
// Draw current length
inRenderer->DrawText3D(0.5_r * (mFixedPosition1 + mFixedPosition2), StringFormat("%.2f", (double)current_length));
}
#endif // JPH_DEBUG_RENDERER
void PulleyConstraint::SaveState(StateRecorder &inStream) const
{
TwoBodyConstraint::SaveState(inStream);
mIndependentAxisConstraintPart.SaveState(inStream);
inStream.Write(mWorldSpaceNormal1); // When distance to fixed point = 0, the normal is used from last frame so we need to store it
inStream.Write(mWorldSpaceNormal2);
}
void PulleyConstraint::RestoreState(StateRecorder &inStream)
{
TwoBodyConstraint::RestoreState(inStream);
mIndependentAxisConstraintPart.RestoreState(inStream);
inStream.Read(mWorldSpaceNormal1);
inStream.Read(mWorldSpaceNormal2);
}
Ref<ConstraintSettings> PulleyConstraint::GetConstraintSettings() const
{
PulleyConstraintSettings *settings = new PulleyConstraintSettings;
ToConstraintSettings(*settings);
settings->mSpace = EConstraintSpace::LocalToBodyCOM;
settings->mBodyPoint1 = RVec3(mLocalSpacePosition1);
settings->mFixedPoint1 = mFixedPosition1;
settings->mBodyPoint2 = RVec3(mLocalSpacePosition2);
settings->mFixedPoint2 = mFixedPosition2;
settings->mRatio = mRatio;
settings->mMinLength = mMinLength;
settings->mMaxLength = mMaxLength;
return settings;
}
JPH_NAMESPACE_END