54 lines
1.9 KiB
C++
54 lines
1.9 KiB
C++
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/////////////////////////////////////////////////////////////////////
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// Created by Dan Andersson 2013
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/////////////////////////////////////////////////////////////////////
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#include "Spring.h"
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using namespace ::Oyster::Math3D;
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using namespace ::Oyster::Physics3D;
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Spring::Spring( Float r, Float s, Float d )
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: restingLength(r), springCoefficiant(s), dampeningCoefficiant(d) {}
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Spring & Spring::operator = ( const Spring &spring )
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{
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this->restingLength = spring.restingLength;
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this->springCoefficiant = spring.springCoefficiant;
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this->dampeningCoefficiant = spring.dampeningCoefficiant;
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return *this;
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}
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Float3 & Spring::GetSpringForce( const Float3 &deltaPosition, Float3 &targetMem ) const
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{
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Float length = deltaPosition.Dot( deltaPosition );
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if( length != 0.0f )
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{
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length = sqrt( length );
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return targetMem = deltaPosition * ( this->springCoefficiant * (length - this->restingLength) / length );
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}
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else return targetMem = Float3::null;
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}
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Float3 & Spring::GetDampeningForce( const Float3 &deltaPosition, const Float3 &deltaLinearVelocity, Float3 &targetMem ) const
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{
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Float projectedSpeed = deltaPosition.Dot(deltaPosition);
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if( projectedSpeed != 0.0f )
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{
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projectedSpeed = deltaLinearVelocity.Dot(deltaPosition) / projectedSpeed;
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return targetMem = deltaPosition * ( this->dampeningCoefficiant * projectedSpeed );
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}
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else return targetMem = Float3::null;
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}
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Float3 & Spring::GetSpringDampeningForce( const Float3 &deltaPosition, const Float3 &deltaLinearVelocity, Float3 &targetMem) const
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{
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Float length = deltaPosition.Dot( deltaPosition );
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if( length != 0.0f )
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{ // f = sprCoeff * (|dP| - rL) + (dV dot dP) * (dampCoeff / |dP|) * (dP / |dP|)
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length = sqrt( length );
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Float force = this->springCoefficiant * (length - this->restingLength);
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force += deltaLinearVelocity.Dot(deltaPosition) * (this->dampeningCoefficiant / length);
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return targetMem = deltaPosition * (force / length);
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}
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else return targetMem = Float3::null;
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}
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