.. _program_listing_file_Source_Physics_Inc_Physics_PBD_Cloth_Constraints.h:

Program Listing for File Constraints.h
======================================

|exhale_lsh| :ref:`Return to documentation for file <file_Source_Physics_Inc_Physics_PBD_Cloth_Constraints.h>` (``Source\Physics\Inc\Physics\PBD\Cloth\Constraints.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   #include <Types.h>
   #include <Containers/Vector.h>
   #include <Math/Core.h>
   #include <array>
   
   namespace Azura {
   namespace Physics {
   namespace PBD {
   
   struct ConstraintPoint {
     U32 m_dataIdx;
   };
   
   struct ConstraintPointDelta {
     U32 m_dataIdx;
     Vector3f m_delta;
   };
   
   class DistanceConstraint {
   
   public:
     DistanceConstraint(const ConstraintPoint& x1,
                        const ConstraintPoint& x2,
                        float restLength);
   
     void Compute(float stiffness, const Containers::Vector<Vector3f>& currentPoints,
                  const Containers::Vector<float>& currentInvMass,
                  Containers::Vector<ConstraintPointDelta>& result);
   
     bool operator<(const DistanceConstraint& rhs) const;
   
     bool operator==(const DistanceConstraint& rhs) const;
   
   private:
     ConstraintPoint m_points[2]{};
     float m_restLength;
   };
   
   class LongRangeConstraint {
   
   public:
     LongRangeConstraint(const ConstraintPoint& x1,
       const ConstraintPoint& x2,
       float restLength);
   
     void Compute(float stiffness, const Containers::Vector<Vector3f>& currentPoints,
       const Containers::Vector<float>& currentInvMass,
       Containers::Vector<ConstraintPointDelta>& result);
   
     bool operator<(const LongRangeConstraint& rhs) const;
   
     bool operator==(const LongRangeConstraint& rhs) const;
   
   private:
     ConstraintPoint m_points[2]{};
     float m_restLength;
   };
   
   
   class BendingConstraint {
   
   public:
     BendingConstraint(const Containers::Vector<Vector3f>& currentPoints,
                       const ConstraintPoint& x0,
                       const ConstraintPoint& x1,
                       const ConstraintPoint& x2,
                       const ConstraintPoint& x3);
   
     void Compute(float stiffness, const Containers::Vector<Vector3f>& currentPoints,
                  const Containers::Vector<float>& currentInvMass,
                  Containers::Vector<ConstraintPointDelta>& result);
   
   private:
     static Vector3f ComputeBendingGradient(const Containers::Vector<Vector3f>& currentPositions,
                                     const Matrix4f& Q,
                                     const std::array<U32, 4>& indices,
                                     U32 rowI);
   
     ConstraintPoint m_points[4]{};
     Matrix4f m_Q{};
   };
   
   } // namespace PBD
   } // namespace Physics
   } // namespace Azura