//-----------------------------------------------------------------------------
// Copyright (c) 2012 GarageGames, LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//-----------------------------------------------------------------------------

#include "math/mAngAxis.h"
#include "math/mQuat.h"
#include "math/mMatrix.h"

AngAxisF & AngAxisF::set( const QuatF & q )
{
   angle = 2.0f * mAcos( q.w );
   F32 sinHalfAngle = mSqrt(q.x * q.x + q.y * q.y + q.z * q.z);
   if (sinHalfAngle != 0.0f)
      axis.set( q.x / sinHalfAngle, q.y / sinHalfAngle, q.z / sinHalfAngle );
   else
      axis.set(1.0f,0.0f,0.0f);
   return *this;
}
AngAxisF& AngAxisF::set(const EulerF& eul)
{
   F32 c1 = mCos(eul.y / 2);
   F32 s1 = mSin(eul.y / 2);
   F32 c2 = mCos(eul.z / 2);
   F32 s2 = mSin(eul.z / 2);
   F32 c3 = mCos(eul.x / 2);
   F32 s3 = mSin(eul.x / 2);

   F32 c1c2 = c1 * c2;
   F32 s1s2 = s1 * s2;

   F32 w = c1c2 * c3 - s1s2 * s3;
   F32 x = c1c2 * s3 + s1s2 * c3;
   F32 y = s1 * c2 * c3 + c1 * s2 * s3;
   F32 z = c1 * s2 * c3 - s1 * c2 * s3;

   angle = 2.0f * mAcos(w);

   F32 norm = x * x + y * y + z * z;
   if (norm < POINT_EPSILON)
   {
      axis.set(1.0f, 0.0f, 0.0f);
   }
   else
   {
      norm = mSqrt(norm);
      x /= norm;
      y /= norm;
      z /= norm;
   }

   axis.set(x, y, z);

   return *this;
}

AngAxisF & AngAxisF::set( const MatrixF & mat )
{
   QuatF q( mat );
   set( q );
   return *this;
}

MatrixF * AngAxisF::setMatrix( MatrixF * mat ) const
{
   QuatF q( *this );
   return q.setMatrix( mat );
}

void AngAxisF::RotateX(F32 angle, MatrixF * mat)
{
   // for now...do it the easy way
   AngAxisF rotX(Point3F(1.0f,0.0f,0.0f),angle);
   rotX.setMatrix(mat);
}

void AngAxisF::RotateY(F32 angle, MatrixF * mat)
{
   // for now...do it the easy way
   AngAxisF rotY(Point3F(0.0f,1.0f,0.0f),angle);
   rotY.setMatrix(mat);
}

void AngAxisF::RotateZ(F32 angle, MatrixF * mat)
{
   // for now...do it the easy way
   AngAxisF rotZ(Point3F(0.0f,0.0f,1.0f),angle);
   rotZ.setMatrix(mat);
}

void AngAxisF::RotateX(F32 angle, const Point3F & from, Point3F * to)
{
   // for now...do it the easy way
   MatrixF mat;
   AngAxisF::RotateX(angle,&mat);
   mat.mulV(from,to);
}

void AngAxisF::RotateY(F32 angle, const Point3F & from, Point3F * to)
{
   // for now...do it the easy way
   MatrixF mat;
   AngAxisF::RotateY(angle,&mat);
   mat.mulV(from,to);
}

void AngAxisF::RotateZ(F32 angle, const Point3F & from, Point3F * to)
{
   // for now...do it the easy way
   MatrixF mat;
   AngAxisF::RotateZ(angle,&mat);
   mat.mulV(from,to);
}

EulerF AngAxisF::toEuler() const
{
   EulerF r;

   F32 s = mSin(angle);
   F32 c = mCos(angle);
   F32 invc = 1 - c;

   if ((axis.x * axis.y * invc + axis.z * s) > (1 - POINT_EPSILON))
   {
      r.y = 2.0f * mAtan2(axis.x * mSin(angle / 2), mCos(angle / 2));
      r.z = -M_HALFPI_F;
      r.x = 0.f;
      return r;
   }

   if ((axis.x * axis.y * invc + axis.z * s) < -(1 - POINT_EPSILON))
   {
      r.y = -2.0f * mAtan2(axis.x * mSin(angle / 2), mCos(angle / 2));
      r.z = -M_HALFPI_F;
      r.x = 0.f;
      return r;
   }

   r.x = mAtan2(axis.x * s - axis.y * axis.z * invc, 1.0f - (axis.x * axis.x + axis.z * axis.z) * invc);
   r.y = mAtan2(axis.y * s - axis.x * axis.z * invc, 1.0f - (axis.y * axis.y + axis.z * axis.z) * invc);
   r.z = mAsin(axis.x * axis.y * invc + axis.z * s);

   return r;

}