I need to change from right handed coord to left handed, however dont know where actually to start , the goal is supposed to look from behind like X points right, Y up, Z points forward,

I found that glFrustum calculattion needs to be changed but they say it will negate the Z axis and i need to swap X axis...

ANYWAY

i believe gluPerspectiveA function has glFrustum code in it

template <class T> void
glLookAt(Matrix44<T> &matrix, t3dpoint<T> eyePosition3D, t3dpoint<T> center3D, t3dpoint<T> upVector3D )
{
   t3dpoint<T>  forward, side, up;
   forward = Normalize( vectorAB(eyePosition3D, center3D) );
   side = Normalize( forward * upVector3D );
   up = side * forward;
  matrix.LoadIdentity();

	matrix.m[0] = side.x;
	matrix.m[1] = side.y;
	matrix.m[2] = side.z;

	matrix.m[4] = up.x;
	matrix.m[5] = up.y;
	matrix.m[6] = up.z;

	matrix.m[8] 	= -forward.x;
	matrix.m[9] 	= -forward.y;
	matrix.m[10] 	= -forward.z;



Matrix44<T> transgender;
transgender.Translate(-eyePosition3D.x, -eyePosition3D.y, -eyePosition3D.z);


matrix = transgender * matrix;
}


template <class T>
void gluPerspectiveA(Matrix44<T> & matrix, T fovy, T aspect, T zmin, T zmax)
{
 T xmin, xmax, ymin, ymax;
 ymax = zmin * tan(fovy * M_PI / 360.0);
 ymin = -ymax;
 xmin = ymin * aspect;
 xmax = ymax * aspect;



matrix.m[0] = 	(2.0*zmin)/(xmax-xmin);
matrix.m[1] = 	0.0;
matrix.m[2] =  	(xmax + xmin) / (xmax - xmin);
matrix.m[3] =	0.0;

matrix.m[4] = 	0.0;
matrix.m[5] = 	(2.0*zmin) / (ymax - ymin);
matrix.m[6] =   (ymax + ymin) / (ymax - ymin);
matrix.m[7] =   0.0;

matrix.m[8] = 	0.0;
matrix.m[9] =  	0.0;
matrix.m[10] =	-(zmax + zmin) / (zmax-zmin);
matrix.m[11] =  (-2.0*zmax*zmin) / (zmax-zmin);

matrix.m[12] =  0.0;
matrix.m[13] =  0.0;
matrix.m[14] =  -1.0;
matrix.m[15] =  0.0;


}