/* Vector normalization function.
* ARGUMENTS:
* - vector to be normalize:
* VEC V;
* RETURNS:
* (VEC) normalized vector value.
*/
VEC VecNormalize( VEC V )
{
DBL len = VecDotVec(V, V);
if (len != 1 && len != 0)
len = sqrt(len), V.X /= len, V.Y /= len, V.Z /= len;
return V;
} /* End of 'VecNormalize' function */
MATR MatrViewLookAt( VEC Loc, VEC At, VEC UpApprox )
{
VEC Right, Up, Dir;
MATR r;
Dir = VecNormalize(VecSubVec(At, Loc));
Right = VecNormalize(VecCrossVec(Dir, UpApprox));
Up = VecCrossVec(Right, Dir);
r.A[0][0] = Right.x; r.A[0][1] = Up.x; r.A[0][2] = -Dir.x; r.A[0][3] = 0;
r.A[1][0] = Right.y; r.A[1][1] = Up.y; r.A[1][2] = -Dir.y; r.A[1][3] = 0;
r.A[2][0] = Right.z; r.A[2][1] = Up.z; r.A[2][2] = -Dir.z; r.A[2][3] = 0;
r.A[3][0] = -VecDotVec(Loc, Right);
r.A[3][1] = -VecDotVec(Loc, Up);
r.A[3][2] = VecDotVec(Loc, Dir);
r.A[3][3] = 1;
return r;
}
/* ‘ункци¤ преобразовани¤ из мировой системы коорлинат в кадр.
* ј–√”ћ≈Ќ“џ:
* - исходна¤ точка:
* VEC Loc, VEC At, VEC Upaprox;
* ¬ќ«¬–јўј≈ћќ≈ «Ќј„≈Ќ»≈:
* (MATR) ћатрица преоброзаваний камеры.
*/
MATR II2_VieverCamera( VEC Loc, VEC At, VEC Upaprox )
{
VEC Right, Up, Dir;
MATR r;
Dir = VecNormalize(VecSubVec(At, Loc));
Right = VecNormalize(VecCrossVec(Dir, Upaprox));
Up = VecCrossVec(Right, Dir);
r.A[0][0] = Right.X; r.A[0][1] = Up.X; r.A[0][2] = -Dir.X; r.A[0][3] = 0;
r.A[1][0] = Right.Y; r.A[1][1] = Up.Y; r.A[1][2] = -Dir.Y; r.A[1][3] = 0;
r.A[2][0] = Right.Z; r.A[2][1] = Up.Z; r.A[2][2] = -Dir.Z; r.A[2][3] = 0;
r.A[3][0] = -VecDotVec(Loc, Right);
r.A[3][1] = -VecDotVec(Loc, Up);
r.A[3][2] = VecDotVec(Loc, Dir);
r.A[3][3] = 1;
/*r.A[0][0] = Right.X;
r.A[1][0] = Up.X;
r.A[2][0] = -Dir.X;
r.A[3][0] = 0;
r.A[0][1] = Right.Y;
r.A[1][1] = Up.Y;
r.A[2][1] = -Dir.Y;
r.A[3][1] = 0;
r.A[0][2] = Right.Z;
r.A[1][2] = Up.Z;
r.A[2][2] = -Dir.Z;
r.A[3][2] = 0;
r.A[0][3] = -VecDotVec(Loc, Right);
r.A[1][3] = -VecDotVec(Loc, Up);
r.A[2][3] = -VecDotVec(Loc, Dir);
r.A[3][3] = 1;*/
return r;
} /* End of 'Ani->WorldToScreen' function */
