/**
* @see <a href="gluLookAt.html">gluLookAt</a>
*/
public void look_at(double eyex, double eyey, double eyez,
double centerx, double centery, double centerz,
double upx, double upy, double upz)
{
Matrix4d matrix = new Matrix4d ();
Vector4d eye = new Vector4d (eyex, eyey, eyez, 1.0);
Vector4d center = new Vector4d (centerx, centery, centerz, 1.0);
Vector4d up = new Vector4d (upx, upy, upz, 1.0);
Vector4d forward = new Vector4d ();
Vector4d side = new Vector4d ();
//-- make rotation matrix
// forward = center - eye
forward.minus (center, eye).normalize ();
// side = (forward x up), then normalized
side.cross (forward, up).normalize ();
// up = side x forward
up.cross (side, forward);
/* [side_x up_x -forward_x 0]
* [side_y up_y -forward_y 0]
* [side_z up_z -forward_z 0]
* [ 0 0 0 1]
*/
matrix.set_column (side, up, forward.negate (), Vector4d.ZERO);
matrix.set_row (3, 0.0, 0.0, 0.0, 1.0);
gl.mult_matrixd (matrix.m);
//-- translate eye to origin
gl.translated (-eyex, -eyey, -eyez);
}
/**
* @see <a href="gluUnProject.html">gluUnProject</a>
*/
public double[] un_project(double window_x, double window_y,
double window_z, double [] modelview, double [] projection,
int [] viewport)
{
Matrix4d product = new Matrix4d ();
Matrix4d.multiply (modelview, projection, product.m);
if (product.invert () == null) return null;
Vector4d A = new Vector4d (window_x, window_y, window_z, 1.0);
// map x and y from window coordinates
A.v [0] = (A.v [0] - viewport [0]) / viewport [2];
A.v [1] = (A.v [1] - viewport [1]) / viewport [3];
// map to range -1 to 1, A = 2*A - I
A.scalar_multiply (2).scalar_minus (1);
A.multiply_right (product);
double d = A.v [3];
if (d == 0) return null;
double [] result = new double [3]; // vs. 4
result [0] = A.v [0] / d;
result [1] = A.v [1] / d;
result [2] = A.v [2] / d;
return result;
}
public Matrix4d set_row(Vector4d V0, Vector4d V1,
Vector4d V2, Vector4d V3)
{
set_row (m, V0.v, V1.v, V2.v, V3.v);
return this;
}
/**
* @see <a href="gluProject.html">gluProject</a>
*/
public double[] project(double object_x, double object_y,
double object_z, double [] modelview, double [] projection,
int [] viewport)
{
Vector4d window = new Vector4d ();
return window.v;
}
public Matrix4d set_column(int i, Vector4d A)
{
set_column (m, i, A.v);
return this;
}
public Matrix4d set_row(int j, Vector4d A)
{
set_row (m, j, A.v);
return this;
}
public Vector4d scalar_minus(Vector4d A, double d)
{
scalar_minus (A.v, d, v);
return this;
}
public Vector4d scalar_multiply(Vector4d A, double d)
{
scalar_multiply (A.v, d, v);
return this;
}
public Vector4d normalize(Vector4d A)
{
normalize (A.v, v);
return this;
}
public Vector4d scalar_divide(Vector4d A, double d)
{
scalar_divide (A.v, d, v);
return this;
}
public Vector4d negate(Vector4d A)
{
negate (A.v, v);
return this;
}
public Vector4d multiply_right(Vector4d V, Matrix4d A)
{
double [] B = v;
if (V == this) B = new double [4];
v = multiply_right (V.v, A.m, B);
return this;
}
public Vector4d multiply_left(Matrix4d A, Vector4d V)
{
double [] B = v;
if (V == this) B = new double [4];
v = multiply_left (A.m, V.v, B);
return this;
}
public Vector4d minus(Vector4d A, Vector4d B)
{
minus (A.v, B.v, v);
return this;
}
public Vector4d cross(Vector4d A, Vector4d B)
{
double [] C = v;
if (A == this || B == this) C = new double [4];
v = cross (A.v, B.v, C);
return this;
}
