/**
* Find out where on the terrain surface the eye would be looking at with the given heading and
* pitch angles.
*
* @param view the orbit view
* @param heading heading direction clockwise from north.
* @param pitch view pitch angle from the surface normal at the center point.
* @return the terrain surface point the view would be looking at in the viewport center.
*/
protected Vec4 computeSurfacePoint(OrbitView view, Angle heading, Angle pitch) {
Globe globe = wwd.getModel().getGlobe();
// Compute transform to be applied to north pointing Y so that it would point in the view
// direction
// Move coordinate system to view center point
Matrix transform = globe.computeSurfaceOrientationAtPosition(view.getCenterPosition());
// Rotate so that the north pointing axes Y will point in the look at direction
transform = transform.multiply(Matrix.fromRotationZ(heading.multiply(-1)));
transform = transform.multiply(Matrix.fromRotationX(Angle.NEG90.add(pitch)));
// Compute forward vector
Vec4 forward = Vec4.UNIT_Y.transformBy4(transform);
// Return intersection with terrain
Intersection[] intersections =
wwd.getSceneController().getTerrain().intersect(new Line(view.getEyePoint(), forward));
return (intersections != null && intersections.length != 0)
? intersections[0].getIntersectionPoint()
: null;
}
/**
* Indicates the transform matrix applied to this document.
*
* @return Transform matrix.
*/
protected Matrix getMatrix() {
// If the matrix has already been computed then just return the cached value.
if (this.matrix != null) return this.matrix;
Matrix m = Matrix.IDENTITY;
if (this.heading != null)
m = m.multiply(Matrix.fromRotationZ(Angle.POS360.subtract(this.heading)));
if (this.pitch != null) m = m.multiply(Matrix.fromRotationX(this.pitch));
if (this.roll != null) m = m.multiply(Matrix.fromRotationY(this.roll));
// Apply scaling factor to convert file units to meters.
double scale = this.getScale();
m = m.multiply(Matrix.fromScale(scale));
if (this.modelScale != null) m = m.multiply(Matrix.fromScale(this.modelScale));
this.matrix = m;
return m;
}
