static void longLatLabel(const string& labelText,
double longitude,
double latitude,
const Vec3d& viewRayOrigin,
const Vec3d& viewNormal,
const Vec3d& bodyCenter,
const Quatd& bodyOrientation,
const Vec3f& semiAxes,
float labelOffset,
Renderer* renderer)
{
double theta = degToRad(longitude);
double phi = degToRad(latitude);
Vec3d pos(cos(phi) * cos(theta) * semiAxes.x,
sin(phi) * semiAxes.y,
-cos(phi) * sin(theta) * semiAxes.z);
float nearDist = renderer->getNearPlaneDistance();
pos = pos * (1.0 + labelOffset);
double boundingRadius = max(semiAxes.x, max(semiAxes.y, semiAxes.z));
// Draw the label only if it isn't obscured by the body ellipsoid
double t = 0.0;
if (testIntersection(Ray3d(Point3d(0.0, 0.0, 0.0) + viewRayOrigin, pos - viewRayOrigin),
Ellipsoidd(Vec3d(semiAxes.x, semiAxes.y, semiAxes.z)), t) && t >= 1.0)
{
// Compute the position of the label
Vec3d labelPos = bodyCenter +
(1.0 + labelOffset) * pos * bodyOrientation.toMatrix3();
// Calculate the intersection of the eye-to-label ray with the plane perpendicular to
// the view normal that touches the front of the objects bounding sphere
double planetZ = viewNormal * bodyCenter - boundingRadius;
if (planetZ < -nearDist * 1.001)
planetZ = -nearDist * 1.001;
double z = viewNormal * labelPos;
labelPos *= planetZ / z;
renderer->addObjectAnnotation(NULL, labelText,
Renderer::PlanetographicGridLabelColor,
Point3f((float) labelPos.x, (float) labelPos.y, (float) labelPos.z));
}
}
Point3d SynchronousOrbit::positionAtTime(double jd) const
{
Quatd q = body.getEquatorialToBodyFixed(jd);
return position * q.toMatrix3();
}