bool
Scene::IsLightObscured(const Point& obj_pos, const Point& light_pos, double obj_radius, Point* impact_point) const
{
Point dir = light_pos - obj_pos;
double len = dir.Normalize();
Scene* pThis = (Scene*) this; // cast-away const
Graphic* g = 0;
bool obscured = false;
ListIter<Graphic> g_iter = pThis->graphics;
while (++g_iter && !obscured) {
g = g_iter.value();
if (g->CastsShadow() && !g->Hidden() && !g->IsInfinite()) {
double gdist = (g->Location() - obj_pos).length();
if (gdist > 0.1 && // different than object being obscured
g->Radius() > obj_radius && // larger than object being obscured
(g->Radius()*400)/gdist > 10) { // projects to a resonable size
Point delta = (g->Location() - light_pos);
if (delta.length() > g->Radius() / 100) { // not the object that is emitting the light
Point impact;
obscured = g->CheckRayIntersection(obj_pos, dir, len, impact, false) ? true : false;
if (impact_point)
*impact_point = impact;
}
}
else if (obj_radius < 0 && gdist < 0.1) { // special case for camera (needed for cockpits)
Point delta = (g->Location() - light_pos);
if (delta.length() > g->Radius() / 100) { // not the object that is emitting the light
Point impact;
obscured = g->CheckRayIntersection(obj_pos, dir, len, impact, false) ? true : false;
}
}
}
}
g_iter.attach(pThis->foreground);
while (++g_iter && !obscured) {
g = g_iter.value();
if (g->CastsShadow() && !g->Hidden()) {
double gdist = (g->Location() - obj_pos).length();
if (gdist > 0.1 && // different than object being obscured
g->Radius() > obj_radius && // larger than object being obscured
(g->Radius()*400)/gdist > 10) { // projects to a resonable size
Point delta = (g->Location() - light_pos);
if (delta.length() > g->Radius() / 100) { // not the object that is emitting the light
Point impact;
obscured = g->CheckRayIntersection(obj_pos, dir, len, impact, false) ? true : false;
if (impact_point)
*impact_point = impact;
}
}
else if (obj_radius < 0 && gdist < 0.1) { // special case for camera (needed for cockpits)
Point delta = (g->Location() - light_pos);
if (delta.length() > g->Radius() / 100) { // not the object that is emitting the light
Point impact;
obscured = g->CheckRayIntersection(obj_pos, dir, len, impact, false) ? true : false;
}
}
}
}
return obscured;
}
