void TraverseRayAndMarkVisible(Vec3i fromPos, Vec3i toPosRel, double yoffset = 0.5)
{
ray.origin.Set(fromPos.X + 0.5, fromPos.Y + yoffset, fromPos.Z + 0.5);
ray.dir.Set(toPosRel);
toPos.Set(fromPos.X + toPosRel.X, fromPos.Y + toPosRel.Y, fromPos.Z + toPosRel.Z);
curpos.Set(fromPos);
BlockFacing fromFace = null, toFace;
int manhattenLength = fromPos.ManhattenDistanceTo(toPos);
int curMhDist;
while ((curMhDist = curpos.ManhattenDistanceTo(fromPos)) <= manhattenLength + 2)
{
// Since chunks are arranged in a uniform grid, all we have to do is to find out on
// what facing (N/E/S/W/U/D) the ray leaves the chunk and move into that direction.
// This may seem inaccurate, but works surpisingly well
toFace = GetExitingFace(curpos);
if (toFace == null)
{
return;
}
long index3d = ((long)curpos.Y * game.WorldMap.chunkMapSizeZFast + curpos.Z) * game.WorldMap.chunkMapSizeXFast + curpos.X;
ClientChunk chunk = null;
game.WorldMap.chunks.TryGetValue(index3d, out chunk);
if (chunk != null)
{
chunk.SetVisible(true);
if (curMhDist > 1 && !chunk.IsTraversable(fromFace, toFace))
{
break;
}
}
curpos.Offset(toFace);
fromFace = toFace.GetOpposite();
if (!game.WorldMap.IsValidChunkPosFast(curpos.X, curpos.Y, curpos.Z) && (!isAboveHeightLimit || curpos.Y <= 0))
{
break;
}
}
}