detect paintings

How do I know whether there is a painting on a block or alternatively how can I detect a painting dropping?
TIA

 

Paintings are a pain (as I discovered when making my PaintingSwitch plugin). They're entity not blocks so dont trigger block events, and they're not living entities so don't trigger the entity events.
With some (rather advanced) minecraft hackery you can search for all paintings within an area. The principals are the same as I layed out in this thread:
http://forums.bukkit.org/threads/monsters-in-an-area.7386/

 

Awesome stuff. I was thinking about going through the whole entities list at first as a last resort, but this seems like a lot more efficient way of finding it. Thanks a bunch.
Edit: I had a look at the craftbukkit code and looks like it doesn't actually have the entities but in a list in the first place, so its not like it speeds up anything. Nonetheless I would never had gotten the blocks on which paintings are without the minecraft hackery you taught me here. But it was very tricky to get them since they behave differently in each direction, so in case anyone is interested in the result of my minecraft hackery:

Code:

			CraftWorld craftWorld = (CraftWorld)w;
			bb= AxisAlignedBB.a((double)ns.xs,(double)ns.ys,(double)ns.zs,(double)ns.xl,(double)ns.yl,(double)ns.zl);
			List entities = craftWorld.getHandle().b(null, bb);

			for(Object o:entities){
				if (o instanceof EntityPainting){
					EntityPainting p=(EntityPainting)o;
					AxisAlignedBB pbb=p.boundingBox;
					int px=p.b;//block its on
					int py=p.c;
					int pz=p.d;
					int sx=Math.max(1,(int)(pbb.d-pbb.a+0.1));//size
					int sy=Math.max(1,(int)(pbb.e-pbb.b+0.1));
					int sz=Math.max(1,(int)(pbb.f-pbb.c+0.1));
					int xmin,ymin=py,zmin,xmax,ymax=py+sy,zmax;
					switch(p.a){//direction
						case 1:
							zmin=pz;
							zmax=pz+sz;
							xmax=1+(xmin=px-1);
							break;
						case 2:
							xmin=px;
							xmax=px+sx;
							zmax=(zmin=pz+1)+1;
							break;
						case 3:
							zmin=(zmax=pz+1)-sz;
							xmax=(xmin=px+1)+1;
							break;
						default:
							xmin=(xmax=px+1)-sx;
							zmax=1+(zmin=pz-1);
					}

					for(int x=xmin;x<xmax;x++)
						for(int y=ymin;y<ymax;y++)
							for(int z=zmin;z<zmax;z++)
								paintingBlocks.add(w.getBlockAt(x,y,z));
				}
			}

 

Nice work!

 

It's actually slightly more efficient than craftbukkit will let you do. It doesn't search the whole entities list. The server keeps separate lists of entities for each chunk. The search only searches through chunks in which the bounding box lies, making it far better than searching every single entity on the server.

But you are right. Paintings are a pain.

 

That's good to hear, I can already feel my painting handler is speeding up now. Anyways thanks again.