only add padding to the node being moved

This keeps the surface more stable as we move things around.

0006-on.mouse_press

@@ -25,7 +25,7 @@ on.mouse_press = function(x,y, mouse_button)
 	local node = on_handle(x,y)
 	if node then
 		-- move node
-		prepare_to_move()
+		prepare_to_move(node)
 		Move = {xoff=App.mouse_x()-vx(node.x), yoff=App.mouse_y()-vy(node.y), node=node}
 		return
 	end

0129-prepare_to_move

@@ -1,11 +1,17 @@
-prepare_to_move = function()
+-- pad out one node fully, and all other nodes just enough to keep them from overlapping.
+-- We don't want cascading movements to get too chaotic.
+prepare_to_move = function(target)
 	for _,def in pairs(Definitions) do
 		assert(def.w)
 		assert(def.h)
 		if def.pos == nil then def.pos = {} end
 		if def.hs == nil then def.hs = {} end
-		def.hs.x = def.w/2 + 50
-		def.hs.y = def.h/2 + math.max(60, math.min(def.h/3, 200))
+		def.hs.x = def.w/2
+		def.hs.y = def.h/2 + 30
+		if def == target then
+			def.hs.x = def.hs.x + 50
+			def.hs.y = def.hs.y + math.max(30, math.min(def.h/3, 200))
+		end
 		def.pos.x = def.x + def.hs.x
 		def.pos.y = def.y + def.hs.y
 	end