public void doPhysics(World world, int i, int j, int k, int l) {
        int i1 = world.getData(i, j, k);

        if ((i1 & 8) != 0) {
            if (world.getTypeId(i, j - 1, k) != this.id) {
                world.setTypeId(i, j, k, 0);
            }

            if (l > 0 && Block.byId[l].isPowerSource()) {
                this.doPhysics(world, i, j - 1, k, l);
            }
        } else {
            boolean flag = false;

            if (world.getTypeId(i, j + 1, k) != this.id) {
                world.setTypeId(i, j, k, 0);
                flag = true;
            }

            if (!world.d(i, j - 1, k)) {
                world.setTypeId(i, j, k, 0);
                flag = true;
                if (world.getTypeId(i, j + 1, k) == this.id) {
                    world.setTypeId(i, j + 1, k, 0);
                }
            }

            if (flag) {
                if (!world.isStatic) {
                    this.b_(world, i, j, k, i1);
                }
            } else if (l > 0 && Block.byId[l].isPowerSource()) {
                boolean flag1 = world.isBlockIndirectlyPowered(i, j, k) || world.isBlockIndirectlyPowered(i, j + 1, k);

                // CraftBukkit start
                org.bukkit.World bworld = world.getWorld();
                org.bukkit.block.Block block = bworld.getBlockAt(i, j, k);
                org.bukkit.block.Block blockTop = bworld.getBlockAt(i, j + 1, k);

                int power = block.getBlockPower();
                int powerTop = blockTop.getBlockPower();
                if (powerTop > power) power = powerTop;
                int oldPower = (world.getData(i, j, k) & 4) > 0 ? 15 : 0;

                if (oldPower == 0 ^ power == 0) {
                    BlockRedstoneEvent eventRedstone = new BlockRedstoneEvent(block, oldPower, power);
                    world.getServer().getPluginManager().callEvent(eventRedstone);

                    flag1 = eventRedstone.getNewCurrent() > 0;

                    this.setDoor(world, i, j, k, flag1);
                }
                // CraftBukkit end
            }
        }
    }