Spreading Lilypads transparently adds growth behaviour to existing lily pads. Lily Pads will now spread (much like mushrooms do) in shallow water that has natural "soil" beneath. This makes Lily Pads a renewable resource. There is no new worldgen. This works with existing lilypads in existing worlds.
World-generated lilypads in swamps and other biomes will begin to spread when the player gets near. The spread is slow, but if the player is near for long enough they'll carpet the swampy shallows, spread out into nearby shallow waters of other biomes, and choke small ponds. It looks pretty neat.
Breaking lily pads works as normal: you get a placeable Lily Pad block item that you can transplant elsewhere. If you want it to grow, make sure you've got shallow water and appropriate soil (dirt, clay, sand, grass). If you don't want it to grow, make sure the water is either too deep, or the bottom is made of a non-soil block (such as smooth stone, brick, hardened clay, etc.).
This is what a swamp biome can look like after several solid days of lilypad growth:
Spreading mechanics in detail
Lily Pads will receive plant growth ticks now, just like crops and mushrooms do. One in 10 ticks will result in a spreading attempt. A lilypad that has five other lilypads within one block of it will not attempt to spread further. Otherwise, a random air block above water within one block will be selected and checked for whether it's a valid spreading location, and this is repeated up to four times before giving up if no valid spread location is found.
A valid spreading location is determined by the depth of the water and the type of block below the water. Lilypads will spread to locations above up to two blocks of still water with a "soil" type block beneath the water. "Soils" include dirt, clay, sand, and grass.
This was developed on Forge 22.214.171.1244 (for Minecraft 1.6.2), but any reasonably-recent Forge version should be compatible.
Spreading Lilypads makes no base edits to vanilla Minecraft classes, so it should be compatible with any Forge-compatible mod that doesn't also attempt to alter Lily Pad blocks.
One block ID is used that defaults to 1700, but which can be changed in the config file.
Drop the zip file in your mods folder (creating the mods folder if necessary).
Remove the zip file from your mods folder.
When you uninstall, all the new lilypads will disappear from your world, leaving only original world-generated lilypads and hand-placed ones. Neat, eh?
So don't worry about the lilypads taking over your wetlands and ponds; if you end up not liking the effect, you can safely revert all the changes this mod makes by simply removing it from your mods folder and loading your world without it.
Spreading Lilypads is open source, using the 2-clause BSD license (see the LICENSE file inside the zip file or LICENSE in the code repo for a copy of the license). That means you have the freedom to do quite a bit with this, including using it in a modpack without needing to ask for my permission first. (Though if you do, feel free to let me know so I can be all proud.)
The source is available in my Spreading Lilypads GitHub repo and may or may not work at any given time, but you are welcome to take a look at it, fork it, and submit issues there (as well as report bugs here).
If i go afk for 1 hour,with 26 lillypads near me,in the ocean,how many lillypads will be there?
Like wheat and mushrooms growing, it's somewhat random. I haven't timed it yet to find out the average growth rate under optimal conditions, but if I had to guess... that will probably at least double in an hour, if not triple? Maybe? Let me know if you try it.
(Of course, they won't do anything if they're in ocean deeper than two water blocks, because they only grow to places of shallow water.)