Gen 3 introduced Dive, a field move that can reach the seafloor, as HM08. Fully implementing Dive is fairly complicated: its in-battle effect is similar to Dig and Fly but not exactly the same, and its field effect requires a lot of changes.

(The code for this feature was adapted from [Pokémon Orange](https://github.com/PiaCarrot/pokeorange/).)

[Here](https://github.com/Rangi42/pokecrystal/commit/c21561ea717feef9b2eb3785c2ea112cd0d19ba0) are all the changes needed to implement Dive, applied to a copy of pokecrystal. You can `clone` [Rangi42/pokecrystal](https://github.com/Rangi42/pokecrystal/tree/dive) and `checkout` the `dive` branch to test it for yourself.

![Screenshot](screenshots/dive.png)


## TOC

TODO


## 1. Start to prepare the Dive move

- constants/move_constants.asm
- data/moves/names.asm
- data/moves/descriptions.asm
- data/moves/moves.asm
- data/pokemon/evos_attacks.asm


## 2. Create the Dive move animation

- constants/battle_anim_constants.asm
- data/battle_anims/objects.asm
- data/moves/animations.asm


## 3. Using Dive hides the Pokémon underwater

- constants/battle_constants.asm
- wram.asm
- engine/battle/core.asm
- engine/battle/effect_commands.asm
- engine/battle_anims/bg_effects.asm
- engine/battle/ai/scoring.asm


## 4. Surf and Whirlpool do double damage to underwater Pokémon

- constants/move_effect_constants.asm
- data/moves/moves.asm (again)
- data/moves/effects_pointers.asm
- data/moves/effects.asm
- macros/scripts/battle_commands.asm
- data/battle/effect_command_pointers.asm
- engine/battle/effect_commands.asm (again)
- engine/battle/ai/scoring.asm (again)


## 5. Prepare the HM08 item

- constants/item_constants.asm
- data/items/names.asm
- data/items/attributes.asm
- data/moves/tmhm_moves.asm
- home/hm_moves.asm
- data/pokemon/base_stats/\*.asm


## 6. Define collision types for Dive water

- constants/collision_constants.asm
- data/collision_permissions.asm
- engine/overworld/tile_events.asm


## 7. Start to prepare the Dive field move effect

- constants/menu_constants.asm
- data/mon_menu.asm
- engine/menus/start_menu.asm


## 8. Define a utility function to check for Dive water

- home/map_objects.asm


## 9. Define text related to using Dive

- data/text/common_2.asm


## 10. Define the `divemap` and `divewarp` event commands

- wram.asm
- macros/scripts/events.asm
- engine/overworld/scripting.asm
- home/flag.asm
- engine/overworld/warp_connection.asm


## 11. Finish the Dive field move effect

- engine/events/overworld.asm


## 12. Press A on Dive water to use Dive

- engine/overworld/events.asm


## 13. Design a sprite for swimming underwater

- gfx/sprites/dive.png
- constants/sprite_constants.asm
- data/sprites/sprites.asm
- gfx/sprites.asm


## 14. Use the sprite for the player when underwater

- constants/wram_constants.asm
- data/sprites/player_sprites.asm
- engine/events/overworld.asm (again)
- engine/overworld/map_setup.asm
- engine/overworld/player_movement.asm


## 15. Start creating a unique tileset for underwater maps

- constants/tileset_constants.asm
- gfx/tilesets/underwater.png
- gfx/tilesets/underwater_palette_map.asm
- data/tilesets/underwater_metatiles.bin
- data/tilesets/underwater_collision.asm
- data/tilesets.asm
- gfx/tileset_palette_maps.asm
- gfx/tilesets.asm


## 16. Can't Fly while underwater

- engine/events/overworld.asm (again)


## 17. Animate underwater seaweed and bubbles

- gfx/tilesets/bubble/1.png
- gfx/tilesets/bubble/2.png
- gfx/tilesets/bubble/3.png
- gfx/tilesets/bubble/4.png
- gfx/tilesets/bubble/5.png
- gfx/tilesets/seaweed/1.png
- gfx/tilesets/seaweed/2.png
- engine/tilesets/tileset_anims.asm


## 17. Use special palettes for underwater tiles and sprites

- gfx/tilesets/underwater.pal
- gfx/tilesets/underwater_sprites.pal
- engine/tilesets/tileset_palettes.asm
- engine/gfx/color.asm


## 18. Fix bugs that affect the Dive features

- engine/overworld/overworld.asm
- home/map.asm


## 19. Receive HM08 Dive and explain it

- constants/event_flags.asm
- maps/CeruleanGym.asm


## 20. Add deep water to an overworld tileset

- gfx/tilesets/johto.png
- gfx/tilesets/johto_palette_map.asm
- data/tilesets/johto_collision.asm
- data/tilesets/johto_metatiles.bin
- gfx/tilesets/water/deep-water.png
- engine/tilesets/tileset_anims.asm (again)


## 21. Add a map with Dive spots

- maps/Route41.blk
- maps/Route41.asm
- maps/Route41Underwater.blk
- maps/Route41Underwater.asm
- constants/event_flags.asm (again)
- constants/map_constants.asm
- data/maps/maps.asm
- data/maps/attributes.asm
- data/wild/johto_grass.asm
- data/maps/blocks.asm
- data/maps/scripts.asm
- data/maps/roofs.asm
- data/maps/outdoor_sprites.asm