pokecrystal-board/docs/develop/workflows.md

Overworld workflow

1. OverworldLoop is called from GameMenu_World with either hMapEntryMethod = MAPSETUP_ENTERLEVEL or hMapEntryMethod = MAPSETUP_CONTINUE.
2. StartMap resets wCurTurn and wCurSpace if MAPSETUP_ENTERLEVEL. StartMap sets hCurBoardEvent to BOARDEVENT_DISPLAY_MENU. wEnabledPlayerEvents is cleared. wMapStatus is set to MAPSTATUS_HANDLE causing HandleMap to be called.
3. MapEvents (from HandleMap) calls PlayerEvents. CheckBoardEvent queues BoardMenuScript which is executed by ScriptEvents.
4. BoardMenuScript.Upkeep saves the game, clears wTurnData[], increases wCurTurn, and loads current space to wCurSpaceStruct[].
   • If player exits, the exitoverworld script sets wMapStatus to MAPSTATUS_DONE. This causes OverworldLoop to return back to the game menu. Exit this workflow.
5. Player rolls die and the animation plays. After the animation, wDisplaySecondarySprites.SECONDARYSPRITES_SPACES_LEFT_F is set and hCurBoardEvent is set to BOARDEVENT_HANDLE_BOARD. At the end of this HandleMap iteration, CheckPlayerState sets wMapEventStatus to MAPEVENTS_ON (wEnabledPlayerEvents is not touched so it remains cleared).
6. In the next HandleMap iteration, CheckBoardEvent from PlayerEvents jumps to .board and then to .no_space_effect due to wEnabledPlayerEvents[4] not being set.
7. Execution continues in PlayerEvents; OWPlayerInput is eventually called, and thus DoPlayerMovement. Here, StepTowardsNextSpace computes based on wCurSpaceNextSpace what direction key to write to wCurInput, causing the player to begin a movement in that direction.
8. The player may need to turn to a different direction through the ChangeDirectionScript (when DoPlayerMovement returns with PLAYERMOVEMENT_TURN). Otherwise or after that, CheckPlayerState sets wMapEventStatus to MAPEVENTS_OFF,
9. When the step finishes (i.e. PLAYERSTEP_STOP_F becomes set) in some HandleMap iteration, CheckPlayerState sets wEnabledPlayerEvents to $ff and wMapEventStatus to MAPEVENTS_ON.
10. In the next HandleMap iteration, CheckBoardEvent.board is called with wEnabledPlayerEvents[4] set.
    • If wCurSpaceNextSpace matches NEXT_SPACE_IS_ANCHOR_POINT: If player is at a tile with an anchor event, wCurSpaceNextSpace is updated with the next space byte of salid anchor event. wEnabledPlayerEvents[4] is reset. Go back to 7.
    • If player is not above a tile (wPlayerTileCollision) with a space collision: wEnabledPlayerEvents[4] is reset. Go back to 7.
    • If player is above a tile, the corresponding space script is queued to be executed by ScriptEvents in the current HandleMap iteration. wEnabledPlayerEvents[4] is reset. Continue to 11.
11. The space script loads the value of wCurSpaceNextSpace into wCurSpace, and loads the new space data to wCurSpaceStruct[]. Unless the space is a Branch Space or a Union Space, wSpacesLeft is decreased.
    • If the space is a Branch Space, the branch data is loaded to wTempSpaceBranchStruct. Then the player is prompted to choose a valid direction. wCurSpaceNextSpace is populated with the next space that corresponds to the chosen direction. Go back to 6.
    • If the space is an End Space, a fading out animation plays and then the exitoverworld script sets wMapStatus to MAPSTATUS_DONE. This causes OverworldLoop to return back to the game menu. Exit this workflow.
12. If wSpacesLeft is non-0, go back to 6.
13. The script code specific to the space type of the landed-on space is executed.
    • If player whites out in battle, Script_BattleWhiteout executes exitoverworld. Exit this workflow.
14. The landed-on space is disabled by executing a block change that converts it into a Grey Space. hCurBoardEvent is set to BOARDEVENT_END_TURN. CheckBoardEvent does nothing in this state. In the first subsequent HandleMap iteration where no other kind of event triggers causing PlayerEvents to return early, hCurBoardEvent is set to BOARDEVENT_DISPLAY_MENU.
15. Go back to 3

View Map mode workflow

1. Pressing SELECT in the board menu triggers View Map mode. hCurBoardEvent is set to BOARDEVENT_VIEW_MAP_MODE, player state (coordinates as well as current map in order to support connected maps) is backed up, wPlayerFlags[INVISIBLE_F] is set, and a static mockup of the player object is loaded to the last wMapObject and, in the background, to the first wObjectStruct is available.
2. The board event handler in CheckBoardEvent listens for the B button being pressed (except when a DPAD key is simultaneously held). When B is pressed, a script (a single reloadmapafterviewmapmode) to exit from View Map mode is queued to be executed by ScriptEvents. Otherwise, DoPlayerMovement.ViewMapMode handles movement input in this mode.
3. When requested exit of View Map mode via B button, reloadmapafterviewmapmode sets hMapEntryMethod to MAPSETUP_EXITVIEWMAP, hMapEntryMethod to SPAWN_FROM_RAM (required by the map setup command EnterMapSpawnPoint to restore the backed up player state), loads MAPSTATUS_ENTER tp wMapStatus, and resets wPlayerFlags[INVISIBLE_F] (the mocked player object naturally disappears when the map reloads).
4. Then: a) If View Map mode was entered from the board menu, BOARDEVENT_REDISPLAY_MENU is loaded. It is the same as BOARDEVENT_DISPLAY_MENU but skips BoardMenuScript.Upkeep. b) If View Map mode was entered from the branch menu, instead BOARDEVENT_RESUME_BRANCH is loaded, using wPlayerSpriteSetupFlags[PLAYERSPRITESETUP_CUSTOM_FACING_F] to maintain the facing direction according to the direction (SPRITEMOVEDATA_*) of the mocked player object. BOARDEVENT_RESUME_BRANCH makes sure to shortcut the branch space script by calling BranchSpaceScript_PromptPlayer directly and avoiding the recomputation of the branch struct that would cause corruption. BOARDEVENT_HANDLE_BOARD is loaded immediately by BOARDEVENT_RESUME_BRANCH.

• In View Map mode, regular collisions except for COLL_OUT_OF_BOUNDS are ignored whereas going off-limits (i.e. outside of the map limits in a direction where there is no connected map) or off-range is accounted for.
• Events other than warpless connections are ignored in View Map mode (as well as button actions, like while in BOARDEVENT_HANDLE_BOARD).
• wTileDown, wTileUp, etc., otherwise unused, are borrowed by in order to signal valid directions to InitSecondarySprites (e.g. wTileDown=COLL_OUT_OF_BOUNDS means that DOWN direction is not valid).
• In View Map mode, the overworld delay is 1 rather than 2.
• UpdatePlayerCoords tracks the displacement during View Map mode in the X and Y axes in order to monitor the allowed range.