From c99444d1b94ce1938fb04022e610ee135720b76a Mon Sep 17 00:00:00 2001 From: xCrystal Date: Wed, 18 Oct 2023 20:04:11 +0200 Subject: [PATCH] Documentation --- docs/develop/index.md | 47 ++++++++++++++++++++++++++++++++++--- engine/overworld/events.asm | 6 ++--- 2 files changed, 47 insertions(+), 6 deletions(-) diff --git a/docs/develop/index.md b/docs/develop/index.md index f368c9fd5..11880cab6 100755 --- a/docs/develop/index.md +++ b/docs/develop/index.md @@ -72,7 +72,7 @@ - **refreshscreen**: RefreshScreen - **reloadmappart**: LoadScreenTilemapAndAttrmapPals + GetMovementPermissions + HDMATransferTilemapAndAttrmap_OverworldEffect + UpdateSprites. Similar to refreshscreen, but does not reanchor. On the other hand, it refreshes movement permissions. Often used after a block change or field move, which can affect collisions. -## Overworld loop +## Overworld loop (pokecrystal) ``` Primary functions are denoted in red and using indentation @@ -300,9 +300,9 @@ wMapStatus == MAPSTATUS_HANDLE: the remainder of the code goes at this level< > **HandleMapBackground** _UpdateSprites + ScrollScreen > CheckPlayerState:\ -> wPlayerStepFlags[PLAYERSTEP_CONTINUE_F] == TRUE:\ +> wPlayerStepFlags[PLAYERSTEP_CONTINUE_F] == FALSE:\ > $~~~~$wMapEventStatus <= MAPEVENTS_ON\ -> wPlayerStepFlags[PLAYERSTEP_STOP_F] == TRUE or wPlayerStepFlags[PLAYERSTEP_MIDAIR_F] == TRUE:\ +> wPlayerStepFlags[PLAYERSTEP_CONTINUE_F] == TRUE and (wPlayerStepFlags[PLAYERSTEP_STOP_F] == FALSE or wPlayerStepFlags[PLAYERSTEP_MIDAIR_F] == TRUE):\ > $~~~~$wMapEventStatus <= MAPEVENTS_OFF\ > else:\ > $~~~~$wScriptFlags2 <= \$ff\ @@ -334,3 +334,44 @@ $~~~~$wPlayerTurningDirection <= \ | 1 << 7\ $~~~~$then always returns PLAYERMOVEMENT_FINISH but often is overwritten by caller --- + +## Board behavior + +### RAM addresses + +- **hCurBoardEvent**: holds a *BOARDEVENT_* value. + +- **wTurnData** ~ **wTurnDataEnd**: not preserved on save, and cleared at the beginning of BoardMenuScript (i.e. on turn begin). It's part of *wMapStatus* ~ *wMapStatusEnd*, so it's also cleared by *StartMap*. + - **wDieRoll** + - **wSpacesLeft** + +- Addresses within *wCurMapData* ~ *wCurMapDataEnd*: preserved on save. + - **wCurTurn** + - **wCurSpace** + - **wCurSpaceData**: + - **wCurSpaceXCoord** + - **wCurSpaceYCoord** + - **wCurSpaceEffect** + - **wCurSpaceNextSpace**. + +- **wTempSpaceData**: shares memory region with string buffers from *wStringBuffer3* onwards. Temporary scope. Same structure as *wCurSpaceData* + +### Workflow + +1) ``OverworldLoop`` is called from ``GameMenu_WorldMap`` 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``. ``wScriptFlags2`` 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 ``wCurSpaceData[]``. + - If player exits, the ``exitoverworld`` script sets ``wMapStatus`` to ``MAPSTATUS_DONE``. This causes ``OverworldLoop`` to return back to the game menu. +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`` (``wScriptFlags2`` 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 ``wScriptFlags2[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 ``wScriptFlags2`` to $ff and ``wMapEventStatus`` to ``MAPEVENTS_ON``. +10) In the next ``HandleMap`` iteration, ``CheckBoardEvent.board`` is called with ``wScriptFlags2[4]`` set. Then ``wScriptFlags2[4]`` is reset. + - If player is not above a tile (``wPlayerTile``) with a space collision, go back to 7). +11) The corresponding space script is queued to be executed by ``ScriptEvents`` in the current ``HandleMap`` iteration. ``wScriptFlags2[4]`` is reset. +12) The space script loads the value of ``wCurSpaceNextSpace`` into ``wCurSpace``, loads the new space data to ``wCurSpaceData[]``, and decreases ``wSpacesLeft``. + - If ``wSpacesLeft`` is non-0, go back to 7). +13) ``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``. +14) Go back to 3) \ No newline at end of file diff --git a/engine/overworld/events.asm b/engine/overworld/events.asm index 5929f7845..3563769d1 100644 --- a/engine/overworld/events.asm +++ b/engine/overworld/events.asm @@ -247,11 +247,11 @@ HandleMapBackground: CheckPlayerState: ld a, [wPlayerStepFlags] bit PLAYERSTEP_CONTINUE_F, a - jr z, .events + jr z, .events ; PLAYERSTEP_CONTINUE_F not set bit PLAYERSTEP_STOP_F, a - jr z, .noevents + jr z, .noevents ; PLAYERSTEP_CONTINUE_F set and PLAYERSTEP_STOP_F not set bit PLAYERSTEP_MIDAIR_F, a - jr nz, .noevents + jr nz, .noevents ; PLAYERSTEP_CONTINUE_F, PLAYERSTEP_STOP_F, and PLAYERSTEP_MIDAIR_F all set call EnableEvents .events ld a, MAPEVENTS_ON