aede7551a3
- Created detailed documentation for the Minecart sprite, outlining its properties, constants, collision setup, main logic, and design patterns. - Added documentation for the Pedestal sprite, including its vanilla overrides, custom logic for item interaction, and event triggering based on area context. - Introduced documentation for the Portal sprite, detailing its two-way warping system, initialization, main logic, and helper routines for seamless transitions. - Documented the Switch Track sprite, explaining its interactive behavior, state-based animation, and integration with external switches for dynamic track manipulation.
96 lines
3.2 KiB
Markdown
96 lines
3.2 KiB
Markdown
# Ranch Girl
|
|
|
|
## Overview
|
|
The `ranch_girl.asm` file defines the behavior for the "Ranch Girl" NPC, who is involved in a "Chicken Easter Egg" quest. This character plays a crucial role in granting Link the Ocarina and teaching him a song. Her behavior is implemented as a vanilla override, modifying the existing `ChickenLady` routine.
|
|
|
|
## Vanilla Overrides
|
|
This file directly modifies the vanilla `ChickenLady` routine at `org $01AFECF` to inject custom logic for the Ranch Girl's interactions.
|
|
|
|
## `RanchGirl_Message`
|
|
This routine handles the dialogue displayed by the Ranch Girl. It checks Link's Ocarina status (`$7EF34C`).
|
|
|
|
* If Link already possesses the Ocarina, it displays message `$010E`.
|
|
* Otherwise, it displays message `$017D` and sets `SprMiscD, X` to `$01`, indicating the start of the Ocarina quest.
|
|
|
|
```asm
|
|
RanchGirl_Message:
|
|
{
|
|
LDA $7EF34C : CMP.b #$01 : BCS .has_ocarina
|
|
%ShowUnconditionalMessage($017D)
|
|
LDA #$01 : STA.w SprMiscD, X
|
|
RTL
|
|
.has_ocarina
|
|
%ShowUnconditionalMessage($010E)
|
|
RTL
|
|
}
|
|
```
|
|
|
|
## `RanchGirl_TeachSong`
|
|
This routine is responsible for teaching Link a song (specifically the "Song of Storms") and granting him the Ocarina. It checks the Ocarina quest flag (`SprMiscD, X`) and Link's current Ocarina status (`$7EF34C`).
|
|
|
|
* If the conditions are met, it plays the "Song of Storms" sound, gives Link the Ocarina (`LDY #$14`, `JSL Link_ReceiveItem`), and sets `$7EF34C` to `$01`.
|
|
|
|
```asm
|
|
RanchGirl_TeachSong:
|
|
{
|
|
LDA.w SprMiscD, X : CMP.b #$01 : BNE .not_started
|
|
LDA $10 : CMP.b #$0E : BEQ .running_dialog
|
|
LDA $7EF34C : CMP.b #$01 : BCS .has_song
|
|
|
|
; Play the song of storms
|
|
LDA.b #$2F
|
|
STA.w $0CF8
|
|
JSL $0DBB67 ; Link_CalculateSFXPan
|
|
ORA.w $0CF8
|
|
STA $012E ; Play the song learned sound
|
|
|
|
; Give Link the Ocarina
|
|
LDY #$14
|
|
; Clear the item receipt ID
|
|
STZ $02E9
|
|
PHX
|
|
JSL Link_ReceiveItem
|
|
PLX
|
|
|
|
LDA #$01 : STA $7EF34C ; The item gives 02 by default, so decrement that for now
|
|
|
|
.not_started
|
|
.running_dialog
|
|
.has_song
|
|
LDA.b $1A : LSR #4 : AND.b #$01 : STA.w $0DC0,X
|
|
|
|
RTL
|
|
}
|
|
```
|
|
|
|
## `ChickenLady` (Vanilla Override)
|
|
This is the main entry point for the Ranch Girl's custom behavior, overriding the vanilla `ChickenLady` routine. It sets `SprMiscC, X` to `$01`, calls vanilla drawing and activity check routines, and then executes `RanchGirl_Message` and `RanchGirl_TeachSong`.
|
|
|
|
```asm
|
|
org $01AFECF
|
|
ChickenLady:
|
|
{
|
|
JSR .main
|
|
RTL
|
|
|
|
.main
|
|
LDA.b #$01 : STA.w SprMiscC, X
|
|
|
|
JSL SpriteDraw_RaceGameLady
|
|
JSR Sprite_CheckIfActive_Bank1A
|
|
|
|
LDA.w SprTimerA, X : CMP.b #$01 : BNE .no_message
|
|
JSL RanchGirl_Message
|
|
.no_message
|
|
JSL RanchGirl_TeachSong
|
|
.return
|
|
RTS
|
|
}
|
|
```
|
|
|
|
## Design Patterns
|
|
* **Vanilla Override**: This file directly modifies a vanilla routine (`ChickenLady`) to implement custom NPC behavior, demonstrating a common ROM hacking technique.
|
|
* **Quest Gating/Progression**: The Ranch Girl's dialogue and the granting of the Ocarina are tied to Link's possession of the Ocarina and the state of the Ocarina quest, integrating her into the game's progression system.
|
|
* **Item Granting**: The Ranch Girl serves as a source for the Ocarina, a key item in the game.
|
|
* **Game State Manipulation**: Directly modifies `$7EF34C` (Ocarina flag) and `SprMiscD, X` (quest flag) to track and influence game state.
|