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.
123 lines
4.0 KiB
Markdown
123 lines
4.0 KiB
Markdown
# Eon Scrub
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## Overview
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The Eon Scrub is a custom enemy sprite, likely a variation of the Business Scrub, that overrides a vanilla sprite ID. It shares similar characteristics with the Business Scrub, including low health and harmless contact damage, implying its primary threat comes from projectiles or other interactions defined within its main logic.
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## Sprite Properties
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* **`!SPRID`**: `$00` (Vanilla sprite ID, likely overridden)
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* **`!NbrTiles`**: `$02`
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* **`!Health`**: `$01`
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* **`!Damage`**: `$00` (Harmless contact)
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* **`!Harmless`**: `$00`
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* **`!Hitbox`**: `$08`
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* **`!ImperviousAll`**: `$00`
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* **`!Statue`**: `$00`
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* **`!Prize`**: `$00`
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* **`!Boss`**: `$00`
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* **Collision Properties**: All collision-related properties (`!Defl`, `!SprColl`, etc.) are set to `$00`, indicating that direct contact damage and knockback are not handled by these properties. Interaction and damage are likely managed within the sprite's main logic.
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## Main Structure (`Sprite_EonScrub_Long`)
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This routine is the main entry point for the Eon Scrub, executed every frame. It sets up bank registers, calls the drawing routine, and then executes the main logic if the sprite is active.
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```asm
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Sprite_EonScrub_Long:
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{
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PHB : PHK : PLB
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JSR Sprite_EonScrub_Draw
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JSL Sprite_DrawShadow
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JSL Sprite_CheckActive : BCC .SpriteIsNotActive
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JSR Sprite_EonScrub_Main
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.SpriteIsNotActive
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PLB
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RTL
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}
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```
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## Initialization (`Sprite_EonScrub_Prep`)
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This routine runs once when the Eon Scrub is spawned. It initializes the sprite's action state to `0` and sets a general-purpose timer (`SprTimerA`) to `120` frames (2 seconds).
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```asm
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Sprite_EonScrub_Prep:
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{
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PHB : PHK : PLB
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%GotoAction(0)
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%SetTimerA(120)
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PLB
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RTL
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}
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```
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## Main Logic & State Machine (`Sprite_EonScrub_Main`)
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The core behavior of the Eon Scrub is managed by a state machine using `%SpriteJumpTable`. The current states are:
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* **`State_Idle`**: The initial state where the scrub is idle. It plays an animation and checks for player proximity. If Link is within 80 pixels, it transitions to `State_Attacking`.
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* **`State_Attacking`**: In this state, the scrub plays an attack animation, moves towards the player, and deals damage on contact. It also checks if it has been hit by the player and transitions to `State_Hurt` if so.
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* **`State_Hurt`**: This state handles the sprite being hit, causing it to flash and be knocked back.
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```asm
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Sprite_EonScrub_Main:
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{
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%SpriteJumpTable(State_Idle, State_Attacking, State_Hurt)
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State_Idle:
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{
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%PlayAnimation(0, 1, 15)
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JSL GetDistance8bit_Long : CMP.b #$50 : BCS .player_is_far
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%GotoAction(1)
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.player_is_far
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RTS
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}
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State_Attacking:
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{
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%PlayAnimation(2, 3, 8)
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%MoveTowardPlayer(12)
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%DoDamageToPlayerSameLayerOnContact()
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JSL Sprite_CheckDamageFromPlayer : BCC .no_damage
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%GotoAction(2)
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.no_damage
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RTS
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}
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State_Hurt:
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{
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JSL Sprite_DamageFlash_Long
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RTS
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}
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}
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```
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## Drawing (`Sprite_EonScrub_Draw`)
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The drawing routine uses the `%DrawSprite()` macro to render the sprite's graphics based on defined OAM data tables.
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```asm
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Sprite_EonScrub_Draw:
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{
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%DrawSprite()
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.start_index
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db $00, $02, $04, $06
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.nbr_of_tiles
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db 1, 1, 1, 1
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.x_offsets
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dw -8, 8, -8, 8, -8, 8, -8, 8
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.y_offsets
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dw -8, -8, -8, -8, -8, -8, -8, -8
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.chr
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db $C0, $C2, $C4, $C6, $C8, $CA, $CC, $CE
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.properties
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db $3B, $7B, $3B, $7B, $3B, $7B, $3B, $7B
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}
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```
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## Design Patterns
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* **State Machine**: Utilizes a clear state machine (`%SpriteJumpTable`) for managing different behaviors (Idle, Attacking, Hurt).
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* **Player Interaction**: Incorporates distance checks (`GetDistance8bit_Long`) to trigger state changes and direct damage on contact (`DoDamageToPlayerSameLayerOnContact`).
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* **Damage Handling**: Includes a basic damage reaction (`Sprite_CheckDamageFromPlayer`, `Sprite_DamageFlash_Long`).
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* **Vanilla ID Override**: The use of `!SPRID = $00` suggests this sprite is intended to replace or modify the behavior of a vanilla sprite with ID $00.
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