1cc7d84782
- Introduced comprehensive documentation for the Puffstool sprite, covering properties, core routines, and key behaviors. - Added analysis for the Sea Urchin sprite, detailing its initialization, state management, and drawing routines. - Included a thorough examination of the Thunder Ghost sprite, highlighting its dynamic health, lightning attack mechanics, and movement patterns.
329 lines
12 KiB
Markdown
329 lines
12 KiB
Markdown
# Darknut Sprite Analysis
|
|
|
|
This document provides a detailed analysis of the `darknut.asm` sprite, outlining its properties, core routines, and behavioral patterns.
|
|
|
|
## 1. Sprite Properties
|
|
|
|
The following `!SPRID` constants define Darknut's fundamental characteristics:
|
|
|
|
```asm
|
|
!SPRID = Sprite_Darknut
|
|
!NbrTiles = 03 ; Number of tiles used in a frame
|
|
!Harmless = 00 ; 00 = Sprite is Harmful, 01 = Sprite is Harmless
|
|
!HVelocity = 00 ; Is your sprite going super fast? put 01 if it is
|
|
!Health = 12 ; Number of Health the sprite have (dynamically set in _Prep)
|
|
!Damage = 00 ; (08 is a whole heart), 04 is half heart
|
|
!DeathAnimation = 00 ; 00 = normal death, 01 = no death animation
|
|
!ImperviousAll = 00 ; 00 = Can be attack, 01 = attack will clink on it
|
|
!SmallShadow = 00 ; 01 = small shadow, 00 = no shadow
|
|
!Shadow = 00 ; 00 = don't draw shadow, 01 = draw a shadow
|
|
!Palette = 00 ; Unused in this template (can be 0 to 7)
|
|
!Hitbox = 12 ; 00 to 31, can be viewed in sprite draw tool
|
|
!Persist = 00 ; 01 = your sprite continue to live offscreen
|
|
!Statis = 00 ; 00 = is sprite is alive?, (kill all enemies room)
|
|
!CollisionLayer = 00 ; 01 = will check both layer for collision
|
|
!CanFall = 00 ; 01 sprite can fall in hole, 01 = can't fall
|
|
!DeflectArrow = 00 ; 01 = deflect arrows
|
|
!WaterSprite = 00 ; 01 = can only walk shallow water
|
|
!Blockable = 00 ; 01 = can be blocked by link's shield?
|
|
!Prize = 00 ; 00-15 = the prize pack the sprite will drop from
|
|
!Sound = 00 ; 01 = Play different sound when taking damage
|
|
!Interaction = 00 ; ?? No documentation
|
|
!Statue = 00 ; 01 = Sprite is statue
|
|
!DeflectProjectiles = 00 ; 01 = Sprite will deflect ALL projectiles
|
|
!ImperviousArrow = 00 ; 01 = Impervious to arrows
|
|
!ImpervSwordHammer = 00 ; 01 = Impervious to sword and hammer attacks
|
|
!Boss = 00 ; 00 = normal sprite, 01 = sprite is a boss
|
|
```
|
|
**Note:** `!Health` is initially set to `12` but is dynamically determined during initialization based on Link's sword level. `!Damage` is `00`, implying damage is handled through other means (e.g., contact with Link's sword).
|
|
|
|
## 2. Core Routines
|
|
|
|
### 2.1. `Sprite_Darknut_Long` (Main Loop)
|
|
|
|
This is the primary entry point for Darknut's per-frame execution, called by the game engine. It handles drawing, shadow rendering, and then dispatches to the main logic routine if the sprite is active.
|
|
|
|
```asm
|
|
Sprite_Darknut_Long:
|
|
{
|
|
PHB : PHK : PLB ; Set up bank registers
|
|
JSR Sprite_Darknut_Draw ; Call drawing routine
|
|
JSL Sprite_DrawShadow ; Draw a shadow (if !Shadow is 01)
|
|
JSL Sprite_CheckActive : BCC .SpriteIsNotActive ; Check if sprite is active
|
|
JSR Sprite_Darknut_Main ; If active, run main logic
|
|
.SpriteIsNotActive
|
|
PLB ; Restore bank register
|
|
RTL ; Return from long routine
|
|
}
|
|
```
|
|
|
|
### 2.2. `Sprite_Darknut_Prep` (Initialization)
|
|
|
|
This routine is executed once when Darknut is first spawned. It dynamically sets Darknut's health based on Link's current sword level, initializes `SprDefl` (deflection timer), and `SprTileDie` (tile for death animation).
|
|
|
|
```asm
|
|
Sprite_Darknut_Prep:
|
|
{
|
|
PHB : PHK : PLB
|
|
LDA.l $7EF359 : TAY ; Get Link's sword level (0-3), adjust to 0-indexed
|
|
LDA.w .health, Y : STA.w SprHealth, X ; Set health based on sword level
|
|
LDA.b #$80 : STA.w SprDefl, X ; Initialize deflection timer
|
|
LDA.b #%01100000 : STA.w SprTileDie, X ; Set tile for death animation
|
|
PLB
|
|
RTL
|
|
|
|
.health ; Health values for each sword level
|
|
db $04, $06, $08, $0A ; 4, 6, 8, 10 HP
|
|
}
|
|
```
|
|
|
|
### 2.3. `Sprite_Darknut_Main` (Behavioral Logic)
|
|
|
|
This routine manages Darknut's AI, including probe spawning, parrying, movement, and animation. It uses `SprAction, X` to control its facing direction and animation.
|
|
|
|
```asm
|
|
Sprite_Darknut_Main:
|
|
{
|
|
JSL GetDistance8bit_Long : CMP.b #$80 : BCS .no_probe ; Check distance to Link
|
|
JSL Sprite_SpawnProbeAlways_long ; If close, spawn a probe
|
|
.no_probe
|
|
|
|
JSL Guard_ParrySwordAttacks ; Handle parrying Link's sword attacks
|
|
|
|
JSL Sprite_Move ; Apply velocity
|
|
JSL Sprite_BounceFromTileCollision ; Handle collision with tiles
|
|
JSL Sprite_DamageFlash_Long ; Handle damage flashing
|
|
|
|
JSL Sprite_CheckIfRecoiling ; Check for recoil state
|
|
|
|
JSL Sprite_CheckDamageFromPlayer : BCC .no_dano ; Check if Link damages Darknut
|
|
LDA.b #$FF : STA.w SprTimerD, X ; If damaged, set timer D
|
|
.no_dano
|
|
|
|
LDA.w SprTimerA, X : BEQ + ; Check timer A
|
|
LDA.b #$90 : STA.w SprTimerD, X ; If timer A is not 0, set timer D
|
|
+
|
|
LDA.w SprTimerD, X : BEQ ++ ; Check timer D
|
|
LDA.b #$08 : JSL Sprite_ApplySpeedTowardsPlayer ; Apply speed towards Link
|
|
JSL Sprite_DirectionToFacePlayer ; Update facing direction
|
|
TYA
|
|
STA.w SprMiscC, X ; Store facing direction in SprMiscC
|
|
STA.w SprMiscE, X ; Store facing direction in SprMiscE
|
|
STA.w SprAction, X ; Set SprAction to facing direction
|
|
JSL Guard_ChaseLinkOnOneAxis ; Chase Link along one axis
|
|
JMP +++
|
|
++
|
|
JSR Sprite_Darknut_BasicMove ; If no timers, use basic movement
|
|
+++
|
|
|
|
JSR Goriya_HandleTileCollision ; Handle tile collision (specific to Goriya, but used here)
|
|
|
|
LDA.w SprAction, X
|
|
JSL JumpTableLocal ; Jump to animation routine based on SprAction
|
|
|
|
dw FaceRight
|
|
dw FaceLeft
|
|
dw FaceDown
|
|
dw FaceUp
|
|
|
|
FaceUp:
|
|
{
|
|
%PlayAnimation(0,1,10) ; Animate frames 0-1 every 10 frames
|
|
RTS
|
|
}
|
|
|
|
FaceDown:
|
|
{
|
|
%StartOnFrame(2)
|
|
%PlayAnimation(2,3,10) ; Animate frames 2-3 every 10 frames
|
|
RTS
|
|
}
|
|
|
|
FaceLeft:
|
|
{
|
|
%StartOnFrame(4)
|
|
%PlayAnimation(4,5,10) ; Animate frames 4-5 every 10 frames
|
|
RTS
|
|
}
|
|
|
|
FaceRight:
|
|
{
|
|
%StartOnFrame(6)
|
|
%PlayAnimation(6,7,10) ; Animate frames 6-7 every 10 frames
|
|
RTS
|
|
}
|
|
}
|
|
```
|
|
|
|
### 2.4. `Sprite_Darknut_BasicMove` (Basic Movement Logic)
|
|
|
|
This routine defines Darknut's basic movement patterns, which are executed when no special conditions (like being damaged or timers) are active. It uses `SprAction, X` to determine the current movement direction.
|
|
|
|
```asm
|
|
Sprite_Darknut_BasicMove:
|
|
{
|
|
LDA.w SprAction, X
|
|
JSL JumpTableLocal ; Jump to movement routine based on SprAction
|
|
|
|
dw MoveRight
|
|
dw MoveLeft
|
|
dw MoveDown
|
|
dw MoveUp
|
|
|
|
MoveUp:
|
|
{
|
|
LDA.b #-DarknutSpeed : STA.w SprYSpeed, X ; Set Y-speed to negative (move up)
|
|
STZ.w SprXSpeed, X ; Clear X-speed
|
|
RTS
|
|
}
|
|
|
|
MoveDown:
|
|
{
|
|
LDA.b #DarknutSpeed : STA.w SprYSpeed, X ; Set Y-speed to positive (move down)
|
|
STZ.w SprXSpeed, X ; Clear X-speed
|
|
RTS
|
|
}
|
|
|
|
MoveLeft:
|
|
{
|
|
LDA.b #-DarknutSpeed : STA.w SprXSpeed, X ; Set X-speed to negative (move left)
|
|
STZ.w SprYSpeed, X ; Clear Y-speed
|
|
RTS
|
|
}
|
|
|
|
MoveRight:
|
|
{
|
|
LDA.b #DarknutSpeed : STA.w SprXSpeed, X ; Set X-speed to positive (move right)
|
|
STZ.w SprYSpeed, X ; Clear Y-speed
|
|
RTS
|
|
}
|
|
}
|
|
```
|
|
|
|
### 2.5. `Sprite_Darknut_Draw` (Drawing Routine)
|
|
|
|
This routine is responsible for rendering Darknut's graphics. It uses a custom OAM (Object Attribute Memory) allocation and manipulation logic, similar to Booki, to handle its multi-tile appearance and animation. It dynamically determines the animation frame and applies offsets for each tile.
|
|
|
|
```asm
|
|
Sprite_Darknut_Draw:
|
|
{
|
|
JSL Sprite_PrepOamCoord ; Prepare OAM coordinates
|
|
JSL Sprite_OAM_AllocateDeferToPlayer ; Allocate OAM slots, deferring to player
|
|
|
|
LDA.w SprGfx, X : CLC : ADC $0D90, X : TAY ; Calculate animation frame index
|
|
LDA .start_index, Y : STA $06 ; Store start index for tiles
|
|
LDA.w SprFlash, X : STA $08 ; Store flash status
|
|
|
|
PHX
|
|
LDX .nbr_of_tiles, Y ; Load number of tiles for current frame (minus 1)
|
|
LDY.b #$00 ; Initialize Y for OAM buffer offset
|
|
.nextTile
|
|
|
|
PHX ; Save current Tile Index
|
|
|
|
TXA : CLC : ADC $06 ; Add Animation Index Offset
|
|
|
|
PHA ; Keep the value with animation index offset
|
|
|
|
ASL A : TAX ; Multiply by 2 for word access
|
|
|
|
REP #$20 ; Set A to 16-bit mode
|
|
|
|
LDA $00 : CLC : ADC .x_offsets, X : STA ($90), Y ; Store Y-coordinate with X-offset
|
|
AND.w #$0100 : STA $0E ; Check if Y-coord is off-screen (high bit)
|
|
INY
|
|
LDA $02 : CLC : ADC .y_offsets, X : STA ($90), Y ; Store X-coordinate with Y-offset
|
|
CLC : ADC #$0010 : CMP.w #$0100
|
|
SEP #$20 ; Set A to 8-bit mode
|
|
BCC .on_screen_y
|
|
|
|
LDA.b #$F0 : STA ($90), Y ; If off-screen, move sprite off-screen
|
|
STA $0E
|
|
.on_screen_y
|
|
|
|
PLX ; Restore Tile Index
|
|
INY
|
|
LDA .chr, X : STA ($90), Y ; Store character (tile) number
|
|
INY
|
|
LDA .properties, X : ORA $08 : STA ($90), Y ; Apply flash and store OAM properties
|
|
|
|
PHY
|
|
|
|
TYA : LSR #2 : TAY ; Calculate OAM buffer index for size
|
|
|
|
LDA.w .sizes, X : ORA $0F : STA ($92), Y ; store size in oam buffer
|
|
|
|
PLY : INY
|
|
|
|
PLX : DEX : BPL .nextTile ; Loop for next tile
|
|
|
|
PLX ; Restore X (sprite index)
|
|
|
|
RTS
|
|
|
|
; =========================================================
|
|
; OAM Data Tables
|
|
.start_index
|
|
db $00, $03, $06, $09, $0C, $0E, $10, $12
|
|
.nbr_of_tiles
|
|
db 2, 2, 2, 2, 1, 1, 1, 1
|
|
.x_offsets
|
|
dw 0, 0, 0
|
|
dw 0, 0, 0
|
|
dw 0, 0, 0
|
|
dw 0, 0, 0
|
|
dw 0, -12
|
|
dw 0, -12
|
|
dw 0, 12
|
|
dw 0, 12
|
|
.y_offsets
|
|
dw -4, 0, -12
|
|
dw -4, 0, -12
|
|
dw 0, 12, 20
|
|
dw 0, 12, 20
|
|
dw 0, 8
|
|
dw 0, 8
|
|
dw 0, 8
|
|
dw 0, 8
|
|
.chr
|
|
db $EF, $E6, $FF
|
|
db $EF, $E6, $FF
|
|
db $E2, $EF, $FF
|
|
db $E2, $EF, $FF
|
|
db $E0, $E8
|
|
db $E4, $E8
|
|
db $E0, $E8
|
|
db $E4, $E8
|
|
.properties
|
|
db $B9, $39, $B9
|
|
db $B9, $79, $B9
|
|
db $39, $39, $39
|
|
db $79, $39, $39
|
|
db $39, $79
|
|
db $39, $79
|
|
db $79, $39
|
|
db $79, $39
|
|
.sizes
|
|
db $00, $02, $00
|
|
db $00, $02, $00
|
|
db $02, $00, $00
|
|
db $02, $00, $00
|
|
db $02, $02
|
|
db $02, $02
|
|
db $02, $02
|
|
db $02, $02
|
|
}
|
|
```
|
|
|
|
## 3. Key Behaviors and Implementation Details
|
|
|
|
* **Dynamic Health:** Darknut's health is determined at spawn time based on Link's current sword level, similar to Booki, allowing for dynamic difficulty scaling.
|
|
* **Probe Spawning:** Darknut has the ability to spawn a probe (`Sprite_SpawnProbeAlways_long`) when Link is within a certain distance, adding a ranged attack or detection mechanism.
|
|
* **Parrying Mechanics:** The `Guard_ParrySwordAttacks` routine suggests Darknut can actively defend against Link's sword attacks, potentially deflecting them or becoming temporarily invulnerable.
|
|
* **Chasing on One Axis:** When damaged or under certain timer conditions, Darknut uses `Guard_ChaseLinkOnOneAxis` to pursue Link along either the horizontal or vertical axis, making its movement more predictable but still challenging.
|
|
* **Basic Movement:** Darknut has a set of basic directional movements (`MoveUp`, `MoveDown`, `MoveLeft`, `MoveRight`) that it cycles through when not actively chasing or reacting to damage.
|
|
* **Custom OAM Drawing:** Darknut utilizes a custom OAM drawing routine, similar to Booki, to handle its multi-tile sprite. This routine precisely positions and animates multiple 8x8 tiles to form the larger Darknut sprite. The use of `REP #$20` and `SEP #$20` for 16-bit coordinate calculations is also present here.
|
|
* **`SprDefl` and `SprTileDie`:** `SprDefl` is used as a deflection timer, likely related to the parrying mechanic. `SprTileDie` specifies a custom tile to be used during its death animation.
|
|
* **`SprMiscC` and `SprMiscE`:** These variables are used to store Darknut's facing direction, which influences both its movement and animation. `SprMiscC` is likely used for animation frame selection, while `SprMiscE` might be used for other directional logic.
|
|
* **`Goriya_HandleTileCollision`:** The use of a collision handler named `Goriya_HandleTileCollision` suggests code reuse from another sprite, indicating a shared collision logic for certain enemy types.
|