oracle-of-secrets/Docs/Sprites/Octoboss.md

Octoboss Sprite Analysis

Overview

The octoboss sprite (ID: Sprite_Octoboss, which is $3C) is a multi-phase boss, likely an octopus-like creature. It features a unique mechanic involving a "brother" Octoboss, and can summon stalfos offspring. The fight progresses through distinct phases including emergence, movement, taunting, ascending, submerging, and a surrender sequence.

Key Properties:

• Sprite ID: Sprite_Octoboss ($3C)
• Description: A multi-phase boss with a "brother" Octoboss, capable of summoning stalfos and engaging in various movement and attack patterns.
• Number of Tiles: 11
• Health: 00 (Health is managed by ReturnTotalHealth and CheckForNextPhase, combining the health of both Octobosses.)
• Damage: 00 (Damage dealt to Link is likely handled by its attacks or spawned offspring.)
• Special Properties:
  • !Boss = $01 (Correctly identified as a boss.)
  • !Shadow = 01 (Draws a shadow.)
  • !Hitbox = 03

Custom Variables:

• !ConsecutiveHits = $AC: Tracks consecutive hits on the boss.
• !KydrogPhase = $7A: Tracks the current phase of the boss fight. (Note: This variable name is KydrogPhase, suggesting shared logic or a copy-paste from the Kydrog boss.)
• !WalkSpeed = 10: Defines the boss's walking speed.
• BrotherSpr = $0EB0: Stores the sprite index of the "brother" Octoboss.

Main Logic Flow (Sprite_Octoboss_Main and Sprite_Octoboss_Secondary):

The Octoboss has two primary main routines, Sprite_Octoboss_Main and Sprite_Octoboss_Secondary, which are called based on SprMiscF, X. This suggests different forms or behaviors for the two Octobosses.

Sprite_Octoboss_Main Jump Table (for the primary Octoboss):

• WaitForPlayerToApproach (0x00): Waits for Link to reach a specific Y-coordinate ($08C8) to trigger activation.
• Emerge (0x01): Emerges from the water, preventing Link's movement.
• EmergedShowMessage (0x02): Displays an introductory message.
• SpawnAndAwakeHisBrother (0x03): Spawns a "brother" Octoboss (Sprite_Octoboss with SprMiscF = $01) and stores its ID in BrotherSpr.
• WaitForBrotherEmerge (0x04): Waits for the brother to emerge and displays a message.
• SpawnPirateHats (0x05): Spawns "boss poof" effects for both Octobosses, changes their frames, and spawns walls using Overworld_DrawMap16_Persist macros.
• IdlePhase (0x06): Idles, can spawn fireballs, and checks total health (ReturnTotalHealth) to potentially trigger surrender.
• PickDirection (0x07): Picks a random direction and speed for movement.
• Moving (0x08): Moves around, handles boundary checks, spawns splash effects, and checks total health to potentially trigger surrender.
• WaitMessageBeforeSurrender (0x09): Displays a surrender message ($004A), sets the brother's action, and transitions to RemoveHat.
• RemoveHat (0x0A): Removes hats from both Octobosses with "boss poof" effects, displays a message ($004B), and transitions to Submerge.
• Submerge (0x0B): Submerges, playing an animation and spawning a splash effect.
• SubmergeWaitWall (0x0C): Submerges further, drawing walls using Overworld_DrawMap16_Persist macros.
• EmergeWaitGiveItem (0x0D): Emerges, spawns a medallion (SpawnMedallion), and sets an SRAM flag.
• SubmergeForeverKill (0x0E): Submerges completely, despawns, and allows Link to move again.

Sprite_Octoboss_Secondary Jump Table (for the secondary/brother Octoboss, when SprMiscF, X is set): This routine largely mirrors Sprite_Octoboss_Main but includes specific states like WaitDialog and Moving2, suggesting slight behavioral differences.

Initialization (Sprite_Octoboss_Long and Sprite_Octoboss_Prep):

• Sprite_Octoboss_Long: Main entry point. Handles sprite initialization, including setting OAM properties, bulletproofing, frame, and palette values. It also checks for boss defeat and medallion spawning.
• Sprite_Octoboss_Prep: Initializes !KydrogPhase to 00, sets initial health ($A0), configures deflection, hitbox, bump damage, and calls JSR KydrogBoss_Set_Damage to set up the damage table. Sets initial sprite speeds and an intro timer.

Health Management (Sprite_Octoboss_CheckIfDead, ReturnTotalHealth, CheckForNextPhase):

• Sprite_Octoboss_CheckIfDead: Monitors SprHealth, X. If health is zero or negative, it triggers the boss's death sequence.
• ReturnTotalHealth: Calculates the combined health of both Octobosses (SprHealth, X and SprHealth, Y of BrotherSpr).
• CheckForNextPhase: Manages the boss's phases based on health thresholds, similar to the Kydrog boss.

Offspring Spawning (RandomStalfosOffspring, Sprite_Offspring_Spawn, Sprite_Offspring_SpawnHead):

• These routines are identical to those found in kydrog_boss.asm, spawning stalfos offspring.

Attacks (Chuchu_SpawnBlast, Mothula_SpawnBeams, Kydrog_ThrowBoneAtPlayer):

• Chuchu_SpawnBlast: Spawns a Chuchu blast projectile.
• Mothula_SpawnBeams: Spawns beam projectiles.
• Kydrog_ThrowBoneAtPlayer: Spawns a bone projectile (reused from Kydrog).

Drawing (Sprite_Octoboss_Draw, Sprite_Octoboss_Draw2):

• Sprite_Octoboss_Draw: Draws the primary Octoboss.
• Sprite_Octoboss_Draw2: Draws the secondary/brother Octoboss.
• Both use standard OAM allocation routines and handle complex animation frames, offsets, character data, properties, and sizes.

Other Routines:

• SpawnSplash: Spawns a splash effect.
• SpawnBossPoof: Spawns a boss poof effect.
• HandleMovingSplash: Handles splash effects during movement.
• SpawnMedallion / SpawnMedallionAlt: Spawns a medallion.

Discrepancies/Notes:

• Shared Variables/Code with Kydrog: The extensive use of !KydrogPhase, KydrogBoss_Set_Damage, and Kydrog_ThrowBoneAtPlayer suggests significant code reuse or copy-pasting from the Kydrog boss. This could lead to unexpected interactions or make maintenance challenging if changes are made to one boss but not the other. Refactoring shared logic into common functions or macros would be beneficial.
• Sprite_Octoboss_Secondary: The existence of a separate main routine for the "brother" Octoboss indicates that the two Octobosses might have slightly different behaviors or phases.

Hardcoded Activation Trigger:

• As noted by the user, the activation trigger for Octoboss is hardcoded. In the WaitForPlayerToApproach routine, the boss checks LDA.b $20 : CMP #$08C8. $20 represents Link's Y position, and $08C8 is a hardcoded Y-coordinate. This means the boss will only activate when Link reaches this specific Y-coordinate, making it difficult to relocate the boss to other overworld maps without modifying this value. This hardcoded dependency needs to be addressed for improved reusability.