Bat
| Entity data | |
|---|---|
| Entity pointer | $82:F03E |
The bat is an entity that is spawned by vampires.
Behavior
A bat starts out moving in a given direction specified in the entity arguments. The initial velocity of the bat is 6 px/frame in this direction. If the direction is diagonal, the velocity is 6 px/frame on both axes. Every frame, the bat will accelerate towards the nearest target at a rate of 1 px/frame2, but its speed will not exceed 6 px/frame. After the acceleration is applied, then the position is updated based on the current velocity.
Every 3 frames the bat will switch to the next animation frame. There are 2 different sprites that it alternates between.
A bat will die if any of the following conditions are met:
- It contacts a tile that is solid to weapons
- It touches a player, victim, or any weapon shot
- It has been alive for 131 frames
Once the bat dies, it plays a 32 frame death animation, then the entity is destroyed.
RAM map
Entity arguments
| Address | Length | Type | Name | Description |
|---|---|---|---|---|
| $00 | 2 | int16 | x | X position |
| $02 | 2 | int16 | y | Y position |
| $04 | 2 | direction x2 | direction | Direction |
Entity memory
| Address | Length | Type | Name | Description |
|---|---|---|---|---|
| $08 | 2 | pointer16 | sprite | Pointer to sprite |
| $0A | 2 | int16 | x | X position |
| $0C | 2 | int16 | y | Y position |
| $0E | 2 | int16 | velocityX | X velocity |
| $10 | 2 | int16 | velocityY | Y velocity |
| $12 | 2 | unused | unused12 | Value is set, but never used |
| $14 | 2 | boolean | dead | Dead |
| $16 | 2 | uint16 | animationFrame | Low bit is the current animation frame |
| $18 | 2 | uint16 0-based | framesUntilAnimUpdate | Number of frames until the next animation frame |
| $1A | 2 | uint16 0-based | framesUntilDeath | Number of frames until death |