Flying Enemy

Flying Enemy

System Summary

The Flying Enemy is a dynamic enemy type that moves between two points in space, a predictable traversal pattern for the player. Unlike Patrol enemies, Flying Enemies are not constrained to ground navigation and instead move freely in straight-line paths between two defined offsets.

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Connected Systems

Connecting Systems:

• Game Manager
• Property Editor
• Entity Manager
• Resource System (FlyingPreset .tres files)

Subsystems:

• None

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Bugs

List of known bugs. Be descriptive but keep it brief!

• None

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Feature List / Breakdown of Features

Base Enemy (Inherited):

• When landed on from above, the player will bounce on and KO the enemy.
• Colliding from other directions damages the player.
• Has variable health, which is auto-set to 1.
• Inherits from BaseEnemyClass.gd.

Flying Enemy:

• Flying Speed: Controls how fast the enemy travels between points. Higher values = faster movement.
• Point B Offset: Defines the second movement point relative to the spawn position. X controls horizontal distance, Y controls vertical distance. Supports diagonal movement if both X and Y values aren't 0.
• Moves in a straight line between Point A (spawn position) and Point B (Point A + Offset).
• Automatically switches direction when reaching a point.
• Uses normalized direction vector for smooth motion.
• Uses direct velocity-based movement (no pathfinding).
• Ignores gravity.
• Can collide with level geometry.

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Important Variables

propertyFile: Resource = Stores the currently assigned FlyingPreset resource.

pointA: Vector2 = Spawn position (set when enemy is placed).

pointB: Vector2 = Calculated endpoint based on offset.

targetPoint: Vector2 = Current movement destination.

speed: float = Movement speed of the enemy.

previewLine: Line2D = A UI graphic displaying the enemy's flight path while editing its properties.

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Important Functions

• func fly_behavior() -> void: Moves the enemy every frame.

• func update_line_preview(x: int, y: int) -> void: Ensures the preview line matches the enemy's points and offset.

• func assign_script(id: String, position: Vector2i) -> void: Assigns a FlyingPreset resource to the enemy based on a generated ID. Loads the correct .tres file from disk, assigns it to propertyFile, and sets the enemy's identity in the editor system.

• func apply_script(file: Resource) -> void: Applies a FlyingPreset resource to the enemy instance. Reads stored data from the resource, updates movement behavior based on saved values, and recalculates patrol path (Point A and Point B). Does NOT reposition the enemy in world space; assumes enemy is already placed correctly by the editor.

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Movement Logic

1. Enemy spawns at Point A (editor placement)
2. Point B is calculated using offset: Point B = Point A + Offset
3. Enemy moves toward target point using normalized direction
4. When close enough to target: switches target to the opposite point and repeats

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Data Flow

1. Editor places enemy
2. assign_script()
3. Resource created/saved (.tres)
4. apply_script() on load
5. Point A set = global position
6. Point B calculated = A + offset
7. Enemy begins patrol movement

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Future Work / Risks

Future Work:

1. Add support for variable movement patterns (e.g., sine wave, circular)
2. Add visual indicators for patrol path in editor

Risks:

• None

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Miscellaneous Notes

Offset-based system was chosen instead of absolute coordinates to:

• Make enemy placement reusable
• Simplify editing in property menu
• Avoid dependency on world coordinates in resources