Godot Tower Defense Structure

Overview

This tutorial covers structuring a tower defense game in Godot, focusing on clean component design to avoid code "spaghetti." It explains how to make game components modular, independent, and easy to prototype, while demonstrating practical Godot scripting techniques.

Identifying Core Game Components

• Game components include attacking units (fish), towers, and projectiles.
• Each component should operate as independently as possible.
• Components must be configurable from the editor for rapid prototyping.

Component Implementation and Refactoring

• Scripts are added to each component (fish, projectile) to handle movement independently.
• Export variables allow in-editor configuration of properties like speed or damage.
• Projectiles and fish are saved as separate scenes for reuse and instantiation.

Projectiles and Collision Handling

• Towers instantiate projectile scenes on a timer using Godot’s signal system.
• Projectiles detect collision with fish using Area nodes and signals, not hard references.
• Fish and projectiles interact via generic methods (like take_damage)—not by knowing each other's specifics.

Health, Damage, and UI

• Fish receive a health bar and configurable health.
• The take_damage contract is introduced: components implement this for health reduction and destruction.
• Tower receives similar health/damage logic with a UI health bar.

Spawner and Randomization

• A spawner component uses random intervals to spawn different fish types.
• The spawner receives a configurable list of spawnable scenes, supporting easy extension.

Collision Layers and Groups

• Collision detection uses Godot’s layers and masks to control interactions (e.g., fish avoid colliding with each other).
• Groups classify objects (e.g., enemy or friend) to manage target selection for damage.

Score, End Condition, and Component Communication

• Score and escaped fish are tracked via UI labels and updated from central game logic.
• Signals are used to relay events like fish destruction to the game manager and scoreboard.
• Decoupling is achieved by using signals instead of direct calls or global singletons (autoloads), keeping components modular.

Cleanups and Best Practices

• Unused autoloads are removed in favor of direct event-driven signal connections via the spawner.
• Game over is handled by calling a function (on_game_over) on all relevant components, using Godot’s propagate_call.

Summary of Key Concepts

• Components remain independent by using export variables, signals, and minimal direct dependencies.
• Godot’s editor features (signals, groups, collision layers) are leveraged for modular and extensible design.
• Trade-offs in design depend on game requirements; over-engineering is discouraged.

Recommendations / Advice

• Favor small, loosely coupled components for maintainability and prototyping speed.
• Use Godot’s signals, groups, and exported variables to facilitate communication and configuration.
• Iterate and refine structure as new features or requirements arise.