Godot Combo Input Buffer System

A lightweight combo system for Godot 4 that buffers player inputs and detects combos based on action sequences.

Overview

This system allows you to:

• Track player inputs using InputMap
• Store inputs in a timed buffer
• Detect combos based on input sequences
• Trigger animations or actions from combos

It is designed for games like fighting games, action games, or any system requiring chained inputs.

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Features

• Input buffering with time limit
• Combo detection using sequence matching
• Priority-based combo resolution (longer combos checked first)
• Easy integration with player scripts
• Fully customizable actions and combos

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How It Works

1. Player inputs are captured in _input()

2. Matching actions are stored in input_buffer

3. A timer controls how long inputs stay valid

4. When the resolve timer expires:

   • The system checks if the buffer matches any combo
   • If matched, the combo name is added to the buffer

5. The player script reads the buffer and executes actions

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Setup

1. Add the Combo System

Attach or instance the Combo_system:

var combo_system := Combo_system.new()
add_child(combo_system)

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2. Define Tracked Actions

These must match your InputMap actions:

combo_system.tracked_actions = ["attack1", "attack2"]

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3. Define Combos

Combos are stored as a dictionary:

combo_system.combos = {
    "combo_3": ["attack1","attack2","attack1","attack1","attack2"],
    "combo_2": ["attack1","attack1","attack2"],
    "combo_1": ["attack1","attack2"],
}

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4. Configure Timers

combo_system.input_buffer_time_limit = 1.0
combo_system.combo_resolve_delay = 0.2

• input_buffer_time_limit: how long inputs stay in buffer
• combo_resolve_delay: delay before checking combos

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Usage Example

Detect and Execute Actions

if combo_system.input_buffer.size() > 0:
    attack(combo_system.excute_action())

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Example Attack Handling

func attack(attack: String):
    match attack:
        "attack1":
            animatedS.play("attack1")
        "attack2":
            animatedS.play("attack2")
        "combo_1":
            animatedS.play("heavy_combo")

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Core Functions

_input(event)

Captures input and adds matching actions to buffer.

_process(delta)

Handles:

• Buffer timing
• Combo resolution timing

check_combos()

Checks if the buffer ends with any combo sequence.

ends_with_sequence(buffer, sequence)

Utility function to match input sequences.

excute_action()

Returns the next action to perform.

cancel_buffer_input()

Clears the input buffer (useful on jump, interruptions, etc.)

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Notes / Limitations

• Uses StringName internally (Godot 4 InputMap)
• All actions must exist in InputMap
• UI actions (ui_*) may be included unless filtered
• excute_action() only returns the first buffered action
• Combo priority depends on sorting (longer combos should be checked first)

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Suggested Improvements

• Convert buffer to queue system with better priority handling
• Add combo cooldowns
• Add directional inputs (for fighting games)
• Support for hold / charge inputs
• Debug visualization of input buffer

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Example Use Case

This system is ideal for:

• Fighting games (combo chains)
• Hack-and-slash combat
• Action platformers with attack chaining

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Credits

Created by Mr. AL Built using Godot 4