gmd-editor 0.1.0

Decode, encode, and edit Geometry Dash .gmd level files

gmdlib

A Python library for decoding, encoding, and editing Geometry Dash .gmd level files.

Installation

pip install -e .

Quick Start

from gmdlib import load, save

# Load a .gmd file
level = load("MyLevel.gmd")

print(f"Object count: {level.object_count}")
print(f"Bounding box: {level.bounding_box()}")

# Iterate over objects
for obj in level:
    print(f"id={obj.id}  x={obj.x}  y={obj.y}")

# Move all objects up by 30 units
level.transform(lambda o: setattr(o, "y", (o.y or 0) + 30))

# Save the modified level
save(level, "MyLevel_modified.gmd")

API Reference

load(path) / save(level, path)

from gmdlib import load, save

level = load("level.gmd")
save(level, "level_out.gmd")

GMDLevel

Attribute / Method	Description
level.objects	list[GDObject] — all objects
level.header	The level settings string
level.object_count	Number of objects
level.bounding_box()	(min_x, min_y, max_x, max_y)
level.unique_object_ids()	Set of GD object IDs used
level.filter(fn)	Filter objects by predicate
level.filter_by_id(id)	Filter objects by GD object ID
level.transform(fn)	Apply a function to every object in-place
level.add_object(obj)	Append a new object
level.remove_objects(fn)	Remove matching objects; returns count removed
level.to_level_string()	Serialise to raw level string
level.to_gmd_string()	Serialise back to full .gmd XML

GDObject

Named property shortcuts (all gettable and settable):

Property	Key	Type
obj.id	"1"	int
obj.x	"2"	float
obj.y	"3"	float
obj.h_flip	"4"	bool
obj.v_flip	"5"	bool
obj.rotation	"6"	float
obj.scale	"36"	float
obj.groups	"57"	list[int]

Raw access for any property:

obj["21"]          # get by numeric key string
obj["21"] = "3"    # set
obj.get("21", "0") # with default
obj.remove("21")   # delete

Low-level codec

from gmdlib.codec import (
    decode_level_string,  # base64url+gzip → plain text
    encode_level_string,  # plain text → base64url+gzip
    extract_b64,          # pull encoded data from .gmd XML
    inject_b64,           # put encoded data back into .gmd XML
    fix_padding,          # fix GD's broken base64 padding
)

Examples

Teleport all objects to a fixed X position

level = load("level.gmd")
level.transform(lambda o: setattr(o, "x", 0.0))
save(level, "level_out.gmd")

Remove all objects of a specific type

level = load("level.gmd")
removed = level.remove_objects(lambda o: o.id == 8)  # remove all spike objects
print(f"Removed {removed} spikes")
save(level, "level_out.gmd")

Create a new object and add it

from gmdlib import load, save
from gmdlib import GDObject

level = load("level.gmd")

new_obj = GDObject()
new_obj.id = 1        # block
new_obj.x = 300.0
new_obj.y = 0.0
level.add_object(new_obj)

save(level, "level_out.gmd")

Work directly with the level string

from gmdlib.level import GMDLevel

level = GMDLevel.from_level_string("kA,1;1,1,2,100,3,200;")
print(level[0].x)   # 100.0
raw = level.to_level_string()