Coding style

Table of Contents

• How to use this guide
• Code formatting
• Naming
  • Local variables
  • Global variables
  • Object variables
  • Functions
  • Structs
  • Struct variables
  • Struct methods
  • Macros
  • Enums
  • Scripts
  • Other resources
• Fluent API

How to use this guide

This document should by no means be understood as a guide for the perfect GML coding style that everyone should follow in their projects. This is simply a style that BBMOD uses, and for sake of consistency, everyone who wishes to contribute to BBMOD must use the same style.

Code formatting

BBMOD uses format-gml to automatically format code, so you don't need to worry about it yourself. (Please make sure to set it up though, before making PRs 🙂) In short, we're using Allman style with tabs for indentation (size 4) and 120 characters line length.

Naming

Naming in BBMOD coding style is quite complicated. It has evolved in early days of GameMaker, when the syntax highlight and code completion was not really good. There are different naming convetions for different things to be able to tell their type and/or scope.

Local variables

Local variables use camelCase and are prefixed with a single underscore _, e.g. _myLocalVariable. The exception to this rule are local variables used as counters in loops, e.g. i, j, k, etc.

Global variables

Global variables use camelCase and bbmod prefix, e.g. global.bbmodGlobalVariable. To express that a global variable is private, use double underscore prefix, e.g. global.__bbmodPrivateGlobalVariable.

Object variables

Object variables use camelCase. To express that an object variable is private, use double underscore prefix, e.g. __privateVariable.

Functions

Functions use snake_case with bbmod_ prefix, e.g. bbmod_do_some_stuff. To express that a function is private, use double underscore prefix, e.g. __bbmod_do_some_private_stuff.

Macros

Macros are UPPERCASE_WITH_UNDERSCORES with BBMOD_ prefix, e.g. BBMOD_MY_MACRO. To express that a macro is private, use double underscore prefix, e.g. __BBMOD_MY_PRIVATE_MACRO.

Structs

Structs use UpperCamelCase with BBMOD_ prefix, e.g. BBMOD_RenderQueue. To express that a struct is private, use double underscore prefix, e.g. __BBMOD_PrivateStruct.

Struct variables

Struct variables use UpperCamelCase. Private struct variables follow the same naming style as private instance variables, i.e. __privateStructVariable!

Struct methods

Same as functions, struct methods also use snake_case and double underscore prefix to express that the method is private.

Unfortunately, there are a few structs that don't follow this rule (e.g. use UpperCamelCase names instead). When adding new methods to such struct, use the same naming style that they use, but when adding new structs, please stick to the snake_case naming!

Enums

Enums use UpperCamelCase and BBMOD_E prefix, e.g. BBMOD_EMyEnum. To express that an enum is private, use double underscore prefix, e.g. __BBMOD_EMyPrivateEnum. Enum members also use UpperCamelCase, with an exception of SIZE, which can be used as the last member of an enum to store the total number of members of the enum, e.g.:

enum BBMOD_EMyEnum
{
    First = 0,
    Second,
    Third,
    SIZE,
};

Scripts

If a script contains a definition of a single struct or a single function, us the same name for the script itself. For other script that contain multiple definitions, use snake_case with __bbmod_ prefix, e.g. __bbmod_array_utils.

Other resources

Resources except for scripts use prefix BBMOD_, followed by the resource type prefix and then the resource name in UpperCamelCase, e.g. BBMOD_RmMain, BBMOD_OPlayer etc. To express that a resource is private, use double underscore prefix, e.g. __BBMOD_SprMyPrivateSprite.

Resource type	Prefix
Animation curve	Ac
Font	Fnt
Object	O
Particle system	Ps
Path	Pth
Room	Rm
Sequence	Sq
Shader	Sh
Sound	Snd
Sprite	Spr
Tile set	Ts
Timeline	Tl

Fluent API

BBMOD structs use fluent API, which means that if a struct method does not have a return value, it returns self so you could chain multiple methods together.