AMX Mod X (Pawn) Code Style Guide

This document provides an overview of coding conventions for AMX Mod X projects. Each topic is covered in detail in its own file.

Core Conventions

Category	Description
Basics	Syntax, basics
Code Style	File structure, formatting, braces, spacing, plugin registration
Naming Conventions	Hungarian notation, variable prefixes, naming patterns
Constants & Enums	Define constants, enums, TASKID constants
Macros	Common macros, IS_PLAYER, patterns to avoid
Function Declarations	Return types, @ prefix, static variables
Validations	FM_NULLENT, entity checks, player validation, early returns

API Patterns

Category	Description
Hooks	Ham, FakeMeta, ReAPI, Event, Message hooks and handles
Forwards	CreateMultiForward, ExecuteForward, pre/post patterns
Natives	Native registration and implementation
Callbacks	Tasks, SQL queries, CVar queries
Menus	Menu creation, callbacks, and patterns
Commands	Client, server, and console commands
CVars	CVar creation, binding, and change hooks

Performance & Data

Category	Description
Optimizations	Native call reduction, dynamic hooks, model path caching
Data Structures	Arrays, Tries, entity access, strings

---

Quick Reference: Best Practices Summary

Code Style

1. Always use #pragma semicolon 1 at file start
2. Use Hungarian notation for all variable names
3. Use K&R brace style (opening brace on same line)
4. Pass plugin info directly to register_plugin() - avoid macros
5. Group hooks and functions with section comments

Constants & Validation

6. Use FM_NULLENT instead of -1 or 0 for null entity checks
7. Always check FM_NULLENT after entity creation before processing
8. Return FM_NULLENT not 0 for failures - 0 is worldspawn
9. Return early for invalid conditions

Macros

10. Don't redefine macros - use shared definitions from includes
11. Never use MACRO()_Suffix patterns in code - only in macro definitions

Function Declarations

12. Use @ prefix only for OOP-like methods: @{EntityName}_{MethodName}
13. Never add public keyword to @ prefixed functions
14. Use const prefix for all handle arguments
15. Use const &this for "this" argument in OOP-like methods
16. Use static variables in frequently called class methods
17. Declare and assign static on same line using semicolon separator

Hooks

18. Ham hooks must return HAM_* constants
19. FakeMeta hooks must return FMRES_* constants
20. ReAPI hooks must return HC_* constants
21. Message hooks must return PLUGIN_* constants
22. Hook handle variables: g_pfwham (Ham), g_pfwfm (FakeMeta)
23. Inline get_user_msgid when only used once in register_message

Forwards

24. Forward names use LibraryName_OnSomething - not Fw_ prefix
25. Multi-forward handle variables use g_pfw prefix

Natives & Callbacks

26. Native implementations use Native_ prefix with const for arguments
27. Task callbacks use Task_ prefix with offset in task ID
28. SQL callbacks use Callback_SQLQuery_{Name} prefix

Menus

29. Menu callbacks use Callback_Menu_{Name} prefix
30. Use enum for menu items to avoid index mistakes
31. Destroy dynamic menus in callback with menu_destroy

Commands & CVars

32. Command handlers use Command_ prefix, server commands use ServerCommand_
33. Use register_concmd for admin commands that should work from RCON
34. Avoid client_cmd - use engclient_cmd for server-side execution
35. Use create_cvar instead of deprecated register_cvar
36. Use bind_pcvar_* instead of get_pcvar_* for cvar access

Optimizations

37. Minimize native calls in hot paths
38. Use single global g_pTrace - never create trace handles per-call
39. Register high-frequency hooks dynamically
40. Use xs_vec_set instead of xs_vec_copy for vector initialization
41. Cache model index with static inside function, not in separate global

Naming Conventions

42. Sound arrays use g_rgsz prefix with g_i*Num counter
43. Message IDs use gmsg prefix (without underscore)
44. Player arrays use g_rg*[MAX_PLAYERS + 1] with type prefix
45. Don't use id for players - use pPlayer
46. Don't use index for entities - use pEntity

Data Structures

47. Always free dynamic handles - ArrayDestroy, TrieDestroy in plugin_end()