This plugin helps you get rid of some tedious work, such as searching for offsets, adding your own extra functions and registering commands like register_clcmd("weapon_mygun", "switch_handler")

Now I'll explain it using an example test plugin that changes the knife's HUD.

First, we include the include file
#include <hud>

Now, for convenience, let's define constants for our old weapon and the new one

Pawn

#define WEAPON_OLD "weapon_knife"
#define WEAPON_NEW1 "weapon_knife1"
#define WEAPON_NEW2 "weapon_knife2"
#define WEAPON_NEW3 "weapon_knife3"
#define WEAPON_NEW4 "weapon_knife4"
#define WEAPON_NEW5 "weapon_knife5"

In plugin_init() we register all these HUDs

Pawn

public plugin_init()
{
	// какой-то код
	n21_register_hud(WEAPON_OLD, WEAPON_NEW1)
	n21_register_hud(WEAPON_OLD, WEAPON_NEW2)
	n21_register_hud(WEAPON_OLD, WEAPON_NEW3)
	n21_register_hud(WEAPON_OLD, WEAPON_NEW4)
	n21_register_hud(WEAPON_OLD, WEAPON_NEW5)
}

Now we need to send the client the sprite itself and the special .txt files named after our new knives, i.e. we have to set up 5 files:
weapon_knife1.txt
weapon_knife2.txt
weapon_knife2.txt
weapon_knife3.txt
weapon_knife5.txt

The files' contents look roughly like this:

Pawn

2
weapon			640 custom_hud/640hud21	0	45	170	45
weapon_s		640 custom_hud/640hud21	0	45	170	45

General format:
<тип> <разрешение> <спрайт> <смещение_по_X> <смещение_по_Y> <ширина> <высота>
The type can be one of the following: weapon, weapon_s, ammo, ammo2, autoaim, crosshair, zoom, zoom_aim.

Now we need to send the player the sprites and .txt files:

Pawn

public plugin_precache()
{
	precache_generic("sprites/weapon_knife1.txt")
	precache_generic("sprites/weapon_knife2.txt")
	precache_generic("sprites/weapon_knife3.txt")
	precache_generic("sprites/weapon_knife4.txt")
	precache_generic("sprites/weapon_knife5.txt")
 
	precache_generic("sprites/custom_hud/640hud21.spr")
}

So we can test all of this, let's register the commands in plugin_init:

Pawn

register_clcmd("say /k1", "knife_1")
register_clcmd("say /k2", "knife_2")
register_clcmd("say /k3", "knife_3")
register_clcmd("say /k4", "knife_4")
register_clcmd("say /k5", "knife_5")
register_clcmd("say /k6", "knife_old")

And here are the functions themselves:

Pawn

public knife_1(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW1)
public knife_2(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW2)
public knife_3(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW3)
public knife_4(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW4)
public knife_5(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW5)
public knife_old(id)    n21_hud_change_to(id, WEAPON_OLD, WEAPON_OLD)

Structure of the function n21_hud_change_to
1st argument - player id
2nd argument - name of the weapon whose HUD we are changing
3rd argument - name of the new weapon

A call of the function like this:
n21_hud_change_to(id, "weapon_knife", "weapon_knife")
returns the standard knife HUD, i.e. to restore the standard HUD of a weapon, you need to specify that weapon in the 2nd and 3rd arguments of the function.

As a result, we get this test plugin:

Pawn

#include <amxmodx>
#include <hud>

#define PLUGIN  "Hud Test"
#define AUTHOR  "trofian"
#define VERSION "1.0"

#define WEAPON_OLD "weapon_knife"
#define WEAPON_NEW1 "weapon_knife1"
#define WEAPON_NEW2 "weapon_knife2"
#define WEAPON_NEW3 "weapon_knife3"
#define WEAPON_NEW4 "weapon_knife4"
#define WEAPON_NEW5 "weapon_knife5"
 
public plugin_precache()
{
        precache_generic("sprites/weapon_knife1.txt")
        precache_generic("sprites/weapon_knife2.txt")
        precache_generic("sprites/weapon_knife3.txt")
        precache_generic("sprites/weapon_knife4.txt")
        precache_generic("sprites/weapon_knife5.txt")
       
        precache_generic("sprites/custom_hud/640hud21.spr")
}
 
public plugin_init()
{
        register_plugin(PLUGIN, VERSION, AUTHOR)
       
        n21_register_hud(WEAPON_OLD, WEAPON_NEW1)
        n21_register_hud(WEAPON_OLD, WEAPON_NEW2)
        n21_register_hud(WEAPON_OLD, WEAPON_NEW3)
        n21_register_hud(WEAPON_OLD, WEAPON_NEW4)
        n21_register_hud(WEAPON_OLD, WEAPON_NEW5)
       
        register_clcmd("say /k1", "knife_1")
        register_clcmd("say /k2", "knife_2")
        register_clcmd("say /k3", "knife_3")
        register_clcmd("say /k4", "knife_4")
        register_clcmd("say /k5", "knife_5")
        register_clcmd("say /k6", "knife_old")
}
 
public knife_1(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW1)
public knife_2(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW2)
public knife_3(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW3)
public knife_4(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW4)
public knife_5(id)      n21_hud_change_to(id, WEAPON_OLD, WEAPON_NEW5)
public knife_old(id)    n21_hud_change_to(id, WEAPON_OLD, WEAPON_OLD)

It's important to understand that this is just an example, it is NOT a ready-made implementation. You can use the functions the plugin provides however and wherever you like; it only saves you from routine work. You design the logic yourself; you are not required to stick to any rigid framework.

The custom_hud.amxx plugin must be higher in the plugins.ini list than the plugins that use the hud.inc include
You must load the custom_hud.amxx plugin!

Changing Weapon HUD (Weapon Custom Hud)

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