Class System

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In the March 17 2008 beta of the SDK, a flexible class system was added. This page will teach programmers how to work with this system.

Todo: Explain how to implement into Half Life 2: Deathmatch

Starting off

Open up the SDK, and run the "Create a Mod" wizard. Select "Start a Multiplayer mod from a template." Don't worry about the "advanced users" warning, since Valve has made this extremely easy. Make sure you check "Enable classes" and most likely "Enable teams."

Bug:After starting a mod from a template, compiling the dlls and playing the mod, the mod hangs when you try to quit. The reason for this is unknown. A fix for this bug is in the Source 2007 Template Fixes page.  [todo tested in ?]

Scripts

Now, most of the configuration for the class itself is done with simple text files. The files that control this are located in <moddir>\scripts, under the names playerclass_blue_class1.txt and such. While most of it is relatively self-explanatory, certain things might be obscure, or not listed.

Variables (on the C++ side)

int m_iTeam; 			// 0 is unassigned, 1 is spectator, 2 is team 1 (BLUE), 3 is team 2 (RED), etc.
int m_iPrimaryWeapon;		// Index of the weapon, as defined in sdk_shareddefs.h (default is NONE, MP5, SHOTGUN, GRENADE, PISTOL, and CROWBAR
int m_iSecondaryWeapon;	// Same as primary, but for secondary, and allowed to be WEAPON_NONE
int m_iMeleeWeapon;		// Same as secondary, but for melee
int m_iNumGrensType1;		// Number of Type 1 Grenades
int m_iGrenType1;		// Same as secondary, but for Type 1 Grenades
int m_iNumGrensType2;		// Number of Type 2 Grenades
int m_iGrenType2;		// Same as secondary, but for Type 2 Grenades
char m_szLimitCvar[64];	// Name of the cvar that controls the class limit for this class
float m_flRunSpeed;		// Run (normal) speed, in units/second. SDK Default is 220, HL2 uses 190
float m_flSprintSpeed;		// Sprint speed, in units/second. Is usually 150% run speed. SDK default is 330, HL2 uses 327.5
float m_flProneSpeed;		// Prone speed, in units/second. SDK defaults to 50
int m_iArmor;			// Amount of extra armor. It will absorb 80% of the damage (to change that, go to player.cpp)
 
char m_szClassImage[SDK_PLAYERCLASS_IMAGE_LENGTH];	// According to comments, this is "HUD player status health images (when the player is hurt)"
char m_szClassImageBG[SDK_PLAYERCLASS_IMAGE_LENGTH];	// However, I can't seem to trace the code for it.

Variables (on the .txt side)

// Mandatory / Strongly Recommended keyvalues
"printname"		"#class_red_class1"			// the name of the class, usually as a localization string. Not used in sdk_playerclass_info_parse.cpp, but it's used in other places in .res files
"playermodel"		"models/player/red_player.mdl"		// the model of the class
"selectcmd"		"cls_red_class1"			// from what the author can tell, the name of the console command used to switch to this class
"team"			"RED"					// The team it goes with. Default code only accepts "BLUE" or "RED"
"primaryweapon"	"pistol"				// The name of the primary weapon. Cannot be "none"
"limitcvar"		"mp_limit_red_class1"			// The console variable that controls the maximum amount of this class allowed
"classimage"		"cls_red_class1_active"			// An image name, apparently for the HUD
"classimagebg"		"cls_red_class1_active_bg"		// Same

// Optional keyvalues
"secondaryweapon"	"none"					// Defaults to none
"meleeweapon"		"crowbar"				// Defaults to none
"grenadetype"		"grenade"				// Defaults to none
"numgrens"		"1"					// Defaults to 0
"grenadetype2"		"grenade"				// Defaults to none
"numgrens2"		"1"					// Defaults to 0
"armor"		"50"					// Defaults to 0
"RunSpeed"		"240"					// Defaults to SDK_DEFAULT_PLAYER_RUNSPEED, which defaults to 220
"SprintSpeed"		"360"					// Defaults to SDK_DEFAULT_PLAYER_SPRINTSPEED, which defaults to 330
"ProneSpeed"		"70"					// Defaults to SDK_DEFAULT_PLAYER_PRONESPEED, which defaults to 50

How it glues together

void unused			= "printname"
int m_iTeam; 			= "team"
int m_iPrimaryWeapon;		= "primaryweapon"
int m_iSecondaryWeapon;	= "secondaryweapon"
int m_iMeleeWeapon;		= "meleeweapon"
int m_iNumGrensType1;		= "numgrens"
int m_iGrenType1;		= "grenadetype"
int m_iNumGrensType2;		= "numgrens2"
int m_iGrenType2;		= "grenadetype2"
char m_szLimitCvar[64];	= "limitcvar"
float m_flRunSpeed;		= "RunSpeed"
float m_flSprintSpeed;		= "SprintSpeed"
float m_flProneSpeed;		= "ProneSpeed"
int m_iArmor;			= "armor"

char m_szClassImage[SDK_PLAYERCLASS_IMAGE_LENGTH];	= "classimage"
char m_szClassImageBG[SDK_PLAYERCLASS_IMAGE_LENGTH];	= "classimagebg"

Todo: Cover adding a special ability to just one class (ex. give one class double-jumping)

The class system reads from txt files in the scripts/ directory named as playerclass_<red/blue>_class<number>.txt

Example Text File:

PlayerClassDatafile
{
	// FilePLayerClassInfo_t members
	"printname"			"#class_blue_class1"
	"playermodel"			"models/player/blue_player.mdl"
	"selectcmd"			"cls_blue_class1"
 
	// CSDKPlayerClassInfo members
 
	// What team has this class, for verification
	"team"				"BLUE"
 
	// Weapon Info
	"primaryweapon"		"pistol"
	"secondaryweapon"	"none"
	"meleeweapon"		"crowbar"
 
	"grenadetype"		"grenade"
	"numgrens"		"1"
 
	"limitcvar"		"mp_limit_blue_class1"
 
	"classimage"		"cls_blue_class1_active"
	"classimagebg"		"cls_blue_class1_active_bg"
 
	"armor"			"50"
 
	// Movement
	"RunSpeed"		"240"
	"SprintSpeed"		"360"
	"ProneSpeed"		"70"
}