Wavelength | Your Game Editing Resource

Do you have a question about editing? Maybe you'd like to just chill with like-minded people and discuss things of a more general nature. We have two options for you!

Our forums are very popular and chances are we will be able to answer your editing based questions fairly quickly.

New! We now have a java IRC applet that you can use to chat LIVE with other Wavelength Members.

Affiliates

World of Macros
The best place on the web for Wow macros. New to wow macros? Check out the wow macro guide.

Wavelength - Half-Life - Coding - Shared Tutorials

Making a Flashbang [Print this Article]

Posted by: PowerSoul
Date posted: Oct 01 2004
User Rating: N/A

Number of views: 8376
Number of comments: 1

Description: Tutorial on making a flashbang grenade, complete with CS-style screen fading & concussion effect.

You must complete omega's orthotriangles tutorial before following this article.

I've seen horrible implementations of flashbangs in numerous smaller mods, and when I had to write one for my own mod, I wanted to do it right.
This is my way of coding a flashbang, enjoy.

First, on the client dll, we're going to modify the TFC's concussion effect so it automatically slows down & goes off, without needing to send a message from the server every second.
We will need to change gHud's m_iConcussion from private member to a public member, so we can modify it later.
Open hud.h, and move int m_iConcussionEffect; from CHud's privates to publics (line 558 -> 561).
Next, open tri.cpp, and add the following to HUD_DrawOrthoTriangles:

	CODE (C++)
	static float nextUpdate = gHUD.m_flTime + 0.2; if (gHUD.m_iConcussionEffect > 0) { if (gHUD.m_flTime > nextUpdate) { gHUD.m_iConcussionEffect -= 1; if (gHUD.m_iConcussionEffect < 0) { gHUD.m_iConcussionEffect = 0; } nextUpdate = gHUD.m_flTime+0.2; } }

This decreases m_iConcussionEffect (strength of the effect, 0 = off) by 1 every 0.2 seconds.
You might be asking why we're adding this here - simply because HUD_DrawOrthoTriangles gets called every frame for sure. You could add this to numerous other places, but I like it there.

That's it for client side, compile & open the server workspace.

What we're going to do first is "re-enable" the concussion message on the server side, so we can use it later.
Open player.cpp, and add this to line 186:

	CODE (C++)
	int gmsgConcussion = 0;

then go to line 233, and add this:

	CODE (C++)
	gmsgConcussion = REG_USER_MSG( "Concuss", 1 );

Now the server dll recognizes the gmsgConcussion-message, which we're going to use as an added effect to the flash.
Next we'll add two new functions to CGrenade, ShootFlashbang & Flash.
So open up weapons.h, and add the following below static CGrenade *ShootSatchelCharge:

	CODE (C++)
	static CGrenade ShootFlashbang( entvars_t pevOwner, Vector vecStart, Vector vecVelocity, float time );

...and the following below void Explode:

	CODE (C++)
	void Flash( TraceResult *pTrace );

Those prototype the added functions.
Next, open ggrenade.cpp, and scroll down around line 425, and our ShootFlashbang function there:

	CODE (C++)
	CGrenade * CGrenade::ShootFlashbang( entvars_t pevOwner, Vector vecStart, Vector vecVelocity, float time ) { CGrenade pGrenade = GetClassPtr( (CGrenade *)NULL ); pGrenade->Spawn(); UTIL_SetOrigin( pGrenade->pev, vecStart ); pGrenade->pev->velocity = vecVelocity; pGrenade->pev->angles = UTIL_VecToAngles(pGrenade->pev->velocity); pGrenade->pev->owner = ENT(pevOwner); // we'll use the handgrenade's bouncetouch pGrenade->SetTouch( BounceTouch ); // this is when our flashbang is going to explode pGrenade->pev->dmgtime = gpGlobals->time + time; pGrenade->SetThink( TumbleThink ); // just some cosmetic stuff here pGrenade->pev->avelocity.y = RANDOM_FLOAT ( -5, -20 ); pGrenade->pev->nextthink = gpGlobals->time + 0.1; if (time < 0.1) { pGrenade->pev->nextthink = gpGlobals->time; pGrenade->pev->velocity = Vector( 0, 0, 0 ); } // sets the model - PLEASE don't email me asking "where's w_flashbang.mdl?" SET_MODEL(ENT(pGrenade->pev), "models/w_flashbang.mdl"); if ( RANDOM_LONG( 1, 2 ) == 1 ) { pGrenade->pev->sequence = 2; } else { pGrenade->pev->sequence = 3; } pGrenade->pev->animtime = gpGlobals->time; pGrenade->pev->framerate = 1.0; pGrenade->pev->gravity = 0.55; pGrenade->pev->friction = 0.6; // important - if this is false, the flashbang explodes like a normal grenade. pGrenade->m_bIsFlashbang = TRUE; pGrenade->pev->dmg = 0; return pGrenade; }

Next go to the Detonate() function, line 217, and modify it so it looks like this:

	CODE (C++)
	void CGrenade::Detonate( void ) { TraceResult tr; Vector vecSpot = pev->origin + Vector ( 0 , 0 , 8 ); UTIL_TraceLine ( vecSpot, vecSpot + Vector ( 0, 0, -40 ), ignore_monsters, ENT(pev), & tr); if ( m_bIsFlashbang == TRUE ) { Flash( &tr ); } else { Explode( &tr, DMG_BLAST ); } }

This is just so it calls Flash() instead of handgrenade's Explode() if the granade is a flashbang.
"Now what the heck is this m_bIsFlashbang?", you might be asking. Indeed, we haven't yet added it.
So open up weapons.h again, and add

	CODE (C++)
	BOOL m_bIsFlashbang;

to the end of CGrenade's publics. It's a boolean we use to tell a flashbang from a normal grenade.
We're almost done - only the most critical part is missing ;)
Go to the start of ggrenade.cpp, and add these below the other includes:

	CODE (C++)
	#include "shake.h" #include "math.h"

We need shake.h to use UTIL_ScreenFade, and math.h, because we'll be using powf() to calculate the duration of the flash, based on player's distance.
Go around line 129, and add our Flash() function there as follows:

	CODE (C++)
	void CGrenade::Flash( TraceResult pTrace ) { pev->model = iStringNull; pev->solid = SOLID_NOT; pev->takedamage = DAMAGE_NO; if ( pTrace->flFraction != 1.0 ) { pev->origin = pTrace->vecEndPos + (pTrace->vecPlaneNormal 100 * 0.1); } // flash, apparently, doesn't work underwater. int iContents = UTIL_PointContents ( pev->origin ); if (iContents != CONTENTS_WATER) { // replace this with YOUR flash-sound. you'll also want to precache the sound in weapons.cpp. EMIT_SOUND(ENT(pev), CHAN_VOICE, "weapons/flashbang/bang.wav", 0.9, ATTN_NORM); // cool decal UTIL_DecalTrace( pTrace, DECAL_SCORCH1 ); CBaseEntity *pEntity = NULL; // we'll loop thru all entities 2000 units or less away from us while ((pEntity = UTIL_FindEntityInSphere( pEntity, pev->origin, 2000 )) != NULL) { // only affect players, duh if ( pEntity->IsPlayer() ) { // get the distance between the flash & the player float flDist = (pEntity->Center() - pev->origin).Length(); // we'll only fade the player's view if he saw the flash if ( FVisible( pEntity ) ) { // you can mess with these values if you're not happy with the original durations float flFadeTime = 150000 / powf(flDist, 2); // we'll use 30 as the maximum limit - else the player's view won't fade back in hours if he stares at the grenade from short distances. // even 30 is kind of high, you'll probably want to lower this. if (flFadeTime > 30) { flFadeTime = 30; } else if (flFadeTime <= 2.0) { flFadeTime = 2.0; } UTIL_ScreenFade( pEntity, Vector(255,255,255), flFadeTime, (flFadeTime / 4), 255, FFADE_IN ); // now the fun part - concussion! // they didn't have this in CS ;D - but I think it really adds to the effect. extern int gmsgConcussion; MESSAGE_BEGIN( MSG_ONE, gmsgConcussion, NULL, pEntity->pev ); if (flFadeTime < 3) { WRITE_BYTE( 20 ); } else if (flFadeTime >= 3 && flFadeTime < 4) { WRITE_BYTE( 34 ); } else if (flFadeTime >= 4 && flFadeTime < 5.5) { WRITE_BYTE( 50 ); } else if (flFadeTime >= 5.5 && flFadeTime < 12) { WRITE_BYTE( 72 ); } else if (flFadeTime >= 12) { WRITE_BYTE( 90 ); } MESSAGE_END(); } } } // heavy sparkage! int sparks = RANDOM_LONG(1,6); for ( int i = 0; i < sparks; i++ ) Create( "spark_shower", pev->origin, pTrace->vecPlaneNormal, NULL ); } // don't draw the model after it has exploded. pev->effects \|= EF_NODRAW; // emit some smoke, & remove self. SetThink( Smoke ); pev->velocity = g_vecZero; pev->nextthink = gpGlobals->time + 0.3; }

One last thing - If we leave the flashbang like it is now, it won't emit smoke - this is because it's "dmg" is 0.
So, replace the CGrenade's Smoke-function with the following:

	CODE (C++)
	void CGrenade::Smoke( void ) { if (UTIL_PointContents ( pev->origin ) == CONTENTS_WATER) { UTIL_Bubbles( pev->origin - Vector( 64, 64, 64 ), pev->origin + Vector( 64, 64, 64 ), 100 ); } else { MESSAGE_BEGIN( MSG_PVS, SVC_TEMPENTITY, pev->origin ); WRITE_BYTE( TE_SMOKE ); WRITE_COORD( pev->origin.x ); WRITE_COORD( pev->origin.y ); WRITE_COORD( pev->origin.z ); WRITE_SHORT( g_sModelIndexSmoke ); WRITE_BYTE( 70 ); // scale * 10 // static amount if it's a flashbang if (m_bIsFlashbang) { WRITE_BYTE( 80 ); } else { WRITE_BYTE( (pev->dmg - 50) * 0.80 ); // scale * 10 } WRITE_BYTE( 12 ); // framerate MESSAGE_END(); } UTIL_Remove( this ); }

That's all - you now have a working flashbang in your mod.
The easiest way to test it off is to change CHandGrenade to use CGrenade::ShootFlashbang instead of CGrenade::ShootTimed.
Have fun ;)

User Comments Showing comments 1-1

Posted By: kidneynabrik on Mar 29 2006 at 01:55:26

hey PowerSoul, like to mention that your code here....

	CODE
	void CGrenade::Smoke( void ) { if (UTIL_PointContents ( pev->origin ) == CONTENTS_WATER) { UTIL_Bubbles( pev->origin - Vector( 64, 64, 64 ), pev->origin + Vector( 64, 64, 64 ), 100 ); } else { MESSAGE_BEGIN( MSG_PVS, SVC_TEMPENTITY, pev->origin ); WRITE_BYTE( TE_SMOKE ); WRITE_COORD( pev->origin.x ); WRITE_COORD( pev->origin.y ); WRITE_COORD( pev->origin.z ); WRITE_SHORT( g_sModelIndexSmoke ); WRITE_BYTE( 70 ); // scale * 10 // static amount if it's a flashbang if (m_bIsFlashbang) { WRITE_BYTE( 80 ); } else { WRITE_BYTE( (pev->dmg - 50) * 0.80 ); // scale * 10 } WRITE_BYTE( 12 ); // framerate MESSAGE_END(); } UTIL_Remove( this ); }

needs to look like this

	CODE
	void CGrenade::Smoke( void ) { if (UTIL_PointContents ( pev->origin ) == CONTENTS_WATER) { UTIL_Bubbles( pev->origin - Vector( 64, 64, 64 ), pev->origin + Vector( 64, 64, 64 ), 100 ); } else { MESSAGE_BEGIN( MSG_PVS, SVC_TEMPENTITY, pev->origin ); WRITE_BYTE( TE_SMOKE ); WRITE_COORD( pev->origin.x ); WRITE_COORD( pev->origin.y ); WRITE_COORD( pev->origin.z ); WRITE_SHORT( g_sModelIndexSmoke ); // WRITE_BYTE( 70 ); // scale * 10 // FIX, THIS IS NULL/VOID unneeded // static amount if it's a flashbang if (m_bIsFlashbang) { WRITE_BYTE( 80 ); } else { WRITE_BYTE( (pev->dmg - 50) * 0.80 ); // scale * 10 } WRITE_BYTE( 12 ); // framerate MESSAGE_END(); } UTIL_Remove( this ); }

everything else is good....

You must register to post a comment. If you have already registered, you must login.