Adding Muzzle Flashes that lights up the world

This tutorial will show how to add dlight muzzle flash that lights up the world around the player dynamically in GoldSrc.

Coding

First navigate to ev_hldm.h and scroll to the bottom. After that, add this

void EV_HLDM_MuzzleFlash( vec3_t pos, float amount );

Then, open ev_hldm.cpp and find:

float EV_HLDM_PlayTextureSound( int idx, pmtrace_t *ptr, float *vecSrc, float *vecEnd, int iBulletType )

Below that, add this:

void EV_HLDM_MuzzleFlash(vec3_t pos, float amount)
{
    // make a dlight first
    dlight_t *dl = gEngfuncs.pEfxAPI->CL_AllocDlight(0);

    // Original color values
    int originalR = 231;
    int originalG = 219;
    int originalB = 14;

    // Randomize color components within the range of +/- 20
    dl->color.r = originalR + gEngfuncs.pfnRandomLong(-20, 20);
    dl->color.g = originalG + gEngfuncs.pfnRandomLong(-20, 20);
    dl->color.b = originalB + gEngfuncs.pfnRandomLong(0, 0);

    // Randomize the die value by +/- 0.01
    dl->die = gEngfuncs.GetClientTime() + 0.05 + gEngfuncs.pfnRandomFloat(-0.01, 0.01);

    // Randomize the radius based on amount
    dl->radius = gEngfuncs.pfnRandomFloat(245.0f, 256.0f);

    // Randomize the decay value
    dl->decay = gEngfuncs.pfnRandomFloat(400.0f, 600.0f);
}

Then, find the function definition:

void EV_FireWeaponName(event_args_t *args) // replace WeaponName with your weapon’s name

Find this in that function:

EV_GetGunPosition( args, vecSrc, origin );

Just after that, add this:

EV_HLDM_MuzzleFlash( vecSrc, 1.0 + gEngfuncs.pfnRandomFloat( -0.2, 0.2 ) );

Credits and Reference

• This guide is a modified version of the guide from VERC and TWHL.

1. https://web.archive.org/web/20061027233737/http://collective.valve-erc.com/index.php?doc=1031137353-13157900
2. https://twhl.info/wiki/page/VERC%3A_Adding_muzzle_flashes_that_also_light_up_world_brushes
3. This article's randomizer code was used here

• Also, there’s something called elights which doesn’t light up the world but entities and models.