Hitscan
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For a more technical article on this topic, see TraceLines.
Half-Life 2 has many hitscan weapons (weapons which don't actually fire bullets, but instead trace a line and spawn an explosion/damage at the end). Sometimes it is useful, however, to hitscan just to find where a line hits a wall/player/etc. So I took some code from CBaseEntity::FireBullets() to create CBaseEntity::HitScan(). I put the following code into baseentity_shared.ccp.
Vector CBaseEntity::HitScan( const FireBulletsInfo_t &info, unsigned int mask )
{
trace_t tr;
CTraceFilterSkipTwoEntities traceFilter( this, info.m_pAdditionalIgnoreEnt, COLLISION_GROUP_NONE );
Vector vecEnd = info.m_vecSrc + info.m_vecDirShooting * info.m_flDistance;
AI_TraceLine(info.m_vecSrc, vecEnd, mask, &traceFilter, &tr);
return tr.endpos;
}
and the definition into BaseEntity.h.
virtual Vector HitScan( const FireBulletsInfo_t &info, unsigned int mask );
This function can easily be adapted to take line definitions in other formats. Simply have it generate the FireBulletsInfo_t structure given a start and end or start and direction.
