Authoring a Brush Entity/Code

//===== Copyright © 1996-2005, Valve Corporation, All rights reserved. ========
//
// Purpose: Simple brush entity that moves when touched
//
//=============================================================================

#include "cbase.h"
#include "triggers.h"

class CMyBrushEntity : public CBaseTrigger
{
public:
	DECLARE_CLASS( CMyBrushEntity, CBaseTrigger );
	DECLARE_DATADESC();

	void Spawn();

	void BrushTouch( CBaseEntity *pOther );
};

LINK_ENTITY_TO_CLASS( my_brush_entity, CMyBrushEntity );

BEGIN_DATADESC( CMyBrushEntity )
	
	// Declare this function as being the touch function
	DEFINE_ENTITYFUNC( BrushTouch ),

END_DATADESC()

//-----------------------------------------------------------------------------
// Purpose: Sets up the entity's initial state
//-----------------------------------------------------------------------------
void CMyBrushEntity::Spawn()
{
	BaseClass::Spawn();

	// We want to capture touches from other entities
	SetTouch( &CMyBrushEntity::BrushTouch );

	// We should collide with physics
	SetSolid( SOLID_VPHYSICS );
	
	// Use our brushmodel
	SetModel( STRING( GetModelName() ) );
	
	// We push things out of our way
	SetMoveType( MOVETYPE_PUSH );

	// Create our physics hull information
	VPhysicsInitShadow( false, false );
}

//-----------------------------------------------------------------------------
// Purpose: Move away from an entity that touched us
// Input  : *pOther - the entity we touched
//-----------------------------------------------------------------------------
void CMyBrushEntity::BrushTouch( CBaseEntity *pOther )
{
	// Get the collision information
	const trace_t &tr = GetTouchTrace();

	// We want to move away from the impact point along our surface
	Vector	vecPushDir = tr.plane.normal;
	vecPushDir.Negate();
	vecPushDir.z = 0.0f;

	// Uncomment this line to print plane information to the console in developer mode
	//DevMsg ( "%s (%s) touch plane's normal: [%f %f]\n", GetClassname(), GetDebugName(),tr.plane.normal.x, tr.plane.normal.y );

	// Move slowly in that direction
	LinearMove( GetAbsOrigin() + ( vecPushDir * 64.0f ), 32.0f );
}

See also

• Authoring a Brush Entity