server: added trigger_teleport_point entity from Diffusion mod

Thanks to @Aynekko for sharing

server/entities/trigger_teleport_point.cpp

@@ -0,0 +1,70 @@
+#include "trigger_teleport_point.h"
+#include "player.h"
+#include "monsters.h"
+
+LINK_ENTITY_TO_CLASS( trigger_teleport_point, CTriggerTeleportPoint );
+
+BEGIN_DATADESC( CTriggerTeleportPoint )
+	DEFINE_KEYFIELD( m_entity, FIELD_STRING, "entityname" ),
+END_DATADESC();
+
+void CTriggerTeleportPoint::KeyValue(KeyValueData* pkvd)
+{
+	if (FStrEq(pkvd->szKeyName, "entityname"))
+	{
+		m_entity = ALLOC_STRING(pkvd->szValue);
+		pkvd->fHandled = TRUE;
+	}
+	else
+		CBaseDelay::KeyValue(pkvd);
+}
+
+void CTriggerTeleportPoint::Use(CBaseEntity *pActivator, CBaseEntity *pCaller, USE_TYPE useType, float value)
+{
+	if (IsLockedByMaster(pActivator))
+		return;
+
+	if (!pActivator || !pActivator->IsPlayer())
+		pActivator = CBaseEntity::Instance(INDEXENT(1));
+
+	CBasePlayer* pPlayer = (CBasePlayer*)pActivator;
+	CBaseEntity* pEntity = NULL;
+
+	if (FStrEq(STRING(m_entity), "player") || !m_entity)
+		pEntity = pPlayer;
+	else
+		pEntity = UTIL_FindEntityByTargetname(pEntity, STRING(m_entity));
+
+	if (!pEntity)
+	{
+		ALERT(at_error, "trigger_teleport_point \"%s\" can't find specified entity!\n", STRING(pev->targetname));
+		return;
+	}
+
+	// this entity acts as a teleport target
+	Vector targetOrg = GetAbsOrigin();
+	Vector targetAng = GetAbsAngles();
+
+	Vector entityVelocity = g_vecZero;
+	if (FBitSet(pev->spawnflags, PT_KEEP_VELOCITY)) {
+		entityVelocity = pEntity->GetAbsVelocity();
+	}
+
+	Vector EntityAngles = targetAng;
+	if (FBitSet(pev->spawnflags, PT_KEEP_ANGLES)) {
+		EntityAngles = pEntity->GetAbsAngles();
+	}
+
+	// offset to correctly teleport the player...
+	if (pEntity->IsPlayer()) {
+		targetOrg.z += 36;
+	}
+
+	pEntity->Teleport(&targetOrg, &EntityAngles, &entityVelocity);
+
+	UTIL_FireTargets(pev->target, pActivator, pCaller, USE_TOGGLE, 0);
+
+	if (FBitSet(pev->spawnflags, PT_REMOVEONFIRE)) {
+		UTIL_Remove(this);
+	}
+}

server/entities/trigger_teleport_point.h

@@ -0,0 +1,26 @@
+#include "extdll.h"
+#include "util.h"
+#include "cbase.h"
+
+//=======================================================================================================================
+// diffusion - teleports entity regardless of its position (no teleport brush needed) - this entity also acts as a target
+//=======================================================================================================================
+
+#define PT_KEEP_VELOCITY	BIT(0) // keep the velocity of the entity
+#define PT_KEEP_ANGLES		BIT(1) // don't snap to new angles
+#define PT_REMOVEONFIRE		BIT(2)
+
+// UNDONE: redirect player's velocity to entity's view origin?
+
+class CTriggerTeleportPoint : public CBaseDelay
+{
+	DECLARE_CLASS(CTriggerTeleportPoint, CBaseDelay);
+public:
+	void Use(CBaseEntity* pActivator, CBaseEntity* pCaller, USE_TYPE useType, float value);
+	void KeyValue(KeyValueData* pkvd);
+	int ObjectCaps(void) { return BaseClass::ObjectCaps() & ~FCAP_ACROSS_TRANSITION; }
+
+	DECLARE_DATADESC();
+
+	string_t m_entity;
+};