A_DetonChase

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A_DetonChase is an action that causes the actor to chase after the target player (set as the actor's tracer) in the manner of a Deton. The actor will automatically be set to move at 3/4 of the top speed of the character they chase to make sure every character can avoid it. As the actor moves towards its target player, it will adjust its movement angle to aim towards the player both horizontally and vertically. When the actor touches the target player, it will explode and damage any Objects within 96 fracunits around it. If the actor's tracer doesn't exist, is dead or is further away than PainChance, the actor will look for a new target player to set as the tracer; if none can be found, the actor stops moving and returns to its SpawnState.

Note that the actor will not actually move until its reaction time value has been set to -42, and this action will adjust the actor's reaction time so it reaches this value – when the reaction time is higher than 1 it will be reduced by 1 each time the action is used; when the reaction time reaches 1 it will be set to -42 and play the actor's SeeSound if it exists; if it is 0, it will be reset to the value of ReactionTime; when it is -42 the actor will move and play sfx_deton at a frequency depending on how far the actor is from its tracer.

Object property	Use
`SpawnState`	Goes back to this state if no players can be found
`SeeSound`	When reaction time = 1, this sound is played
`ReactionTime`	When reaction time = 0, this value sets the new reaction time
`PainChance`	If the actor is further away from the player target than this value, the actor stops chasing

Code – A_DetonChase

// Function: A_DetonChase
//
// Description: Chases a Deton after a player.
//
// var1 = unused
// var2 = unused
//
void A_DetonChase(mobj_t *actor)
{
	angle_t exact;
	fixed_t xydist, dist;
#ifdef HAVE_BLUA
	if (LUA_CallAction("A_DetonChase", actor))
		return;
#endif

	// modify tracer threshold
	if (!actor->tracer || actor->tracer->health <= 0)
		actor->threshold = 0;
	else
		actor->threshold = 1;

	if (!actor->tracer || !(actor->tracer->flags & MF_SHOOTABLE))
	{
		// look for a new target
		if (P_LookForPlayers(actor, true, true, 0))
			return; // got a new target

		actor->momx = actor->momy = actor->momz = 0;
		P_SetMobjState(actor, actor->info->spawnstate);
		return;
	}

	if (multiplayer && !actor->threshold && P_LookForPlayers(actor, true, true, 0))
		return; // got a new target

	// Face movement direction if not doing so
	exact = R_PointToAngle2(actor->x, actor->y, actor->tracer->x, actor->tracer->y);
	actor->angle = exact;
	/*if (exact != actor->angle)
	{
		if (exact - actor->angle > ANGLE_180)
		{
			actor->angle -= actor->info->raisestate;
			if (exact - actor->angle < ANGLE_180)
				actor->angle = exact;
		}
		else
		{
			actor->angle += actor->info->raisestate;
			if (exact - actor->angle > ANGLE_180)
				actor->angle = exact;
		}
	}*/
	// movedir is up/down angle: how much it has to go up as it goes over to the player
	xydist = P_AproxDistance(actor->tracer->x - actor->x, actor->tracer->y - actor->y);
	exact = R_PointToAngle2(0, 0, xydist, actor->tracer->z - actor->z);
	actor->movedir = exact;
	/*if (exact != actor->movedir)
	{
		if (exact - actor->movedir > ANGLE_180)
		{
			actor->movedir -= actor->info->raisestate;
			if (exact - actor->movedir < ANGLE_180)
				actor->movedir = exact;
		}
		else
		{
			actor->movedir += actor->info->raisestate;
			if (exact - actor->movedir > ANGLE_180)
				actor->movedir = exact;
		}
	}*/

	// check for melee attack
	if (actor->tracer)
	{
		if (P_AproxDistance(actor->tracer->x-actor->x, actor->tracer->y-actor->y) < actor->radius+actor->tracer->radius)
		{
			if (!((actor->tracer->z > actor->z + actor->height) || (actor->z > actor->tracer->z + actor->tracer->height)))
			{
				P_ExplodeMissile(actor);
				return;
			}
		}
	}

	// chase towards player
	if ((dist = P_AproxDistance(xydist, actor->tracer->z-actor->z))
		> FixedMul((actor->info->painchance << FRACBITS), actor->scale))
	{
		P_SetTarget(&actor->tracer, NULL); // Too far away
		return;
	}

	if (actor->reactiontime == 0)
	{
		actor->reactiontime = actor->info->reactiontime;
		return;
	}

	if (actor->reactiontime > 1)
	{
		actor->reactiontime--;
		return;
	}

	if (actor->reactiontime > 0)
	{
		actor->reactiontime = -42;

		if (actor->info->seesound)
			S_StartScreamSound(actor, actor->info->seesound);
	}

	if (actor->reactiontime == -42)
	{
		fixed_t xyspeed;

		actor->reactiontime = -42;

		exact = actor->movedir>>ANGLETOFINESHIFT;
		xyspeed = FixedMul(FixedMul(actor->tracer->player->normalspeed,3*FRACUNIT/4), FINECOSINE(exact));
		actor->momz = FixedMul(FixedMul(actor->tracer->player->normalspeed,3*FRACUNIT/4), FINESINE(exact));

		exact = actor->angle>>ANGLETOFINESHIFT;
		actor->momx = FixedMul(xyspeed, FINECOSINE(exact));
		actor->momy = FixedMul(xyspeed, FINESINE(exact));

		// Variable re-use
		xyspeed = (P_AproxDistance(actor->tracer->x - actor->x, P_AproxDistance(actor->tracer->y - actor->y, actor->tracer->z - actor->z))>>(FRACBITS+6));

		if (xyspeed < 1)
			xyspeed = 1;

		if (leveltime % xyspeed == 0)
			S_StartSound(actor, sfx_deton);
	}
}

	Actions – Enemy thinkers	[view]
A_BuzzFly • A_CrawlaCommanderThink • A_DetonChase • A_EggShield • A_FaceStabChase • A_FaceStabRev • A_FaceStabHurl • A_FaceStabMiss • A_StatueBurst • A_GuardChase • A_HoodThink • A_HoodFall • A_JetbThink • A_JetChase • A_JetgShoot • A_JetgThink • A_JetJawChomp • A_JetJawRoam • A_MinusCheck • A_MinusDigging • A_MinusPopup • A_PointyThink • A_SharpChase • A_SharpSpin • A_SharpDecel • A_SkimChase • A_SnailerThink • A_VultureCheck • A_VultureVtol

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