qengine, un fork du moteur de jeu de Quake II est disponible en open source

Pour les développeurs en proie à la nostalgie

qengine, un fork du moteur de jeu de Quake II est disponible en open source
Pour les développeurs en proie à la nostalgie


La liste des projets qui dérivent du code source de Quake II s’allonge. Après la publication du code source du jeu de tir à la première personne en décembre 2001, de nombreuses initiatives (dont Yamagi Quake II, Quake2maX, EGL, Quake II Evolved ou encore KMQuake II) de développeurs tiers ont vu le jour. En 2018, il faudra également compter avec qengine.

qengine est un moteur de jeu rétro conçu pour une multitude de plateformes. Il s'adresse aux développeurs nostalgiques, en manque de moments simples et qui seraient heureux de créer des jeux comme c’était le cas en 1997.

qengine est un fork du moteur Quake II développé par id Software. D’après l’auteur, le moteur est conçu « pour servir de base aux jeux vidéos autonomes. »

À l’inverse d’autres dérivés, qengine n’a pas été mis sur pied pour être compatible avec les mods ou le jeu Quake II dans sa version la plus simple. À la réalité, nous nous sommes débarrassés de plusieurs fonctionnalités afin de réduire la complexité de la base de code et rendre le processus de création de nouveaux jeux [basés sur ce moteur] plus aisé et rapide.


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qengine c’est la fusion de tous les modules dans un unique paquetage, mais une séparation claire entre les composants chargés du rendu logiciel et ceux responsables du déroulement d’une partie. Klaus Silveira n’a conservé qu’une vingtaine de briques de la dernière catégorie (dont l’intelligence artificielle de détection des ennemis). La manœuvre participe de l'atteinte des objectifs poursuivis lors de la phase de conception : fournir un moteur propre et d’une maintenance aisée, améliorer la stabilité sur diverses plateformes, ainsi que les performances de la brique de rendu logiciel.


/*
* Copyright (C) 1997-2001 Id Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*
* =======================================================================
*
* The basic AI functions like enemy detection, attacking and so on.
*
* =======================================================================
*/

#include "../server/header/server.h"

extern cvar_t *maxclients;

qboolean enemy_vis;
qboolean enemy_infront;
int enemy_range;
float enemy_yaw;

qboolean FindTarget(edict_t *self);

qboolean ai_checkattack(edict_t *self);

/*
* Called once each frame to set level.sight_client
* to the player to be checked for in findtarget.
* If all clients are either dead or in notarget,
* sight_client will be null.
* In coop games, sight_client will cycle
* between the clients.
*/
void AI_SetSightClient(void)
{
edict_t *ent;
int start, check;

if (level.sight_client == NULL) {
start = 1;
} else {
start = level.sight_client - g_edicts;
}

check = start;

while (1) {
check++;

if (check > game.maxclients) {
check = 1;
}

ent = &g_edicts;

if (ent->inuse && (ent->health > 0) && !(ent->flags & FL_NOTARGET)) {
level.sight_client = ent;
return; /* got one */
}

if (check == start) {
level.sight_client = NULL;
return; /* nobody to see */
}
}
}

/*
* Move the specified distance at current facing.
*/
void ai_move(edict_t *self, float dist)
{
if (!self) {
return;
}

M_walkmove(self, self->s.angles, dist);
}

/*
*
* Used for standing around and looking
* for players Distance is for slight
* position adjustments needed by the
* animations
*/
void ai_stand(edict_t *self, float dist)
{
vec3_t v;

if (!self) {
return;
}

if (dist) {
M_walkmove(self, self->s.angles, dist);
}

if (self->monsterinfo.aiflags & AI_STAND_GROUND) {
if (self->enemy) {
VectorSubtract(self->enemy->s.origin, self->s.origin, v);
self->ideal_yaw = vectoyaw(v);

if ((self->s.angles != self->ideal_yaw) && self->monsterinfo.aiflags & AI_TEMP_STAND_GROUND) {
self->monsterinfo.aiflags &= ~(AI_STAND_GROUND | AI_TEMP_STAND_GROUND);
self->monsterinfo.run(self);
}

M_ChangeYaw(self);
ai_checkattack(self);
} else {
FindTarget(self);
}

return;
}

if (FindTarget(self)) {
return;
}

if (level.time > self->monsterinfo.pausetime) {
self->monsterinfo.walk(self);
return;
}

if (!(self->spawnflags & 1) && (self->monsterinfo.idle) && (level.time > self->monsterinfo.idle_time)) {
if (self->monsterinfo.idle_time) {
self->monsterinfo.idle(self);
self->monsterinfo.idle_time = level.time + 15 + random() * 15;
} else {
self->monsterinfo.idle_time = level.time + random() * 15;
}
}
}

/*
* The monster is walking it's beat
*/
void ai_walk(edict_t *self, float dist)
{
if (!self) {
return;
}

M_MoveToGoal(self, dist);

/* check for noticing a player */
if (FindTarget(self)) {
return;
}

if ((self->monsterinfo.search) && (level.time > self->monsterinfo.idle_time)) {
if (self->monsterinfo.idle_time) {
self->monsterinfo.search(self);
self->monsterinfo.idle_time = level.time + 15 + random() * 15;
} else {
self->monsterinfo.idle_time = level.time + random() * 15;
}
}
}

/*
* Turns towards target and advances
* Use this call with a distance of 0
* to replace ai_face
*/
void ai_charge(edict_t *self, float dist)
{
vec3_t v;

if (!self) {
return;
}

if (self->enemy) {
VectorSubtract(self->enemy->s.origin, self->s.origin, v);
}

self->ideal_yaw = vectoyaw(v);
M_ChangeYaw(self);

if (dist) {
M_walkmove(self, self->s.angles, dist);
}
}

/*
* Don't move, but turn towards
* ideal_yaw. Distance is for
* slight position adjustments
* needed by the animations
*/
void ai_turn(edict_t *self, float dist)
{
if (!self) {
return;
}

if (dist) {
M_walkmove(self, self->s.angles, dist);
}

if (FindTarget(self)) {
return;
}

M_ChangeYaw(self);
}

/* ============================================================================
*/

/*
* .enemy
* Will be world if not currently angry at anyone.
*
* .movetarget
* The next path spot to walk toward. If .enemy, ignore .movetarget.
* When an enemy is killed, the monster will try to return to it's path.
*
* .hunt_time
* Set to time + something when the player is in sight, but movement straight
* for him is blocked. This causes the monster to use wall following code for
* movement direction instead of sighting on the player.
*
* .ideal_yaw
* A yaw angle of the intended direction, which will be turned towards at up
* to 45 deg / state. If the enemy is in view and hunt_time is not active,
* this will be the exact line towards the enemy.
*
* .pausetime
* A monster will leave it's stand state and head towards it's .movetarget when
* time > .pausetime.
*/

/* ============================================================================
*/

/*
* returns the range categorization of an entity relative to self
* 0 melee range, will become hostile even if back is turned
* 1 visibility and infront, or visibility and show hostile
* 2 infront and show hostile
* 3 only triggered by damage
*/
int range(edict_t *self, edict_t *other)
{
vec3_t v;
float len;

if (!self || !other) {
return 0;
}

VectorSubtract(self->s.origin, other->s.origin, v);
len = VectorLength(v);

if (len < MELEE_DISTANCE) {
return RANGE_MELEE;
}

if (len < 500) {
return RANGE_NEAR;
}

if (len < 1000) {
return RANGE_MID;
}

return RANGE_FAR;
}

/*
* returns 1 if the entity is visible
* to self, even if not infront
*/
qboolean visible(edict_t *self, edict_t *other)
{
vec3_t spot1;
vec3_t spot2;
trace_t trace;

if (!self || !other) {
return false;
}

VectorCopy(self->s.origin, spot1);
spot1 += self->viewheight;
VectorCopy(other->s.origin, spot2);
spot2 += other->viewheight;
trace = SV_Trace(spot1, vec3_origin, vec3_origin, spot2, self, MASK_OPAQUE);

if (trace.fraction == 1.0) {
return true;
}

return false;
}

/*
* returns 1 if the entity is in
* front (in sight) of self
*/
qboolean infront(edict_t *self, edict_t *other)
{
vec3_t vec;
float dot;
vec3_t forward;

if (!self || !other) {
return false;
}

AngleVectors(self->s.angles, forward, NULL, NULL);

VectorSubtract(other->s.origin, self->s.origin, vec);
VectorNormalize(vec);
dot = DotProduct(vec, forward);

if (dot > 0.3) {
return true;
}

return false;
}

/* ============================================================================
*/

void HuntTarget(edict_t *self)
{
vec3_t vec;

if (!self) {
return;
}

self->goalentity = self->enemy;

if (self->monsterinfo.aiflags & AI_STAND_GROUND) {
self->monsterinfo.stand(self);
} else {
self->monsterinfo.run(self);
}

if (visible(self, self->enemy)) {
VectorSubtract(self->enemy->s.origin, self->s.origin, vec);
}

self->ideal_yaw = vectoyaw(vec);

/* wait a while before first attack */
if (!(self->monsterinfo.aiflags & AI_STAND_GROUND)) {
AttackFinished(self, 1);
}
}

void FoundTarget(edict_t *self)
{
if (!self || !self->enemy || !self->enemy->inuse) {
return;
}

/* let other monsters see this monster for a while */
if (self->enemy->client) {
level.sight_entity = self;
level.sight_entity_framenum = level.framenum;
level.sight_entity->light_level = 128;
}

self->show_hostile = (int) level.time + 1; /* wake up other monsters */

VectorCopy(self->enemy->s.origin, self->monsterinfo.last_sighting);
self->monsterinfo.trail_time = level.time;

if (!self->combattarget) {
HuntTarget(self);
return;
}

self->goalentity = self->movetarget = G_PickTarget(self->combattarget);

if (!self->movetarget) {
self->goalentity = self->movetarget = self->enemy;
HuntTarget(self);
PF_dprintf("%s at %s, combattarget %s not found\n", self->classname, vtos(self->s.origin), self->combattarget);
return;
}

/* clear out our combattarget, these are a one shot deal */
self->combattarget = NULL;
self->monsterinfo.aiflags |= AI_COMBAT_POINT;

/* clear the targetname, that point is ours! */
self->movetarget->targetname = NULL;
self->monsterinfo.pausetime = 0;

/* run for it */
self->monsterinfo.run(self);
}

/*
* Self is currently not attacking anything,
* so try to find a target
*
* Returns TRUE if an enemy was sighted
*
* When a player fires a missile, the point
* of impact becomes a fakeplayer so that
* monsters that see the impact will respond
* as if they had seen the player.
*
* To avoid spending too much time, only
* a single client (or fakeclient) is
* checked each frame. This means multi
* player games will have slightly
* slower noticing monsters.
*/
qboolean FindTarget(edict_t *self)
{
edict_t *client;
qboolean heardit;
int r;

if (!self) {
return false;
}

if (self->monsterinfo.aiflags & AI_GOOD_GUY) {
return false;
}

/* if we're going to a combat point, just proceed */
if (self->monsterinfo.aiflags & AI_COMBAT_POINT) {
return false;
}

/* if the first spawnflag bit is set, the monster
will only wake up on really seeing the player,
not another monster getting angry or hearing
something */

heardit = false;

if ((level.sight_entity_framenum >= (level.framenum - 1)) && !(self->spawnflags & 1)) {
client = level.sight_entity;

if (client->enemy == self->enemy) {
return false;
}
} else if (level.sound_entity_framenum >= (level.framenum - 1)) {
client = level.sound_entity;
heardit = true;
} else if (!(self->enemy) && (level.sound2_entity_framenum >= (level.framenum - 1)) && !(self->spawnflags & 1)) {
client = level.sound2_entity;
heardit = true;
} else {
client = level.sight_client;

if (!client) {
return false; /* no clients to get mad at */
}
}

/* if the entity went away, forget it */
if (!client->inuse) {
return false;
}

if (client == self->enemy) {
return true;
}

if (client->client) {
if (client->flags & FL_NOTARGET) {
return false;
}
} else if (client->svflags & SVF_MONSTER) {
if (!client->enemy) {
return false;
}

if (client->enemy->flags & FL_NOTARGET) {
return false;
}
} else if (heardit) {
if (client->owner->flags & FL_NOTARGET) {
return false;
}
} else {
return false;
}

if (!heardit) {
r = range(self, client);

if (r == RANGE_FAR) {
return false;
}

/* is client in an spot too dark to be seen? */
if (client->light_level <= 5) {
return false;
}

if (!visible(self, client)) {
return false;
}

if (r == RANGE_NEAR) {
if ((client->show_hostile < (int) level.time) && !infront(self, client)) {
return false;
}
} else if (r == RANGE_MID) {
if (!infront(self, client)) {
return false;
}
}

self->enemy = client;

if (strcmp(self->enemy->classname, "player_noise") != 0) {
self->monsterinfo.aiflags &= ~AI_SOUND_TARGET;

if (!self->enemy->client) {
self->enemy = self->enemy->enemy;

if (!self->enemy->client) {
self->enemy = NULL;
return false;
}
}
}
} else /* heardit */
{
vec3_t temp;

if (self->spawnflags & 1) {
if (!visible(self, client)) {
return false;
}
} else {
if (!PF_inPHS(self->s.origin, client->s.origin)) {
return false;
}
}

VectorSubtract(client->s.origin, self->s.origin, temp);

if (VectorLength(temp) > 1000) /* too far to hear */
{
return false;
}

/* check area portals - if they are different
and not connected then we can't hear it */
if (client->areanum != self->areanum) {
if (!CM_AreasConnected(self->areanum, client->areanum)) {
return false;
}
}

self->ideal_yaw = vectoyaw(temp);
M_ChangeYaw(self);

/* hunt the sound for a bit; hopefully find the real player */
self->monsterinfo.aiflags |= AI_SOUND_TARGET;
self->enemy = client;
}

FoundTarget(self);

if (!(self->monsterinfo.aiflags & AI_SOUND_TARGET) && (self->monsterinfo.sight)) {
self->monsterinfo.sight(self, self->enemy);
}

return true;
}

/* =============================================================================
*/

qboolean FacingIdeal(edict_t *self)
{
float delta;

if (!self) {
return false;
}

delta = anglemod(self->s.angles - self->ideal_yaw);

if ((delta > 45) && (delta < 315)) {
return false;
}

return true;
}

/* =============================================================================
*/

qboolean M_CheckAttack(edict_t *self)
{
vec3_t spot1, spot2;
float chance;
trace_t tr;

if (!self || !self->enemy || !self->enemy->inuse) {
return false;
}

if (self->enemy->health > 0) {
/* see if any entities are in the way of the shot */
VectorCopy(self->s.origin, spot1);
spot1 += self->viewheight;
VectorCopy(self->enemy->s.origin, spot2);
spot2 += self->enemy->viewheight;

tr = SV_Trace(spot1, NULL, NULL, spot2, self,
CONTENTS_SOLID | CONTENTS_MONSTER | CONTENTS_SLIME | CONTENTS_LAVA | CONTENTS_WINDOW);

/* do we have a clear shot? */
if (tr.ent != self->enemy) {
return false;
}
}

/* melee attack */
if (enemy_range == RANGE_MELEE) {
/* don't always melee in easy mode */
if ((skill->value == 0) && (randk() & 3)) {
return false;
}

if (self->monsterinfo.melee) {
self->monsterinfo.attack_state = AS_MELEE;
} else {
self->monsterinfo.attack_state = AS_MISSILE;
}

return true;
}

/* missile attack */
if (!self->monsterinfo.attack) {
return false;
}

if (level.time < self->monsterinfo.attack_finished) {
return false;
}

if (enemy_range == RANGE_FAR) {
return false;
}

if (self->monsterinfo.aiflags & AI_STAND_GROUND) {
chance = 0.4;
} else if (enemy_range == RANGE_MELEE) {
chance = 0.2;
} else if (enemy_range == RANGE_NEAR) {
chance = 0.1;
} else if (enemy_range == RANGE_MID) {
chance = 0.02;
} else {
return false;
}

if (skill->value == 0) {
chance *= 0.5;
} else if (skill->value >= 2) {
chance *= 2;
}

if (random() < chance) {
self->monsterinfo.attack_state = AS_MISSILE;
self->monsterinfo.attack_finished = level.time + 2 * random();
return true;
}

if (self->flags & FL_FLY) {
if (random() < 0.3) {
self->monsterinfo.attack_state = AS_SLIDING;
} else {
self->monsterinfo.attack_state = AS_STRAIGHT;
}
}

return false;
}

/*
* Turn and close until within an
* angle to launch a melee attack
*/
void ai_run_melee(edict_t *self)
{
if (!self) {
return;
}

self->ideal_yaw = enemy_yaw;
M_ChangeYaw(self);

if (FacingIdeal(self)) {
if (self->monsterinfo.melee) {
self->monsterinfo.melee(self);
self->monsterinfo.attack_state = AS_STRAIGHT;
}
}
}

/*
* Turn in place until within an
* angle to launch a missile attack
*/
void ai_run_missile(edict_t *self)
{
if (!self) {
return;
}

self->ideal_yaw = enemy_yaw;
M_ChangeYaw(self);

if (FacingIdeal(self)) {
if (self->monsterinfo.attack) {
self->monsterinfo.attack(self);
self->monsterinfo.attack_state = AS_STRAIGHT;
}
}
}

/*
* Strafe sideways, but stay at
* approximately the same range
*/
void ai_run_slide(edict_t *self, float distance)
{
float ofs;

if (!self) {
return;
}

self->ideal_yaw = enemy_yaw;
M_ChangeYaw(self);

if (self->monsterinfo.lefty) {
ofs = 90;
} else {
ofs = -90;
}

if (M_walkmove(self, self->ideal_yaw + ofs, distance)) {
return;
}

self->monsterinfo.lefty = 1 - self->monsterinfo.lefty;
M_walkmove(self, self->ideal_yaw - ofs, distance);
}

/*
* Decides if we're going to attack
* or do something else used by
* ai_run and ai_stand
*/
qboolean ai_checkattack(edict_t *self)
{
vec3_t temp;
qboolean hesDeadJim;

if (!self || !self->enemy || !self->enemy->inuse) {
enemy_vis = false;

return false;
}

/* this causes monsters to run blindly
to the combat point w/o firing */
if (self->goalentity) {
if (self->monsterinfo.aiflags & AI_COMBAT_POINT) {
return false;
}

if ((self->monsterinfo.aiflags & AI_SOUND_TARGET) && !visible(self, self->goalentity)) {
if ((level.time - self->enemy->last_sound_time) > 5.0) {
if (self->goalentity == self->enemy) {
if (self->movetarget) {
self->goalentity = self->movetarget;
} else {
self->goalentity = NULL;
}
}

self->monsterinfo.aiflags &= ~AI_SOUND_TARGET;

if (self->monsterinfo.aiflags & AI_TEMP_STAND_GROUND) {
self->monsterinfo.aiflags &= ~(AI_STAND_GROUND | AI_TEMP_STAND_GROUND);
}
} else {
self->show_hostile = (int) level.time + 1;
return false;
}
}
}

enemy_vis = false;

/* see if the enemy is dead */
hesDeadJim = false;

if ((!self->enemy) || (!self->enemy->inuse)) {
hesDeadJim = true;
} else if (self->monsterinfo.aiflags & AI_MEDIC) {
if (self->enemy->health > 0) {
hesDeadJim = true;
self->monsterinfo.aiflags &= ~AI_MEDIC;
}
} else {
if (self->monsterinfo.aiflags & AI_BRUTAL) {
if (self->enemy->health <= -80) {
hesDeadJim = true;
}
} else {
if (self->enemy->health <= 0) {
hesDeadJim = true;
}
}
}

if (hesDeadJim) {
self->enemy = NULL;

if (self->oldenemy && (self->oldenemy->health > 0)) {
self->enemy = self->oldenemy;
self->oldenemy = NULL;
HuntTarget(self);
} else {
if (self->movetarget) {
self->goalentity = self->movetarget;
self->monsterinfo.walk(self);
} else {
/* we need the pausetime otherwise the stand code
will just revert to walking with no target and
the monsters will wonder around aimlessly trying
to hunt the world entity */
self->monsterinfo.pausetime = level.time + 100000000;
self->monsterinfo.stand(self);
}

return true;
}
}

/* wake up other monsters */
self->show_hostile = (int) level.time + 1;

/* check knowledge of enemy */
enemy_vis = visible(self, self->enemy);

if (enemy_vis) {
self->monsterinfo.search_time = level.time + 5;
VectorCopy(self->enemy->s.origin, self->monsterinfo.last_sighting);
}

/* look for other coop players here */
if (coop->value && (self->monsterinfo.search_time < level.time)) {
if (FindTarget(self)) {
return true;
}
}

if (self->enemy) {
enemy_infront = infront(self, self->enemy);
enemy_range = range(self, self->enemy);
VectorSubtract(self->enemy->s.origin, self->s.origin, temp);
enemy_yaw = vectoyaw(temp);
}

if (self->monsterinfo.attack_state == AS_MISSILE) {
ai_run_missile(self);
return true;
}

if (self->monsterinfo.attack_state == AS_MELEE) {
ai_run_melee(self);
return true;
}

/* if enemy is not currently visible,
we will never attack */
if (!enemy_vis) {
return false;
}

return self->monsterinfo.checkattack(self);
}

/*
* The monster has an enemy
* it is trying to kill
*/
void ai_run(edict_t *self, float dist)
{
vec3_t v;
edict_t *tempgoal;
edict_t *save;
qboolean new;
edict_t *marker;
float d1, d2;
trace_t tr;
vec3_t v_forward, v_right;
float left, center, right;
vec3_t left_target, right_target;

if (!self || !self->enemy || !self->enemy->inuse) {
return;
}

/* if we're going to a combat point, just proceed */
if (self->monsterinfo.aiflags & AI_COMBAT_POINT) {
M_MoveToGoal(self, dist);
return;
}

if (self->monsterinfo.aiflags & AI_SOUND_TARGET) {
VectorSubtract(self->s.origin, self->enemy->s.origin, v);

if (VectorLength(v) < 64) {
self->monsterinfo.aiflags |= (AI_STAND_GROUND | AI_TEMP_STAND_GROUND);
self->monsterinfo.stand(self);
return;
}

M_MoveToGoal(self, dist);

if (!FindTarget(self)) {
return;
}
}

if (ai_checkattack(self)) {
return;
}

if (self->monsterinfo.attack_state == AS_SLIDING) {
ai_run_slide(self, dist);
return;
}

if (enemy_vis) {
M_MoveToGoal(self, dist);
self->monsterinfo.aiflags &= ~AI_LOST_SIGHT;
VectorCopy(self->enemy->s.origin, self->monsterinfo.last_sighting);
self->monsterinfo.trail_time = level.time;
return;
}

if ((self->monsterinfo.search_time) && (level.time > (self->monsterinfo.search_time + 20))) {
M_MoveToGoal(self, dist);
self->monsterinfo.search_time = 0;
return;
}

save = self->goalentity;
tempgoal = G_Spawn();
self->goalentity = tempgoal;

new = false;

if (!(self->monsterinfo.aiflags & AI_LOST_SIGHT)) {
/* just lost sight of the player, decide where to go first */
self->monsterinfo.aiflags |= (AI_LOST_SIGHT | AI_PURSUIT_LAST_SEEN);
self->monsterinfo.aiflags &= ~(AI_PURSUE_NEXT | AI_PURSUE_TEMP);
new = true;
}

if (self->monsterinfo.aiflags & AI_PURSUE_NEXT) {
self->monsterinfo.aiflags &= ~AI_PURSUE_NEXT;

/* give ourself more time since we got this far */
self->monsterinfo.search_time = level.time + 5;

if (self->monsterinfo.aiflags & AI_PURSUE_TEMP) {
self->monsterinfo.aiflags &= ~AI_PURSUE_TEMP;
marker = NULL;
VectorCopy(self->monsterinfo.saved_goal, self->monsterinfo.last_sighting);
new = true;
} else if (self->monsterinfo.aiflags & AI_PURSUIT_LAST_SEEN) {
self->monsterinfo.aiflags &= ~AI_PURSUIT_LAST_SEEN;
marker = PlayerTrail_PickFirst(self);
} else {
marker = PlayerTrail_PickNext(self);
}

if (marker) {
VectorCopy(marker->s.origin, self->monsterinfo.last_sighting);
self->monsterinfo.trail_time = marker->timestamp;
self->s.angles = self->ideal_yaw = marker->s.angles;
new = true;
}
}

VectorSubtract(self->s.origin, self->monsterinfo.last_sighting, v);
d1 = VectorLength(v);

if (d1 <= dist) {
self->monsterinfo.aiflags |= AI_PURSUE_NEXT;
dist = d1;
}

VectorCopy(self->monsterinfo.last_sighting, self->goalentity->s.origin);

if (new) {
tr = SV_Trace(self->s.origin, self->mins, self->maxs, self->monsterinfo.last_sighting, self, MASK_PLAYERSOLID);

if (tr.fraction < 1) {
VectorSubtract(self->goalentity->s.origin, self->s.origin, v);
d1 = VectorLength(v);
center = tr.fraction;
d2 = d1 * ((center + 1) / 2);
self->s.angles = self->ideal_yaw = vectoyaw(v);
AngleVectors(self->s.angles, v_forward, v_right, NULL);

VectorSet(v, d2, -16, 0);
G_ProjectSource(self->s.origin, v, v_forward, v_right, left_target);
tr = SV_Trace(self->s.origin, self->mins, self->maxs, left_target, self, MASK_PLAYERSOLID);
left = tr.fraction;

VectorSet(v, d2, 16, 0);
G_ProjectSource(self->s.origin, v, v_forward, v_right, right_target);
tr = SV_Trace(self->s.origin, self->mins, self->maxs, right_target, self, MASK_PLAYERSOLID);
right = tr.fraction;

center = (d1 * center) / d2;

if ((left >= center) && (left > right)) {
if (left < 1) {
VectorSet(v, d2 * left * 0.5, -16, 0);
G_ProjectSource(self->s.origin, v, v_forward, v_right, left_target);
}

VectorCopy(self->monsterinfo.last_sighting, self->monsterinfo.saved_goal);
self->monsterinfo.aiflags |= AI_PURSUE_TEMP;
VectorCopy(left_target, self->goalentity->s.origin);
VectorCopy(left_target, self->monsterinfo.last_sighting);
VectorSubtract(self->goalentity->s.origin, self->s.origin, v);
self->s.angles = self->ideal_yaw = vectoyaw(v);
} else if ((right >= center) && (right > left)) {
if (right < 1) {
VectorSet(v, d2 * right * 0.5, 16, 0);
G_ProjectSource(self->s.origin, v, v_forward, v_right, right_target);
}

VectorCopy(self->monsterinfo.last_sighting, self->monsterinfo.saved_goal);
self->monsterinfo.aiflags |= AI_PURSUE_TEMP;
VectorCopy(right_target, self->goalentity->s.origin);
VectorCopy(right_target, self->monsterinfo.last_sighting);
VectorSubtract(self->goalentity->s.origin, self->s.origin, v);
self->s.angles = self->ideal_yaw = vectoyaw(v);
}
}
}

M_MoveToGoal(self, dist);

G_FreeEdict(tempgoal);

if (self) {
self->goalentity = save;
}
}
Code source de l'IA de détection des ennemis

En allant faire usage de qengine, les développeurs devront intégrer le fait que Klaus Silveira a opté pour SDL 2.0 – une bibliothèque pour diverses plateformes dédiée à l’accès aux ressources de bas niveau (clavier, souris, manettes de jeu, etc.) et publiée sous licence zlib. Noter à ce propos particulier qu’OpenGL est hors course ; dans sa note d’information, Klaus Silveira annonce que l’API est mise de côté. Le moteur qengine est pour sa part publié sous licence GPL 2.0.

Source : GitHub

Et vous ?

:fleche: Qu’en pensez-vous ?
:fleche: D'après vous quels sont les choix dans la conception de ce moteur qui nécessitent une révision ?
:fleche: Le choix de la GPL peut-il constituer un frein à l’adoption de ce moteur de jeu ?

Voir aussi :

:fleche: Le moteur de jeux open source Godot passe en version 2.0 et apporte des fonctionnalités de débogage avancées
:fleche: Le moteur de jeux vidéo JavaScript Impact Engine est maintenant gratuit et open source
:fleche: Un nouveau moteur de jeux vidéo voit le jour : Lumberyard développé par Amazon
:fleche: Le moteur de jeux vidéo WebGL open source PlayCanvas atteint la version 1.0 avec tous les outils nécessaires pour créer une application graphique 3D