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/*
base/platform.cc
This file is part of the Osirion project and is distributed under
the terms and conditions of the GNU General Public License version 2
*/
#include "core/gameserver.h"
#include "core/entityprojectile.h"
#include "base/game.h"
#include "base/faction.h"
#include "base/platform.h"
#include "base/ship.h"
#include "base/weapon.h"
#include "sys/sys.h"
#include <cassert>
namespace game
{
Platform::Platform() : Entity()
{
entity_moduletypeid = platform_enttype;
platform_cannon = 0;
platform_turret = 0;
}
Platform::~Platform()
{
}
void Platform::set_cannon(const Weapon *cannon)
{
platform_cannon = cannon;
}
void Platform::set_turret(const Weapon *turret)
{
platform_turret = turret;
}
void Platform::frame(const unsigned long elapsed)
{
const float weapon_range = math::max((cannon() ? cannon()->projectile_range() : 0.0f), (turret() ? turret()->projectile_range() : 0.0f));
if ((weapon_range > 0.0f) && slots() && zone()->keepalive_run()) {
// create list of potential enemies
std::list<Ship *> enemylist;
for (core::Zone::Content::iterator zit = zone()->content().begin(); zit != zone()->content().end(); ++zit) {
if ((*zit)->moduletype() == ship_enttype) {
Ship *other_ship = static_cast<Ship *>((*zit));
if ((other_ship->state() != Normal) && (other_ship->state() != ImpulseInitiate) && (other_ship->state() != Impulse)) {
continue;
}
const float d = math::distance(location(), other_ship->location());
const float r = radius() + other_ship->radius();
// too far
if (d > weapon_range + r) {
continue;
}
// reputation is interprated as "what others think of me"
float reputation = 0.0f;
if (other_ship->owner()) {
// check owner reputation for the faction this platform belongs to
reputation = other_ship->owner()->reputation(faction());
} else if (other_ship->faction()) {
// check other ships's faction for the faction this platform belongs to
assert(other_ship->faction()->type() == Faction::infotype());
reputation = static_cast<const Faction *>(other_ship->faction())->reputation(faction());
}
// reputation threshold to get attacked
if (reputation > core::range::reputation_hostile) {
continue;
}
enemylist.push_back(other_ship);
}
}
// platforms do not need weapons in inventory to fire
if (enemylist.size()) {
for (core::Slots::iterator slit = slots()->begin(); slit != slots()->end(); slit++) {
core::Slot *slot = (*slit);
// found out if this slot is a cannon or a turret
const Weapon *weapon = 0;
if (slot->type() == model::Slot::Cannon) {
weapon = cannon();
} else if (slot->type() == model::Slot::Turret) {
weapon = turret();
}
if ((!weapon) || (weapon->projectile_interval() == 0)) {
continue;
}
if ((slot->last_fired() + weapon->projectile_interval() > core::server()->timestamp())) {
continue;
}
// target location in world coordinates
Ship *current_enemy = 0; // The enemy ship the slot will be targetting
float current_distance = 0.0f; // Distance to the target location
math::Vector3f current_aim; // Location to aim at
// slot and projectile location in world coordinates
const math::Vector3f projectile_location(location() + (axis() * slot->location()));
math::Vector3f projectile_direction;
math::Axis projectile_axis(axis() * slot->axis());
// we only need half the cone angle for the cosine calculation
const float conecos = cosf(slot->cone() * 0.5f);
for (std::list<Ship *>::const_iterator enemy_it = enemylist.begin(); enemy_it != enemylist.end(); enemy_it++)
{
// apply aim correction
// see https://www.reddit.com/r/gamedev/comments/16ceki/turret_aiming_formula/c7vbu2j
const math::Vector3f v((*enemy_it)->axis().forward() * (*enemy_it)->speed());
const math::Vector3f w((*enemy_it)->location() - projectile_location);
const float a = v.lengthsquared() - weapon->projectile_speed() * weapon->projectile_speed();
const float b = 2.0f * math::dotproduct(v, w);
const float c = w.lengthsquared();
const float D = b * b - 4.0f * a * c;
if (D < 0.0f)
{
continue;
}
const float t = math::min(sqrtf(D) - b , -sqrtf(D) - b) / (2.0f * a);
const math::Vector3f hitpoint((*enemy_it)->location() + v * t);
// verify the hitpoint is within weapon's range
const float d = math::distance(hitpoint, projectile_location);
if (d > weapon->projectile_range() + (*enemy_it)->radius())
{
continue;
}
if ((current_distance > 0.0f) && (d > current_distance))
{
continue;
}
projectile_direction.assign(hitpoint - projectile_location);
projectile_direction.normalize();
// verify the hitpoint is in the slot's cone-of-fire
const float cosa = math::dotproduct(projectile_direction, projectile_axis.forward());
if (cosa >= conecos)
{
current_distance = d;
current_enemy = (*enemy_it);
current_aim.assign(hitpoint);
}
}
if (current_enemy)
{
projectile_direction.assign(current_aim - projectile_location);
projectile_direction.normalize();
const float cosa = math::dotproduct(projectile_direction, projectile_axis.forward());
// point the projectile into the fire direction
math::Vector3f normal(math::crossproduct(projectile_direction, projectile_axis.forward()));
if (normal.length() > MIN_DELTA)
{
float sina = sqrt(1.0f - cosa * cosa);
normal.normalize();
projectile_axis.rotate(normal, cosa, sina);
}
// spawn a new projectile
core::EntityProjectile *projectile = new core::EntityProjectile(this);
projectile->set_damage(weapon->damage());
projectile->set_lifespan(weapon->projectile_lifespan());
projectile->set_projectile_modelname(weapon->projectile_modelname());
projectile->set_projectile_soundname(weapon->projectile_soundname());
projectile->set_axis(projectile_axis);
projectile->set_location(projectile_location);
projectile->set_speed(weapon->projectile_speed());
projectile->reset();
slot->set_last_fired(core::server()->timestamp());
}
}
}
}
}
} // namespace game
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