Lephisto/src/weapon.c

#include <math.h>
#include <malloc.h>
#include <string.h>

#include "outfit.h"
#include "physics.h"
#include "lephisto.h"
#include "log.h"
#include "rng.h"
#include "pilot.h"
#include "collision.h"
#include "player.h"
#include "spfx.h"
#include "weapon.h"

#define weapon_isSmart(w) (w->think)

#define VOICE_PRIORITY_BOLT  10  // Default.
#define VOICE_PRIORITY_AMMO  8  // Higher.

#define WEAPON_CHUNK 32

// Some stuff from pilot.
extern Pilot** pilot_stack;
extern int pilots;

// Player stuff.
extern unsigned int player_target;

// Ai stuff.
extern void ai_attacked(Pilot* attacked, const unsigned int attacker);

typedef struct Weapon_ {
  Solid* solid; // Actually has its own solid. :D

  unsigned int parent; // The pilot that just shot at you!
  unsigned int target; // Target to hit. Only used by seeking stuff.
  const Outfit* outfit; // Related outfit that fired.
  unsigned int timer; // Mainly used to see when the weapon was fired.

  alVoice* voice; // Virtual voise.

  // Update position and render.
  void(*update)(struct Weapon_*, const double, WeaponLayer); // Position update and render.
  void(*think)(struct Weapon_*, const double); // Some missiles need to be inteligent.a

  double pid_last;
  double pid_int;
} Weapon;

// Behind Pilot layer.
static Weapon** wbackLayer = NULL; // Behind pilots.
static int nwbackLayer     = 0;    // Number of elements.
static int mwbackLayer     = 0;    // Allocated memory size.
// Behind player layer.
static Weapon** wfrontLayer = NULL;  // Behind pilots.
static int nwfrontLayer    = 0;    // Number of elements.
static int mwfrontLayer    = 0;    // Allocated memory size.

static Weapon* weapon_create(const Outfit* outfit, const double dir,
                             const Vec2* pos, const Vec2* vel,
                             const unsigned int parent,
                             const unsigned int target);

static void weapon_render(const Weapon* w);
static void weapons_updateLayer(const double dt, const WeaponLayer layer);
static void weapon_update(Weapon* w, const double dt, WeaponLayer layer);
static void weapon_hit(Weapon* w, Pilot* p, WeaponLayer layer);
static void weapon_destroy(Weapon* w, WeaponLayer layer);
static void weapon_free(Weapon* w);
// Think.
static void think_seeker(Weapon* w, const double dt);
static void think_smart(Weapon* w, const double dt);

// Draw the minimap weapons (player.c).
#define PIXEL(x,y) if((shape == RADAR_RECT && ABS(x) < w/2. && ABS(y)<h/2.) || \
  (shape == RADAR_CIRCLE && (((x)*(x)+(y)*(y))<rc))) glVertex2i((x),(y))
void weapon_minimap(const double res,
                    const double w, const double h, const RadarShape shape) {
  int i, rc;
  double x, y;

  if(shape == RADAR_CIRCLE) rc = (int)(w*w);

  for(i = 0; i < nwbackLayer; i++) {
    x = (wbackLayer[i]->solid->pos.x - player->solid->pos.x) / res;
    y = (wbackLayer[i]->solid->pos.y - player->solid->pos.y) / res;
    PIXEL(x,y);
  }

  for(i = 0; i < nwfrontLayer; i++) {
    x = (wfrontLayer[i]->solid->pos.x - player->solid->pos.x) / res;
    y = (wfrontLayer[i]->solid->pos.y - player->solid->pos.y) / res;
    PIXEL(x,y);
  }
}
#undef PIXEL

// Pause/Unpause the weapon system.
void weapons_pause(void) {
  int i;
  unsigned int t = SDL_GetTicks();
  for(i = 0; i < nwbackLayer; i++)
    wbackLayer[i]->timer -= t;
  for(i = 0; i < nwfrontLayer; i++)
    wfrontLayer[i]->timer -= t;
}


void weapons_unpause(void) {
  int i;
  unsigned int t = SDL_GetTicks();
  for(i = 0; i < nwbackLayer; i++)
    wbackLayer[i]->timer += t;
  for(i = 0; i < nwfrontLayer; i++)
    wfrontLayer[i]->timer += t;
}

void weapons_delay(unsigned int delay) {
  int i;
  for(i = 0; i < nwbackLayer; i++)
    wbackLayer[i]->timer += delay;
  for(i = 0; i < nwfrontLayer; i++)
    wfrontLayer[i]->timer += delay;
}

// Seeker brain, You get what you pay for. :)
static void think_seeker(Weapon* w, const double dt) {
  double diff;
  if(w->target == w->parent) return; // HEY! Self harm is not allowed.

  Pilot* p = pilot_get(w->target);
  if(p == NULL) {
    limit_speed(&w->solid->vel, w->outfit->u.amm.speed, dt);
    return;
  }

  // Ammo isn't locked on yet..
  if(SDL_GetTicks() > (w->timer + w->outfit->u.amm.lockon)) {
    diff = angle_diff(w->solid->dir, vect_angle(&w->solid->pos, &p->solid->pos));
    w->solid->dir_vel = 10 * diff * w->outfit->u.amm.turn;
    // Face the target.
    if(w->solid->dir_vel > w->outfit->u.amm.turn)
      w->solid->dir_vel = w->outfit->u.amm.turn;
    else if(w->solid->dir_vel < -w->outfit->u.amm.turn)
      w->solid->dir_vel = -w->outfit->u.amm.turn;
  }

  vect_pset(&w->solid->force, w->outfit->u.amm.thrust, w->solid->dir);

  limit_speed(&w->solid->vel, w->outfit->u.amm.speed, dt);
}

// ========================================================
// Smart seeker brain. Much better at homing.
// ========================================================
static void think_smart(Weapon* w, const double dt) {
  Vec2 sv, tv;
  double t;

  if(w->target == w->parent) return; // No self shooting here.

  Pilot* p = pilot_get(w->target); // No null pilots..

  if(p == NULL) {
    limit_speed(&w->solid->vel, w->outfit->u.amm.speed, dt);
    return;
  }

  if(SDL_GetTicks() > (w->timer + w->outfit->u.amm.lockon)) {
    vect_cset(&tv, VX(p->solid->pos) + dt*VX(p->solid->vel),
              VY(p->solid->pos) + dt*VY(p->solid->vel));

    vect_cset(&sv, VX(w->solid->pos) + dt*VX(w->solid->vel),
              VY(w->solid->pos) + dt*VY(w->solid->vel));

    t = -angle_diff(w->solid->dir, vect_angle(&tv, &sv));

    w->solid->dir_vel = t * w->outfit->u.amm.turn; // Face the target.

    if(w->solid->dir_vel > w->outfit->u.amm.turn)
      w->solid->dir_vel = w->outfit->u.amm.turn;
    else if(w->solid->dir_vel < -w->outfit->u.amm.turn)
      w->solid->dir_vel = -w->outfit->u.amm.turn;
  }

  vect_pset(&w->solid->force, w->outfit->u.amm.thrust, w->solid->dir);

  limit_speed(&w->solid->vel, w->outfit->u.amm.speed, dt);

}

// Update all the weapon layers.
void weapons_update(const double dt) {
  weapons_updateLayer(dt, WEAPON_LAYER_BG);
  weapons_updateLayer(dt, WEAPON_LAYER_FG);
}

// Update all weapons in the layer.
static void weapons_updateLayer(const double dt, const WeaponLayer layer) {
  Weapon** wlayer;
  int* nlayer;

  switch(layer) {
  case WEAPON_LAYER_BG:
    wlayer = wbackLayer;
    nlayer = &nwbackLayer;
    break;
  case WEAPON_LAYER_FG:
    wlayer = wfrontLayer;
    nlayer = &nwfrontLayer;
    break;
  }
  int i;
  Weapon* w;
  for(i = 0; i < (*nlayer); i++) {
    w = wlayer[i];
    switch(wlayer[i]->outfit->type) {
    // Most missiles behave the same.
    case OUTFIT_TYPE_MISSILE_SEEK_AMMO:
    case OUTFIT_TYPE_MISSILE_SEEK_SMART_AMMO:
    case OUTFIT_TYPE_MISSILE_SWARM_AMMO:
    case OUTFIT_TYPE_MISSILE_SWARM_SMART_AMMO:
      if(SDL_GetTicks() >
         (wlayer[i]->timer + wlayer[i]->outfit->u.amm.duration)) {
        weapon_destroy(wlayer[i], layer);
        continue;
      }
      break;
    case OUTFIT_TYPE_BOLT:
      // Check see if it exceeds distance.
    case OUTFIT_TYPE_TURRET_BOLT:
      if(SDL_GetTicks() > wlayer[i]->timer) {
        weapon_destroy(wlayer[i],layer);
        continue;
      }
      break;
    default:
      break;
    }
    weapon_update(wlayer[i], dt, layer);
    // If the weapon has been deleted we are going to have to hold back one.
    if(w != wlayer[i]) i--;
  }
}

// Render all the weapons.
void weapons_render(const WeaponLayer layer) {
  Weapon** wlayer;
  int* nlayer;
  int i;

  switch(layer) {
  case WEAPON_LAYER_BG:
    wlayer = wbackLayer;
    nlayer = &nwbackLayer;
    break;
  case WEAPON_LAYER_FG:
    wlayer = wfrontLayer;
    nlayer = &nwfrontLayer;
    break;
  }
  for(i = 0; i < (*nlayer); i++)
    weapon_render(wlayer[i]);
}

// Render the weapons.
static void weapon_render(const Weapon* w) {
  int sx, sy;
  glTexture* gfx;

  gfx = outfit_gfx(w->outfit);

  // Get the sprite corresponding to the direction facing.
  gl_getSpriteFromDir(&sx, &sy, gfx, w->solid->dir);

  gl_blitSprite(gfx, w->solid->pos.x, w->solid->pos.y, sx, sy, NULL);
}

// Update the weapon.
static void weapon_update(Weapon* w, const double dt, WeaponLayer layer) {
  int i, wsx, wsy, psx, psy;
  glTexture* gfx;

  gfx = outfit_gfx(w->outfit);

  gl_getSpriteFromDir(&wsx, &wsy, gfx, w->solid->dir);

  for(i = 0; i < pilots; i++) {
    psx = pilot_stack[i]->tsx;
    psy = pilot_stack[i]->tsy;

    if(w->parent == pilot_stack[i]->id) continue; // Hey! That's you.

    if((weapon_isSmart(w)) && (pilot_stack[i]->id == w->target) &&
       CollideSprite(gfx, wsx, wsy, &w->solid->pos,
                     pilot_stack[i]->ship->gfx_space, psx, psy, &pilot_stack[i]->solid->pos)) {
      weapon_hit(w, pilot_stack[i], layer);
      return;
    }
    else if(!weapon_isSmart(w) &&
            !areAllies(pilot_get(w->parent)->faction, pilot_stack[i]->faction) &&
            CollideSprite(gfx, wsx, wsy, &w->solid->pos,
                          pilot_stack[i]->ship->gfx_space, psx, psy, &pilot_stack[i]->solid->pos)) {
      weapon_hit(w, pilot_stack[i], layer);
      return;
    }
  }

  if(weapon_isSmart(w)) (*w->think)(w,dt);

  (*w->solid->update)(w->solid, dt);

  // Update the sound.
  if(w->voice)
    voice_update(w->voice, w->solid->pos.x, w->solid->pos.y,
                 w->solid->vel.x, w->solid->vel.y);
}

// Good shot.
static void weapon_hit(Weapon* w, Pilot* p, WeaponLayer layer) {
  // Someone should let the ai know it's been attacked.
  if(!pilot_isPlayer(p)) {
    if((player_target == p->id) || (RNG(0,2) == 0)) {
      if((w->parent == PLAYER_ID) &&
          (!pilot_isFlag(p, PILOT_HOSTILE) || (RNG(0, 2) == 0)))
        faction_modPlayer(p->faction, -1); // Slowly lower faction.
      ai_attacked(p, w->parent);
    }
    spfx_add(outfit_spfx(w->outfit),
             VX(w->solid->pos), VY(w->solid->pos),
             VX(p->solid->vel), VY(p->solid->vel), SPFX_LAYER_BACK);
  } else
    spfx_add(outfit_spfx(w->outfit),
             VX(w->solid->pos), VY(w->solid->pos),
             VX(p->solid->vel), VY(p->solid->vel), SPFX_LAYER_FRONT);

  if(w->parent == PLAYER_ID)
    // Make hostile to player.
    pilot_setFlag(p, PILOT_HOSTILE);

  // Let the ship know that is should take some kind of damage.
  pilot_hit(p, w->solid, w->parent, outfit_dmgShield(w->outfit), outfit_dmgShield(w->outfit));
  // We don't need the weapon particle any longer.
  weapon_destroy(w, layer);
}

static Weapon* weapon_create(const Outfit* outfit, const double dir, const Vec2* pos,
                             const Vec2* vel, unsigned int parent, const unsigned int target) {
  Vec2 v;
  double mass = 1; // Presumer lasers have a mass of 1.
  double rdir = dir; // Real direction (accuracy).
  Weapon* w = MALLOC_L(Weapon);
  w->parent = parent; // Non-Changeable.
  w->target = target; // Non-Changeable.
  w->outfit = outfit; // Non-Changeable.
  w->update = weapon_update;
  w->timer = SDL_GetTicks();
  w->think = NULL;

  switch(outfit->type) {
  case OUTFIT_TYPE_BOLT:
    // Need accuracy and speed based on player. -- Another contribution from VLack.
    rdir += RNG(-outfit->u.blt.accuracy/2., outfit->u.blt.accuracy/2.)/180.*M_PI;
    if((rdir > 2.*M_PI) || (rdir < 0.)) rdir = fmod(rdir, 2.*M_PI);
    vectcpy(&v, vel);
    vect_cadd(&v, outfit->u.blt.speed*cos(rdir), outfit->u.blt.speed*sin(rdir));
    w->timer += 1000*(unsigned int)outfit->u.blt.range/outfit->u.blt.speed;
    w->solid = solid_create(mass, rdir, pos, &v);
    w->voice = sound_addVoice(VOICE_PRIORITY_BOLT,
                              w->solid->pos.x, w->solid->pos.y,
                              w->solid->vel.x, w->solid->vel.y, w->outfit->u.blt.sound, 0);
    break;
  case OUTFIT_TYPE_MISSILE_SEEK_AMMO:
    mass = w->outfit->mass;
    w->solid = solid_create(mass, dir, pos, vel);
    w->think = think_seeker; // Eeek!!!
    w->voice = sound_addVoice(VOICE_PRIORITY_AMMO,
                              w->solid->pos.x, w->solid->pos.y,
                              w->solid->vel.x, w->solid->vel.y, w->outfit->u.amm.sound, 0);
    break;
  case OUTFIT_TYPE_MISSILE_SEEK_SMART_AMMO:
    mass = w->outfit->mass;
    w->solid = solid_create(mass, dir, pos, vel);
    w->think = think_smart; // Smartass.
    w->voice = sound_addVoice(VOICE_PRIORITY_AMMO,
                              w->solid->pos.x, w->solid->pos.y,
                              w->solid->vel.x, w->solid->vel.y, w->outfit->u.amm.sound, 0);
    break;
  case OUTFIT_TYPE_TURRET_BOLT:
    if(w->parent != w->target)
      rdir = vect_angle(pos, &pilot_get(w->target)->solid->pos);
    rdir += RNG(-outfit->u.blt.accuracy/2.,
                outfit->u.blt.accuracy/2.)/180.*M_PI;
    if((rdir > 2.*M_PI) || (rdir < 0.)) rdir = fmod(rdir, 2.*M_PI);
    vectcpy(&v, vel);
    vect_cadd(&v, outfit->u.blt.speed*cos(rdir), outfit->u.blt.speed*sin(rdir));
    w->timer += 1000*(unsigned int)outfit->u.blt.range / outfit->u.blt.speed;
    w->solid = solid_create(mass, rdir, pos, &v);
    w->voice = sound_addVoice(VOICE_PRIORITY_BOLT,
                              w->solid->pos.x, w->solid->pos.y,
                              w->solid->vel.x, w->solid->vel.y, w->outfit->u.blt.sound, 0);
    break;
  default:
    // Just dump it where the player is.
    w->voice = NULL;
    w->solid = solid_create(mass, dir, pos, vel);
    break;
  }
  return w;
}

// Add a new weapon.
void weapon_add(const Outfit* outfit, const double dir, const Vec2* pos,
                const Vec2* vel, unsigned int parent, unsigned int target) {

  if(!outfit_isWeapon(outfit) &&
     !outfit_isAmmo(outfit) && !outfit_isTurret(outfit)) {
    ERR("Trying to create a weapon from a non-Weapon type Outfit");
    return;
  }

  WeaponLayer layer = (parent == PLAYER_ID) ? WEAPON_LAYER_FG : WEAPON_LAYER_BG;
  Weapon* w = weapon_create(outfit, dir, pos, vel, parent, target);

  // Set the propper layer.
  Weapon** curLayer = NULL;
  int* mLayer = NULL;
  int* nLayer = NULL;
  switch(layer) {
  case WEAPON_LAYER_BG:
    curLayer = wbackLayer;
    nLayer = &nwbackLayer;
    mLayer = &mwbackLayer;
    break;
  case WEAPON_LAYER_FG:
    curLayer = wfrontLayer;
    nLayer = &nwfrontLayer;
    mLayer = &mwfrontLayer;
    break;
  default:
    ERR("Invalid WEAPON_LAYER specified.");
    return;
  }
  if(*mLayer > *nLayer) // More memory allocated than what we need.
    curLayer[(*nLayer)++] = w;
  else { // Need to allocate more memory.
    switch(layer) {
    case WEAPON_LAYER_BG:
      (*mLayer) += WEAPON_CHUNK;
      curLayer = wbackLayer = realloc(curLayer, (*mLayer)*sizeof(Weapon*));
      break;
    case WEAPON_LAYER_FG:
      (*mLayer) += WEAPON_CHUNK;
      curLayer = wfrontLayer = realloc(curLayer, (*mLayer)*sizeof(Weapon*));
      break;
    }
    curLayer[(*nLayer)++] = w;
  }
}

// Destroy the weapon.
static void weapon_destroy(Weapon* w, WeaponLayer layer) {
  int i;
  Weapon** wlayer;
  int* nlayer;
  switch(layer) {
  case WEAPON_LAYER_BG:
    wlayer = wbackLayer;
    nlayer = &nwbackLayer;
    break;
  case WEAPON_LAYER_FG:
    wlayer = wfrontLayer;
    nlayer = &nwfrontLayer;
    break;
  }
  for(i = 0; wlayer[i] != w; i++); // Get us to the current posision.
  weapon_free(wlayer[i]);
  wlayer[i] = NULL;
  (*nlayer)--;

  for(; i < (*nlayer); i++)
    wlayer[i] = wlayer[i+1];
}

// Clear the weapon.
static void weapon_free(Weapon* w) {
  sound_delVoice(w->voice);
  solid_free(w->solid);
  free(w);
}

// Clear all the weapons, do not free the layers.
void weapon_clear(void) {
  int i;
  for(i = 0; i < nwbackLayer; i++)
    weapon_free(wbackLayer[i]);
  nwbackLayer = 0;
  for(i = 0; i < nwfrontLayer; i++)
    weapon_free(wfrontLayer[i]);
  nwfrontLayer = 0;
}

void weapon_exit(void) {
  weapon_clear();
  free(wbackLayer);
  free(wfrontLayer);
}