// bullet.js
//  Handling enemys' bullets.
var BULLET_TYPE_AIM = 0;
var BULLET_TYPE_SHOTGUN = 1;
var BULLET_TYPE_3WAY = 2;
var BULLET_TYPE_5WAY = 3;
var bicons = new Array;
var bicon = new GIcon;
bicon.image = "images/bullet.png";
bicon.shadow = "images/dummy_shadow.png";
bicon.iconSize = new GSize(16, 16);
bicon.shadowSize = new GSize(1, 1);
bicon.iconAnchor = new GPoint(8, 8);
var bsicon;
bsicon = new GIcon(bicon);
bsicon.iconSize = new GSize(4, 4);
bsicon.iconAnchor = new GPoint(2, 2);
bicons.push(bsicon);
bsicon = new GIcon(bicon);
bsicon.iconSize = new GSize(8, 8);
bsicon.iconAnchor = new GPoint(4, 4);
bicons.push(bsicon);
bsicon = new GIcon(bicon);
bsicon.iconSize = new GSize(12, 12);
bsicon.iconAnchor = new GPoint(6, 6);
bicons.push(bsicon);
bicons.push(bicon);

function Bullet() {
  this.type;
  this.deg;
  this.speed;
  this.cnt;
  this.climbRatio;
  this.iconIdx;
  this.exists = false;
  this.marker = new GMarker(
    new GPoint(mapManager.centerX, mapManager.centerY), bicon);

  this.set = function(type, x, y, d, sp) {
    this.type = type;
    this.marker.point.x = x;
    this.marker.point.y = y;
    this.deg = d;
    this.speed = sp;
    this.cnt = 0;
    this.climbRatio = 1;
    this.iconIdx = 0;
    this.exists = true;
    map.addOverlay(this.marker);
    this.marker.remove();
    this.marker.icon = bicons[this.iconIdx];
    this.marker.initialize(map);
  }

  this.setClimbed = function(type, x, y, d, sp) {
    this.set(type, x, y, d, sp);
    this.climbRatio = 0;
    this.marker.remove();
    this.marker.icon = bicons[3];
    this.marker.initialize(map);
  }

  this.update = function() {
    if (!this.exists)
      return;
    if (this.climbRatio > 0) {
      this.marker.point.x += Math.sin(this.deg) * this.speed * this.climbRatio;
      this.marker.point.y += Math.cos(this.deg) * this.speed * this.climbRatio;
      this.marker.point.y += this.climbRatio * 0.00004;
      this.climbRatio -= 0.05;
      var ii = Math.floor((1 - this.climbRatio) / 0.33);
      if (ii > this.iconIdx) {
        this.iconIdx = ii;
        this.marker.remove();
        this.marker.icon = bicons[this.iconIdx];
        this.marker.initialize(map);
      }
      if (this.climbRatio <= 0) {
        var d = Math.atan2(ship.marker.point.x - this.marker.point.x,
                           ship.marker.point.y - this.marker.point.y);
        switch (this.type) {
        case BULLET_TYPE_AIM:
          this.deg = d;
          break;
        case BULLET_TYPE_SHOTGUN:
          for (var i = 0; i < 5; i++) {
            var b;
            b = getBulletInstance();
            if (b == null)
              break;
            b.setClimbed(0, this.marker.point.x, this.marker.point.y,
                         d + Math.random() * 0.3 - 0.15,
                         this.speed * (1 + Math.random() * 0.6 - 0.3));
          }
          this.deg = d;
          break;
        case BULLET_TYPE_3WAY:
          var ds = d - 0.4;
          for (var i = 0; i < 2; i++) {
            var b;
            b = getBulletInstance();
            if (b == null)
              break;
            b.setClimbed(0, this.marker.point.x, this.marker.point.y,
                         ds, this.speed);
            ds += 0.8;
          }
          this.deg = d;
          break;
        case BULLET_TYPE_5WAY:
          var ds = d - 0.6 - 0.3;
          for (var i = 0; i < 5; i++) {
            ds += 0.3;
            if (i == 2)
              continue;
            var b;
            b = getBulletInstance();
            if (b == null)
              break;
            b.setClimbed(0, this.marker.point.x, this.marker.point.y,
                         ds, this.speed);
          }
          this.deg = d;
          break;
        }
      }
    } else {
      this.marker.point.x += Math.sin(this.deg) * this.speed;
      this.marker.point.y += Math.cos(this.deg) * this.speed;
      ship.checkHit(this.marker.point);
    }
    this.marker.point.x += mapManager.velX;
    this.marker.point.y += mapManager.velY;
    if (this.marker.point.x < mapManager.bounds.minX ||
        this.marker.point.x > mapManager.bounds.maxX ||
        this.marker.point.y < mapManager.bounds.minY ||
        this.marker.point.y > mapManager.bounds.maxY) {
      this.exists = false;
      map.removeOverlay(this.marker);
      return;
    }
    this.cnt++;
    this.marker.redraw(true);
  }
}