Function DoSnowEffect

Descent3/weather.cpp:172–228

Creates snow for this frame

// Creates snow for this frame
void DoSnowEffect() {
  if (OBJECT_OUTSIDE(Viewer_object)) {
    int num = 20 + (ps_rand() % 15);

    if (Weather.snowflakes_to_create + num > 250) {
      num = 250 - Weather.snowflakes_to_create;

      if (num < 1) {
        Weather.snowflakes_to_create = 0;
        return;
      }
    }

    // angvec angs;
    matrix mat;

    // vm_ExtractAnglesFromMatrix (&angs,&Viewer_object->orient);
    // vm_AnglesToMatrix (&mat,0,angs.h,0);

    mat = Viewer_object->orient;

    for (int i = 0; i < num; i++) {
      vector pos = Viewer_object->pos;

      float z = ((ps_rand() % 1000) / 1000.0) * 300;
      float x = (((ps_rand() % 1000) - 500) / 500.0) * 200;
      int y = (ps_rand() % 80);

      pos += x * mat.rvec;
      pos += y * mat.uvec;
      pos += z * mat.fvec;

      if (pos.z < 0 || pos.z >= TERRAIN_DEPTH * TERRAIN_SIZE)
        continue;
      if (pos.x < 0 || pos.x >= TERRAIN_WIDTH * TERRAIN_SIZE)
        continue;

      // Create falling rain
      vector down_vec = {0, -30, 0};
      int visnum = VisEffectCreate(VIS_FIREBALL, SNOWFLAKE_INDEX, Viewer_object->roomnum, &pos);
      if (visnum >= 0) {
        vis_effect *vis = &VisEffects[visnum];
        float life = 1.5 + ((ps_rand() % 100) / 100.0);
        vis->lifeleft = life;
        vis->lifetime = life;
        vis->lighting_color = GR_RGB16(200, 200, (ps_rand() % 50) + 200);
        vis->size = ((ps_rand() % 1000) / 1000.0) + .5;

        vis->flags |= VF_WINDSHIELD_EFFECT | VF_USES_LIFELEFT;

        vis->velocity = down_vec;
      }
    }
  }

  Weather.snowflakes_to_create = 0;
}