Function InitFireballs

Descent3/fireball.cpp:681–717

Initializes the explosion system, loading needed bitmaps, etc

// Initializes the explosion system, loading needed bitmaps, etc
void InitFireballs() {
  int i, num_fireballs = NUM_FIREBALLS;
  for (i = 0; i < num_fireballs; i++) {
    if (!(stricmp(Fireballs[i].name, "NOIMAGE")))
      continue;
    int bm_handle = LoadTextureImage(IGNORE_TABLE(Fireballs[i].name), NULL, Fireballs[i].tex_size, 0);
    if (bm_handle < 0) {
      Error("Couldn't load fireball %s in InitFireballs.", Fireballs[i].name);
      return;
    }
    ASSERT(bm_handle >= 0);
    Fireballs[i].bm_handle = bm_handle;
  }

  // convert the grey spark into grayscale
  uint16_t *data;
  int size;
  float recip32 = 1.0f / 32.0f;
  data = bm_data(Fireballs[GRAY_SPARK_INDEX].bm_handle, 0);
  size = bm_w(Fireballs[GRAY_SPARK_INDEX].bm_handle, 0) * bm_h(Fireballs[GRAY_SPARK_INDEX].bm_handle, 0);
  for (i = 0; i < size; i++) {
    uint16_t col565 = data[i];
    if (col565 == 0x07e0) {
      data[i] = NEW_TRANSPARENT_COLOR;
    } else {
      uint8_t r = (uint8_t)((col565 & 0xf800) >> 11);
      uint8_t g = (uint8_t)((col565 & 0x07c0) >> 6);
      uint8_t b = (uint8_t)(col565 & 0x001f);
      float brightness = ((r * 0.30f) + (g * 0.59f) + (b * 0.11f)) * recip32;
      uint8_t elem = (uint8_t)(255.0f * brightness);
      if (brightness > 1.0f)
        elem = 255;
      data[i] = GR_RGB16(elem, elem, elem) | OPAQUE_FLAG;
    }
  }
  GameBitmaps[Fireballs[GRAY_SPARK_INDEX].bm_handle].flags |= BF_CHANGED;
}

// Given an object, renders the representation of this fireball
void DrawFireballObject(object *obj) {