int AGS_EngineOnEvent (int event, int data) {
  if (event == AGSE_POSTSCREENDRAW) {
    if (clutslot > 0)
    {
        // Get a reference to the screen we'll draw onto
        BITMAP *virtsc = engine->GetVirtualScreen();
        BITMAP *clutspr = engine->GetSpriteGraphic (clutslot);
        BITMAP *rain = engine->GetSpriteGraphic (920);
        // Get its surface, in both 8-bit and 16-bit flavours
        unsigned char **charbuffer = engine->GetRawBitmapSurface (virtsc);
        unsigned char **clutarray = engine->GetRawBitmapSurface (clutspr);
        unsigned char **rainarray = engine->GetRawBitmapSurface (rain);
        // Find out the screen width and colour depth
        int x = 0;
        int y = 0;
        int transamount = 256 * 4;
        while (y < 200)
        {
            while (x < 320)
            {
                charbuffer[x][y] = clutarray [charbuffer[x][y]][rainarray [x][y+transamount]];
                x++;
            }
            x=0;
            y++;
        }

        // Release the screen so that the engine can continue
        engine->ReleaseBitmapSurface (virtsc);
        engine->ReleaseBitmapSurface (clutspr);
        engine->ReleaseBitmapSurface (rain);
    }
    }
  return 0;
}