private int getMiddle(int v1, Point2D p1, int v2, Point2D p2) {
String key = "" + Math.min(v1, v2) + "_" + Math.max(v1, v2);
if (map.get(key) != null) {
return map.get(key);
}
texCoord1.add(p1.add(p2).multiply(0.5f));
map.put(key, index.get());
return index.getAndIncrement();
}
