public boolean intersects(Shape shape) {
if (shape == null) {
return false;
}
checkPoints();
boolean result = false;
float points[] = getPoints();
float thatPoints[] = shape.getPoints();
int length = points.length;
int thatLength = thatPoints.length;
double unknownA;
double unknownB;
if (!closed()) {
length -= 2;
}
if (!shape.closed()) {
thatLength -= 2;
}
for (int i = 0; i < length; i += 2) {
int iNext = i + 2;
if (iNext >= points.length) {
iNext = 0;
}
for (int j = 0; j < thatLength; j += 2) {
int jNext = j + 2;
if (jNext >= thatPoints.length) {
jNext = 0;
}
unknownA =
(((points[iNext] - points[i]) * (double) (thatPoints[j + 1] - points[i + 1]))
- ((points[iNext + 1] - points[i + 1]) * (thatPoints[j] - points[i])))
/ (((points[iNext + 1] - points[i + 1]) * (thatPoints[jNext] - thatPoints[j]))
- ((points[iNext] - points[i]) * (thatPoints[jNext + 1] - thatPoints[j + 1])));
unknownB =
(((thatPoints[jNext] - thatPoints[j]) * (double) (thatPoints[j + 1] - points[i + 1]))
- ((thatPoints[jNext + 1] - thatPoints[j + 1]) * (thatPoints[j] - points[i])))
/ (((points[iNext + 1] - points[i + 1]) * (thatPoints[jNext] - thatPoints[j]))
- ((points[iNext] - points[i]) * (thatPoints[jNext + 1] - thatPoints[j + 1])));
if (unknownA >= 0 && unknownA <= 1 && unknownB >= 0 && unknownB <= 1) {
result = true;
break;
}
}
if (result) {
break;
}
}
return result;
}