How can I tell if a closed path contains a given point?

Question

In Android, I have a Path object which I happen to know defines a closed path, and I need to figure out if a given point is contained within the path. What I was hoping for

Answer 1

Here is what I did and it seems to work:

RectF rectF = new RectF();
path.computeBounds(rectF, true);
region = new Region();
region.setPath(path, new Region((int) rectF.left, (int) rectF.top, (int) rectF.right, (int) rectF.bottom));

Now you can use the region.contains(x,y) method.

Point point = new Point();
mapView.getProjection().toPixels(geoPoint, point);

if (region.contains(point.x, point.y)) {
  // Within the path.
}

** Update on 6/7/2010 ** The region.setPath method will cause my app to crash (no warning message) if the rectF is too large. Here is my solution:

// Get the screen rect.  If this intersects with the path's rect
// then lets display this zone.  The rectF will become the 
// intersection of the two rects.  This will decrease the size therefor no more crashes.
Rect drawableRect = new Rect();
mapView.getDrawingRect(drawableRect);

if (rectF.intersects(drawableRect.left, drawableRect.top, drawableRect.right, drawableRect.bottom)) {
   // ... Display Zone.
}