/**
* Return the point where this LineSegment intersects another line segment.
*
* @param other the other line segment.
* @return the point where the two segments intersect, or null if they do not.
*/
public PointF findIntercept(LineSegment other) {
// Special case for vertical lines
if (Float.isInfinite(m) && Float.isInfinite(other.m)) {
if (start.x == other.start.x)
return new PointF(Float.POSITIVE_INFINITY, Float.POSITIVE_INFINITY);
return null;
}
// special case for horizontal lines
if (m == 0 && other.m == 0) {
if (start.y == other.start.y)
return new PointF(Float.POSITIVE_INFINITY, Float.POSITIVE_INFINITY);
return null;
}
float x, y;
if (Float.isInfinite(other.m)) {
x = other.start.x;
} else if (Float.isInfinite(m)) {
return other.findIntercept(this);
} else {
// first find intercept.
// solve for X
// m1x + b1 = m2x + b2
// b1 - b2 = (m2 - m1)x
x = (b - other.b) / (other.m - m);
}
// Now solve for y
y = m * x + b;
// now see if this point is on both line segments.
if (isPointInSegment(x, y) && other.isPointInSegment(x, y)) {
return new PointF(x, y);
}
return null;
}
