/**
* Check to see if stroke is a standard arrow
*
* @return true if test passes; else false
*/
protected bool checkStandardArrow()
{
bool passed = true;
StylusPointCollection last = m_subStrokes[m_subStrokes.Count - 1];
StylusPointCollection secondLast = m_subStrokes[m_subStrokes.Count - 2];
StylusPointCollection thirdLast = m_subStrokes[m_subStrokes.Count - 3];
StylusPointCollection fourthLast = m_subStrokes[m_subStrokes.Count - 4];
double lastLength = Recognizer.getStrokeLength(last);
double secondLastLength = Recognizer.getStrokeLength(secondLast);
double thirdLastLength = Recognizer.getStrokeLength(thirdLast);
// test 1: last two sub-strokes must be close in size
m_lastTwoDiff = Math.Abs(lastLength - secondLastLength)
/ (lastLength + secondLastLength);
if (m_lastTwoDiff > 0.5)
{
passed = false;
}
// test 2: two points at the "head" of the arrow should be close
m_headDistance = distance(last[0],
thirdLast[0])
/ recognizer.getStrokeLength();
if (m_headDistance > 0.11)
{
passed = false;
}
m_standardSum = m_headDistance;
// test 3: line connecting tips of arrow head should intersect shaft of
// arrow
Line2D.Double line1 = new Line2D.Double(
thirdLast[thirdLast.Count - 1].X, thirdLast[thirdLast.Count - 1].Y,
last[last.Count - 1].X, last[last.Count - 1].Y);
List <Point2D> intersect = Recognizer.getIntersection(
fourthLast, line1);
m_numIntersect = intersect.Count;
if (m_numIntersect <= 0)
{
passed = false;
}
// Line2D.Double line2 = new Line2D.Double(fourthLast.getPoints().get(
// fourthLast.getNumPoints() / 2).getX(), fourthLast.getPoints()
// .get(fourthLast.getNumPoints() / 2).getY(), fourthLast
// .getLastPoint().getX(), fourthLast.getLastPoint().getY());
// double perpDiff = Math.abs(getSlope(line1) - (1.0 /
// getSlope(line2)));
// if (perpDiff > 5)
// passed = false;
return(passed);
}
/**
* Estimate the minor axis of the ellipse (perpendicular bisector of the
* major axis; clipped where it intersects the stroke)
*/
protected void calcMinorAxis()
{
PerpendicularBisector bisect = new PerpendicularBisector(
m_majorAxis.GetP1(), m_majorAxis.GetP2(),
recognizer.getBounds());
List <Point2D> intersectPts = recognizer.getIntersection(bisect
.getBisector());
if (intersectPts.Count < 2)
{
m_minorAxis = null;
m_minorAxisLength = 0.0;
}
else
{
double d1, d2;
d1 = m_center.Distance(intersectPts[0]);
d2 = m_center.Distance(intersectPts[1]);
m_minorAxis = new Line2D.Double(intersectPts[0].X,
intersectPts[0].Y, intersectPts[1].X,
intersectPts[1].Y);
m_minorAxisLength = d1 + d2;
}
}
public PerpendicularBisector(Point2D p1, Point2D p2, BoundingBox bounds)
{
this.point2D1 = p1;
this.point2D2 = p2;
this.boundingBox = bounds;
double xMid = ((p2.X - p1.X) / 2) + p1.X;
double yMid = ((p2.Y - p1.Y) / 2) + p1.Y;
midPoint = new Point2D(xMid, yMid);
if ((p2.Y - p1.Y) == 0)
{
// line is horizontal, slope 0
// perpendicular bisector is slope infinity
bisectorSlope = double.NaN;
}
else if ((p2.X - p1.X) == 0)
{
// line is vertical, slope infinity
// perpendicular bisector is slope 0
bisectorSlope = 0;
}
else
{
bisectorSlope = -1 * (p2.X - p1.X)
/ (p2.Y - p1.Y);
}
double x1, y1, x2, y2;
if (double.IsNaN(bisectorSlope))
{
// vertical
bisectorYIntercept = double.NaN;
y1 = bounds.getMinY();
y2 = bounds.getMaxY();
x1 = midPoint.X;
x2 = midPoint.X;
}
else if (bisectorSlope == 0)
{
// horizontal
bisectorYIntercept = midPoint.Y;
y1 = midPoint.Y;
y2 = midPoint.Y;
x1 = bounds.getMinX();
x2 = bounds.getMaxX();
}
else
{
// solve for y intercept
// y = mx + b
double y = midPoint.Y;
double x = midPoint.X;
double m = bisectorSlope;
double b = y - (m * x);
bisectorYIntercept = b;
x1 = bounds.getMinX();
x2 = bounds.getMaxX();
if (double.IsNaN(m))
{
y1 = bounds.getMinY();
y2 = bounds.getMaxY();
}
else
{
y1 = m * x1 + b;
y2 = m * x2 + b;
}
}
bisector = new Line2D.Double(x1, y1, x2, y2);
}