/**
* Return the number of corners in the specified stroke. This calls numCorners with threshold
* values either initialized in the constructor or specified by the user.
*
* <p>First check to see if this feature already exists in the stroke's property table (access
* using PROPERTY_KEY). If so, return that value (cast to double). Otherwise call numCorners to
* compute and cache the result in the table.
*
* <p>
*/
public double apply(TimedStroke s) {
Integer num = (Integer) s.getProperty(PROPERTY_KEY);
if (num == null) {
int val = numCorners(s, _threshDot, _threshMagRatio, _threshRelaxedDot);
s.setProperty(PROPERTY_KEY, new Integer(val));
return (double) val;
} else {
return num.doubleValue();
}
}
/**
* Return the indices where the corners occur in the given stroke. Return null if no corners exist
* in the stroke. Iterate over the points in the stroke, for every three points (p1, p2, p3) we
* form two vectors, (p1,p2) and (p2, p3). If the dot product of these two vectors is less than
* threshDot, then there is definitely an angle at p2. If the dot product is greater than
* threshDot but less than threshRelaxedDot, it is likely that there is an angle at p2, but we're
* not sure. In this case, the magnitudes of both vectors are calculated, m1 and m2. Let 'plen' be
* the stroke path length, we calculate r1 = m1/plen and r2 = m2/plen. If either r1 or r2 is
* greater than threshMagRatio, then we say that there is a corner. If both vectors are really
* short (r1<threshMagRatio && r2<threshMagRatio), then they are not significant enough to be used
* to determine a corner. They are more likely to be noise due to the pen/tablet hardware.
*/
public static final int[] cornerIndices(
TimedStroke s, double threshMagRatio, double threshDot, double threshRelaxedDot) {
if (s == null) {
return null;
} else if (s.getVertexCount() < 3) {
return null;
} else {
int numPoints = s.getVertexCount();
ArrayList cornerIndices = new ArrayList();
double pathLength = PathLengthFE.pathLength(s);
double x1, y1, x2, y2, x3, y3;
for (int i = 0; i < numPoints - 2; i++) {
x1 = s.getX(i);
y1 = s.getY(i);
x2 = s.getX(i + 1);
y2 = s.getY(i + 1);
x3 = s.getX(i + 2);
y3 = s.getY(i + 2);
double dot = FEUtilities.dotProduct(x1, y1, x2, y2, x3, y3);
if (dot < threshDot) { // definitely an angle
double angle = Math.acos(dot);
angle = Math.toDegrees(angle);
int j = i + 1;
cornerIndices.add(new Integer(j));
// numCorners++;
} else if (dot < threshRelaxedDot) {
// likely to be an angle
double l1 = FEUtilities.distance(x1, y1, x2, y2);
double l2 = FEUtilities.distance(x2, y2, x3, y3);
l1 = l1 / pathLength;
l2 = l2 / pathLength;
if ((l1 > threshMagRatio) || (l2 > threshMagRatio)) {
double angle = Math.acos(dot);
angle = Math.toDegrees(angle);
// numCorners++;
int j = i + 1;
cornerIndices.add(new Integer(j));
}
}
}
if (cornerIndices.size() == 0) {
return null;
} else {
int arr[] = new int[cornerIndices.size()];
// System.out.println("Corner indices:-----");
int k = 0;
for (Iterator i = cornerIndices.iterator(); i.hasNext(); ) {
Integer index = (Integer) i.next();
int val = index.intValue();
arr[k++] = val;
// System.out.println(val+":("+s.getX(val)+", "+s.getY(val)+")");
}
// System.out.println("--------------------");
return arr;
}
}
}
/** Treat the current stroke as a lasso selection if it is mostly closed. */
public void actionPerformed(ActionEvent evt) {
_interp.removeCurrentSymbol();
TimedStroke stroke = _interp.getCurrentStroke();
int num = stroke.getVertexCount();
/*
double length = PathLengthFE.pathLength(stroke);
double dist = FEUtilities.distance(stroke.getX(0), stroke.getY(0),
stroke.getX(num-1), stroke.getY(num-1));
double ratio = dist/length;
if(ratio <= CLOSE_PROPORTION){
*/
Polygon2D poly = new Polygon2D.Float();
poly.moveTo(stroke.getX(0), stroke.getY(0));
for (int i = 1; i < num; i++) {
poly.lineTo(stroke.getX(i), stroke.getY(i));
}
poly.closePath();
Iterator iter = _interp.getController().containedSketchFigures(poly);
ArrayList hitFigures = new ArrayList();
while (iter.hasNext()) {
Figure f = (Figure) iter.next();
if (f instanceof FigureDecorator) {
f = ((FigureDecorator) f).getDecoratedFigure();
}
hitFigures.add(f);
}
// }
toggleSelection(hitFigures);
}
/** Normalize an individual stroke to time increments given by timestep. */
public static TimedStroke interpolate(TimedStroke s, int timestep) {
long t0 = s.getTimestamp(0);
long tN = s.getTimestamp(s.getVertexCount() - 1);
int nsteps = (int) ((tN - t0) / timestep);
TimedStroke out = new TimedStroke();
long tcur = t0;
int j = 0;
for (int i = 0; i < nsteps; i++) {
while (j < s.getVertexCount() && s.getTimestamp(j) <= tcur) {
j++;
}
if (j >= s.getVertexCount()) {
throw new RuntimeException("not enough points!");
} else {
long tplus = s.getTimestamp(j);
long tminus = s.getTimestamp(j - 1);
double xcur = (tplus - tcur) * s.getX(j - 1) + (tcur - tminus) * s.getX(j);
xcur = xcur / (tplus - tminus);
double ycur = (tplus - tcur) * s.getY(j - 1) + (tcur - tminus) * s.getY(j);
ycur = ycur / (tplus - tminus);
out.addVertex((float) xcur, (float) ycur, tcur);
tcur += timestep;
}
}
return out;
}
