private double findCurvature(InputCursor in) {
if (in.getEventCount() < 3) return 0.0f;
List<AbstractCursorInputEvt> events = in.getEvents();
AbstractCursorInputEvt posEvt = events.get(events.size() - 1);
AbstractCursorInputEvt prev = events.get(events.size() - 2);
AbstractCursorInputEvt prev2 = events.get(events.size() - 3);
if (prev == null) return 0;
if (prev2 == null) return 0;
return findCurvature(
posEvt.getPosX(),
posEvt.getPosY(),
prev.getPosX(),
prev.getPosY(),
prev2.getPosX(),
prev2.getPosY());
}
@Override
public void update(InputCursor in) {
double val = 0.0f;
val = (float) (findCurvature(in) / (Math.PI));
pastValues.add(new double[] {val});
// filter, no. average? Yes.
// float pastEvtCount = in.getEvents(10).size();
// val = (currentValue*pastEvtCount + val)/(pastEvtCount+1);
// int size = in.getEvents(200).size();
// //if (size > 2) { //this is the.... other method. using least squares.
// if (size < 0) { //nonsense, for now.
// //size=3;
// double[][] b = new double[size][2];
// double[][] a = new double[size][2];
// int pastValuesSize = pastValues.size();
// System.out.println("Size of pastValuesL: "+pastValuesSize+" Size of b:"+size);
// for (int x = 0; x < size; x++) {
// b[x][0] = pastValues.get(pastValuesSize-x-1)[0];
// b[x][1] = size-x;
// a[x][0] = 1;
// a[x][1] = x+1;
// }
//
//
// Matrix A = new Matrix(a);
// Matrix B = new Matrix(b);
// System.out.println("A: "+A+" B:"+B);
// Matrix sol = A.solve(B);
// System.out.println(sol);
// for (double[] row : sol.getArray())
// System.out.println("Row: ["+row[0]+","+row[1]+"]");
// val = (float) sol.getArray()[0][0];
// }
// if (size > 2) {
//
// }
// this is the spline method http://www.faculty.idc.ac.il/arik/Java/ex2/index.html
int n = 15;
List<AbstractCursorInputEvt> past = in.getEvents();
int sizeofpast = in.getEvents().size();
if (sizeofpast > n) {
Point2D[] s = new Point2D[n + 1];
for (int i = 0; i < n + 1; i++) {
AbstractCursorInputEvt p = past.get(sizeofpast - i - 1);
s[i] = new Point2D.Double(p.getPosX(), p.getPosY());
}
Point2D p2, p1, p0;
p0 = s[0];
p1 = Geometry.evalBezier(s, 0.1);
p2 = Geometry.evalBezier(s, 0.2);
val = findCurvature(p0.getX(), p0.getY(), p1.getX(), p1.getY(), p2.getX(), p2.getY());
}
// System.out.println("Curvature: "+val);
// filter.correct(new Matrix(new double[][]{{val}}));
// filter.predict();
// System.out.println("0:"+filter.getX().get(0,0));
// System.out.println("1:"+filter.getX().get(1,0));
// System.out.println("2:"+filter.getX().get(2,0));
// val = (float) filter.getX().get(0,0);
// System.out.println("Curvature: "+val);
currentValue = val;
engine.gestureQualityChange(name, (float) val, in);
}