/* ********************************************************************************* */
public static void Create_Control_Point(
PointX Prev, PointX CornerPnt, PointX Next, PointX CtrlPnt) {
PointX before = new PointX(Prev), after = new PointX(Next);
before.Subtract(CornerPnt);
before.Normalize();
after.Subtract(CornerPnt);
after.Normalize();
before.Add(after); // this now divides the angle between the two lines
before.Normalize(); // this gives us normalized output
// CtrlPnt.CopyFrom(before);
double x0, y0, sin, cos;
double d =
(after.x * before.y)
- (after.y * before.x); // winding order: d=(x-x1)*(y2-y1)-(y-y1)*(x2-x1)
if (d > 0) {
sin = Sin90; // 90 degrees
cos = Cos90;
} else {
sin = Sin270; // 270 degrees
cos = Cos270;
}
x0 = (before.x * cos) - (before.y * sin); // precalculated all to constants
y0 = (before.y * cos) + (before.x * sin);
CtrlPnt.Assign(x0, y0); // result is one point, 1 unit long, 'tangent' to the corner.
/*
position = sign((Bx - Ax) * (Y - Ay) - (By - Ay) * (X - Ax))// alternative: cross product
*/
}
/* ********************************************************************************* */
public static void Cheap_Spline(
Graphics2D gr,
PointX p0,
PointX ctr,
PointX p1,
PointX[] results) { // cheap spline, cross spline, cross curve
PointX p0prime = new PointX(ctr), p1prime = new PointX(ctr);
// p0prime.CopyFrom(ctr);
p0prime.Subtract(p0);
p0prime.Add(ctr);
// p1prime.CopyFrom(ctr);
p1prime.Subtract(p1);
p1prime.Add(ctr);
Line lcross0 = new Line(p0, p1prime), lcross1 = new Line(p0prime, p1);
// gr.setColor(Globals.ToColorWheel(Globals.RandomGenerator.nextDouble()));
// gr.drawLine((int) lcross0.pnt[0].x, (int) lcross0.pnt[0].y, (int) lcross0.pnt[1].x, (int)
// lcross0.pnt[1].y);
//
// gr.setColor(Globals.ToColorWheel(Globals.RandomGenerator.nextDouble()));
// gr.drawLine((int) lcross1.pnt[0].x, (int) lcross1.pnt[0].y, (int) lcross1.pnt[1].x, (int)
// lcross1.pnt[1].y);
// lcross0.Assign(p0, p1prime); lcross1.Assign(p0prime, p1);
PointX results0 = new PointX(), results1 = new PointX(), resultsmeta = new PointX();
Line crossmeta = new Line();
int len = results.length; // 6;
for (int cnt = 0; cnt < len; cnt++) {
double Fract = ((double) cnt) / (double) len;
System.out.println("lcross");
lcross0.FractAlong(Fract, results0);
lcross1.FractAlong(Fract, results1);
// System.out.println("Fract:" + Fract + " results0 x0:" + results0.x + " y0:" + results0.y +
// " x1:" + results1.x + " y1:" + results1.y);
crossmeta.Assign(results0, results1);
System.out.println("crossmeta");
crossmeta.FractAlong(Fract, resultsmeta);
// gr.setColor(Globals.ToColorWheel(Globals.RandomGenerator.nextDouble()));
// gr.drawLine((int) crossmeta.pnt[0].x, (int) crossmeta.pnt[0].y, (int)
// crossmeta.pnt[1].x, (int) crossmeta.pnt[1].y);
results[cnt].CopyFrom(resultsmeta); // resultsmeta is the point we want to plot.
// System.out.println("Fract:" + Fract + " crossmeta x0:" + crossmeta.pnt[0].x + " y0:" +
// crossmeta.pnt[0].y + " x1:" + crossmeta.pnt[1].x + " y1:" + crossmeta.pnt[1].y);
}
}
