toxiclibs - tangent spline - Processing Forum

Contributed Library Questions

clankill3r

in Contributed Library Questions • 1 year ago

If you click you add points. From that it creates some kind of curve.

What i want is to draw the tangent as well.

It should be possible to calculate it by it's neighbors i suppose.

I only don't know how to do it since a Iterator does not support previous().

Or is it possible to loop over this without a Iterator as well?

could someone help?

import toxi.geom.*;
ArrayList<Vec2D> deformVectors = new ArrayList<Vec2D>();
Spline2D spline = new Spline2D();
void setup() {
size(400, 400);
smooth();
}
void draw() {
background(255);
stroke(255, 0, 0);
noFill();
beginShape();
for (Iterator i=spline.pointList.iterator(); i.hasNext();) {
Vec2D v = (Vec2D)i.next();
vertex(v.x, v.y);
}
endShape();
stroke(0, 0, 255);
if (deformVectors.size() > 2) {
for (Iterator i = spline.getDecimatedVertices(5, false).iterator(); i.hasNext();) {
Vec2D v = (Vec2D)i.next();
line(v.x-2, v.y, v.x+2, v.y);
line(v.x, v.y-2, v.x, v.y+2);
// tangent ?
}
}
}
void mousePressed() {
deformVectors.add(new Vec2D(mouseX, mouseY));
spline = new Spline2D();
for (Vec2D v : deformVectors) {
spline.add(v);
}
}