curve within borders || equalizer

Programming Questions

marvmarvm..

curve within borders || equalizer

in Programming Questions • 1 year ago

Hey guys,

I'm working on a problem and I just wanted to ask here, if maybe somebody got a clever idea solving it.

I'm drawing a curve trough points, that I have placed each one by clicking somewhere on the sketch. If I click on an existing point, I delete it. The ArrayList of points is sorted by the x-positions eveytime a new point appears. So always the curve is drawn from left to right trough the points. We could call that thing a graphic equalizer, right?

So I use that thing as an equalizer, but not to manipulate sound, but a pattern. Anyway. My problem is, that if I have two points close to the border, sometimes the curve reaches beyond the borders:

Do you have any clue how could I solve the problem?

Here's the code, that I use:

in void setup: (obvious)

for (int i = myPoints.size()-1; i >= 0; i--) {
GrapPoint p = (GrapPoint) myPoints.get(i);
p.display();
}

and in void draw:

beginShape();
for (int i = myPoints.size()-1; i >= 0; i--) {
GrapPoint p = (GrapPoint) myPoints.get(i);
p.update();
if (i == 0 || i == myPoints.size()-1) {
curveVertex(p.posX, p.posY);
}
curveVertex(p.posX, p.posY);
}
endShape();

There is as well code to add a Point: (I know this could be much more elegant!)

void mouseClicked() {
if (mouseX < 120+350 && mouseX > 120 && mouseY < 32+80 && mouseY > 32) {
boolean pointThere = false;
int b=0;
for (int i = 0; i < myPoints.size(); i++) {
GrapPoint p = (GrapPoint) myPoints.get(i);
if (mouseX < p.posX+15 && mouseX > p.posX-15 && mouseY < p.posY+15 && mouseY > p.posY-15) {
b = i;
pointThere = true;
}
println("p "+i+" x:"+p.posX+" y:"+p.posY);
}
if (pointThere == false) {
myPoints.add(new GrapPoint(mouseX, mouseY));
}
else {
myPoints.remove(b);
}
println(myPoints.size());
// Bubble Sort
boolean swapped = true;
int c;
int n = 1;
while (swapped) {
swapped = false;
for (int i = 0; i < myPoints.size()-n; i++) {
GrapPoint p = (GrapPoint) myPoints.get(i);
GrapPoint q = (GrapPoint) myPoints.get(i+1);
if (q.posX < p.posX) {
c = p.posX;
p.posX = q.posX;
q.posX = c;
c = p.posY;
p.posY = q.posY;
q.posY = c;
swapped = true;
n++;
}
}
}
}
}

And to drag it:

void mouseDragged() {
if (mouseX < 120+350-2 && mouseX > 122 && mouseY < 32+80-2 && mouseY > 34) {
for (int i = 0; i < myPoints.size(); i++) {
GrapPoint p = (GrapPoint) myPoints.get(i);
if (mouseX < p.posX+4 && mouseX > p.posX-4 && mouseY < p.posY+4 && mouseY > p.posY-4) {
p.posX = mouseX;
p.posY = mouseY;
}
}
}
}

Replies(3)

amnon.owed

Re: curve within borders || equalizer

1 year ago

Between points 0 and 1 there is (or might be) an intersection through x=0 as you show in your image.

You can find this intersection with curvePoint. It is at t>0 and x=0.

Once you have this point you could use it to solve your problem. There are different options for this. For example you could replace point 0, by the intersection point. Or you could add a vertex (not a curveVertex) at the intersection point. You'll have to see what works best for you.

(sidenote: if you define the type of your arraylist when you declare it, then you don't have to explictly cast it each time you get something from the arraylist because java will already know it'll be a GrapPoint. Plus you'll be able to use generics - shortening the code of your for loops - when you don't need the i)

scratchis..

Re: Re: curve within borders || equalizer

1 year ago

And about that sidenote:

You can define the type of your ArrayList like this:

ArrayList<type> name = new ArrayList<type>();

marvmarvm..

Re: curve within borders || equalizer

1 year ago

Thank a lot guys!!

I solved the problem with curvePoint, exactly like amnon described it.

Thanks as well for the sidenote^^

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