Creating instances from a class with a for-loop

Programming Questions

audiopulse

Creating instances from a class with a for-loop

in Programming Questions • 9 months ago

Hello,

im still quite new to processing && programming in general, so bear with me if this is actually an obvious thing to you :)

What im trying to get is a circle divided in a certain number of segments. The number of segments can be controlled via the keyboard (Later ControlP5).

I already wrote a class creating a segment. Right now I made it so the Constructor asks for the center of the circle (which is width/2, height/2) and the "void display" is fed with the angles of the starting-anchorpoint, the ending-anchorpoint and the radius of course.

The Sketch works without giving out an error, but it doesnt show anything.

What am I doing wrong?

Edit: The Code its all about:

Kreissegment meinSegment;
int segmentzahl = 4;
int segmentmaximum = 12;
//░░███░░░████░░█████░░█░░░█░░████░░░░░░░
//░█░░░░░░█░░░░░░░█░░░░█░░░█░░█░░░█░░░░░░
//░░███░░░████░░░░█░░░░█░░░█░░████░░░░░░░
//░░░░░█░░█░░░░░░░█░░░░█░░░█░░█░░░░░░░░░░
//░░███░░░████░░░░█░░░░░███░░░█░░░░░░░░░░
void setup() {
size(600,600);
meinSegment = new Kreissegment(width/2, height/2);
}
//░░███░░░████░░░░█░░░░░███░░░█░░░░░░░░░░
//░████░░░████░░░░███░░░█░░░░░░░█░░░░░░░░
//░█░░░█░░█░░░█░░█░░░█░░█░░░░░░░█░░░░░░░░
//░█░░░█░░████░░░█░░░█░░░█░░█░░█░░░░░░░░░
//░█░░░█░░█░░░█░░█████░░░█░█░█░█░░░░░░░░░
//░████░░░█░░░█░░█░░░█░░░░█░░░█░░░░░░░░░░
void draw(){
//CONTROL FOR INCREASING /DECREASING SPLITS
if(keyPressed) {
if (key == 'a' || key == 'A') {
segmentzahl ++;
}
if (key == 'y' || key =='Y') {
segmentzahl --;
}
}
for (int segmentnumber = 1; segmentnumber <= segmentmaximum; segmentnumber += 1){
meinSegment.display (0 + ((segmentnumber -1) *(360 /segmentzahl)), ((360 /segmentzahl)*(segmentnumber)), 200);
}
if (segmentzahl <=0) {
segmentzahl = 1;
}
}
//█░DRAW-ENDE░░░░░░░░░░░░░░░░░░░░░░░░DRAW-ENDE░█
//██░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ██
class Kreissegment {
//GLOBAL VARIABLES
float x = 0;
float y = 0;
float wina = 0;
float winb = 0;
float rad = 0;
//CONSTRUCTOR
Kreissegment(float _x, float _y) {
x = _x;
y = _y;
// wina = _wina;
// winb = _winb;
// rad = _rad;
}
//FUNCTIONS
void display(float _wina, float _winb, float _rad) {
//Zierelement setzen
float winc = (((winb - wina)/2) + wina); //Winkelhalbierende d. Kreissegments für Zierelement
float radc = ((rad /5) *6); //Setzen des Radius für den Zierpart des Kreissegments
//░░░░░
//Curve-start
float curvestartx = x + (sin(radians(wina))*rad);
float curvestarty = y + (cos(radians(wina))*rad);
//Controlpoint-start /where does it come from?
float controlstartx = curvestartx + (sin(radians(wina-90))*rad);
float controlstarty = curvestarty + (cos(radians(wina-90))*rad);
//Curve-end
float curveendx = x + (sin(radians(winb))*rad);
float curveendy = y + (cos(radians(winb))*rad);
//Controlpoint-end /in what direction will it lead to?
float controlendx = curveendx + (sin(radians(winb))*rad);
float controlendy = curveendy + (sin(radians(winb))*rad);
//Zierelement
float distortionx = x + (sin(radians(winc))*radc);
float distortiony = y + (cos(radians(winc))*radc);
//░░░░░
beginShape();
curveVertex(controlstartx, controlstarty); //Control start
curveVertex(curvestartx, curvestarty); //Anchor start
curveVertex(distortionx, distortiony); //Zierelement
curveVertex(curveendx, curveendy); //Anchor end
curveVertex(controlendx, controlendy); //Control end
endShape();
}
}

Replies(10)

GoToLoop

Re: Creating instances from a class with a for-loop

9 months ago

W/o the source code, there's not much we can do!

PhiLho

Re: Creating instances from a class with a for-loop

9 months ago

" What am I doing wrong?"
You are describing vaguely an algorithm which is fine, without showing your implementation, which can have errors in many places, from not making an instance of your class to not calling its display() method, etc.
In other words, as GoToLoop said, show your source code! (Otherwise, I will just move this topic to General Discussions, since we remain in a general ground).

audiopulse

Re: Creating instances from a class with a for-loop

9 months ago

Apologies ... my mistake. I added the Code in the Opening-post.

My guess is, the way im feeding my data to the class is faulty so the segments all start and end at 0 degrees and overlay each other.

But thats just my feeling.

Ale_

Re: Creating instances from a class with a for-loop

9 months ago

Hi audiopulse. German is quite intimidating, so it's hard to dive into your code. :-)
Despite that fact in the display method you're using wina, winb and rad variables instead of _wina, _winb and _rad. ;-)
Regards!

Ale · http://60rpm.tv/i

quarks

Re: Creating instances from a class with a for-loop

9 months ago

Add the line below to the display method

void display(float _wina, float _winb, float _rad) {
wina = _wina; winb = _winb; rad = _rad;

also the line below to the drawmethod

void draw(){
backgrond(255);

audiopulse

Re: Creating instances from a class with a for-loop

9 months ago

Thanks for the quick help everyone. I really appreciate that a lot! :)

Just adding these lines didnt solve it. Im going over the code right now, cleaning it up a little and translating everything in english so its easier for you to "dive in" ;)

While I am doing this Id like to ask a few things:
Did I do right by initializing the instance with just _x and _y and feeding the angles and radii later with the display-call?
Ive never seen that in any tutorials, I just guessed this was right.

Also: Is it even correct to initialize the instance just once ("Kreissegment meinSegment;") and then call it multiple times in the forloop like that? I must admit, I didnt think it would work when i wrote that code. I thougth I would just feed multiple angles and radii in the very same instance with every loop.
I thougt Id have to initialize multiple "meinSegment"s in some way...

Circlesegment mySegment;
int segmentamount = 4;
int segmentmaximum = 12;
//░░███░░░████░░█████░░█░░░█░░████░░░░░░░
//░█░░░░░░█░░░░░░░█░░░░█░░░█░░█░░░█░░░░░░
//░░███░░░████░░░░█░░░░█░░░█░░████░░░░░░░
//░░░░░█░░█░░░░░░░█░░░░█░░░█░░█░░░░░░░░░░
//░░███░░░████░░░░█░░░░░███░░░█░░░░░░░░░░
void setup() {
size(600, 600);
mySegment = new Circlesegment(width/2, height/2);
}
//░████░░░████░░░░███░░░█░░░░░░░█░░░░░░░░
//░█░░░█░░█░░░█░░█░░░█░░█░░░░░░░█░░░░░░░░
//░█░░░█░░████░░░█░░░█░░░█░░█░░█░░░░░░░░░
//░█░░░█░░█░░░█░░█████░░░█░█░█░█░░░░░░░░░
//░████░░░█░░░█░░█░░░█░░░░█░░░█░░░░░░░░░░
void draw() {
//CONTROL FOR INCREASING /DECREASING SPLITS
if (keyPressed) {
if (key == 'a' || key == 'A') {
segmentamount ++;
}
if (key == 'y' || key =='Y') {
segmentamount --;
}
}
//CREATING THE SEGMENTS WITHIN A FORLOOP
for (int segmentnumber = 1; segmentnumber <= segmentmaximum; segmentnumber += 1) {
mySegment.display ((0 + ((segmentnumber -1) *(360 /segmentamount))), ((360 /segmentamount)*(segmentnumber)), 200);
}
if (segmentamount <=0) {
segmentamount = 1;
}
background(255);
}
//DRAW-ENDE
//██░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░██
Tab2 - "class-segment"
class Circlesegment {
//GLOBAL VARIABLES
float x = 0;
float y = 0;
float wina = 0;
float winb = 0;
float rad = 0;
//CONSTRUCTOR
Circlesegment(float _x, float _y) {
x = _x;
y = _y;
// wina = _wina;
// winb = _winb;
// rad = _rad;
}
//FUNCTIONS
void display(float _wina, float _winb, float _rad) {
// x = _x;
// y = _y;
wina = _wina;
winb = _winb;
rad = _rad;
//Calculationg angle && radius for Distortion
float winc = (((winb - wina)/2) + wina); //Bisection of the Circlesegments
float radc = ((rad /5) *6); //Calculating radius for the distortion. For now its just "+ 1/5"
//░░░░░ //Calculation the actual
//Curve-start
float curvestartx = x + (sin(radians(wina))*rad);
float curvestarty = y + (cos(radians(wina))*rad);
//Controlpoint-start /where does it come from?
float controlstartx = curvestartx + (sin(radians(wina-90))*rad);
float controlstarty = curvestarty + (cos(radians(wina-90))*rad);
//Curve-end
float curveendx = x + (sin(radians(winb))*rad);
float curveendy = y + (cos(radians(winb))*rad);
//Controlpoint-end /in what direction will it lead to?
float controlendx = curveendx + (sin(radians(winb))*rad);
float controlendy = curveendy + (sin(radians(winb))*rad);
//Distortion
float distortionx = x + (sin(radians(winc))*radc);
float distortiony = y + (cos(radians(winc))*radc);
//░░░░░
beginShape();
curveVertex(controlstartx, controlstarty); //Control start
curveVertex(curvestartx, curvestarty); //Anchor start
curveVertex(distortionx, distortiony); //Zierelement
curveVertex(curveendx, curveendy); //Anchor end
curveVertex(controlendx, controlendy); //Control end
endShape();
}
}

Ale_

Re: Re: Creating instances from a class with a for-loop

9 months ago

Hi again!

You're cleaning the background at each frame! That's the reason you don't see anything... You only have to erase that 'background(255)'...

Btw, I'd say you have a strange logic in the approach you use. If the objects you create have fixed values (as wina=260, say) store them in object fields. If you're going, instead, to create dinamically that values at each frame (in the display method as you do) don't store them, just use them.

The standard approach would be to have another method, 'void updateAngles()', say. So you have now three stages: constructor, updating, displaying. The constructor can create the values once. Update will change them if you need it. Display will display the segment using the values stored, without changing them. This design is still simple, but it's more efficient and flexible.

Ale · http://60rpm.tv/i

quarks

Re: Creating instances from a class with a for-loop

9 months ago

Just adding these lines didnt solve it.

It did for me, I got this picture when I did it. The adjusted code is below.

Kreissegment meinSegment;
int segmentzahl = 4;
int segmentmaximum = 12;
void setup() {
size(600, 600);
meinSegment = new Kreissegment(width/2, height/2);
}
void draw() {
background(255);
//CONTROL FOR INCREASING /DECREASING SPLITS
if (keyPressed) {
if (key == 'a' || key == 'A') {
segmentzahl ++;
}
if (key == 'y' || key =='Y') {
segmentzahl --;
}
}
for (int segmentnumber = 1; segmentnumber <= segmentmaximum; segmentnumber += 1) {
meinSegment.display (0 + ((segmentnumber -1) *(360 /segmentzahl)), ((360 /segmentzahl)*(segmentnumber)), 200);
}
if (segmentzahl <=0) {
segmentzahl = 1;
}
}
class Kreissegment {
//GLOBAL VARIABLES
float x = 0;
float y = 0;
float wina = 0;
float winb = 0;
float rad = 0;
//CONSTRUCTOR
Kreissegment(float _x, float _y) {
x = _x;
y = _y;
// wina = _wina;
// winb = _winb;
// rad = _rad;
}
//FUNCTIONS
void display(float _wina, float _winb, float _rad) {
wina = _wina;
winb = _winb;
rad = _rad;
//Zierelement setzen
float winc = (((winb - wina)/2) + wina); //Winkelhalbierende d. Kreissegments für Zierelement
float radc = ((rad /5) *6); //Setzen des Radius für den Zierpart des Kreissegments
//░░░░░
//Curve-start
float curvestartx = x + (sin(radians(wina))*rad);
float curvestarty = y + (cos(radians(wina))*rad);
//Controlpoint-start /where does it come from?
float controlstartx = curvestartx + (sin(radians(wina-90))*rad);
float controlstarty = curvestarty + (cos(radians(wina-90))*rad);
//Curve-end
float curveendx = x + (sin(radians(winb))*rad);
float curveendy = y + (cos(radians(winb))*rad);
//Controlpoint-end /in what direction will it lead to?
float controlendx = curveendx + (sin(radians(winb))*rad);
float controlendy = curveendy + (sin(radians(winb))*rad);
//Zierelement
float distortionx = x + (sin(radians(winc))*radc);
float distortiony = y + (cos(radians(winc))*radc);
//░░░░░
beginShape();
curveVertex(controlstartx, controlstarty); //Control start
curveVertex(curvestartx, curvestarty); //Anchor start
curveVertex(distortionx, distortiony); //Zierelement
curveVertex(curveendx, curveendy); //Anchor end
curveVertex(controlendx, controlendy); //Control end
endShape();
}
}

audiopulse

Re: Creating instances from a class with a for-loop

9 months ago

Amazing! It works! Why did put the background at the end of draw? My god I feel silly now :D

Anyways, Ale, youre right about my class-structure. Ill work it that way and implement a mySegment.update now.
Thanks a ton, everyone. Ill certainly be having more questions about processing. I hope I can come back and ask you again. :)

Edit: quark was faster.

Youre right, quark, the changes you suggested were correct. I did a mistake, though, and put the "background();" at the end of void-draw, instead of its beginning. That way I overwrote my Visuals with every draw, of course.

Its working now and I can finetune my curve-Vertices. :)

GoToLoop

Re: Creating instances from a class with a for-loop

9 months ago

An alternative for mousePressed variable checking, is to use its corresponding callback function mousePressed():
You can also check variable keyCode in place of variable key to avoid worrying about checking for letter cases!

//CONTROL FOR INCREASING/DECREASING SPLITS:

void keyPressed() {
  if (keyCode == 'A')       ++segmentamount;
  else if (keyCode == 'Y')  --segmentamount;
}

Also you have to place -> if (segmentamount == 0) segmentamount = 1;
before the mySegment loop, lest you end up w/ a division by zero error!

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