pulsating ellipse

Programming Questions

ganon

in Programming Questions • 1 year ago

hey there!,

I just started out programming and need a little help.

i'm trying to pulsate an ellipse between a min. and a max. value.

the sketch i made sort of does what i want it to do except for the minimum size i've set.

i'm probably doing it all wrong, but that's why i came here.

best case scenario:

i would be able to control the speed of the pulse and the min/max values between which it pulsates.

here's the sketch:

int growth=50;

void setup()

{

size(500, 350);

background(127);

stroke(127);

smooth();

}

void draw()

{

fill(0,200,200);

if(mousePressed)

{

ellipse(mouseX, mouseY, growth, growth);

}

growth++;

if(growth<50) {growth=growth*+1;}

if(growth>70) {growth=growth*-1;}

}

thanks in advance!

Replies(2)

calsign

You're close... BTW, this kind of question tends to get answered a lot.
The best solution involves a global increment variable, and every frame, you add increment to growth. When growth exceeds the defined bounds, you negate increment (multiply by -1). This way, you can change the rate of pulsation by changing increment's initial value.

ganon

Re: pulsating ellipse

1 year ago

Yes sir!

With your help i got it to work.

thank you very much.

Here it is.. My first Sketch ever:

int growth=60; // initial size of ellipse

int increment=1; // larger increment faster pulsating-speed

void setup()

{

size(500, 350);

background(100);

stroke(100);

smooth();

}

void draw()

{

fill(0,200,200);

if(mousePressed)

{

ellipse(mouseX, mouseY, growth, growth);

}

growth=growth+increment;

if(growth>60) {increment=increment*-1;} //max ellipse size

if(growth<30) {increment=+1;} //min ellipse size

}

PS:

i had searched the forum for a bit before posting.

As you said, The topic has been discussed, but mostly in larger, harder to understand for the novice, sketches.

This made it hard to pinpoint the possible solution.

i appreciate the help!

As will anybody else searching the forum for "pulsating ellipse"

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