I need help with a conditional! N00b here.

Programming Questions

itsliv

I need help with a conditional! N00b here.

in Programming Questions • 1 year ago

Hello all.

I'd be forever thankful if one of you could help me out. I need to create a simple piece of code for class. So far I have this:

float a = 200;

void setup()

{

size(700, 480);

loop();

}

void draw()

{

background(51);

a = a - 1.5;

if (a < 0) {

a = height;

}

line(0, a, width, a);

stroke(255);

line(0, a*.5, width, a*.5);

stroke(#90102E);

line(0, a*.2, width, a*.2);

stroke(#54C8CB);

line(0,a-300, width, a-300);

stroke(0);

line(0, a*.3, width, a*.3);

stroke(#F2F7B6);

line(0,a*.1,width,a*.1);

stroke(#8D9817);

}

I'd like to set a condition so that if the line's reach the top of the canvas, they bounce back into the screen. Help?

Replies(4)

Chrisir

Re: I need help with a conditional! N00b here.

1 year ago

why not ask in class?

use an array that holds different values for a
use a for loop to loop through that beast

find all here:
http://processing.org/reference/

rrhrrh

Re: I need help with a conditional! N00b here.

1 year ago

If I get what you're saying, you need another variable to keep track of the direction.

Your "a" variable is keeping track of the y position of the line, but you just subtract 1.5 from it. If you want it to bounce, you could add a variable instead.

background(51);
a = a + dy;
if (a < 0) {
dy =1.5;
} else if (a > height) {
dy = -1.5;
}

peayad

Re: I need help with a conditional! N00b here.

1 year ago

if you are having just one Line you could check for it's y coordinates

if(y>height || y<0) a *= -1;
y += a;

but if you are having more than one Line with different speeds it's much easier to make a class for them, it could be like this:

class Ln{
float y;
float yspeed;
color c;
Ln(float _y,float _yspeed,color _c){
y = _y;
yspeed = _yspeed;
c = _c;
}
void update(){
if(y<0 || y>height) yspeed *=-1;
y += yspeed;
stroke(c);
line(0,y,0,y);
}
}

and then create your new Ln and call it's update function in draw

Ln myLine = new Ln(10,2,#90102E);
void draw(){
background(0);
myLine.update();
}

this is just for one Ln, however if you want to create more you could put them in a loop

Ln[] myLine = new Ln[4];
myLine[0] = new Ln(50,1,#90102E);
myLine[1] = new Ln(60,3,#54C8CB);
myLine[2] = new Ln(70,5,#F2F7B6);
myLine[3] = new Ln(80,10, #8D9817);
void draw(){
background(0);
for(int i=0;i<Ln.length;i++)
myLine[i].render();
}

you could also initiate them in a loop by a sequence, that depends on what you want to do

i hope that helps

goodluck

itsliv

Re: I need help with a conditional! N00b here.

1 year ago

Thank you for all of your help!

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