if mousePressed .........(create a triangle of random radius around the mouse)

Programming Questions

sriiyer89

if mousePressed .........(create a triangle of random radius around the mouse)

in Programming Questions • 5 months ago

Hi!

The following is my code:

Tri pTri;
void setup()
{
size (500, 500);
pTri = new Tri();
}
void draw()
{
background (255);
pTri.display();
}
class Tri
{
color c;
float x1, y1;
float x2, y2;
float x3, y3;
Tri()
{
c = color (255, 0, 0);
x1 = random(0, 150);
y1 = random(0, 150);
x2 = random(0, 150);
y2 = random(0, 150);
x3 = random(0, 150);
y3 = random(0, 150);
}
void display()
{
if (mousePressed=true)
{
stroke (c);
triangle (mouseX, y1, x2, mouseY, x3, y3);
}
}
}

In this, how do i say, if mousePressed create the triangle around the mouse, using random radius for each vertices????

Replies(7)

PhiLho

Re: if mousePressed .........(create a triangle of random radius around the mouse)

5 months ago

First, you have an error in your code:
if (mousePressed=true)
Here, you both assign true to mousePressed, and you test the value of the result, which is thus always true...
That's why I say that using == for booleans is redundant, useless and dangerous...
if (mousePressed)
is more than enough, more readable (once you get used to it) and safe...

If that's what you were asking, all right. Well, you need to create several triangles in a loop, and store them in an array (in setup()), and iterate on them in draw() to display them, of course.

sriiyer89

Re: if mousePressed .........(create a triangle of random radius around the mouse)

5 months ago

Hi! Thanks. Infact I have changed a little bit in the class and tried something like what you've told, but I don understand where I am making the mistake:

Tri[] pTri = new Tri[100];
void setup()
{
size (500, 500);
//pTri = new Tri();
for (int i=0; i<pTri.length;++i)
{
pTri[i] = new Tri();
}
}
void polygon(int n, float cx, float cy, float r)
{
float angle = 360.0 / n;
beginShape();
for (int i = 0; i < n; i++)
{
vertex(cx + r * cos(radians(angle * i)),
cy + r * sin(radians(angle * i)));
}
endShape(CLOSE);
}
void draw()
{
background (255);
for (int i=0; i<pTri.length;++i)
{
pTri[i].display();
}
}
class Tri
{
color c;
Tri()
{
c = color (255, 0, 0);
}
void display()
{
if (mousePressed)
{
stroke (c);
polygon (3, mouseX, mouseY, random(0,100));
}
}
}

PhiLho

Re: if mousePressed .........(create a triangle of random radius around the mouse)

5 months ago

Well, this code seems to work. Where is the problem?

sriiyer89

Re: if mousePressed .........(create a triangle of random radius around the mouse)

5 months ago

No...Actually I want the triangle the stay on screen even after having clicked the mouse. And, i want to display only one triangle to be displayed....which is not happening in this code..

tfguy44

Re: if mousePressed .........(create a triangle of random radius around the mouse)

5 months ago

Like this?

void setup(){
size (500, 500);
stroke(255,0,0);
background(255);
}
void draw(){}
void mousePressed(){
background(255);
polygon (3, mouseX, mouseY, random(0, 100));
}
void polygon(int n, float cx, float cy, float r){
float angle = 360.0 / n;
beginShape();
for (int i = 0; i < n; i++){
vertex(cx + r * cos(radians(angle * i)), cy + r * sin(radians(angle * i)));
}
endShape(CLOSE);
}

sriiyer89

Re: if mousePressed .........(create a triangle of random radius around the mouse)

5 months ago

precisely!..thanks!

but jus to understand...

what wrong did I do in my code?

tfguy44

Re: if mousePressed .........(create a triangle of random radius around the mouse)

5 months ago

Quite simply, your code was overkill for what you were trying to accomplish.

You didn't need an array or a class at all. Since the only time your sketch would change is when the mouse is clicked, you can just have the mousePressed() function draw the triangle directly, and have it persist by not redrawing over it in draw().

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