basic object question

Programming Questions

codeduder

in Programming Questions • 3 years ago

i used to programm in flash, and i am new to processing.

my main-understanding-question in processing is:

if i create objects to the stage, how can i call them? (like instances)

for example i have a array of objects like this:

int numSpots = 10;
Spot[] spots = new Spot[numSpots];
void setup() {
size(450,150);
smooth();
background(0);
for (int i = 0; i < spots.length; i++) {
float x = (40 + 5)*i;
spots[i] = new Spot(x);
}
}
class Spot {
float x;
Spot(float xpos) {
x = xpos;
fill(255,10);
rect(x, 0, 40, 150);
}
}

now as an example i like to do a MouseRollover, and print the objects instance ( the "i" nr) by rollover an object.

like this:

print("im over" + i);

Replies(4)

kooogy

your spots aren't objects in the flash sense, they aren't intelligent, and don't know when the mouse has entered them.

so you have to iterate over them checking their positions against current mouse pos.

or use a picking library (search old forum)

bjordal

Re: basic object question

3 years ago

What kooogy said.

this code should give you the basic idea (add it to your program and run it).

void draw(){
for (int i = 0; i < spots.length; i++) {
if(mouseX>spots[i].x && mouseX < spots[i].x+40 && mouseY > 0 &&mouseY <150){
//the magic numbers are the width height and y in your code
println("im over " + i);
}
}
}

kooogy

Re: Re: basic object question

3 years ago

except i'd've made it a method belonging to the spot class given that it knows where and how big it is (or should) then

for (int i = 0 ; i < spots.length ; i++) {
if (spots[i].isMouseIn(mouseX, mouseY)) {
println("I'm over " + i);
// break; // can skip the rest if you only want the first match
}
}

codeduder

Re: basic object question

3 years ago

big thanks to all!

now i understand more. (the void draw() was suspect to me)

but if i wanna interact between objects?

basic like this:

redraw all the time these objects (with void draw()) and check if they for example touch each other?!

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