Controlling each instance of an array of object separately

Programming Questions

lauraage

Controlling each instance of an array of object separately

in Programming Questions • 9 months ago

Hello!

I've created a sketch that selects a screen amongst several ones when the mouse is pressed. When ScreenA is selected, it should display Rain made of several Drops. But I don't succeed to make each Drop behave independantly. I would like that at a certain height y2, the Drop changes its transparency alphaDrop and at another height y2, reinitialize itself and appears to another place. Currently, when an height y2 is attained, every drops change their alpha, and then every drops are reinitialized together.
I've tryed to use this example http://wiki.processing.org/w/From_several_arrays_to_classes but obviously I'm doing something wrong.

Thanks for your help!
Laura

Screen[]     screens;
int          NUMBER_SCREENS = 2;
int          lastScreen, currentScreen;

void setup()
{
size(768,768,P2D);
smooth();
background(0);

screens = new Screen[NUMBER_SCREENS];
screens[0] = new ScreenA();
screens[1] = new ScreenB();

currentScreen = 0;
screens[currentScreen].init();

}

void draw()
{
    rect(100,100,100,100);
    //display current visual
    screens[currentScreen].display();
}

void mousePressed() {
{
// pick a different visual
lastScreen=currentScreen;
currentScreen=int(random(screens.length-1));
if( lastScreen <= currentScreen )
    currentScreen=(currentScreen+1)%screens.length;
}

// The init function contains the parameters of the clear selected screen
// So call it allows to restart the screen from 0 next time it appears
screens[currentScreen].init();
}
class Screen
{
Screen()
{
}

void init()
{

}

void display()
{
}

void update()
{
}
}
final int DROP_NB = 2;
Drop[] dropArray = new Drop[DROP_NB];
color[] colourArray = {color(26,200,214),color(154,214,226)};
boolean val = false;

class ScreenA extends Screen
{

ScreenA()
{
}

void init()
{
   noStroke();
   for (int i = 0; i<DROP_NB; i++)
   {
     dropArray[i] = new Drop(int(random(0,width)),int(random(-100,0)),colourArray[(int) random(colourArray.length)]);
     dropArray[i].init();
   }
}

void display()
{
   background(#0AA08A);

   for (int i = 0; i<DROP_NB; i++)
   {
     boolean t = dropArray[i].rebirth(val);
     if (t == true)
     {
       blop();
       init();
     }
     dropArray[i].update();
     dropArray[i].show();
     dropArray[i].setSpeed(mouseY/10);
   }
}
}

void blop()
{
fill(255,0,0);
rect(100,100,100,100);
}
class Drop
{
int      x1;
int      y1;
int      x2;
int      y2;
int      speed;
color    c;
int      alphaDrop;

Drop(int x1, int y1, color c)
{
    this.x1 = x1;
    this.y1 = y1;
    this.c   = c;
}

void init()
{
    x2       = 20;
    y2       = 20;
    speed    = 1;
    alphaDrop= 255;
}

void show()
{
    //if (y2<=height)
    //{
      //println(y2);
      fill(c, alphaDrop);
      ellipse(x1, y1, x2, y2);
    /*}else
    {
      init();
    }*/
}

void update()
{
    y2 = y2 + 1 * speed;
    if (y2 >=200)
    {
      alphaDrop = 80;
    }
    else
    {
      alphaDrop = 255;
    }
}

boolean rebirth(boolean dropCreation)
{
    if (y2>=height/2)
    {
      dropCreation = true;
    }
    return dropCreation;
}

void setSpeed(int speedRate)
{
    speed = speedRate;
}

}
class ScreenB extends Screen
{

ScreenB()
{
}

void init()
{
}

void display()
{
background(#EAD211);
}
}

Replies(5)

Chrisir

Re: Controlling each instance of an array of object separately

9 months ago

here...

Screen[] screens;
int NUMBER_SCREENS = 2;
int lastScreen, currentScreen;
void setup()
{
size(768, 768, P2D);
smooth();
background(0);
screens = new Screen[NUMBER_SCREENS];
screens[0] = new ScreenA();
screens[1] = new ScreenB();
currentScreen = 0;
screens[currentScreen].init();
}
void draw()
{
background(0);
rect(100, 100, 100, 100);
//display current visual
screens[currentScreen].display();
}
void mousePressed() {
{
// pick a different visual
lastScreen=currentScreen;
currentScreen=int(random(screens.length-1));
if ( lastScreen <= currentScreen )
currentScreen=(currentScreen+1)%screens.length;
}
// The init function contains the parameters of the clear selected screen
// So call it allows to restart the screen from 0 next time it appears
screens[currentScreen].init();
}
class Screen
{
Screen()
{
}
void init()
{
}
void display()
{
}
void update()
{
}
}
final int DROP_NB = 2;
Drop[] dropArray = new Drop[DROP_NB];
color[] colourArray = {
color(26, 200, 214), color(154, 214, 226)
};
boolean val = false;
class ScreenA extends Screen
{
ScreenA()
{
}
void init()
{
noStroke();
for (int i = 0; i<DROP_NB; i++)
{
dropArray[i] = new Drop(int(random(0, width)), int(random(-100, 0)), colourArray[(int) random(colourArray.length)]);
dropArray[i].init();
}
}
void display()
{
background(#0AA08A);
for (int i = 0; i<DROP_NB; i++)
{
boolean t = dropArray[i].rebirth(val);
if (t == true)
{
blop();
// init();
}
dropArray[i].update();
dropArray[i].show();
dropArray[i].setSpeed(mouseY/10);
}
}
}
void blop()
{
fill(255, 0, 0);
rect(100, 100, 100, 100);
}
// ===================================================================================
class Drop
{
int x1;
int y1;
int x2;
int y2;
int speed;
color c;
int alphaDrop;
Drop(int x1, int y1, color c)//parameters that are different from one Drop to another from the start *Blue Drop or Red Drop
{
this.x1 = x1;
this.y1 = y1;
this.c = c;
}
void init()
{
x2 = 20;
y2 = 20;
speed = 1;
alphaDrop= 255;
}
void show()
{
//if (y2<=height)
//{
//println(y2);
fill(c, alphaDrop);
ellipse(x1, y1, x2, y2);
/*}else
{
init();
}*/
}
void update()
{
y2 = y2 + 1 * speed;
if (y2 >=200)
{
alphaDrop = 80;
}
else
{
alphaDrop = 255;
}
}
boolean rebirth(boolean dropCreation)
{
boolean dropCreation1 = false;
if (y2>=height)
{
dropCreation1 = true;
}
return dropCreation1;
}
void setSpeed(int speedRate)
{
speed = speedRate;
}
}
class ScreenB extends Screen
{
ScreenB()
{
}
void init()
{
}
void display()
{
background(#EAD211);
}
}

lauraage

Re: Re: Controlling each instance of an array of object separately

9 months ago

Thanks for replying Chrisir, but I've tried what you changed, and I don't see any difference.
In addition by removing init() in the display() function of the ScreenA Object, you remove the randomization of the new drops falling, and you get drops that always fall at the same position.
What is the advantage of adding Dropcreation1? I can't see any.

Did I miss something, and in that case, can you explain?

Cheers,
Laura

Chrisir

Re: Controlling each instance of an array of object separately

9 months ago

hi,

I can't see different drops, I see only lines, going down. Why? Maybe you need a background in screen 1?

I changed line 140, not sure about that.

I took out 78 because you have 66. Ah, I see what you mean. For restarting you need init

I can't see red drops.

With alphaDrop what's gonna change? a slight change in the color? I saw that in my code.

When you say init you give all the same x and y. Why?

You check y2 once in rebirth once in update. Why not in one place?

Greetings, Chrisir

lauraage

Re: Re: Controlling each instance of an array of object separately

9 months ago

Hey Chrisir,

Sorry, my explanations might have been a bit confusing:
- I've named 'drop' the lines, because to me they kind of look like drops (and when better coded, they look very much like rain drops). But indeed here you only have the test version so it doesn't look exactly like drops.
- I saw the change line 140, but tried it and didn't see any visual change
- Yes
- Again, I used red drops for testing at some point, and then didn't change my comment. Sorry for that. (I've suppressed the comment in my first message to avoid any further confusion)
- Yes, alphaDrop defines the transparency, so I want that at a certain height the transparency changes, but not for all drops together, only the drops that reach that height. (which should be at a different time as the drop have different heights)
- I give same x and y for init to reinitialize everything to 0, and allow the new drops to fall for the top.
- I check y2 in rebirth because this is the height where the drop have to be reinitialized, when the y2 checked in update is the one that controls the alpha value of the drop, which changes at a different height.

Hope everything is clearer now.

Chrisir

Re: Controlling each instance of an array of object separately

8 months ago

hello,

when your problem is that the drops don't change after a 200 pixels:

In my version I think they do, it is just too fast to notice.

Try with

final int DROP_NB = 2000;

It almost freezes then but you can see a color change because it's slow.
Or set framerate(4) or so.

Sorry, I don't mean to be rude, I just have a hard time to understand....

Greetings, Chrisir

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