Processing 1.0 - Processing Discourse - [newbie]

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Index › Programming Questions & Help › Programs › [newbie] - adapting code to 0090

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[newbie] - adapting code to 0090 (Read 1610 times)

a__

[newbie] - adapting code to 0090
May 11^th, 2005, 1:18am

hi there,

i'm a newbie using proce55ing and currently trying to convert an old code, written for a beta version older than 0070, to beta 0090. its a particle system with attractors. i've already made some changes, i.e. BImage to PImage, etc. But I don't really know how to change imageMode(CENTER_DIAMETER). And the script does not work... does anybody have an idea...??!?

code:

int NUM_PARTICLES = 10000;
int NUM_ATTRACTORS = 8;

int SPRITE_SIZE = 2;

Particle[] particle;
Attractor[] attractor;

float damp = 0.0002;
float accel = 10000;

PImage part;

class Particle {
float x,y,vx,vy;
Particle() {
x = random(width);
y = random(height);
vx = random(-accel/2,accel/2);
vy = random(-accel/2,accel/2);
}
void step() {
for (int i = 0; i < attractor.length; i++) {
float d2 = sq(attractor[i].x-x) + sq(attractor[i].y-y);
if (d2 > 0.1) {
vx += accel * (attractor[i].x-x) / d2;
vy += accel * (attractor[i].y-y) / d2;
}
}
x += vx;
y += vy;
vx *= damp;
vy *= damp;
}
}

class Attractor {
float x,y;
Attractor() {
x = random(width);
y = random(height);
}
}

void setup() {
size(800,600);
part = new PImage(SPRITE_SIZE,SPRITE_SIZE);
attractor = new Attractor[NUM_ATTRACTORS];
particle = new Particle[NUM_PARTICLES];
scatter();
float md = 0.5*sqrt(sq(part.width/2)+sq(part.height/2));
for (int x = 0; x < part.width; x++) {
for (int y = 0; y < part.height; y++) {
float d = sqrt(sq(x-part.width/2)+sq(y-part.height/2));
float r = 255-(255*d/md);
float g = 128-(128*d/md);
float b = 32-(32*d/md);
part.set(x,y,color(r,g,b,8-8*d/md));
}
}
imageMode(CENTER_DIAMETER);
}

void loop() {
for (int j = 0; j < particle.length; j++) {
particle[j].step();
blend(part,0,0,part.width,part.height,(int)particle[j].x-part.width/2,(int)particle[j].y-part.height/2,(int)particle[j].x+part.width/2,(int)particle[j].y+part.height/2,ADD);
}
}

void scatter() {
background(0);
for (int i = 0; i < attractor.length; i++) {
attractor[i] = new Attractor();
}
for (int i = 0; i < particle.length; i++) {
particle[i] = new Particle();
}
}

void mousePressed() {
scatter();
}

JohnG Ex Member	Re: [newbie] - adapting code to 0090 Reply #1 - May 11^th, 2005, 1:27am change "void loop()" to be "void draw()" and imageMode(CENTRE_DIAMETER) is unfortunately not around, so you may have to just subtrace image.width/2 and image.height/2 from the co-ordinates of call to draw the image.

a__

Re: [newbie] - adapting code to 0090
Reply #2 - May 11^th, 2005, 10:28am

thx for your answer

but can you please specify what you wrote about the imageMode(). im did not really found out yet whats the task of this part... its my first time with processing and i try to understand how this particle/attractor system works and wanna adapt in to 0090. but i don't understand what loadImage is doing here... does it place the start point of the process in the center of the image?!? can you help me?

tia!
peter

fjen

Re: [newbie] - adapting code to 0090
Reply #3 - May 11^th, 2005, 2:58pm

imageMode() changes the way blend() works ...

http://processing.org/reference/blend_.html
http://processing.org/reference/imageMode_.html

( blend() does not seem to work with the default java2d renderer ... so i switched to P3D in size() )
Code:


int NUM_PARTICLES  = 1000; 
int NUM_ATTRACTORS = 8; 
 
int SPRITE_SIZE = 2; 
 
Particle[] particle; 
Attractor[] attractor; 
 
float damp = 0.0002; 
float accel = 10000; 
 
PImage part; 
 
class Particle { 
  float x,y,vx,vy; 
  Particle() { 
    x = random(width); 
    y = random(height); 
    vx = random(-accel/2,accel/2); 
    vy = random(-accel/2,accel/2); 
  } 
  void step() { 
    for (int i = 0; i < attractor.length; i++) { 
	  float d2 = sq(attractor[i].x-x) + sq(attractor[i].y-y); 
	  if (d2 > 0.1) { 
		vx += accel * (attractor[i].x-x) / d2; 
		vy += accel * (attractor[i].y-y) / d2; 
	  } 
    } 
    x += vx; 
    y += vy; 
    vx *= damp; 
    vy *= damp; 
  } 
} 
 
class Attractor { 
  float x,y; 
  Attractor() { 
    x = random(width); 
    y = random(height); 
  } 
} 
 
void setup() { 
  size(800,600, P3D); 
  part = new PImage(SPRITE_SIZE,SPRITE_SIZE); 
  attractor = new Attractor[NUM_ATTRACTORS]; 
  particle = new Particle[NUM_PARTICLES]; 
  scatter(); 
  float md = 0.5*sqrt(sq(part.width/2)+sq(part.height/2)); 
  for (int x = 0; x < part.width; x++) { 
    for (int y = 0; y < part.height; y++) { 
	  float d = sqrt(sq(x-part.width/2)+sq(y-part.height/2)); 
	  float r = 255-(255*d/md);
	  float g = 128-(128*d/md);
	  float b = 32-(32*d/md); 
	  part.set(x,y,color(r,g,b,8-8*d/md)); 
    }   
  } 
  imageMode(CORNER); 
} 
 
void draw() {
  for (int j = 0; j < particle.length; j++) { 
    particle[j].step(); 
    blend( part, 0,0, part.width, part.height ,
	     (int)particle[j].x-part.width/2, (int)particle[j].y-part.height/2,
	     (int)particle[j].x+part.width/2,(int)particle[j].y+part.height/2, ADD );
  }
} 
 
void scatter() { 
  background(0); 
  for (int i = 0; i < attractor.length; i++) { 
    attractor[i] = new Attractor(); 
  } 
  for (int i = 0; i < particle.length; i++) { 
    particle[i] = new Particle(); 
  } 
} 
 
void mousePressed() { 
  scatter(); 
}

a__ YaBB Newbies Offline Posts: 4	Re: [newbie] - adapting code to 0090 Reply #4 - May 17^th, 2005, 4:50pm ahhh, ok.... thx fjen!

a__

Re: [newbie] - adapting code to 0090
Reply #5 - May 17^th, 2005, 4:51pm

thanks a lot - now i understand (a little bit more... *g*)

i tried to adapt this one next - it doesn't work...
changed loop() to draw() but nothing happens...
do you have an idea for this one??

i know, i'm an annoying newbie... Wink

but its my first time with processing and i'm not very familiar with programming.
i'm trying to learn - learning by doing...
i can retrace the parts of the code, but i do not
find the specific point which is responsible for
the problem in beta 0090...

can anybody please help me?!?!

thx

code:

int NUM_PARTICLES = 10000;
int NUM_ATTRACTORS = 6;

Particle[] particle;
Attractor[] attractor;

float damp = 0.00002;
float accel = 10000;

class Particle {
float x,y,vx,vy;
Particle() {
x = random(width);
y = random(height);
vx = random(-accel/2,accel/2);
vy = random(-accel/2,accel/2);
}
void step() {
for (int i = 0; i < attractor.length; i++) {
float d2 = sq(attractor[i].x-x) + sq(attractor[i].y-y);
if (d2 > 0.1) {
vx += accel * (attractor[i].x-x) / d2;
vy += accel * (attractor[i].y-y) / d2;
}
}
x += vx;
y += vy;
vx *= damp;
vy *= damp;
line(x,y,x,y);
}
}

class Attractor {
float x,y;
Attractor() {
x = random(width);
y = random(height);
}
}

void setup() {
size(800,600);
attractor = new Attractor[NUM_ATTRACTORS];
particle = new Particle[NUM_PARTICLES];
scatter();
}

void loop() {
for (int j = 0; j < particle.length; j++) {
particle[j].step();
}
}

void scatter() {
background(255);
stroke(0,0,0,8);
for (int i = 0; i < attractor.length; i++) {
attractor[i] = new Attractor();
}
for (int i = 0; i < particle.length; i++) {
particle[i] = new Particle();
}
}

void mousePressed() {
scatter();
}

TomC

Re: [newbie] - adapting code to 0090
Reply #6 - May 17^th, 2005, 6:13pm

Ah, the problem here is that loop() should now be draw() and again that the renderer should be switched using size(800,600,P3D).

By the way - wouldn't it be nice to at least mention where you found this code?

There's a BETA-compatible release of lots of my attractor code in the works right now as it happens. If you'd asked me you could have found that out for yourself and saved yourself some trouble!

Thanks anyway everyone for helping to update my code Wink

{sketches,links,blogs,hacks}

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