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Index › Programming Questions & Help › Syntax Questions › not drawing objects
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not drawing objects (Read 528 times)
roboguy
not drawing objects
Feb 18th, 2010, 5:23am  
basically ive written some simple code to make a few bouncing circles, ive been trying to learn arrays.

there must be something ive forgotten because when i run the program it shows nothing just white

heres the code

Code:
int numcircles;

float[] x = new float[numcircles];
float[] y = new float[numcircles];
float[] diameter = new float[numcircles];
int maxdiameter = 30;
float[] xspeed = new float[numcircles];
float[] yspeed = new float[numcircles];
color[] circlecolour = new color[numcircles];

int i;



void setup(){
  
  size(600,600);
  createcircles();
  smooth();
  
  
}
  
void draw(){
  
  background(255);
  movecircles();
  drawcircles();
  
  
}

void createcircles(){
  
  for( i = 0; i < numcircles; i++){
    
    x[i] = random(width);
    y[i] = random(height);
    diameter[i] = random(maxdiameter)*2;
   
    xspeed[i] = random(5);
    yspeed[i] = random(5);
    
  }
  
}

void drawcircles(){
  
  for(i = 0; i < numcircles; i++) {
  
  
  ellipse(x[i],y[i],diameter[i],diameter[i]);
  
  
  
  }
  
}

void movecircles(){
  
  for (i = 0; i < numcircles; i++){
    
    x[i] += xspeed[i];
    y[i] += yspeed[i];
    
    if (x[i] - diameter[i] <= 0 || x[i] + diameter[i] >= width) {
	
	xspeed[i] *= -1;
	
    }
    
    if (y[i] - diameter[i] <= 0 || y[i] + diameter[i] >= width) {
	
	yspeed[i] *= -1;
	
    }
	
  }
  
}
	

  
    


can anyone see anything wrong with this?
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koogy
Re: not drawing objects
Reply #1 - Feb 18th, 2010, 5:41am  
what colour are your circles?
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Horst von Forst
Re: not drawing objects
Reply #2 - Feb 18th, 2010, 5:48am  
in your very first line you have to give your numcircles variable a value. Like:   int numcircles = 4;
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