Use of delay() in Processing Environment

Question

I am using Processing language to sketch a rectangle that grows in size with time. Following code is not giving any output.

void setup()
{
    size(900,900);
}
void draw()
{
    int edge=100;
    for(int i=0;i<300;i++)
    {
        delay(100);  
        edge++;      
        rect(100,100,edge,edge);
    }
}

I suspect having wrongly used delay() function.

score 10 · Answer 1 · answered Dec 23 '13 at 21:26

10

Here is one such "roll your own" delay method which is good for most purposes. Just change the values passed into the delay method to alter the timing. This just outputs "start" and "end" roughly every 2 seconds for example.

void draw()
{
  System.out.println("start");
  delay(2000);
  System.out.println("end");
  delay(2000);
}

void delay(int delay)
{
  int time = millis();
  while(millis() - time <= delay);
}

answered Dec 23 '13 at 21:26

cditcher

358
3
12

This example works for println() but not for drawing shapes - the whole program is delayed before anything is drawn - regardless of where the delay is placed in the code. – Kokodoko Sep 17 '14 at 16:28

score 7 · Accepted Answer · edited May 23 '17 at 11:50

7

I recommend rolling your own delay system using the millis() function.

Have a look at this example.

edited May 23 '17 at 11:50

Community

1
1

answered Jul 14 '13 at 09:59

George Profenza

50,687
19
144
218

score 4 · Answer 3 · answered Nov 17 '14 at 23:45

With processing, the screen does not get refreshed until the program flow reaches the end of draw()
Try the following:

 void setup()
 {
   size(900,900);
   frameRate(10);
 }
int edge = 100;
void draw()
{ 
     edge++;      
     rect(100,100,edge,edge);
}

Use of delay() in Processing Environment

3 Answers3