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Index › Programming Questions & Help › Syntax Questions › Recursive calls to draw() function
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Recursive calls to draw() function (Read 500 times)
GrandMasterG
Recursive calls to draw() function
Apr 9th, 2008, 6:26pm  
Am trying to implement a timer which only allows the draw method in my main class to run for a minute however when I put   a while loop around the call to draw() nothing happens however  it works fine when outside the loop any ideas??
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stier4
Re: Recursive calls to draw() function
Reply #1 - Apr 9th, 2008, 6:47pm  
Quote:


int stopTime;

void setup(){
 stopTime = 60000;
}

void draw(){
 if (millis() > stopTime){
   noLoop();
 }
 else{
   //do something
 }  
}
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GrandMasterG
Re: Recursive calls to draw() function
Reply #2 - Apr 9th, 2008, 7:20pm  
Hi thanks for the answer much appreciated however the problem is not solved by this. I'll try and explain it a bit better. I am trying to evolve some robots. Firstly I initiliase a population of robots. Then train them for a number of epochs using evolutionary approach as follows:

Firstly select 2 random members of the population.
Allow them in turn to explore the environment for 1 minute.
Using a fitness function rank the robots and evolve weaker one.

The problem is in my explore method I need to allow the robots to only explore for one minute. As you can see as the number of training epochs are very high I cannot statically define the time and use millis().

Pseudo-code of the problem below. noLoop() is active:


void draw() {
       
 image( ground, 0, 0);
 currentMap.draw();
       
 for(int i =0; i<epochs; i++){
   getContestants();
   explore();
 }


void explore(){  //This method works
 
 currentRobot = robots[robot2];

 currentRobot.move();
 currentRobot.draw();
 
 }

void explore(){ //This doesn't
 
 currentRobot = robots[robot2];

 while(timer > 1){
   currentRobot.move();
   currentRobot.draw();
}
}
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djones
Re: Recursive calls to draw() function
Reply #3 - Apr 11th, 2008, 5:15pm  
You can still use the solution posted earlier ...

You just need to update the "stopTime" each time
you start one of your robot simulations.

Something like this:
  stopTime = millis() + duration;

-- djones
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GrandMasterG
Re: Recursive calls to draw() function
Reply #4 - Apr 11th, 2008, 6:16pm  
Hey thanks yer have been fiddling around and now have the timer working. Still don't understand why a draw call won't work from within a while loop but blah nvm!!!
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JohnG
Re: Recursive calls to draw() function
Reply #5 - Apr 11th, 2008, 7:17pm  
It won't work because the screen doesn't get updated until the original draw function has finished.

Behind the scenes Processing does (in pseudo code):
Code:
 pre();
draw();
post();
updateScreen();


So even if you call draw from within draw, it still won't update the screen until that original draw has finished.
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