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Index › Programming Questions & Help › Syntax Questions › can redraw be used to translate something
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can redraw be used to translate something? (Read 569 times)
gte999s
can redraw be used to translate something?
May 25th, 2007, 4:51am  
I'm trying to use a loop in a function that calls redraw to translate a a letter, but it does not seem to update until the while loop completes. Basically, i just want the letter to rotate and then fall away from the screen.

Any ideas as to why it doesn't seem to be refreshing with the redraw?

Any help would be greatly appreciated. And sorry if this is a topic already. I was only able to get one discussion to show when i searched for 'redraw'.

void draw()
{
 background(0);
 translate(width/2,height/2);
 pushMatrix();
   ctime=millis()-start_time;
   
   theta=ctime*rotvel;
   
   //rotateX(textWidth(k)/70.0);
   //scale(1.1);
   
   
   translate(textWidth(buff)/2,0,-pos);
   rotateY(theta);
   translate(-textWidth(buff)/2,0);
   text(buff,0,0);
   
 
 popMatrix();
}

void myzoom()
{
 float postime=millis();
 
 while (pos<800)
 {
   pos=(millis()-postime)*.5;
   redraw();
 }
 buff=' ';
 pos=0;
}
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st33d
Re: can redraw be used to translate something?
Reply #1 - May 25th, 2007, 10:43am  
while() for() do() and other loops in all programming languages will halt the computer until the loop is completed. Entering any of these loops commits your program to complete the loop - you cannot change this.

The animation you are trying to achieve must be performed by turning the draw() function into your loop.

eg:

Code:

float theta = 0.0;
void setup(){
  size(200,200,P3D);
}
void draw(){
  background(100);
  translate(width*0.5, height*0.5);
  rotateX(theta);
  rotateY(theta);
  rect(0,0,width*0.5, height*0.5);
  theta += 0.05;
}


This I am afraid is the way it is done.
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gte999s
Re: can redraw be used to translate something?
Reply #2 - Jun 18th, 2007, 6:21am  
Does this mean that 'redraw' just sets a flag somewhere that allows 'draw()' to be called? (does not actually call draw)
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fry
Re: can redraw be used to translate something?
Reply #3 - Jun 18th, 2007, 2:14pm  
that's correct (we're at the mercy of the operating system). i've added some clarification to the reference for future releases.
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