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Index › Programming Questions & Help › Syntax Questions › displaying image problem
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displaying image problem (Read 477 times)
frannyglass79
displaying image problem
Jan 6th, 2008, 7:11pm  
hi

i work on a project where a long text is written on the screen character by character. when the end of the screen is reached it starts over at the top. the characters are displayed as images. now, when there is a character from the previous pass, before i display the new one i would like to delete the old one by displaying a blank black image briefly. however even if i set the time between drawing the blank and the new image to, say, 2 seconds it seems as if they are both drawn at the same time, so the blank is actually lost.

this is my code:

Quote:
void display(int idx) {
 if (words[idx] != '$') {
   image(imgSpace, c, l);
   float a = millis();

   while((millis()-a)<1000){
   }

   image((PImage)alphabet.get(new Character(words[idx])), c, l);
 }
}


i call display() from draw().

any ideas?

cheers
nadja
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JohnG
Re: displaying image problem
Reply #1 - Jan 6th, 2008, 7:23pm  
Nothing actually gets drawn to screen until draw() finishes, so putting any kind of delay in a function called during draw will just make it take longer to give the same result.

To get the effect you want, you'll have to have two states, one "do nothing during draw" and the other "do something". When you get to a point you want to pause, you clear the letter you want to remove, then set a value to "do nothing next time", next time comes, and it does nothing until however long has passed, and then changes the variable back to "do something next time"
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frannyglass79
Re: displaying image problem
Reply #2 - Jan 6th, 2008, 7:26pm  
that was quick. thanks a lot.

cheers
nadja
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