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Index › Programming Questions & Help › Programs › Greenberg Code

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Greenberg Code (Read 394 times)

johnclavin

Greenberg Code
Mar 3^rd, 2008, 10:04am

I am trying to run the Chapter 2 example "algorithmic tree sketch" from the Ira Greenberg book. I get a blank screen.
I think I can show the problem with a small program.
The import statement seems to cause the problem, but if you reduce the size to 400 x 300 it seems to work.
The import statement is not needed in this example program, but the Greenberg program uses it.

Quote:

// If the import statement is added to the program,
// even though it is not used,
// you will not see the line().

// import java.awt.geom.Point2D;

void setup() {
size(900, 600);
background(255);
strokeWeight(6);
stroke(0);
trunk();
}

void trunk() {
line(0, 0, width, height);
}

Maybe someone can double check this.
I am using: WinXP, Java 1.4, and Processing -0135 beta

movax

Re: Greenberg Code
Reply #1 - Mar 3^rd, 2008, 7:29pm

Try:

Code:


// If the import statement is added to the program,
  // even though it is not used,1
  // you will not see the line().
 
// import java.awt.geom.Point2D;
 
void setup() {
  size(900, 600,P3D);
  background(255);
  strokeWeight(6);
  stroke(0); 

}

void draw(){
  trunk();

}
 
void trunk() {
  line(0, 0, width, height);
}

Flickr Stream of mostly Processing work:&&http://www.flickr.com/photos/87132003@N00/&&

johnclavin

Re: Greenberg Code
Reply #2 - Mar 3^rd, 2008, 8:21pm

Thanks,

Adding the draw() and putting the trunk() in the draw works for the example program.
With the Greenberg program "algorithmic tree sketch" you have to also add noLoop() to the setup() so that trunk() is only called once.
I think that Ira added that program in the book as something we could play around with. It is a good example of recursive programming that always gives my head a spin.

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