Just reset to zero the depth variable before the return...
A more traditional and reliable way to handle recursion depth is to pass the counter as parameter of the function.

That's great, thanks. I would like each step of the two recursions to be called at the same time though, rather than one after another..

At the moment it calls all levels of recursion of the first function, before moving onto the second. Is there a way to execute both, one step at a time?

thanks again


void drawArrows(float rotation, float x1, float y1, boolean inc, int depth) {
  if(depth==maxDepth) {
    return;
  }
 
  depth++;
  translate(x1,y1);
  rotate(PI/rotation);
  scale(ratio);

  float x2 = 0;
  float y2 = 0 - lineLength;
  stroke(100);
  line(0, 0, x2, y2);
 
  drawArrows(rotator,x2,y2,true,depth);
  drawArrows(0-rotator,x2,y2,false,depth);
}

Mmm, I am not sure, I don't see what this fragment is supposed to do. I tried to run it with the following code:

1. int maxDepth = 7;
2. float rotator = 45;
3. float ratio = 0.8;
4. float lineLength = 50;
5. 
   
6. void setup() {
7.   size(500, 500);
8.   drawArrows(30, 250, 250, 0);
9. }
10. 
    
11. void drawArrows(float rotation, float x1, float y1, int depth) {
12.   if (depth == maxDepth) {
13.     return;
14.   }
15.  
16.   depth++;
17.   translate(x1, y1);
18.   rotate(PI / rotation);
19.   scale(ratio);
20.   float x2 = 0;
21.   float y2 = -lineLength;
22.   stroke(100);
23.   line(0, 0, x2, y2);
24.  
25.   drawArrows( rotator, x2, y2, depth);
26.   drawArrows(-rotator, x2, y2, depth);
27. }

but it isn't really spectacular...
I had an idea to toggle the sign of rotator, but actually I don't see the point, since actually all lines will be drawn at once, so the order of calls isn't important.

It's just an example that is going to illustrate what I want to do with recursion simply enough for me to get my head round it.. as a learning exercise that's all.

What I'd like the example to do would be to create a mirror image the lines, as opposed to appending a smaller reversed version of itself on the end. Hope this makes sense.

int sHeight = 800;
int depth = 0;
int maxDepth = 7;
int originX = 600;
int originY = 800;
float ratio = .618;
float lineLength = sHeight;
int rotator = 4;

void setup() {
  background(255);
  size(1200,sHeight);
  drawArrows(0.25,originX,originY,true,0);
}


void draw() {
}


void drawArrows(float rotation, float x1, float y1, boolean inc, int depth) {
  if(depth==maxDepth) {
    return;
  }
 
  depth++;
  translate(x1,y1);
  rotate(PI/rotation);
  scale(ratio);

  float x2 = 0;
  float y2 = 0 - lineLength;
  stroke(100);
  line(0, 0, x2, y2);
 
  drawArrows(rotator,x2,y2,true,depth);
  drawArrows(0-rotator,x2,y2,false,depth);
}

The overall effect I am trying to create is of a line that forks in to two (each at 45% from the top of the first line). These two lines then each fork into 2 more, and the recursion grows exponentially. It just seems to be a little more difficult than I anticipated.