Drawing Arrowhead curve with words (Objective-c cocos2D) - cocos2d-iphone

Question

I'm trying to draw an arrowhead-curve using Fibonacci-esque words. I may use method calls instead of building onto a string later on, but for now I want to preserve the string.
// create string. Initially set to "A"
NSMutableString *s1 = [[NSMutableString alloc] init];
[s1 setString:#"A"];
// loop through and replace A and B with the following strings. Toned down iterations to 5 here
for(int i=0; i<5; ++i){
[s1 replaceOccurrencesOfString:#"A"
withString:#"+B-A-B+"
options:NSLiteralSearch
range:NSMakeRange(0, s1.length)];
[s1 replaceOccurrencesOfString:#"B"
withString:#"-A+B+A-"
options:NSLiteralSearch
range:NSMakeRange(0, s1.length)];
}
// set line color, thickness
ccDrawColor4F(0.8, 1.0, 0.76, 1.0);
glLineWidth(1.0f);
float angle = 0;
float travelDist = 1; // distance in pixels the line is drawn. Can be changed to whatever
CGPoint p = CGPointMake(300,100);
for(int i = 0; i < [s1 length]; i++){
if([[NSString stringWithFormat:#"%c",[s1 characterAtIndex:i]] isEqualToString:#"+"]){ // turn right
angle += 60;
}else if([[NSString stringWithFormat:#"%c",[s1 characterAtIndex:i]] isEqualToString:#"-"]){ // turn left
angle -= 60;
}else{ // any other character, draw line
float cosAngle = cosf(CC_DEGREES_TO_RADIANS(angle));
float newDist = travelDist * cosAngle;
float sinAngle = sinf(CC_DEGREES_TO_RADIANS(angle));
float newDist2 = travelDist *sinAngle;
ccDrawLine( ccp(p.x, p.y), ccp(p.x + newDist, p.y + newDist2) );
p = CGPointMake(p.x + newDist, p.y + newDist2);
}
}
I've read up on several sites about arrowhead curves, and the rules they must follow. It seems like I should be doing the right thing, but it doesn't turn out quite right. I get something representing a Sierpinski's triangle, but not a proper arrowhead curve.
You may not have to know Objective-c/Cocos2d to answer this, as I'm probably just doing something logistically incorrect.

Answer 1

I need to create a new temporary string based on the current string, and go through one character at a time, and make the string the temporary one at the end of each iteration:
NSMutableString *s1 = [[NSMutableString alloc] init];
[s1 setString:#"A"];
NSMutableString *sTemp = [[NSMutableString alloc] init];
[sTemp setString:#""];
for(int i=0; i<6; ++i){
for(int j = 0; j < [s1 length]; j++){
unichar character = [s1 characterAtIndex:j];
if(character == 'A'){
[sTemp appendString:#"B-A-B"];
}
else if(character == 'B'){
[sTemp appendString:#"A+B+A"];
}else{
[sTemp appendString:[NSString stringWithFormat:#"%C",character]];
}
}
[s1 setString:sTemp];
[sTemp setString:#""];
}