ObjectiveC UIBezierPath path close issue - ios

Question

I try to hexagon and I have some issue in the close path.
Here is my hexagon, and the close path is not smooth.
Here is my drawing code
CAShapeLayer* shapeLayer = [CAShapeLayer layer];
UIBezierPath* path = [UIBezierPath bezierPath];
// [path setLineJoinStyle:kCGLineJoinRound];
// [path setLineJoinStyle:kCGLineJoinBevel];
[path setLineJoinStyle:kCGLineJoinMiter];
// CGFloat dashes[] = {6, 2};
// [path setLineDash:dashes count:2 phase:0];
// [path stroke];
CGFloat radians = 100.0;
NSInteger num = 6;
CGFloat interval = 2*M_PI/num;
NSInteger initX = radians*cosf(interval);
NSInteger initY = radians*sinf(interval);
[path moveToPoint:CGPointMake(location.x - semiWidth + initX, location.y - semiHeight + initY)];
for(int i=1; i<=num; i++){
CGFloat x = radians*cosf(i*interval);
CGFloat y = radians*sinf(i*interval);
[path addLineToPoint:CGPointMake(location.x - semiWidth + x, location.y - semiHeight + y)];
}
[path closePath];
shapeLayer.path = [path CGPath];
shapeLayer.strokeColor = [[UIColor yellowColor] CGColor];
shapeLayer.fillColor = [[UIColor brownColor] CGColor];
shapeLayer.lineWidth = 4.0f;
Also I try to use different options as following with no luck
[path setLineJoinStyle:kCGLineJoinRound];
[path setLineJoinStyle:kCGLineJoinBevel];
[path setLineJoinStyle:kCGLineJoinMiter];

Answer 1

The problem is that you're not making your first point (the point you move-to) the same way you're making your other points (the points you line-to).
NSInteger initX = radians*cosf(interval);
NSInteger initY = radians*sinf(interval);
[path moveToPoint:CGPointMake(
location.x - semiWidth + initX, location.y - semiHeight + initY)];
Instead, make the first point completely parallel with the others:
CGFloat x = radians*cosf(0*interval);
CGFloat y = radians*sinf(0*interval);
[path moveToPoint:CGPointMake(
location.x - semiWidth + x, location.y - semiHeight + y)];
That's exactly the same as what you'll do later with i*interval, and to emphasize that parallelism, I've written 0 as 0*interval. Here's what I ended up with: