Objective C: fix distance between images in touches moved - objective-c

Question

How could i set up my images(points) with same fix distance to new image(point) when performing a touches moved?
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:touch.view];
UIImageView *imageView=[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"Crayon_Black.png"]];
imageView.center = touchLocation;
[drawImage addSubview:imageView];
}
I hope this make sense. I just need to finish my school project. Thanks guys in advance.

Answer 1

This solution works as long as you don't move finger too fast:
#interface ViewController : UIViewController {
CGPoint lastLocation_;
CGFloat accumulatedDistance_;
}
...
-(CGFloat) distanceFromPoint:(CGPoint)p1 ToPoint:(CGPoint)p2 {
CGFloat xDist = (p2.x - p1.x);
CGFloat yDist = (p2.y - p1.y);
return sqrt((xDist * xDist) + (yDist * yDist));
}
-(void) addImageAtLocation:(CGPoint)location {
UIImageView *imageView=[[UIImageView alloc] initWithImage:[UIImage imageNamed:#"Crayon_Black.png"]];
imageView.center = location;
[self.view addSubview:imageView];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesBegan:touches withEvent:event];
lastLocation_ = [[touches anyObject] locationInView:self.view];
accumulatedDistance_ = 0;
[self addImageAtLocation:lastLocation_];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:self.view];
CGFloat distance = [self distanceFromPoint:touchLocation ToPoint:lastLocation_];
accumulatedDistance_ += distance;
CGFloat fixedDistance = 40;
if (accumulatedDistance_ > fixedDistance) {
[self addImageAtLocation:touchLocation];
while (accumulatedDistance_ > fixedDistance) {
accumulatedDistance_ -= fixedDistance;
}
}
lastLocation_ = touchLocation;
}