Untitled

Stop the knob from rotating past xyz degrees and prevent it from rotating backward from 0 degrees
- (void)rotating:(KTOneFingerRotationGestureRecognizer *)recognizer {

    [self doRotation:recognizer.rotation];
    [recognizer setRotation:0];
}

- (void)doRotation:(float)rot {

    CGFloat theAngle = atan2(knob.transform.b, knob.transform.a);

    float temp_var = RADIANS_TO_DEGREES(theAngle);

    if(temp_var < 0) temp_var = 360 - fabs(temp_var);

    float percent = (temp_var / 315) * 100;
    float val = ((float)(percent))/100;

    knob.transform = CGAffineTransformRotate([knob transform], rot);

    if(percent < 100 && percent > 0) {
        display.text = [[NSString alloc] initWithFormat:@"%.f", percent];
    }
}

if(temp_var < 0) temp_var = 360 - fabs(temp_var);
// add this next line:
if (temp_var > 340) { return; }

float percent = (temp_var / 315) * 100;