Smooth CGPath from Array of Points

path.m

// build a smooth CGPath from an array of CGPoints (stored as NSValues)

- (CGMutablePathRef)newPathFromPoints:(NSArray *)points {
    
    CGMutablePathRef mutablePath = CGPathCreateMutable();
    
    NSUInteger pointCount = [points count];
        
    if (pointCount > 0) {
        CGPoint p0 = [points[0] CGPointValue];
        CGPathMoveToPoint(mutablePath, NULL, p0.x, p0.y);

        // for a single point, create a circle. When drawing, fill this.
        if (pointCount == 1) {
            CGFloat strokeWidth = self.lineStyle.strokeWidth;
            CGRect pointRect = CGRectMake(p0.x - strokeWidth/2.0,
                                          p0.y - strokeWidth/2.0,
                                          strokeWidth,
                                          strokeWidth);
            CGPathAddPath(mutablePath, NULL, CGPathCreateWithEllipseInRect(pointRect, NULL));

        // for pointCount > 1 stroke the path
        } else if (pointCount == 2) {
            CGPoint p1 = [points[1] CGPointValue];
            CGPathAddLineToPoint(mutablePath, NULL, p1.x, p1.y);
        } else {
            CGPoint p1 = p0;
            CGPoint p2;
            for (NSUInteger i=0; i<pointCount-1; i++) {
                p2 = [points[i+1] CGPointValue];
                CGPoint midPoint = CGPointMake((p1.x + p2.x)/2.0,
                                               (p1.y + p2.y)/2.0);
                CGPathAddQuadCurveToPoint(mutablePath, NULL, p1.x, p1.y, midPoint.x, midPoint.y);
                p1 = p2;
            }
        }        
    }

    return mutablePath;
}