封闭的三次贝塞尔曲线的填充

接上一篇博文，记载一下怎样将封闭的贝塞尔曲线填充颜色。
设计师要求的效果图如下：

我的步骤是先描点，然后将其组成一个封闭区间，最后上色。上代码：（代码可能写的不怎么样，以后尽量追求优质代码。）

//根据points中的点画出曲线- (void)drawCurveChartWithPoints:(NSMutableArray *)points{    UIBezierPath* path1 = [UIBezierPath bezierPath];    [path1 moveToPoint:[[points objectAtIndex:0] CGPointValue]];//这一步很重要    //遍历各个点，画曲线    for(int i=0; i<[points count]-1; i++){        CGPoint startPoint = [[points objectAtIndex:i] CGPointValue];        CGPoint endPoint = [[points objectAtIndex:i+1] CGPointValue];        [UIView animateWithDuration:.1 animations:^(){            [path1 addCurveToPoint:endPoint controlPoint1:CGPointMake((endPoint.x-startPoint.x)/2+startPoint.x, startPoint.y) controlPoint2:CGPointMake((endPoint.x-startPoint.x)/2+startPoint.x, endPoint.y)];        }];    }    CGPoint firstPoint = [[points firstObject] CGPointValue];    CGPoint lastPoint = [[points lastObject] CGPointValue];    CGPoint secondPoint = CGPointMake(lastPoint.x+2, lastPoint.y);    CGPoint thirdPoint = CGPointMake(secondPoint.x, ViewHeight(self)+1);    CGPoint forthPoint = CGPointMake(firstPoint.x-1, thirdPoint.y);    CGPoint fifthPoint = CGPointMake(forthPoint.x, firstPoint.y);    //把曲线封闭起来    [path1 addLineToPoint:secondPoint];    [path1 addLineToPoint:thirdPoint];    [path1 addLineToPoint:forthPoint];    [path1 addLineToPoint:fifthPoint];    [path1 addLineToPoint:firstPoint];    [path1 closePath];    [[UIColor colorWithRed:80.0/255.0 green:187.0/255.0 blue:255/255.0 alpha:0.5] setFill];    [path1 fill];    [self.lineColor set];       //设置画笔颜色    [path1 setLineWidth:2];     //设置画笔宽度    path1.lineCapStyle = kCGLineCapRound;    [path1 strokeWithBlendMode:kCGBlendModeNormal alpha:1];}

代码里面本来只要将首位端点拉下来，然后相连就行的。我这里因为当时设计的原因，所以连到了外界区域。

之后添加点后的图如下：

基本完成了设计师的要求。
（看过后觉得有什么地方可以更正或者改进的地方，请给我回复，谢谢。。）