Objective c 检测曲线上的抽头？

我想画一条特定宽度的线。我在网上搜索了一些例子，但我只找到了使用直线的例子。我需要曲线。此外，我需要检测用户是否在线路内触摸。使用Objective C和Sprite工具包是否可以实现这一目标？如果是，有人能举个例子吗

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您可以使用

UIBezierPath

创建贝塞尔曲线（平滑曲线）。您可以为

CAShapeLayer

指定此路径，并将其作为子层添加到视图中：

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(10, 150)];
[path addCurveToPoint:CGPointMake(110, 150) controlPoint1:CGPointMake(40,  100) controlPoint2:CGPointMake(80,  100)];
[path addCurveToPoint:CGPointMake(210, 150) controlPoint1:CGPointMake(140, 200) controlPoint2:CGPointMake(170, 200)];
[path addCurveToPoint:CGPointMake(310, 150) controlPoint1:CGPointMake(250, 100) controlPoint2:CGPointMake(280, 100)];

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 10;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;

[self.view.layer addSublayer:layer];

---

如果你想随机化一点，你可以随机化一些曲线。如果你想要一些模糊，添加一些阴影。如果希望端点为圆形，请指定圆形线帽：

UIBezierPath *path = [UIBezierPath bezierPath];
CGPoint point = CGPointMake(10, 100);
[path moveToPoint:point];

CGPoint controlPoint1;
CGPoint controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
for (NSInteger i = 0; i < 5; i++) {
    controlPoint1 = CGPointMake(point.x + (point.x - controlPoint2.x), 50.0);
    point.x += 40.0 + arc4random_uniform(20);
    controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
    [path addCurveToPoint:point controlPoint1:controlPoint1 controlPoint2:controlPoint2];
}

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 5;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;
layer.shadowColor = [UIColor redColor].CGColor;
layer.shadowRadius = 2.0;
layer.shadowOpacity = 1.0;
layer.shadowOffset = CGSizeZero;
layer.lineCap = kCALineCapRound;

[self.view.layer addSublayer:layer];

通过识别用户点击的像素颜色，获取用户点击坐标处的像素颜色

- (void)handleTap:(UITapGestureRecognizer *)gesture
{
    CGPoint point = [gesture locationInView:gesture.view];

    CGFloat red, green, blue, alpha;
    UIColor *color = [self image:self.image colorAtPoint:point];
    [color getRed:&red green:&green blue:&blue alpha:&alpha];

    if (green < 0.9 && blue < 0.9 && red > 0.9)
        NSLog(@"tapped on curve");
    else
        NSLog(@"didn't tap on curve");
}

---

您可以使用

UIBezierPath

创建贝塞尔曲线（平滑曲线）。您可以为

CAShapeLayer

指定此路径，并将其作为子层添加到视图中：

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(10, 150)];
[path addCurveToPoint:CGPointMake(110, 150) controlPoint1:CGPointMake(40,  100) controlPoint2:CGPointMake(80,  100)];
[path addCurveToPoint:CGPointMake(210, 150) controlPoint1:CGPointMake(140, 200) controlPoint2:CGPointMake(170, 200)];
[path addCurveToPoint:CGPointMake(310, 150) controlPoint1:CGPointMake(250, 100) controlPoint2:CGPointMake(280, 100)];

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 10;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;

[self.view.layer addSublayer:layer];

---

如果你想随机化一点，你可以随机化一些曲线。如果你想要一些模糊，添加一些阴影。如果希望端点为圆形，请指定圆形线帽：

UIBezierPath *path = [UIBezierPath bezierPath];
CGPoint point = CGPointMake(10, 100);
[path moveToPoint:point];

CGPoint controlPoint1;
CGPoint controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
for (NSInteger i = 0; i < 5; i++) {
    controlPoint1 = CGPointMake(point.x + (point.x - controlPoint2.x), 50.0);
    point.x += 40.0 + arc4random_uniform(20);
    controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
    [path addCurveToPoint:point controlPoint1:controlPoint1 controlPoint2:controlPoint2];
}

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 5;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;
layer.shadowColor = [UIColor redColor].CGColor;
layer.shadowRadius = 2.0;
layer.shadowOpacity = 1.0;
layer.shadowOffset = CGSizeZero;
layer.lineCap = kCALineCapRound;

[self.view.layer addSublayer:layer];

通过识别用户点击的像素颜色，获取用户点击坐标处的像素颜色

- (void)handleTap:(UITapGestureRecognizer *)gesture
{
    CGPoint point = [gesture locationInView:gesture.view];

    CGFloat red, green, blue, alpha;
    UIColor *color = [self image:self.image colorAtPoint:point];
    [color getRed:&red green:&green blue:&blue alpha:&alpha];

    if (green < 0.9 && blue < 0.9 && red > 0.9)
        NSLog(@"tapped on curve");
    else
        NSLog(@"didn't tap on curve");
}

---

您可以使用

UIBezierPath

创建贝塞尔曲线（平滑曲线）。您可以为

CAShapeLayer

指定此路径，并将其作为子层添加到视图中：

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(10, 150)];
[path addCurveToPoint:CGPointMake(110, 150) controlPoint1:CGPointMake(40,  100) controlPoint2:CGPointMake(80,  100)];
[path addCurveToPoint:CGPointMake(210, 150) controlPoint1:CGPointMake(140, 200) controlPoint2:CGPointMake(170, 200)];
[path addCurveToPoint:CGPointMake(310, 150) controlPoint1:CGPointMake(250, 100) controlPoint2:CGPointMake(280, 100)];

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 10;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;

[self.view.layer addSublayer:layer];

---

如果你想随机化一点，你可以随机化一些曲线。如果你想要一些模糊，添加一些阴影。如果希望端点为圆形，请指定圆形线帽：

UIBezierPath *path = [UIBezierPath bezierPath];
CGPoint point = CGPointMake(10, 100);
[path moveToPoint:point];

CGPoint controlPoint1;
CGPoint controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
for (NSInteger i = 0; i < 5; i++) {
    controlPoint1 = CGPointMake(point.x + (point.x - controlPoint2.x), 50.0);
    point.x += 40.0 + arc4random_uniform(20);
    controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
    [path addCurveToPoint:point controlPoint1:controlPoint1 controlPoint2:controlPoint2];
}

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 5;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;
layer.shadowColor = [UIColor redColor].CGColor;
layer.shadowRadius = 2.0;
layer.shadowOpacity = 1.0;
layer.shadowOffset = CGSizeZero;
layer.lineCap = kCALineCapRound;

[self.view.layer addSublayer:layer];

通过识别用户点击的像素颜色，获取用户点击坐标处的像素颜色

- (void)handleTap:(UITapGestureRecognizer *)gesture
{
    CGPoint point = [gesture locationInView:gesture.view];

    CGFloat red, green, blue, alpha;
    UIColor *color = [self image:self.image colorAtPoint:point];
    [color getRed:&red green:&green blue:&blue alpha:&alpha];

    if (green < 0.9 && blue < 0.9 && red > 0.9)
        NSLog(@"tapped on curve");
    else
        NSLog(@"didn't tap on curve");
}

---

您可以使用

UIBezierPath

创建贝塞尔曲线（平滑曲线）。您可以为

CAShapeLayer

指定此路径，并将其作为子层添加到视图中：

UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(10, 150)];
[path addCurveToPoint:CGPointMake(110, 150) controlPoint1:CGPointMake(40,  100) controlPoint2:CGPointMake(80,  100)];
[path addCurveToPoint:CGPointMake(210, 150) controlPoint1:CGPointMake(140, 200) controlPoint2:CGPointMake(170, 200)];
[path addCurveToPoint:CGPointMake(310, 150) controlPoint1:CGPointMake(250, 100) controlPoint2:CGPointMake(280, 100)];

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 10;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;

[self.view.layer addSublayer:layer];

---

如果你想随机化一点，你可以随机化一些曲线。如果你想要一些模糊，添加一些阴影。如果希望端点为圆形，请指定圆形线帽：

UIBezierPath *path = [UIBezierPath bezierPath];
CGPoint point = CGPointMake(10, 100);
[path moveToPoint:point];

CGPoint controlPoint1;
CGPoint controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
for (NSInteger i = 0; i < 5; i++) {
    controlPoint1 = CGPointMake(point.x + (point.x - controlPoint2.x), 50.0);
    point.x += 40.0 + arc4random_uniform(20);
    controlPoint2 = CGPointMake(point.x - 5.0 - arc4random_uniform(50), 150.0);
    [path addCurveToPoint:point controlPoint1:controlPoint1 controlPoint2:controlPoint2];
}

CAShapeLayer *layer = [CAShapeLayer layer];
layer.lineWidth = 5;
layer.strokeColor = [UIColor redColor].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;
layer.path = path.CGPath;
layer.shadowColor = [UIColor redColor].CGColor;
layer.shadowRadius = 2.0;
layer.shadowOpacity = 1.0;
layer.shadowOffset = CGSizeZero;
layer.lineCap = kCALineCapRound;

[self.view.layer addSublayer:layer];

通过识别用户点击的像素颜色，获取用户点击坐标处的像素颜色

- (void)handleTap:(UITapGestureRecognizer *)gesture
{
    CGPoint point = [gesture locationInView:gesture.view];

    CGFloat red, green, blue, alpha;
    UIColor *color = [self image:self.image colorAtPoint:point];
    [color getRed:&red green:&green blue:&blue alpha:&alpha];

    if (green < 0.9 && blue < 0.9 && red > 0.9)
        NSLog(@"tapped on curve");
    else
        NSLog(@"didn't tap on curve");
}

---

你说划一条线是什么意思？用户绘制它？你有一个特定的贝塞尔路径，你想画上吗？嗨，当游戏开始时，用户会看到线，他会按照线使用手指触摸谢谢！你说划一条线是什么意思？用户绘制它？你有一个特定的贝塞尔路径，你想画上吗？嗨，当游戏开始时，用户会看到线，他会按照线使用手指触摸谢谢！你说划一条线是什么意思？用户绘制它？你有一个特定的贝塞尔路径，你想画上吗？嗨，当游戏开始时，用户会看到线，他会按照线使用手指触摸谢谢！你说划一条线是什么意思？用户绘制它？你有一个特定的贝塞尔路径，你想画上吗？嗨，当游戏开始时，用户会看到线，他会按照线使用手指触摸谢谢！非常感谢你的解释和时间。我在试你告诉我的。只要一个问题，如果我想改变线的形状有一个螺旋。在这种情况下，我必须修改addcurvetopointcorrect方法？是的，您必须调整添加的各个贝塞尔曲线的端点和控制点。请参阅中关于beziers的讨论（虽然它讨论的是beziers的较低级别核心图形API，但“将曲线添加到路径”部分中的控制点说明可能很有启发性）。非常感谢您的解释和时间。我在试你告诉我的。只要一个问题，如果我想改变线的形状有一个螺旋。在这种情况下，我必须修改addcurvetopointcorrect方法？是的，您必须调整添加的各个贝塞尔曲线的端点和控制点。请参阅中关于beziers的讨论（虽然它讨论的是beziers的较低级别核心图形API，但“将曲线添加到路径”部分中的控制点说明可能很有启发性）。非常感谢您的解释和时间。我在试你告诉我的。只要一个问题，如果我想改变线的形状有一个螺旋。在这种情况下，我必须修改addcurvetopointcorrect方法？是的，您必须调整添加的各个贝塞尔曲线的端点和控制点。请参阅中关于beziers的讨论（虽然它讨论的是beziers的较低级别核心图形API，但“将曲线添加到路径”部分中的控制点说明可能很有启发性）。非常感谢您的解释和时间。我在试你告诉我的。只要一个问题，如果我想改变线的形状有一个螺旋。在这种情况下，我必须修改addcurvetopointcorrect方法？是的，您必须调整添加的各个贝塞尔曲线的端点和控制点。请参阅中关于beziers的讨论（虽然它讨论的是beziers的较低级别的核心图形API，但“将曲线添加到路径”部分中的控制点说明可能很有启发性）。