curve

I got an arbitrary shaped curve, enclosing some area. I would like to approximate the number of pixels that the curve is enclosing on an iPhone/iPad screen. How can I do so? A curve is defined as a successive x/y coordinates of points. A curve is closed. A curve is drawn by a user's touches (touchesMoved method), and I have no knowledge of what it looks like I was thinking of somehow filling the closed curve with color, then calculating the number of pixels of this color in a screenshot of a screen. This means I need to know how to programmatically fill a closed curve with color. Is there some

Considering the following nice solution for finding cubic Bézier control points for a curve passing through 4 points: How to find control points for a BezierSegment given Start, End, and 2 Intersection Pts in C# - AKA Cubic Bezier 4-point Interpolation I wonder, if there is a straightforward extension to this for making the Bézier curve pass through N points, for N > 2 and maybe N ≤ 20? This is a really old question, but I'm leaving this here for people who have the same question in the future. @divanov has mentioned that there's no Bezier curve passing through N arbitrary points for N >4. I

I need to find out Y coordinate of specific point of bezier curve in canvas. Do you know, how to find it out? Thank you Using de Casteljau's algorithm you can find the coordinates x and y of a bezier curve for any t, the percentage or interpolation step. So a t of .1 would give you the x and y at 10% of the curve from the beginning. A t of .9 would be 90% from the beginning, and so on. In our cubic bezier we have p0 (point 0), cp0 (control point 0), cp1 (control point 1), and p1 (point 1). In the first step of the algorithm we draw a line connecting p0 and cp0, another line connecting cp0 and

I want to draw some bezier lines and I want to animate them with a wave effect, Example Do you have some ideas about how I can do this ? Bezier line is it the best method to do it ? I found only 2 libs for this, but they are not really useful for what I need, I try to modify the code of one lib, unfortunately without success https://github.com/yourtion/YXWaveView I found this lib, https://antiguab.github.io/bafluidview/ which does the work, but it written in obj-c, maybe you know something like this in swift You can use a display link , a special kind of timer optimized for screen refresh

One example for curve is shown as below. The elbow point might be x=3 or 4. How to compute the elbow for a curve automatically and mathematically? You might want to look for the point with the maximum absolute second derivative which, for a set of discrete points x[i] as you have there, can be approximated with a central difference: secondDerivative[i] = x[i+1] + x[i-1] - 2 * x[i] As noted above, what you really want is the point with maximum curvature, but the second derivative will do, and this central difference is a good proxy for the second derivative. I created a Python package that

Good day, friends. There is a task: to draw repeating objects (UIImageView and UILabel) along the curve (if more exactly, it's an arc). What classes should be used for it? DarkDust As an alternative to Android's Path , you can use either UIBezierPath or CGPath . The former is Objective-C, the later pure C. I recommend going with UIBezierPath as it's easier to use. To rotate a view, use the transform property of UIView (see this question for an example on how to use it). But note that you then need to ignore the frame (it's undefined) and need to move the view by modifying the center instead.