API tools faq
paste
Advertisement
starkrights

Untitled

starkrights
Jul 10th, 2024
66
0
Never
Add comment
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
Objective C 2.83 KB | None | 0 0
raw download clone embed print report
  1. // Based on code from Erica Sadun
  2.  
  3. #import "UIBezierPath+Smoothing.h"
  4.  
  5. void getPointsFromBezier(void *info, const CGPathElement *element);
  6. NSArray *pointsFromBezierPath(UIBezierPath *bpath);
  7.  
  8.  
  9. #define VALUE(_INDEX_) [NSValue valueWithCGPoint:points[_INDEX_]]
  10. #define POINT(_INDEX_) [(NSValue *)[points objectAtIndex:_INDEX_] CGPointValue]
  11.  
  12. @implementation UIBezierPath (Smoothing)
  13.  
  14. // Get points from Bezier Curve
  15. void getPointsFromBezier(void *info, const CGPathElement *element)
  16. {
  17.     NSMutableArray *bezierPoints = (__bridge NSMutableArray *)info;    
  18.  
  19.     // Retrieve the path element type and its points
  20.     CGPathElementType type = element->type;
  21.     CGPoint *points = element->points;
  22.  
  23.     // Add the points if they're available (per type)
  24.     if (type != kCGPathElementCloseSubpath)
  25.     {
  26.         [bezierPoints addObject:VALUE(0)];
  27.         if ((type != kCGPathElementAddLineToPoint) &&
  28.             (type != kCGPathElementMoveToPoint))
  29.             [bezierPoints addObject:VALUE(1)];
  30.     }    
  31.     if (type == kCGPathElementAddCurveToPoint)
  32.         [bezierPoints addObject:VALUE(2)];
  33. }
  34.  
  35. NSArray *pointsFromBezierPath(UIBezierPath *bpath)
  36. {
  37.     NSMutableArray *points = [NSMutableArray array];
  38.     CGPathApply(bpath.CGPath, (__bridge void *)points, getPointsFromBezier);
  39.     return points;
  40. }
  41.  
  42. - (UIBezierPath*)smoothedPathWithGranularity:(NSInteger)granularity;
  43. {
  44.     NSMutableArray *points = [pointsFromBezierPath(self) mutableCopy];
  45.  
  46.     if (points.count < 4) return [self copy];
  47.  
  48.     // Add control points to make the math make sense
  49.     [points insertObject:[points objectAtIndex:0] atIndex:0];
  50.     [points addObject:[points lastObject]];
  51.  
  52.     UIBezierPath *smoothedPath = [self copy];
  53.     [smoothedPath removeAllPoints];
  54.  
  55.     [smoothedPath moveToPoint:POINT(0)];
  56.  
  57.     for (NSUInteger index = 1; index < points.count - 2; index++)
  58.     {
  59.         CGPoint p0 = POINT(index - 1);
  60.         CGPoint p1 = POINT(index);
  61.         CGPoint p2 = POINT(index + 1);
  62.         CGPoint p3 = POINT(index + 2);
  63.  
  64.         // now add n points starting at p1 + dx/dy up until p2 using Catmull-Rom splines
  65.         for (int i = 1; i < granularity; i++)
  66.         {
  67.             float t = (float) i * (1.0f / (float) granularity);
  68.             float tt = t * t;
  69.             float ttt = tt * t;
  70.  
  71.             CGPoint pi; // intermediate point
  72.             pi.x = 0.5 * (2*p1.x+(p2.x-p0.x)*t + (2*p0.x-5*p1.x+4*p2.x-p3.x)*tt + (3*p1.x-p0.x-3*p2.x+p3.x)*ttt);
  73.             pi.y = 0.5 * (2*p1.y+(p2.y-p0.y)*t + (2*p0.y-5*p1.y+4*p2.y-p3.y)*tt + (3*p1.y-p0.y-3*p2.y+p3.y)*ttt);
  74.             [smoothedPath addLineToPoint:pi];
  75.         }
  76.  
  77.         // Now add p2
  78.         [smoothedPath addLineToPoint:p2];
  79.     }
  80.  
  81.     // finish by adding the last point
  82.     [smoothedPath addLineToPoint:POINT(points.count - 1)];
  83.  
  84.     return smoothedPath;
  85. }
  86.  
  87.  
  88. @end
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement
Public Pastes
Advertisement
We use cookies for various purposes including analytics. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy.  OK, I Understand
Not a member of Pastebin yet?
Sign Up, it unlocks many cool features!