线条绘制+该线条与self的交点,还可以检测绘制线条内的CCSprites

Question

我正在使用以下代码绘制线条,它的工作效果令人惊叹,

http://www.merowing.info/2012/04/drawing-smooth-lines-with-cocos2d-ios-inspired-by-paper/

现在我想......

1>检测线是否与自身相交.2)检测CCSprite是否在此闭合线内.

在搜索时,我遇到了LineIntersection的许多逻辑,但没有一个是准确的.我给它们中的一个检测交叉点,但是当没有交叉线时它也检测到它.

1. 第一种方法

   - (BOOL) lineIntersectOccured:(CGPoint)t1 pointEnd:(CGPoint)t2
   {
       BOOL result = NO;
       int pointsCount = [arrlinePoints count];
   
       CGPoint cp1;
       CGPoint cp2;
   
       for(int i = 0, j = 1; j < pointsCount; i++,j++)
       {
           [[arrlinePoints objectAtIndex:i] getValue:&cp1];
           [[arrlinePoints objectAtIndex:j] getValue:&cp2];
   
           // lines connected do not need to be included.
           if((cp2.x == t1.x && cp2.y == t1.y) || (cp1.x == t2.x && cp1.y == t2.y))
           {
               continue;
           }
   
           CGPoint diffLA = CGPointMake(cp2.x - cp1.x,cp2.y - cp1.y);
           CGPoint diffLB = CGPointMake(t2.x - t1.x, t2.y - t1.y);
   
           float compA = diffLA.x*cp1.y - diffLA.y * cp1.x;
           float compB = diffLB.x*t1.y - diffLB.y*t1.x;
   
           BOOL compA1 = (diffLA.x*t1.y - diffLA.y*t1.x) < compA;
           BOOL compA2 = (diffLA.x*t2.y - diffLA.y*t2.x) < compA;
           BOOL compB1 = (diffLB.x*cp1.y - diffLB.y*cp1.x) < compB;
           BOOL compB2 = (diffLB.x*cp2.y - diffLB.y*cp2.x) < compB;
   
           if(((!compA1 && compA2) || (compA1 && !compA2)) && ((!compB1 && compB2) || (compB1 && !compB2)))
           {
               result = YES;
           }
       }
       return result;
   }
   

这就是我称之为这种方法的方法,我已将我的点存储在来自pangesture识别器方法的arrLinePoints中

  if ([self lineIntersectOccured:[[arrlinePoints objectAtIndex:0] CGPointValue] pointEnd:[[arrlinePoints objectAtIndex:[arrlinePoints count] - 1] CGPointValue]] )
  {
      NSLog(@"Line Intersected");
  }

即使有以下情况,这也让我真实

通过在CCDirector的视图中添加视图,我也尝试了不同方法的相同功能

UIBezierPath相交

但这是性能问题,我的fps降低到接近3到6.而且这个交叉点问题仍然是一样的.

交叉口的完美情况是

请尽快帮忙!感谢所有支持.

Answer 1

虽然没有实现，但我想您可以使用在 TouchMoved 方法中绘制的线条的像素值来检测绘制的线条的像素值。或者您可以参考这里了解详细方法。这里也做了同样的工作。