我尝试了几种不同的解决方案但到目前为止没有运气.
- (CGPoint)contractLineTemp:(CGPoint)point :(CGPoint)circle :(float)circleRadius {
CGFloat x,y;
x = point.x - circle.x;
y = point.y - circle.y;
CGFloat theta = atan2(x, y);
CGPoint newPoint;
newPoint.x = circle.x + circleRadius * sin(theta);
newPoint.y = circle.y + circleRadius * cos(theta);
return newPoint;
}
- (CGPoint)contractLineTemp:(CGPoint)startPoint :(CGPoint)endPoint :(float)scaleBy {
float dx = endPoint.x - startPoint.x;
float dy = endPoint.y - startPoint.y;
float scale = scaleBy * Q_rsqrt(dx * dx + dy * dy);
return CGPointMake (endPoint.x - dx * scale, endPoint.y - …