2014/10/15 下午 10:12:27

iphone Programming Glossary: p3.y

Find a point, a given distance, along a simple cubic bezier curve. (On an iPhone!)

http://stackoverflow.com/questions/4058979/find-a-point-a-given-distance-along-a-simple-cubic-bezier-curve-on-an-iphone

t 1.00001 t 0.05 CGPoint point CGPointMake bezierInterpolation t p1.x p2.x p3.x p4.x bezierInterpolation t p1.y p2.y p3.y p4.y UIBezierPath pointPath UIBezierPath bezierPathWithArcCenter point radius 5 startAngle 0 endAngle 2 M_PI clockwise YES..

Find the tangent of a point on a cubic bezier curve (on an iPhone)

http://stackoverflow.com/questions/4089443/find-the-tangent-of-a-point-on-a-cubic-bezier-curve-on-an-iphone

setStroke CGPoint point CGPointMake bezierInterpolation t p1.x p2.x p3.x p4.x bezierInterpolation t p1.y p2.y p3.y p4.y there use either bezierInterpolation or altBezierInterpolation identical results for the position just draw that.. on stackoverflow knows how CGPoint vel CGPointMake bezierTangent t p1.x p2.x p3.x p4.x bezierTangent t p1.y p2.y p3.y p4.y the following code simply draws an indication of the tangent CGPoint demo CGPointMake point.x vel.x 0.3 point.y vel.y..

Drawing Smooth Curves - Methods Needed

http://stackoverflow.com/questions/8702696/drawing-smooth-curves-methods-needed

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 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 smoothedPath addLineToPoint pi Now add p2 smoothedPath addLineToPoint p2 finish by adding.. 4 p2.x p3.x tt 3 p1.x p0.x 3 p2.x p3.x ttt 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 smoothedPath addLineToPoint pi Now add p2 smoothedPath addLineToPoint p2 finish by adding the last point smoothedPath.. 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 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 smoothedPath addLineToPoint pi Now add p2 smoothedPath addLineToPoint p2 finish by adding..