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2014/10/15 ¤U¤È 10:12:27
iphone Programming Glossary: p3.xFind 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 brownColor setStroke for CGFloat t 0.0 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..
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 CGFloat t 0.0 t 1.00001 t 0.05 UIColor brownColor 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.. stroke now find the tangent if someone 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..
Drawing Smooth Curves - Methods Needed http://stackoverflow.com/questions/8702696/drawing-smooth-curves-methods-needed granularity float tt t t float ttt tt t CGPoint pi intermediate point 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 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.. ttt tt t CGPoint pi intermediate point 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 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.. granularity float tt t t float ttt tt t CGPoint pi intermediate point 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 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..
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