2014/10/15 下午 10:04:55

iphone Programming Glossary: catmull

how can i trace the finger movement on touch for drawing smooth curves?

http://stackoverflow.com/questions/1052119/how-can-i-trace-the-finger-movement-on-touch-for-drawing-smooth-curves

can simply sample the finger location at set intervals and then interpolate the sample points using something like a Catmull Rom spline. This is easier than it sounds since you can easily convert a Catmull Rom spline into a series of cubic Bezier.. sample points using something like a Catmull Rom spline. This is easier than it sounds since you can easily convert a Catmull Rom spline into a series of cubic Bezier curves. Here's how. Say you have four consecutive sample points P0 P1 P2 and P3.. point so that you have enough points for the curve to pass through each of the original samples. To get an idea of how Catmull Rom curves look you can try out this Java applet demonstrating Catmull Rom splines . Fit a curve to your samples A more..

Drawing Smooth Curves - Methods Needed

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

POINT index CGPoint p2 POINT index 1 CGPoint p3 POINT index 2 now add n points starting at p1 dx dy up until p2 using Catmull Rom splines for int i 1 i granularity i float t float i 1.0f float granularity float tt t t float ttt tt t CGPoint pi intermediate.. improve this question I just implemented something similar in a project I am working on. My solution was to use a Catmull Rom spline instead of using Bezier splines. These provide a very smooth curve THROUGH a set a points rather then a bezier.. POINT index CGPoint p2 POINT index 1 CGPoint p3 POINT index 2 now add n points starting at p1 dx dy up until p2 using Catmull Rom splines for int i 1 i granularity i float t float i 1.0f float granularity float tt t t float ttt tt t CGPoint pi intermediate..