Difference between revisions of "Circular arc approximation by cubic Bezier curve"
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var A = brd.create('glider', [1,0,c], {name:'A'}); | var A = brd.create('glider', [1,0,c], {name:'A'}); | ||
var B = brd.create('glider', [0,1,c], {name:'B'}); | var B = brd.create('glider', [0,1,c], {name:'B'}); | ||
| + | |||
| + | var k = function(M, A, B) { | ||
| + | var ax = A.X()-M.X(), | ||
| + | ay = A.Y()-M.Y(), | ||
| + | bx = B.X()-M.X(), | ||
| + | by = B.Y()-M.Y(), | ||
| + | d, r; | ||
| + | r = M.Dist(A); | ||
| + | d = Math.sqrt((ax+bx)*(ax+bx) + (ay+by)*(ay+by)); | ||
| + | |||
| + | if (Math.abs(by-ay)>JXG.Math.eps) { | ||
| + | return (ax+bx)*(r/d-0.5)*8.0/3.0/(by-ay); | ||
| + | } else { | ||
| + | return (ay+by)*(r/d-0.5)*8.0/3.0/(ax-bx); | ||
| + | } | ||
| + | }; | ||
| + | var P1 = brd.create('point', [ | ||
| + | function(){ return M.X()+A.X()-k(M,A,B)*(A.Y()-M.Y()); }, | ||
| + | function(){ return M.Y()+A.Y()+k(M,A,B)*(A.X()-M.X()); } | ||
| + | ], {}); | ||
| + | |||
| + | |||
| + | |||
| + | |||
</jsxgraph> | </jsxgraph> | ||
