mirror of
https://github.com/EGroupware/egroupware.git
synced 2024-12-23 15:18:58 +01:00
76 lines
1.6 KiB
JavaScript
76 lines
1.6 KiB
JavaScript
/*
|
|
DynAPI Distribution
|
|
Bezier Class
|
|
|
|
Bezier Algorithm Reference: http://astronomy.swin.edu.au/~pbourke/curves/bezier/
|
|
|
|
The DynAPI Distribution is distributed under the terms of the GNU LGPL license.
|
|
|
|
requires: dynapi.fx.Thread
|
|
*/
|
|
|
|
|
|
function Bezier(cp, n) {
|
|
var l = cp.length;
|
|
var p = [];
|
|
for (var i=0; i<n; i++) p = p.concat(Bezier._plot(cp,i/n));
|
|
return p.concat([cp[l-2],cp[l-1]]);
|
|
}
|
|
|
|
Bezier._plot = function (cp, mu) {
|
|
var n = (cp.length/2)-1;
|
|
var k,kn,nn,nkn;
|
|
var blend;
|
|
var b = [0,0];
|
|
|
|
var muk = 1;
|
|
var munk = Math.pow(1-mu, n);
|
|
|
|
for (k=0;k<=n;k++) {
|
|
nn = n;
|
|
kn = k;
|
|
nkn = n - k;
|
|
blend = muk * munk;
|
|
muk *= mu;
|
|
munk /= (1-mu);
|
|
while (nn >= 1) {
|
|
blend *= nn;
|
|
nn--;
|
|
if (kn > 1) {
|
|
blend /= kn;
|
|
kn--;
|
|
}
|
|
if (nkn > 1) {
|
|
blend /= nkn;
|
|
nkn--;
|
|
}
|
|
}
|
|
|
|
b[0] += cp[k*2] * blend;
|
|
b[1] += cp[k*2+1] * blend;
|
|
}
|
|
b[0] = Math.round(b[0]);
|
|
b[1] = Math.round(b[1]);
|
|
return b;
|
|
}
|
|
|
|
/*function Bezier3(cp,mu) {
|
|
var x1=cp[0],y1=cp[1],x2=cp[2],y2=cp[3],x3=cp[4],y3=cp[5];
|
|
var mu2 = mu * mu;
|
|
var mum1 = 1 - mu;
|
|
var mum12 = mum1 * mum1;
|
|
var x = Math.round(x1 * mum12 + 2 * x2 * mum1 * mu + x3 * mu2);
|
|
var y = Math.round(y1 * mum12 + 2 * y2 * mum1 * mu + y3 * mu2);
|
|
return [x,y];
|
|
}
|
|
|
|
function Bezier4(cp,mu) {
|
|
var x1=cp[0],y1=cp[1],x2=cp[2],y2=cp[3],x3=cp[4],y3=cp[5],x4=cp[6],y4=cp[7];
|
|
var mum1 = 1 - mu;
|
|
var mum13 = mum1 * mum1 * mum1;
|
|
var mu3 = mu * mu * mu;
|
|
var x = Math.round(mum13*x1 + 3*mu*mum1*mum1*x2 + 3*mu*mu*mum1*x3 + mu3*x4);
|
|
var y = Math.round(mum13*y1 + 3*mu*mum1*mum1*y2 + 3*mu*mu*mum1*y3 + mu3*y4);
|
|
return [x,y];
|
|
}*/
|