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Simplify Curve.solve() and improve documentation.

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This commit is contained in:
Jürg Lehni 2011-07-04 23:42:16 +02:00
parent c5269ecbab
commit 4924d683e4
1 changed files with 8 additions and 10 deletions
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18
src/path/Curve.js
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@ -484,17 +484,15 @@ var Curve = this.Curve = Base.extend(/** @lends Curve# */{
];
},
// Converts from the point coordinates (p1, c1, c2, p2) to the
// polynomial coefficients and solve the polynomial for val
// Converts from the point coordinates (p1, c1, c2, p2) for one axis to
// the polynomial coefficients and solve the polynomial for val
solve: function (p1, c1, c2, p2, val) {
var p1m3 = 3 * p1,
c1m3 = 3 * c1,
c2m3 = 3 * c2,
a = p2 - c2m3 + c1m3 - p1,
b = c2m3 - c1m3 - c1m3 + p1m3,
c = c1m3 - p1m3,
d = p1 - val;
return Numerical.solveCubic(a, b, c, d, Numerical.TOLERANCE);
return Numerical.solveCubic(
p2 - p1 + 3 * (c1 - c2), // a
3 * (c2 + p1) - 6 * c1, // b
3 * (c1 - p1), // c
p1 - val, // d
Numerical.TOLERANCE);
},
// TODO: Find better name