skia2/experimental/Intersection/QuadraticUtilities.h
caryclark@google.com 27accef223 Intersection work in progress
Review URL: https://codereview.appspot.com/5576043

git-svn-id: http://skia.googlecode.com/svn/trunk@3087 2bbb7eff-a529-9590-31e7-b0007b416f81
2012-01-25 18:57:23 +00:00

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513 B
C

/* Parameterization form, given A*t*t + 2*B*t*(1-t) + C*(1-t)*(1-t)
*
* a = A - 2*B + C
* b = 2*B - 2*C
* c = C
*/
inline void set_abc(const double* quad, double& a, double& b, double& c) {
a = quad[0]; // a = A
b = 2 * quad[2]; // b = 2*B
c = quad[4]; // c = C
b -= c; // b = 2*B - C
a -= b; // a = A - 2*B + C
b -= c; // b = 2*B - 2*C
}
int quadraticRoots(double A, double B, double C, double t[2]);