| caryclark@google.com | 27accef | 2012-01-25 18:57:23 +0000 | [diff] [blame^] | 1 | #include "QuadraticUtilities.h" |
| 2 | |||||
| 3 | int quadraticRoots(double A, double B, double C, double t[2]) { | ||||
| 4 | B *= 2; | ||||
| 5 | double square = B * B - 4 * A * C; | ||||
| 6 | if (square < 0) { | ||||
| 7 | return 0; | ||||
| 8 | } | ||||
| 9 | double squareRt = sqrt(square); | ||||
| 10 | double Q = (B + (B < 0 ? -squareRt : squareRt)) / -2; | ||||
| 11 | int foundRoots = 0; | ||||
| 12 | if ((Q <= A) ^ (Q < 0)) { | ||||
| 13 | t[foundRoots++] = Q / A; | ||||
| 14 | } | ||||
| 15 | if ((C <= Q) ^ (C < 0)) { | ||||
| 16 | t[foundRoots++] = C / Q; | ||||
| 17 | } | ||||
| 18 | return foundRoots; | ||||
| 19 | } | ||||
| 20 | |||||
| 21 | |||||