| 43 | } |
| 44 | |
| 45 | LNLib::XYZ LNLib::Projection::Stereographic(const XYZ& pointOnSphere, double radius) |
| 46 | { |
| 47 | double x = pointOnSphere.GetX(); |
| 48 | double y = pointOnSphere.GetY(); |
| 49 | double z = pointOnSphere.GetZ(); |
| 50 | |
| 51 | double alpha = -2 * radius / (z - 2 * radius); |
| 52 | double u = alpha * x; |
| 53 | double v = alpha * y; |
| 54 | |
| 55 | return XYZ(u, v, 0); |
| 56 | } |