diff options
Diffstat (limited to 'svg-flatten/include/geom2d.hpp')
| -rw-r--r-- | svg-flatten/include/geom2d.hpp | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/svg-flatten/include/geom2d.hpp b/svg-flatten/include/geom2d.hpp index 47cf3be..9650575 100644 --- a/svg-flatten/include/geom2d.hpp +++ b/svg-flatten/include/geom2d.hpp @@ -113,9 +113,38 @@ namespace gerbolyze { double doc2phys_skew(double dist_doc) { /* https://math.stackexchange.com/a/3521141 */ + /* https://stackoverflow.com/a/70381885 */ /* xx yx x0 * xy yy y0 */ - s_x = sqrt(); + double s_x = sqrt(xx*xx + xy*xy); + + if (xx == 0 && xy == 0) { + return std::numeric_limits<double>::infinity; + } + + double theta = atan2(xy, xx); + double f = (xx*yy - xy*yx); + + if (f == 0) { + return std::numeric_limits<double>::infinity; + } + + double m = (xx*yx + yy*xy) / f; + + double f = xx + m*xy; + double s_y = 0; + + if (f == 0) { + f = m*xx - xy; + if (f == 0) { + return std::numeric_limits<double>::infinity; + } + s_y = yx*s_x / f; + } else { + s_y = yy*s_x / f; + } + + return s_x - s_y > } double doc2phys_min(double dist_doc) { |