diff options
| author | Simon Puchert <simonpuchert@alice.de> | 2019-07-06 17:41:13 +0200 |
|---|---|---|
| committer | Simon Puchert <simonpuchert@alice.de> | 2019-07-06 17:41:13 +0200 |
| commit | 4b78e17b1587611e3e6cfdb6074f85ffbfc933f8 (patch) | |
| tree | e54006d5154bc8c76ed413bf5efda34be0c43d6d /core | |
| parent | 0b6b49a897b35bec53765e1288c32d57afa1a293 (diff) | |
Optimize get_closest_point_to_segment*.
By combining all scalar factors we can get rid of a scalar * vector
multiplication and a square root operation, since the resulting formula
only uses the squared length.
Diffstat (limited to 'core')
| -rw-r--r-- | core/math/geometry.h | 32 |
1 files changed, 14 insertions, 18 deletions
diff --git a/core/math/geometry.h b/core/math/geometry.h index 0e144e491f..e4f3ff799e 100644 --- a/core/math/geometry.h +++ b/core/math/geometry.h @@ -455,16 +455,15 @@ public: Vector3 p = p_point - p_segment[0]; Vector3 n = p_segment[1] - p_segment[0]; - real_t l = n.length(); - if (l < 1e-10) + real_t l2 = n.length_squared(); + if (l2 < 1e-20) return p_segment[0]; // both points are the same, just give any - n /= l; - real_t d = n.dot(p); + real_t d = n.dot(p) / l2; if (d <= 0.0) return p_segment[0]; // before first point - else if (d >= l) + else if (d >= 1.0) return p_segment[1]; // after first point else return p_segment[0] + n * d; // inside @@ -474,12 +473,11 @@ public: Vector3 p = p_point - p_segment[0]; Vector3 n = p_segment[1] - p_segment[0]; - real_t l = n.length(); - if (l < 1e-10) + real_t l2 = n.length_squared(); + if (l2 < 1e-20) return p_segment[0]; // both points are the same, just give any - n /= l; - real_t d = n.dot(p); + real_t d = n.dot(p) / l2; return p_segment[0] + n * d; // inside } @@ -488,16 +486,15 @@ public: Vector2 p = p_point - p_segment[0]; Vector2 n = p_segment[1] - p_segment[0]; - real_t l = n.length(); - if (l < 1e-10) + real_t l2 = n.length_squared(); + if (l2 < 1e-20) return p_segment[0]; // both points are the same, just give any - n /= l; - real_t d = n.dot(p); + real_t d = n.dot(p) / l2; if (d <= 0.0) return p_segment[0]; // before first point - else if (d >= l) + else if (d >= 1.0) return p_segment[1]; // after first point else return p_segment[0] + n * d; // inside @@ -521,12 +518,11 @@ public: Vector2 p = p_point - p_segment[0]; Vector2 n = p_segment[1] - p_segment[0]; - real_t l = n.length(); - if (l < 1e-10) + real_t l2 = n.length_squared(); + if (l2 < 1e-20) return p_segment[0]; // both points are the same, just give any - n /= l; - real_t d = n.dot(p); + real_t d = n.dot(p) / l2; return p_segment[0] + n * d; // inside } |